Document ID: EPA-HQ-OW-2002-0061-0040
Agency: epa
Document Type: Rule
Title: National Primary Drinking Water Regulations: Ground Water Rule
Posted Date: 2006-11-08T12:54:54Z

[Federal Register: November 8, 2006 (Volume 71, Number 216)]
[Rules and Regulations]               
[Page 65573-65660]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08no06-15]                         

[[Page 65573]]

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Part II

Environmental Protection Agency

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40 CFR Parts 9, 141, and 142

 National Primary Drinking Water Regulations: Ground Water Rule; Final 
Rule

[[Page 65574]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9, 141 and 142

[EPA-HQ-OW-2002-0061; FRL-8231-9]
RIN 2040-AA97

 
National Primary Drinking Water Regulations: Ground Water Rule

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency is promulgating a National 
Primary Drinking Water Regulation, the Ground Water Rule, to provide 
for increased protection against microbial pathogens in public water 
systems that use ground water sources. This final rule is in accordance 
with the Safe Drinking Water Act as amended, which requires the 
Environmental Protection Agency to promulgate National Primary Drinking 
Water Regulations requiring disinfection as a treatment technique for 
all public water systems, including surface water systems and, as 
necessary, ground water systems.
    The Ground Water Rule establishes a risk-targeted approach to 
target ground water systems that are susceptible to fecal 
contamination, instead of requiring disinfection for all ground water 
systems. The occurrence of fecal indicators in a drinking water supply 
is an indication of the potential presence of microbial pathogens that 
may pose a threat to public health. This rule requires ground water 
systems that are at risk of fecal contamination to take corrective 
action to reduce cases of illnesses and deaths due to exposure to 
microbial pathogens.

DATES: This final rule is effective on January 8, 2007. The 
incorporation by reference of certain publications listed in this rule 
is approved by the Director of the Federal Register as of January 8, 
2007. For judicial review purposes, this final rule is promulgated as 
of 1 p.m. Eastern time on November 22, 2006, as provided in 40 Code of 
Federal Regulations (CFR) 23.7. The compliance date, unless otherwise 
noted, for the rule requirements is December 1, 2009.

ADDRESSES: The Environmental Protection Agency (EPA) has established a 
docket for this action under Docket ID No. EPA-HQ-OW-2002-0061. All 
documents in the docket are listed on the http://www.regulations.gov 

Web site. Although listed in the index, some information is not 
publicly available, e.g., CBI or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available either electronically through http://www.regulations.gov or 

in hard copy at the Water Docket.

    Note: The EPA Docket Center suffered damage due to flooding 
during the last week of June 2006. The Docket Center is continuing 
to operate. However, during the cleanup, there will be temporary 
changes to Docket Center telephone numbers, addresses, and hours of 
operation for people who wish to visit the Public Reading Room to 
view documents. Consult EPA's Federal Register notice at 71 FR 54815 
(September 19, 2006) or the EPA Web site at http://www.epa.gov/epahome/dockets.htm
 for current information on docket status, 

locations and telephone numbers.

FOR FURTHER INFORMATION CONTACT: Crystal Rodgers, 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) 564-5275; e-mail address: 
rodgers.crystal@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

    Entities potentially regulated by the Ground Water Rule (GWR) are 
public water systems (PWSs) using ground water as a drinking water 
source. Regulated categories and entities include the following:

------------------------------------------------------------------------
                                               Examples of  regulated
                 Category                             entities
------------------------------------------------------------------------
Industry..................................  Public ground water systems.
State, Local, Tribal or Federal             Public ground water systems.
 Governments.
------------------------------------------------------------------------

    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 the table could also be regulated. To determine whether 
your facility is regulated by this action, you should carefully examine 
the applicability criteria found in Sec.  141.400 of this 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.

Abbreviations Used in This Document

AIDS Acquired Immune Deficiency Syndrome
AGI Acute Gastrointestinal Illness
AWWA American Water Works Association
ASDWA Association of State Drinking Water Administrators
AWWARF American Water Works Association Research Foundation
AWWSCo American Water Works Service Company
BGLB Brilliant green lactose bile broth
BGM Buffalo Green Monkey
BMPs Best Management Practices
CAFO Concentrated Animal Feeding Operation
CBI Confidential Business Information
CCR Consumer Confidence Report
CDBG Community Development Block Grant
CDC Centers for Disease Control and Prevention
CFR Code of Federal Regulation
COI Cost of Illness
CT The Residual Concentration of Disinfectant (mg/L) Multiplied by 
the Contact Time (in minutes)
CWS Community Water System
CWSS Community Water System Survey
DBPs Disinfection Byproducts
DWSRF Drinking Water State Revolving Fund
EA Economic Analysis
EPA United States Environmental Protection Agency
FR Federal Register
GAO United States Government Accountability Office
GI Gastrointestinal
GWUDI Ground Water Under the Direct Influence of Surface Water
GWR Ground Water Rule
GWS Ground Water System
HAV Hepatitis A Virus
HRRCA Health Risk Reduction and Cost Analysis
HSA Hydrogeologic Sensitivity Assessment
ICR Information Collection Request
IESWTR Interim Enhanced Surface Water Treatment Rule
IRFA Initial Regulatory Flexibility Analysis
LTB Lauryl tryptose broth
m Meters
mL Milliliters
MCL Maximum Contaminant Level
mg/L Milligrams per Liter
MPNIU Most Probable Number of Infectious Units
MRDL Maximum Residual Disinfectant Level
MWCO Molecular Weight Cut-Off
NCWS Non-Community Water System
NDWAC National Drinking Water Advisory Council
NF Nanofiltration
NODA Notice of Data Availability
NTNCWS Non-Transient Non-Community Water System
NTTAA National Technology Transfer and Advancement Act of 1995
NPDWR National Primary Drinking Water Regulation
O&M Operation and Maintenance

[[Page 65575]]

OMB Office of Management and Budget
P-A Presence-absence
PCR Polymerase Chain Reaction
PNR Public Notification Rule
PWS Public Water System
RFA Regulatory Flexibility Act
RIA Regulatory Impact Analysis
RO Reverse Osmosis
RT-PCR Reverse Transcriptase--Polymerase Chain Reaction
SAB Science Advisory Board
SBREFA Small Business Regulatory Enforcement Fairness Act
SD Standard Deviation
SDWA Safe Drinking Water Act
SDWIS Safe Drinking Water Information System
SEFA Small Entity Flexibility Analysis
Stage 2 DBPR Stage 2 Disinfectants and Disinfection Byproducts Rule
SWAP Source Water Assessment Program
SWTR Surface Water Treatment Rule
TCR Total Coliform Rule
TNCWS Transient Non-Community Water System
UIC Underground Injection Control
UMRA Unfunded Mandates Reform Act
US United States
USGS United States Geological Survey
UV Ultraviolet Radiation
VSL Value of Statistical Life
WHO World Health Organization
WTP Willingness To Pay

Table of Contents

I. General Information
II. Summary
    A. Why Is EPA Promulgating the GWR?
    B. What Does the GWR Require?
    1. Sanitary Surveys
    2. Source Water Monitoring
    3. Treatment Technique Requirements
    4. Compliance Monitoring
    C. How Has the Final Rule Changed From What EPA Proposed?
    D. Does This Regulation Apply to My Water System?
III. Background
    A. What Is the Statutory Authority for the GWR?
    B. What Is the Regulatory History of the GWR and How Were 
Stakeholders Involved?
    C. What Public Health Concerns Does the GWR Address?
    1. Introduction
    2. Waterborne Disease Outbreaks in Ground Water Systems
    3. Microbial Contamination in Public Ground Water Systems
    4. Potential Risk Implications From Occurrence Data
IV. Discussion of GWR Requirements
    A. Sanitary Surveys
    1. What Are the Requirements of This Rule?
    2. What Is EPA's Rationale for the GWR Sanitary Survey 
Requirements?
    3. What Were the Key Issues Raised by Commenters on the Proposed 
GWR Sanitary Survey Requirements?
    B. Source Water Monitoring
    1. What Are the Requirements of This Rule?
    2. What Is EPA's Rationale for the GWR Source Water Monitoring 
Requirements?
    3. What Were the Key Issues Raised by Commenters on the Proposed 
GWR Source Water Monitoring Requirements?
    C. Corrective Action Treatment Techniques for Systems With 
Significant Deficiencies or Source Water Fecal Contamination
    1. What Are the Requirements of This Rule?
    2. What Is EPA's Rationale for the GWR Treatment Technique 
Requirements?
    3. What Were the Key Issues Raised by Commenters on the Proposed 
GWR Treatment Technique Requirements?
    D. Providing Notification and Information to the Public
    1. What Are the Requirements of This Rule?
    2. What Is EPA's Rationale for the Public Notice Requirements?
    3. What Were the Key Issues Raised by Commenters on the Proposed 
GWR Public Notification Requirements?
    E. What Are the Reporting and Recordkeeping Requirements for 
Systems?
    1. Reporting Requirements
    2. Recordkeeping Requirements
    3. What Were the Key Issues Raised by Commenters on the Proposed 
GWR Reporting and Recordkeeping Requirements for Systems?
    F. What Are the Special Primacy, Reporting, and Recordkeeping 
Requirements for States?
    1. Primacy Requirements
    2. Reporting Requirements
    3. Recordkeeping Requirements
    4. What Were the Key Issues Raised by Commenters on the Proposed 
GWR Special Primacy, Reporting, and Recordkeeping Requirements for 
States?
    G. Variances and Exemptions
    1. Variances
    2. Exemptions
V. Explanation of Extent of GWR
    A. Mixed Systems
    B. Cross-Connection Control
VI. Implementation
VII. Economic Analysis (Health Risk Reduction and Cost Analysis)
    A. How Has the Final Rule Alternative Changed From the Proposed 
Rule Alternative?
    B. Analyses That Support This Rule
    1. Occurrence Analysis
    2. Risk Analyses
    C. What Are the Benefits of the GWR?
    1. Calculation of Baseline Health Risk
    2. Calculation of Avoided Illnesses and Deaths
    3. Derivation of Quantified Benefits
    4. Nonquantifiable Benefits
    5. How Have the Benefits Changed Since the Proposal?
    D. What Are the Costs of the GWR?
    1. Summary of Quantified Costs
    2. Derivation of Quantified Costs
    3. Nonquantifiable Costs
    4. How Have the Costs Changed Since the Proposal?
    E. What Is the Potential Impact of the GWR on Households?
    F. What Are the Incremental Costs and Benefits of the GWR?
    G. Are There Any Benefits From Simultaneous Reduction of Co-
Occurring Contaminants?
    H. Is There Any Increase in Risk From Other Contaminants?
    I. What Are the Effects of the Contaminant on the General 
Population and Groups Within the General Population That Are 
Identified as Likely To Be at Greater Risk of Adverse Health 
Effects?
    1. Risk of Acute Viral Illness to Children and Pregnant Women
    2. Risk of Viral Illness to the Elderly and Immunocompromised
    J. What Are the Uncertainties in the Risk, Benefit, and Cost 
Estimates for the GWR?
    1. The Baseline Numbers of Ground Water Systems, Populations 
Served, and Associated Disinfection Practice
    2. The Numbers of Wells Designated as More Versus Less 
Vulnerable
    3. The Baseline Occurrence of Viruses and E. coli in Ground 
Water Wells
    4. For the Sanitary Survey Provisions, the Percentage of Systems 
Identified as Having Significant Deficiencies, the Percentage of 
These Deficiencies That Are Corrected, and State Costs for 
Conducting Surveys
    5. The Predicted Rates at Which Virally Contaminated (and Non-
Contaminated) Wells Will Be Required To Take Action After Finding E. 
coli Ground Water Sources
    6. The Infectivity of Echovirus and Rotavirus Used to Represent 
Viruses That Occur in Ground Water
    7. The Costs of Illnesses Due to Ingestion of Contaminated 
Ground Water
    8. The Costs of Taking Action After Finding E. coli in Ground 
Water Sources
    9. Nonquantifiable Benefits
    10. Optional Assessment Source Water Monitoring
    11. Corrective Actions and Significant Deficiencies
    12. Uncertainty Summary
    K. What Is the Benefit/Cost Determination for the GWR?
    L. What Were Some of the Major Comments Received on the Economic 
Analysis and What Are EPA's Responses?
    1. Costs
    2. Benefits
    3. Risk Management
VIII. Statutory and Executive Order Reviews
    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
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    1. Energy Supply
    2. Energy Distribution
    3. Energy Use

[[Page 65576]]

    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. Congressional Review Act
    L. Analysis of the Likely Effect of Compliance With the GWR on 
the Technical, Financial, and Managerial Capacity of Public Water 
Systems
IX. Consultation With Science Advisory Board, National Drinking 
Water Advisory Council, and the Secretary of Health and Human 
Services; and Peer Review
X. References

II. Summary

    This section includes a discussion of the purpose of the Ground 
Water Rule (GWR) and a summary of the GWR requirements.

A. Why Is EPA Promulgating the GWR?

    EPA is promulgating the GWR to provide for increased protection 
against microbial pathogens, specifically viral and bacterial 
pathogens, in public water systems (PWSs) that use ground water 
sources. EPA is particularly concerned about ground water systems 
(GWSs) that are susceptible to fecal contamination because these 
systems may be at risk of supplying water that contains harmful 
microbial pathogens. Viral pathogens found in GWSs may include enteric 
viruses such as Echovirus, Coxsackie viruses, Hepatitis A and E, 
Rotavirus and Noroviruses (i.e., Norwalk-like viruses) and enteric 
bacterial pathogens such as Escherichia coli (most E. coli is harmless 
but a few species are pathogenic, including E. coli O157:H7), 
Salmonella species, Shigella species, and Vibrio cholerae. Ingestion of 
these pathogens can cause gastroenteritis or, in certain cases, serious 
illnesses such as meningitis, hepatitis, or myocarditis. Health 
implications in sensitive subpopulations (e.g., children, elderly, 
immuno-compromised) may be severe (e.g., hemolytic uremic syndrome) and 
may cause death.
    One goal of the GWR is to identify and target GWSs that are 
susceptible to fecal contamination because such contamination is the 
likely source of viral and bacterial pathogens in drinking water 
supplies. Ground water is fecally contaminated when fecal indicators 
(e.g., E. coli, enterococci, or coliphage) are present. While fecal 
indicators typically are not harmful when ingested, their presence 
demonstrates that there is a pathway for pathogenic viruses and 
bacteria to enter ground water sources. Another key objective of the 
rule is to protect public health by requiring these higher risk GWSs to 
monitor and, when necessary, take corrective action. Corrective action 
can include correcting all significant deficiencies; providing an 
alternate source of water; eliminating the source of contamination; or 
providing treatment that reliably achieves at least 99.99 percent (4-
log) treatment of viruses (using inactivation, removal, or a State-
approved combination of 4-log virus inactivation and removal) for each 
contaminated ground water source. Each of these corrective actions is 
intended to remove all or nearly all fecal contamination, including 
both viral and bacterial pathogens. This rule implements section 
1412(b)(8) of the 1996 Safe Drinking Water Act (SDWA) Amendments to 
promulgate a rule requiring GWSs to disinfect ``as necessary.'' The 
risk-targeted approach in this rule is a critical distinction from the 
approach outlined in the 1986 SDWA, which would have required all PWSs 
using surface water or ground water to disinfect. Because there are so 
many GWSs (approximately 147,000) in the United States, such a 
requirement would have been a great challenge for systems and States to 
implement.
    This rule is necessary to protect public health because current 
regulatory provisions for GWSs (for example, sanitary survey 
requirements in the Total Coliform Rule (TCR) (54 FR 27544, June 29, 
1989) (USEPA, 1989a)) do not adequately address fecal contamination at 
the ground water source. In fact, no Federal regulation exists that 
requires either monitoring of ground water sources or corrective action 
upon finding fecal contamination or identifying a significant 
deficiency during a sanitary survey. In addition, the U.S. Government 
Accountability Office (GAO) 1993 report (USGAO, 1993) found that many 
sanitary surveys did not evaluate one or more of the components that 
EPA recommended be evaluated, and that efforts to ensure correction 
were often limited. Also, GAO found that follow-up on major problems 
was often lacking. Moreover, the report found that problems associated 
with system infrastructure identified during sanitary surveys 
frequently remain uncorrected. The GWR provides much needed public 
health protection by requiring systems that do not treat their ground 
water sources to monitor their ground water source and to take 
corrective actions when fecal contamination or a significant deficiency 
is found.
    In addition, EPA has evaluated data on outbreaks and the occurrence 
of waterborne viral and bacterial pathogens and indicators of fecal 
contamination in ground water supplying PWS wells. These data indicate 
that there is a subset of GWSs that are susceptible to fecal 
contamination; therefore, EPA believes that risk management strategies 
are needed to protect public health. Specifically, the Centers for 
Disease Control and Prevention (CDC) reports that between 1991 (the 
year in which the TCR became effective) and 2000, GWSs were associated 
with 68 waterborne disease outbreaks that caused 10,926 illnesses 
(Moore et al. (1993); Kramer et al. (1996); Levy et al. (1998); Barwick 
et al. (2000); and Lee et al. (2002)). These outbreaks accounted for 51 
percent of all waterborne disease outbreaks in the United States during 
that time period. The major deficiencies identified by the CDC report 
as the likely cause of the outbreaks were source water contamination 
and inadequate treatment (or treatment failures); see Section III.C.2 
for a summary of these outbreak data. Studies of viral and bacterial 
pathogens and/or fecal indicator occurrence in ground waters that 
supply PWSs show that dozens of the public ground water wells sampled 
had fecal indicator or viral presence in their wells. See Section 
III.C.3 of this preamble for a summary of occurrence studies. Based on 
these outbreak and occurrence data, along with concern about lack of 
monitoring and follow-up actions for GWSs, EPA has concluded that GWSs 
need to implement targeted, risk management strategies to protect 
public health from bacterial and viral pathogens in fecally 
contaminated ground water sources.
    To provide a flexible, risk-targeted approach to achieve public 
health protection, this rule builds on existing State programs--some 
that emphasize the importance of disinfection and others that emphasize 
assessments and technical assistance--to identify and target 
susceptible GWSs. In addition, the GWR establishes treatment technique 
requirements, which provide public GWSs with multiple options to 
correct source water fecal contamination and significant deficiencies 
that present a public health risk. Furthermore, this rule establishes 
compliance monitoring requirements to ensure that treatment 
effectiveness is maintained.

B. What Does the GWR Require?

    The GWR establishes a risk-targeted approach to identify GWSs 
susceptible to fecal contamination and requires corrective action to 
correct significant deficiencies and source water fecal contamination 
in public GWSs. A central objective of the GWR is to identify the 
subset of ground water sources that are at higher risk of fecal 
contamination among the large number

[[Page 65577]]

of existing GWSs (approximately 147,000), and then further target those 
systems that must take corrective action to protect public health. This 
risk-targeting strategy includes the following:
     Regular GWS sanitary surveys to check for significant 
deficiencies in eight key operational areas;
     A flexible program for identifying higher risk systems 
through existing TCR monitoring and State determinations; and
     Ground water source monitoring to detect fecal 
contamination at targeted GWSs that do not provide 4-log treatment of 
viruses.
    Measures to protect public health include the following:
     Treatment technique requirements to address sanitary 
survey significant deficiencies and fecal contamination in ground 
water; and
     Compliance monitoring to ensure that 4-log treatment of 
viruses is maintained where it is used to comply with this rule.
    To meet the treatment technique requirements of this rule, GWSs 
with a significant deficiency or evidence of source water fecal 
contamination, following consultation with their primacy agency (herein 
referred to as ``the State''), must implement one or more of the 
following corrective action options: Correct all significant 
deficiencies; provide an alternate source of water; eliminate the 
source of contamination; or provide treatment that reliably achieves at 
least 99.99 percent (4-log) treatment of viruses (using inactivation, 
removal, or a State-approved combination of 4-log virus inactivation 
and removal) for each ground water source. Each of these corrective 
actions is intended to remove all or nearly all fecal contamination, 
including both viral and bacterial pathogens. In addition, the GWS must 
inform its customers of any uncorrected significant deficiencies or 
fecal indicator-positive ground water source samples.
    The following sections provide more detailed information on the 
provisions of the GWR.
1. Sanitary Surveys
    Sanitary surveys are an important tool for identifying potential 
vulnerabilities to fecal contamination at GWSs. The final GWR includes 
Federal sanitary survey requirements for all GWSs for the first time. 
This rule requires States, as a condition for primacy, to perform 
regular comprehensive sanitary surveys of the following eight critical 
components to the extent that they apply to the individual water system 
being surveyed: (1) Source; (2) treatment; (3) distribution system; (4) 
finished water storage; (5) pumps, pump facilities, and controls; (6) 
monitoring, reporting, and data verification; (7) system management and 
operation; and (8) operator compliance with State requirements. This 
rule includes conditions of primacy in 40 CFR part 142 under which 
States will have until December 31, 2012 to complete the initial 
sanitary survey cycle for community water systems (CWSs), except those 
that meet performance criteria, and until December 31, 2014 to complete 
the initial sanitary survey cycle for all non-community water system 
(NCWSs) and CWSs that meet performance criteria (refer to Section 
IV.A.1 for crtieria). Following the initial sanitary survey cycle, 
States must conduct these surveys every three years for CWSs (defined 
in Sec.  141.2), and every five years for all NCWSs and CWSs that meet 
certain performance criteria as discussed in Section IV.A.1.
    If a significant deficiency is identified as a result of a sanitary 
survey, the system must take corrective action. If the system does not 
complete corrective action within 120 days of receiving notification 
from the State, or is not in compliance with a State-approved 
corrective action plan and schedule, the system will be in violation of 
the treatment technique requirements of this rule.
    The final GWR sanitary survey provision provides comprehensive and 
effective public health protection by specifying the scope and 
frequency of sanitary surveys and by requiring corrective action for 
systems with significant deficiencies.
2. Source Water Monitoring
    This rule requires triggered source water monitoring and provides 
States with the option to require assessment source water monitoring. 
Source water monitoring is an effective tool to target at-risk systems 
that must take corrective action to protect public health. Indications 
of risk may come from total coliform monitoring, hydrogeologic 
sensitivity analyses, or other system-specific data and information.
    In this rule, a GWS with a distribution system TCR sample that 
tests positive for total coliform is required to conduct triggered 
source water monitoring to evaluate whether the total coliform presence 
in the distribution system is due to fecal contamination in the ground 
water source. A GWS that does not provide at least 4-log treatment of 
viruses must conduct triggered source water monitoring upon being 
notified that a TCR sample is total coliform-positive. Within 24 hours 
of receiving the total coliform-positive notice, the system must 
collect at least one ground water sample from each ground water source 
(unless the GWS has an approved triggered source water monitoring plan 
that specifies the applicable source for collecting source samples). 
The GWS must test the ground water source sample(s) for the presence of 
one of three State-specified fecal indicators (E. coli, enterococci, or 
coliphage). If the source sample is fecal indicator-positive, this rule 
requires the GWS to notify the State and the public. Unless directed by 
the State to take immediate corrective action, the GWS must collect and 
test five additional source water samples for the presence of the same 
State-specified fecal indicator within 24 hours. If any one of the five 
additional source water samples tests positive for the State-specified 
fecal indicator (E. coli, enterococci, or coliphage), this rule 
requires the GWS to notify the State and the public and comply with the 
treatment technique requirements, which require the system to take one 
of four corrective actions discussed in the following section. The 
compliance date of the triggered source water monitoring requirement is 
December 1, 2009.
    As a complement to the triggered source water monitoring provision, 
States have the option of requiring GWSs to conduct assessment source 
water monitoring. This flexible provision gives States the opportunity 
to target higher risk GWSs for additional source water monitoring and 
evaluation. The State may require a GWS to conduct assessment source 
water monitoring as needed. EPA recommends that States use 
Hydrogeologic Sensitivity Assessments (HSAs) and TCR/triggered source 
water monitoring results, along with other information to identify 
higher risk systems for assessment source water monitoring. For 
assessment source water monitoring, EPA recommends that GWSs take 12 
monthly samples and test them for one of the GWR indicators (E. coli, 
enterococci, or coliphage). Corrective action for systems performing 
assessment source water monitoring is determined by the State.
3. Treatment Technique Requirements
    This rule requires a GWS to comply with the treatment technique 
requirements if a significant deficiency is identified during a 
sanitary survey. Also, the rule requires a GWS to comply with the 
treatment technique requirements if one of the five additional ground 
water source samples (or at State discretion, the initial source

[[Page 65578]]

sample) has tested positive for fecal contamination (i.e., the sample 
is positive for one of the three fecal indicators and is not 
invalidated by the State). The treatment technique requires that a GWS 
implement at least one of the following corrective actions: correct all 
significant deficiencies; provide an alternate source of water; 
eliminate the source of contamination; or provide treatment that 
reliably achieves at least 4-log treatment of viruses. Furthermore, the 
GWS must inform the public served by the water system of any 
uncorrected significant deficiencies and/or fecal contamination in the 
ground water source. The compliance date of the treatment technique 
requirements is December 1, 2009.
4. Compliance Monitoring
    Compliance monitoring requirements are the final defense against 
viral and bacterial pathogens provided by this rule. All GWSs that 
provide at least 4-log treatment of viruses using chemical 
disinfection, membrane filtration, or a State-approved alternative 
treatment technology must conduct compliance monitoring to demonstrate 
treatment effectiveness. The compliance date of the compliance 
monitoring requirement is December 1, 2009.

C. How Has the Final Rule Changed From What EPA Proposed?

    The primary elements of the proposed GWR were sanitary surveys, 
triggered monitoring, HSAs, routine monitoring, corrective action, and 
compliance monitoring. EPA received numerous comments on the proposed 
GWR and has carefully considered those comments in developing the final 
GWR. This consideration has led to a number of changes that the Agency 
believes will result in a more flexible, more targeted, more protective 
final GWR.
    Most of the changes are minor and are discussed throughout this 
preamble in the pertinent sections. The most significant change from 
the proposed rule to the final rule is to the routine monitoring 
provision. The proposed routine monitoring provision would have 
required GWSs in sensitive aquifers, as defined by a State performed 
HSA, to collect monthly source water samples.
    EPA received many negative comments on the HSA provision. Some 
States said that the proposed GWR did not allow sufficient time to 
conduct the HSA prior to the start of routine monitoring, which would 
result in GWSs in non-sensitive aquifers being required to monitor. 
Others stated that they would not do the HSA; rather, they would 
require all GWSs to conduct routine monitoring. In addition, EPA 
received comments that the routine monitoring provision was too 
burdensome.
    If the HSA provision would not be implemented in many States to 
target the routine monitoring to systems in sensitive aquifers that are 
most at risk, then the Agency agrees with the commenters that the 
routine monitoring provision would be overly burdensome. This is 
because some systems, located in non-sensitive aquifers, would be 
conducting routine monitoring unnecessarily. Moreover, EPA now believes 
that it is more difficult to capture contamination than estimated in 
the proposal, which further highlights the importance of correctly 
identifying systems for which source water monitoring would be prudent. 
Furthermore, commenters strongly supported revision of the GWR proposal 
to maximize State flexibility and discretion in making system-specific 
decisions.
    Given the importance of correctly targeting systems for source 
water monitoring, in conjunction with the State's desire for enough 
flexibility to ensure sensible decisions on a case-by-case basis, EPA 
decided to redesign the source water monitoring provision. Accordingly, 
the final rule does not include a national requirement for HSAs and 
routine monitoring for systems in sensitive aquifers. Rather, EPA 
concludes that the States are in the best position to assess which 
systems would most benefit from a source water monitoring program. The 
final provision is similar to routine monitoring but is now optional 
for States and has been renamed assessment source water monitoring. 
States argued in their comments that the information available to them 
from other programs such as source water assessments, wellhead 
protection plans, and historical data would be important factors to 
consider when determining the need for source water monitoring. Because 
States are best able to identify higher risk systems, the final GWR 
provides States with the option to require GWSs to perform assessment 
source water monitoring. The Agency finds the comments received on the 
proposal to be persuasive and to support the approach in the final GWR.
    The purpose of the optional assessment source water monitoring 
requirement is to allow States to target such monitoring to GWSs that 
the State believes are at higher risk for fecal contamination. States 
specifically requested this flexibility and discretion in their 
comments to EPA. The flexibility of this provision provides many 
benefits. First, it gives States the ability to make case-by-case 
determinations of the need for source water monitoring. Given the 
variety of aquifer and well conditions across the United States and 
even within each State, State programs make more sense than a 
nationally-directed program. Second, the optional assessment source 
water monitoring requirement allows States to require assessment source 
water monitoring as needed. System conditions change over time and the 
ability of States to target this requirement to a specific system and 
time period will reduce burden and be critical to protecting public 
health by allowing States to focus attention on problem systems. The 
lack of time constraints will also allow States to prioritize 
susceptibility assessments and further target those systems most in 
need.
    EPA recommends that States use HSAs as one tool to identify high 
risk systems for assessment source water monitoring. HSAs can be an 
effective screening tool to identify sensitive hydrogeologic settings 
that transmit water, and any pathogens in that water, quickly from the 
surface to the aquifer. States have other information available to them 
to target high risk systems, such as source water assessments, wellhead 
protection plans, and historical monitoring data. Data on past 
indications of source water fecal contamination, particularly from TCR 
monitoring, in combination with GWR triggered source water monitoring 
results, can be another important tool.

D. Does This Regulation Apply to My Water System?

    The requirements in this final rule apply to all PWSs (CWSs and 
NCWSs) that use ground water sources, in whole or in part (including 
consecutive systems that receive finished ground water from another 
PWS), except that they do not apply to PWSs that combine all of their 
ground water with surface water or ground water under the direct 
influence of surface water (GWUDI) prior to treatment under the Surface 
Water Treatment Rule (SWTR) (54 FR 27486, June 29, 1989) (USEPA, 
1989b). The GWR ensures that the same level of public health protection 
is provided to persons served solely by GWSs as to those served by 
mixed systems supplied by both ground water and surface water sources. 
See Section V.A of this preamble for more information on mixed systems.

III. Background

    This section includes a discussion of the statutory requirements, 
regulatory

[[Page 65579]]

history, stakeholder involvement, and the public health concerns that 
this rule addresses.

A. What Is the Statutory Authority for the GWR?

    Section 1412(b)(8) of the SDWA, as amended on August 6, 1996, 
requires EPA to promulgate National Primary Drinking Water Regulations 
(NPDWRs) requiring disinfection as a treatment technique for all PWSs, 
including surface water systems and, as necessary, GWSs. In addition, 
section 1412(b)(8) requires EPA to promulgate criteria as part of the 
regulations for determining whether disinfection should be required as 
a treatment technique for any PWS served by ground water. In contrast, 
the 1986 Amendments to the SDWA directed EPA to promulgate regulations 
requiring disinfection at all PWSs using either surface water or ground 
water. The SWTR implemented that requirement for surface water systems, 
but when Congress amended the SDWA again in 1996, EPA had not 
promulgated regulations requiring disinfection for PWSs that use ground 
water. In the legislative history of the 1996 Amendments to the SDWA, 
Congress identified several reasons for the delay, including the 
recognition that not all GWSs are at risk of contamination, as well as 
the high cost of across-the-board disinfection. This rule implements 
section 1412(b)(8) of the SDWA, as amended, by establishing a 
regulatory framework for determining which GWSs are susceptible to 
fecal contamination and requiring those systems to implement corrective 
action options, only one of which is to provide 4-log treatment of 
viruses (e.g., disinfection).
    Section 1413(a)(1) of the SDWA allows EPA to grant a State primary 
enforcement responsibility (``primacy'') for NPDWRs when EPA has 
determined that the State has adopted regulations that are no less 
stringent than EPA's. To obtain primacy for this rule, States must 
adopt comparable regulations within two years of EPA's promulgation of 
the final rule, unless EPA grants the State a two-year extension. State 
primacy requires, among other things, adequate enforcement (including 
monitoring and inspections) authority and reporting requirement. EPA 
must approve or deny State primacy applications within 90 days of 
submission to EPA (SDWA section 1413(b)(2)). In some cases, a State 
submitting revisions to adopt an NPDWR has primacy enforcement 
authority for the new regulation while EPA's decision on the revision 
is pending (SDWA section 1413(c)). Section 1445 of the SDWA authorizes 
the Administrator to establish monitoring, recordkeeping, and reporting 
regulations to assist the Administrator in determining compliance with 
the SDWA and in advising the public of the risks of unregulated 
contaminants. Section 1450 of the SDWA authorizes the Administrator to 
prescribe such regulations as are necessary or appropriate to carry out 
his or her functions under the Act.

B. What Is the Regulatory History of the GWR and How Were Stakeholders 
Involved?

    EPA has devoted a tremendous effort to engage stakeholders in the 
development of the GWR. EPA began developing the GWR in 1987 to address 
potential fecal contamination of GWSs by requiring across-the-board 
disinfection, as directed by the 1986 Amendments to the SDWA. A 
preliminary public meeting on issues related to GWSs was held in 1990 
(55 FR 21093, May 22, 1990) (USEPA, 1990). By 1992, EPA had developed a 
draft proposed rule that would have required disinfection for all GWSs 
(57 FR 33960, July 31, 1992) (USEPA, 1992). The draft proposed rule 
incorporated stakeholder input and was made available for stakeholder 
review. While some stakeholders supported the increased public health 
protection for people drinking ground water, most stakeholders were 
concerned that the rule was crafted such that all GWSs were assumed to 
be contaminated until monitoring proved otherwise and that disinfection 
waivers would be difficult to obtain.
    Throughout the early and mid-1990s, EPA conducted technical 
discussions with ad hoc working groups during more than 50 conference 
calls, with participation of EPA Headquarters, EPA Regional offices, 
States, local governments, academicians, and trade associations. In 
1996, Congress amended the SDWA and required EPA, under section 
1412(b)(8), to develop regulations requiring disinfection as a 
treatment technique for GWSs ``as necessary.'' As discussed previously, 
this Amendment to the SDWA called for a different regulatory framework 
to address fecal contamination in GWSs. In light of this statutory 
change in direction, EPA determined that further stakeholder 
involvement would be crucial to establishing an effective approach for 
regulating fecal contamination in PWSs that use ground water sources.
    Technical meetings were held in Irvine, California in July 1996 
(USEPA, 1996), and in Austin, Texas in March 1997 (USEPA, 1997a). These 
technical discussions focused primarily on establishing a reasonable 
means for determining if a ground water source was vulnerable to fecal 
contamination. EPA evaluated the possibility of developing a 
vulnerability assessment tool that would consider hydrogeologic 
information and sources of fecal contamination.
    In addition, EPA held a series of stakeholder meetings (in 
Portland, OR; Madison, WI; Dallas, TX; Lincoln, NE; and Washington, DC) 
designed to engage all stakeholders in developing a risk-based 
regulatory framework. The purpose of these meetings was to review 
available information on risk and to discuss methods to identify GWSs 
that are susceptible to fecal contamination, and therefore, should be 
required to take corrective actions. EPA also held three early 
involvement meetings with State representatives (in Portland, OR; 
Chicago, IL; and Washington, DC) and received valuable input from small 
system operators as part of an Agency outreach initiative under the 
Small Business Regulatory Enforcement Fairness Act. Over the course of 
these stakeholder meetings, the participants evaluated a continuum of 
regulatory approaches. The meetings fostered EPA's understanding of how 
State strategies fit together as a part of a national strategy. Taken 
together, the meetings were crucial in guiding the Agency's development 
of regulatory components for the GWR proposal.
    On February 3, 1999, EPA distributed a preliminary draft preamble 
using the approach developed during the stakeholder meetings. Eighty 
individual comment letters were received from representatives of State 
and local governments, trade associations, academic institutions, 
individual PWSs, and other Federal agencies. EPA considered all of the 
comments received from this informal process as the Agency revised the 
draft proposal.
    The proposed GWR was published in the Federal Register in 2000 (65 
FR 30194, May 10, 2000) (USEPA, 2000a). The comment period closed on 
August 9, 2000, and EPA received comments from over 250 individuals, 
corporations, organizations, PWSs, States and Tribes, industry and 
trade associations, and environmental groups. EPA has carefully 
considered all of these comments in developing this final rule. 
Comments received on the proposed rule, along with EPA's responses, are 
compiled in the Public Comment and Response Document for the Final 
Ground Water Rule (USEPA, 2006c).
    EPA published a Notice of Data Availability (NODA) in the Federal 
Register in 2006 (71 FR 15105, March

[[Page 65580]]

27, 2006) (USEPA, 2006e). The purpose of the NODA was to present 
additional studies that the Agency was considering in conducting its 
economic analysis for the final rule. The comment period closed on 
April 26, 2006. EPA received 14 sets of comments from individuals, 
trade associations, State and local governments, an organization, and a 
university. Comments received on the NODA, along with EPA's responses, 
are also compiled in the Public Comment and Response Document for the 
Final Ground Water Rule (USEPA, 2006c).

C. What Public Health Concerns Does the GWR Address?

    This section explains the public health concerns associated with 
fecal contamination in GWSs by summarizing information on how ground 
water sources could become fecally contaminated, the causes of ground 
water outbreaks, and the health effects of consuming contaminated 
water.
1. Introduction
    EPA estimates that approximately 114 million people consume 
drinking water from PWSs that use ground water sources (Table III-1). 
These PWSs (total of about 147,000) distribute disinfected or 
undisinfected ground water to their customers. Approximately 18 percent 
(20 million) of people served by PWSs that use ground water sources 
receive undisinfected water, while over 60 percent (70 million) receive 
either undisinfected water or water treated to less than 4-log 
inactivation or removal of viruses.
    Over 100 million people receive ground water from community water 
systems (CWSs) (Table III-1), while about 14 million people receive 
ground water from non-community water systems (NCWSs); non-transient 
non-community water systems (NTNCWSs) serve ground water to about five 
million people and transient non-community water systems (TNCWSs) serve 
ground water to about nine million people. Table III-1 shows that, of 
the number of people receiving water from CWSs, NTNCWSs, and TNCWSs, 
approximately 9.3 million (9.2 percent), 3.6 million (71 percent), and 
7.2 million, (83 percent), respectively, receive water that is not 
disinfected at all. The Table also shows that 56.8 million people 
served by CWSs, 4.7 million people served by NTNCWSs, and 8.6 million 
people served by TNCWSs receive water that is either undisinfected or 
treated to less than 4-log.

                             Table III-1.--Population Served by Ground Water Systems
                                                   [Millions]
----------------------------------------------------------------------------------------------------------------
                                                                                              Population served
                                                                                              ground water that
                                                     Total population    Population served        is either
                                                     served by ground     untreated ground     undisinfected or
                                                      water systems            water           treated to less
                                                                                                  than 4-log
----------------------------------------------------------------------------------------------------------------
CWSs.............................................                100.4                  9.3                 56.8
NTNCWSs..........................................                  5.1                  3.6                  4.7
TNCWSs...........................................                  8.7                  7.2                 8.6
----------------------------------------------------------------------------------------------------------------
Source: Exhibit 4.4 of the GWR EA (USEPA, 2006d).

    As discussed previously in Section II.A, the CDC identified source 
water contamination and inadequate treatment as the major causes for 
ground water-related outbreaks between 1991 and 2000. Untreated or 
inadequately treated ground water may contain viral and bacterial 
pathogens. Therefore, undisinfected ground water or water treated to 
less than 4-log may pose a public health risk to consumers.
    Waterborne disease attributable to viral and bacterial pathogens is 
a significant public health problem. EPA's Science Advisory Board cited 
drinking water contamination, particularly contamination by pathogenic 
microorganisms, as one of the most important environmental risks 
(USEPA/SAB, 1990). The CDC reports significant numbers of recent 
waterborne disease outbreaks and cases of illness associated with 
ground waters (Moore et al. (1993); Kramer et al. (1996); Levy et al. 
(1998); Barwick et al. (2000); Lee et al. (2002)).
    Most waterborne pathogens, including viral and bacterial pathogens, 
cause gastrointestinal (GI) illness with diarrhea, abdominal 
discomfort, nausea, vomiting, and other symptoms. The effects of a 
waterborne disease are usually acute, resulting from a single exposure. 
Most GI illnesses are generally of short duration and result in mild 
illness, but some can result in severe illness and even death. For 
example, during a recent ground water outbreak in New York, a healthy 
three-year old child died from hemolytic uremic syndrome (kidney 
failure) (New York State Department of Health, 2000). Waterborne 
pathogens also cause other serious disorders such as hepatitis, 
Legionnaires Disease, myocarditis, paralysis, acute hemorrhagic 
conjunctivitis, meningitis, and reactive arthritis. Waterborne 
pathogens have also been associated with diabetes, encephalitis, and 
other diseases (Lederberg, 1992).
    Sensitive populations are at greater risk from waterborne disease 
from viral and bacterial pathogens than the general population. These 
sensitive subpopulations include children (especially the very young); 
the elderly; the malnourished; pregnant women; chronically ill patients 
(e.g., those with diabetes or cystic fibrosis); and a broad category of 
those with compromised immune systems, such as AIDS patients, those 
with autoimmune disorders (e.g., rheumatoid arthritis, lupus 
erythematosus, and multiple sclerosis), organ transplant recipients, 
and those receiving chemotherapy (Rose, 1997). Sensitive subpopulations 
(or those with compromised immune systems) represent almost 20 percent 
of the population in the United States (Gerba et al., 1996). The 
severity and duration of illness is often greater in sensitive 
subpopulations than in healthy individuals, and may occasionally result 
in death.
    When humans are exposed to and infected by an enteric pathogen, 
such as a bacterium or virus, the pathogen becomes 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 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, etc.), which is referred to 
as secondary spread.

[[Page 65581]]

Waterborne pathogens thus may infect people via a variety of routes.
    Fecal contamination of drinking water is a primary cause of 
waterborne disease (Szewzyk et al., 2000). Viral and bacterial 
pathogens associated with fecal contamination can reach ground water 
via pathways in the subsurface and near surface. First, fecal 
contamination from, for example, improper storage or management of 
manure, runoff from land-applied manure, leaking sewer lines, or failed 
septic systems can reach the ground water source by traveling--
sometimes great distances--through the subsurface (especially through 
transmissive materials such as karst, gravel, or fractured bedrock). 
Twenty-five million households in the United States use conventional 
onsite wastewater treatment systems, according to the 1990 Census. 
These systems include septic systems and leach fields. A national 
estimate of failure rates of these systems is not available; however, a 
National Small Flows Clearinghouse survey reports that in 1993 alone, 
90,632 failures were reported (USEPA, 1997b). The volume of septic tank 
waste alone that is released into the subsurface has been estimated at 
one trillion gallons per year (Canter and Knox, 1984). This 
contamination may eventually reach the intake zone of a drinking water 
well.
    Second, fecal contamination from the surface may enter a drinking 
water well along the casing or through cracks in the sanitary seal if 
it is not properly constructed, protected, or maintained. In addition 
to source contamination, fecal contamination may also enter the 
distribution system when cross-connection controls fail or when 
negative pressure in a leaking pipe allows contaminant infiltration. A 
subset of GWSs is susceptible to contamination by one or more of these 
routes.
2. Waterborne Disease Outbreaks in Ground Water Systems
    The Centers for Disease Control and Prevention (CDC) reports that 
between 1991 (the year in which implementation of the TCR began) and 
2000, GWSs (both CWSs and NCWSs) were associated with 68 outbreaks that 
caused 10,926 illnesses (Table III-2). These account for 51 percent of 
all waterborne disease outbreaks in the United States during that 
period. The outbreak data illustrate that the major deficiency in GWSs 
was source water contamination. Contaminated source water was the cause 
of 79 percent of the outbreaks in GWSs (63 percent of CWS outbreaks and 
86 percent of NCWS outbreaks), shown as untreated ground water and 
treatment deficiencies in Table III-2. Consumers of undisinfected water 
are especially vulnerable to source water contamination. Approximately 
70 percent of GWSs provide either untreated ground water or provide 
treatment of less than 4-log virus inactivation or removal as discussed 
in the GWR EA (USEPA, 2006d).
    Of the 68 outbreaks in GWSs, 14 (21 percent) were associated with 
specific bacterial pathogens (see Table III-3). The fecal bacterial 
pathogen Shigella caused more reported outbreaks (five, seven percent) 
than any other bacterial agent. Identified viral pathogens were 
associated with four (six percent) reported outbreaks. Etiologic agents 
were not identified in 39 (57 percent) outbreaks; however, EPA suspects 
that many of these outbreaks were caused by viruses given that it is 
generally more difficult to analyze for viral pathogens than bacterial 
pathogens. EPA regulates for protozoa, including Giardia and 
Cryptosporidium, under the SWTRs, which also cover GWUDI systems. For 
the most part, the outbreaks associated with protozoa that occurred in 
GWSs were later determined by the State to be GWUDI systems.

BILLING CODE 6560-50-P

[[Page 65582]]

[GRAPHIC] [TIFF OMITTED] TR08NO06.000

BILLING CODE 6560-50-C

    Large outbreaks are rarely associated with GWSs because most GWSs 
are small. In addition, the number of identified and reported outbreaks 
in the CDC database is believed to substantially understate the actual 
incidence of waterborne disease outbreaks and cases of illness (Craun 
and Calderon, 1996; National Research Council, 1997). This 
underestimation is due to a number of factors. Many people experiencing 
gastrointestinal illness do not seek medical attention. Where medical 
attention is provided, testing to identify the pathogenic agent is 
often not done and even if it is, the pathogenic agent may not be 
identified through correct testing (e.g., when a sample is tested for a 
limited number of pathogens). Physicians often lack sufficient 
information to attribute gastrointestinal illness to any specific 
origin, such as drinking water, and few

[[Page 65583]]

States have an active outbreak surveillance program. Furthermore, the 
outbreak reporting system in the U.S. is paper-based and voluntary. 
Consequently, waterborne disease outbreaks are often not recognized in 
a community or, if recognized, are not traced to a drinking water 
source even though it may be the cause of the outbreak. Although it 
occurred in a community served by a surface water source, the 1993 
Cryptosporidium outbreak in Milwaukee, Wisconsin is an example of how 
difficult it is to recognize a drinking waterborne disease outbreak. In 
one study of this large outbreak, only six percent sought health care 
and only six percent of those health care cases were tested for 
parasites (with only four percent of those cases specifically tested 
for Cryptosporidium) (Juranek, 1997). Thus, over 99 percent of 
estimated cases of illness went undiagnosed in this outbreak. In 
addition to epidemic illness, an unknown but probably significant 
portion of waterborne disease is endemic (i.e., isolated cases not 
associated with an outbreak) and is even more difficult to recognize.
    Collectively, the data indicate that outbreaks in GWSs are a 
problem and that source water contamination and inadequate treatment 
(or treatment failures) are responsible for the great majority of 
outbreaks.
3. Microbial Contamination in Public Ground Water Systems
    The extent to which viral and bacterial pathogens occur in public 
ground water supplies influences the risk of exposure to populations 
consuming ground water from PWSs. Such risks of exposure pertain to 
populations using both undisinfected and disinfected water supplies. 
For undisinfected supplies, pathogens in the water are an immediate 
risk, since no treatment barrier exists prior to consumption. For 
disinfected supplies, if disinfection is inadequate or if treatment 
plant upsets occur, pathogens can reach consumers. These exposure risks 
were discussed in Section III.C.2 from an outbreak perspective. This 
section will discuss data on the occurrence of waterborne viral 
pathogens and indicators of fecal contamination in ground water 
supplying PWS wells.
    a. Occurrence studies and data. For this rule, EPA examined the 
occurrence of viral pathogens and some fecal indicators. EPA reviewed 
data from 24 studies on pathogen and fecal indicator occurrence in 
ground water wells that supply PWSs. This total includes 16 studies 
described in the proposal, seven studies that became available since 
proposal as described in the NODA (USEPA, 2006e), and one study that 
was provided to EPA in comment as a result of the NODA. Each study was 
conducted independently and with a different objective and scope. The 
Occurrence and Monitoring Document for the Final Ground Water Rule 
(USEPA, 2006b) provides a detailed discussion of each examined 
occurrence study. The available data show a wide range of enterovirus 
and fecal indicator occurrence in water drawn from wells across the 
U.S. EPA selected 15 studies to estimate national viral and fecal 
indicator occurrence in ground water. To arrive at the conclusion that 
these 15 studies provide the best possible representation of ground 
water contamination at a national level, EPA evaluated all available 
studies (24 studies) that were applicable to the risk assessment 
analyses (USEPA, 2006d). See Section VII.B.1 of this preamble for a 
discussion of study selection.
    Enterovirus cell culture data from the 15 studies were used to 
estimate the baseline risk related to virus occurrence in ground water. 
EPA believes that enterovirus cell culture measurements provide the 
best available basis for estimating pathogenic viral occurrence since 
they capture viruses that are infectious. However, because the cell 
culture procedure only captures a portion of all viruses that may 
actually occur in well water due to assay limitations, use of this 
method may underestimate viral occurrence.
    EPA used data on the indicator E. coli from these same studies to 
inform estimates of fecal contamination occurrence. Indicator data are 
important because illness can result from consuming ground water with 
fecal contamination in the absence of identified viruses. For example, 
some viruses such as infectious norovirus are not recoverable, other 
viruses such as enteroviruses have variable and limited recovery, and a 
variety of bacteria of fecal origin can cause disease. EPA chose to use 
E. coli data instead of other fecal indicator data for this analysis. 
This choice was driven by EPA's assessment that E. coli will be the 
most likely fecal indicator used when PWSs implement the GWR, because 
E. coli is frequently used to fulfill follow-up monitoring requirements 
under the TCR. Therefore national estimates of E. coli occurrence can 
be used to inform potential cost implications for implementing the GWR. 
EPA recognizes that any indicator organism, including E. coli, may or 
may not co-occur with pathogens and that co-occurrence could be 
intermittent. E. coli is an imperfect indicator of viral occurrence. 
Some wells with E. coli have no viral occurrence. Some wells with viral 
occurrence have no E. coli.
    b. Estimates of national occurrence of viral and fecal indicator 
contamination. This section discusses national occurrence of viral and 
fecal indicator (E. coli) contamination, which includes estimates of 
viral concentrations in contaminated wells and estimates of the 
probability that a well may have detectable viral and/or fecal 
indicator contamination. For purposes of this analysis, EPA uses the 
term ``sometime contamination'' as contamination that occurs at one or 
more points in time. Because fecal contamination is intermittent, 
viruses and E. coli will only be present at detectable levels some 
fraction of the time in a contaminated well. These fractions will vary 
from well to well. Some wells may be frequently contaminated but others 
may only be contaminated for a small fraction of time.
    EPA analyzed the 15 studies for data to inform the concentration 
analysis. Among the 15 studies used for the national occurrence 
analysis, 12 provided data on occurrence of enterovirus cell culture 
and 11 provided data on occurrence of E. coli. Among the 12 data sets 
with enterovirus cell culture measurement, three included viral 
concentration data. Concentration measurements in the three surveys 
ranged from 0.09 to 212 enteric virus infectious units (plaque forming 
units) per 100 liters. Although the measurement methods were often not 
capable of detecting viruses at concentrations below 0.2 units per 100 
liters, it is likely that viruses also occur at levels below the 
detection limit.
    Data from each of the 15 studies were combined into one complete 
data set to determine the probabilities of sometime well contamination 
for viral (indicated by enterovirus cell culture) or fecal indicator 
(indicated by E. coli) contamination. The results of this effort led 
naturally to a combined analysis, which models occurrence and co-
occurrence of viruses and E. coli. EPA's analysis also considers 
uncertainty and variability about these estimates. The model serves as 
the basis of EPA's national quantitative occurrence estimates. See the 
Occurrence and Monitoring Document for the Final Ground Water Rule for 
more information (USEPA, 2006b).
    Overall, the analysis indicates a public health concern in that 
approximately 26 percent of the wells sometimes have fecal 
contamination (indicated by E. coli) and approximately 27 percent of 
the wells sometimes have

[[Page 65584]]

viral contamination. Due to the intermittent nature of fecal 
contamination, some of these wells are only contaminated for a small 
fraction of time. On average, wells with sometime virus occurrence have 
detectable concentrations about 11 percent of the time, and wells with 
sometime E. coli occurrence have detectable concentrations about 14 
percent of the time. The remainder of the time, the well's water is 
essentially virus free (assuming that concentration is zero when not 
detected by measurement methods like those used in the occurrence 
studies). Compared to the analysis in the proposal, the number of wells 
with fecal contamination is greater but the frequency at which 
contamination occurs in each well is less.
    In summary, EPA's occurrence analysis shows that fecal 
contamination is intermittent and that some individuals are at risk 
because pathogens and/or fecal indicators occur at PWSs that use ground 
water as a source of drinking water. The next section discusses this 
risk.
4. Potential Risk Implications From Occurrence Data
    As discussed previously, to assess the public health risk 
associated with drinking ground water, EPA evaluated information and 
conducted analyses on (1) Health effects data from a range of 
pathogens, (2) waterborne disease outbreak data, and (3) occurrence 
data from ground water studies and surveys. As a result of this 
evaluation and analysis, EPA concludes that the potential risk to 
public health posed by a subset of PWSs with contaminated ground water 
sources is significant enough to warrant regulation.
    When a PWS uses contaminated source water, its customers are at 
risk of infection and illness. Their risk depends on a number of 
factors including whether the system provides at least 4-log treatment 
of viruses, the frequency at which the well is contaminated, the level 
of contamination (i.e., concentration), and the infectivity of the 
pathogens that are present.
    To develop risk estimates from viral exposure, EPA considered two 
types of viruses, Type A (represented by data available on rotavirus) 
and Type B (represented by data available on enterovirus or echovirus), 
which are used to estimate risk from exposure to viral-contaminated 
wells. These two virus types have different infection morbidity and 
disease severity characteristics. Type A viruses are considered to be 
highly infectious but cause primarily mild illness, while Type B 
viruses are considered much less infectious but may cause more severe 
illnesses.
    The infectivity of a virus relates the probability of infection to 
a given amount, or dose, of virus consumed. Together with infectivity, 
morbidity (risk of illness given infection) and mortality (risk of 
premature death given an illness) are used to predict the disease 
burden associated with a particular virus level in drinking water. As 
discussed in the previous section, a typical contaminated well may have 
detectable virus concentrations 11 percent of the time. The remainder 
of the time, the well's water is essentially virus free (assuming that 
concentration is zero when not detected by measurement methods like 
those used in the occurrence studies). EPA has viral concentration data 
from the three studies as discussed in Section III.C.3.b of this 
preamble. Virus concentration data combined with viral exposure data 
can be used to predict infection rates given viral dose-response 
information. Figure III-1 indicates the annual risk of infection from 
exposure to rotavirus, assuming one liter of water consumed per day, 
based on a range of possible mean annual source water concentrations 
and different levels of treatment. For example, if an untreated ground 
water source had a mean annual source water concentration of 0.1 
viruses per 100 L (e.g., a source water concentration of one virus per 
100 L, 10 percent of the time), people consuming one liter of this 
water per day would have approximately a seven percent probability of 
being infected in the course of the year (90 percent confidence 
interval of three percent to 13 percent). The risk of infection 
implications from exposure to echovirus are 10 to 100 times less than 
those from rotavirus, assuming the same levels of exposure. However, 
illness resulting from infection of echovirus may be more severe than 
illness resulting from infection by rotavirus.
    It is important to recognize that EPA's quantitative risk analysis 
is limited by the data available, specifically data on rotavirus and 
echovirus. Other pathogenic viruses also cause disease and may be more 
or less infectious than those modeled. Pathogens may cause chronic and 
acute illnesses in addition to those considered in the quantitative 
risk analysis. Furthermore, EPA's quantitative risk analysis does not 
consider bacterial illness and deaths resulting from contaminated 
drinking water due to limited data. Taken together, these limitations 
imply an underestimate of the actual illnesses and deaths that result 
from exposure to contaminated ground water when only these sources of 
uncertainty are considered. The GWR national risk implications from 
exposure to pathogenic viruses and bacteria are discussed in Section 
VII of this preamble and more fully discussed in the GWR EA (USEPA, 
2006d).
    Even at the levels EPA is able to quantify, the risk analysis 
supports the conclusion that a substantial number of people served by 
GWSs are at risk of exposure to waterborne pathogens. EPA's occurrence 
analysis (USEPA, 2006b) demonstrates that some wells have high viral 
occurrence while others have lower occurrence, and thus lower risk. For 
public health protection, it is most important to target those wells 
with higher occurrence. In addition, the occurrence analysis 
demonstrates that contamination is intermittent. Because of the 
intermittent nature of contamination, an ongoing monitoring program is 
critical to effectively target higher risk systems.
    The intent of the GWR is to reduce risk by targeting susceptible 
systems for corrective action. The corrective action options are: 
Correct all significant deficiencies; provide an alternate source of 
water; eliminate the source of contamination; or provide treatment that 
reliably achieves at least 4-log treatment of viruses. As illustrated 
in Figure III-1, treatment will provide large improvements in public 
health. Thus, the final GWR components of sanitary surveys, source 
water monitoring, and corrective action are each critical steps to 
improving public health in communities served by undisinfected (or 
inadequately disinfected) GWSs.
    Implementation of this rule is expected to result in approximately 
42,000 avoided viral illnesses and one avoided death annually. The 
analysis is uncertain and these estimates could be an over-or under-
estimate of actual illnesses and deaths. The nonquantified benefits are 
those that the Agency was unable to quantify due to data limitations, 
which include decreased incidence of other acute viral disease 
endpoints, decreased incidence of chronic viral illness sequelae, 
decreased incidence of bacterial illness and death, decreased incidence 
of waterborne disease outbreaks and epidemic illness, and decreased 
illness through minimizing treatment and distribution system failures. 
The nonquantified benefits associated with this rule are significant 
and are discussed in detail in Section 5.4 of the GWR EA (USEPA, 
2006d).

[[Page 65585]]

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IV. Discussion of GWR Requirements

    This section describes the rule requirements and rationale for each 
component of the risk-targeted strategy of this rule. A summary of, and 
responses to, key comments on the proposed rule are also provided.

A. Sanitary Surveys

    EPA believes that comprehensive, periodic sanitary surveys and the 
identification and correction of significant deficiencies are 
indispensable for ensuring the long-term safety of drinking water 
supplies. They are an important tool for identifying potential 
vulnerabilities to fecal contamination at GWSs. The final GWR includes 
Federal requirements for sanitary surveys of all GWSs for the first 
time.
    This rule provides the States with flexibility to prioritize and 
carry out the sanitary survey process, while ensuring that the survey 
is an effective, preventive tool for GWSs. The sanitary survey 
provision in this rule builds on existing State sanitary survey 
programs established under the 1989 TCR and the Interim Enhanced 
Surface Water Treatment Rule (IESWTR) (63 FR 69477, December 16, 1998) 
(USEPA, 1998b) and gives States the authority to define both 
outstanding performance and significant deficiencies. At the same time, 
the GWR's sanitary survey requirements for minimum frequencies, scope, 
documentation, and mandatory corrective action strengthen existing 
sanitary survey programs and address many of the concerns associated 
with current sanitary survey programs as identified by the GAO (USGAO, 
1993).

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BILLING CODE 6560-50-C
1. What Are the Requirements of This Rule?
    This rule requires States to perform sanitary surveys for all GWSs. 
Ground water systems must provide the State with any pertinent, 
existing information that will enable the State to perform the sanitary 
survey. This rule goes beyond the existing definition of sanitary 
survey at Sec.  141.2, explicitly references the use and relevance of 
source water assessments required under the 1996 SDWA Amendments, and 
specifies in more detail the scope of a sanitary survey. Specifically, 
this rule requires that States evaluate eight components as part of the 
sanitary survey to the extent that they apply to an individual system: 
(1) Source; (2) treatment; (3) distribution system; (4) finished water 
storage; (5) pumps, pump facilities, and controls; (6) monitoring, 
reporting, and data verification; (7) system management and operation; 
and (8) operator compliance with State requirements. This rule outlines 
the eight minimum elements using broad categories and recognizes that 
certain elements may not be present in a particular system depending on 
its size or complexity.
    This rule requires States to conduct sanitary surveys of ground 
water CWSs every three years (every five years for CWSs that meet 
performance criteria as described in the following paragraph) and of 
ground water NCWSs every five years. States are required to complete 
the initial sanitary survey cycle by December 31, 2012 for CWSs, except 
those that meet performance criteria, and December 31, 2014 for all 
NCWSs and CWSs that meet performance criteria. States may conduct more 
frequent sanitary survey cycles for any GWS as appropriate.
    This rule allows individual components of a sanitary survey to be 
conducted according to a phased review process (e.g., as part of 
ongoing State assessment programs). While all

[[Page 65587]]

applicable components need not be evaluated at the same time, they must 
be evaluated within the required three-or five-year frequency interval. 
Also, this rule allows the three-year CWS schedule to be extended to a 
five-year frequency if the system meets certain criteria (referred to 
in this preamble as ``performance criteria''). These performance 
criteria are:
     Provides 4-log treatment of viruses (using inactivation, 
removal, or a State-approved combination of 4-log virus inactivation 
and removal) before or at the first customer for all its ground water 
sources, or
     Has an outstanding performance record (as defined by the 
State) documented in previous sanitary surveys, and has no history of 
total coliform MCL or monitoring violations under the TCR since the 
last sanitary survey.
    Finally, this rule requires that GWSs correct any significant 
deficiencies identified in sanitary surveys. Significant deficiencies, 
as determined by the State, include, but are not limited to, defects in 
design, operation, or maintenance, or a failure or malfunction of the 
sources, treatment, storage, or distribution system that the State 
determines to be causing, or have the potential for causing, the 
introduction of contamination into the water delivered to consumers.
    Significant deficiencies may include, but are not limited to, the 
following:
    Source
     Well near a source of fecal contamination (e.g., failing 
septic systems or a leaking sewer line).
     Well in a flood zone.
     Improperly constructed well (e.g., improper surface or 
subsurface seal).
     Spring boxes that are poorly constructed and/or subject to 
flooding.
    Treatment
     Inadequate application of treatment chemicals (e.g., 
disinfection contact time is inadequate).
     Lack of redundant mechanical components where disinfection 
is required.
     Unprotected cross-connections with treatment chemical 
systems.
     Inadequate treatment process monitoring.
    Distribution System
     Negative pressures that could result in the entrance of 
contaminants.
     Inadequate disinfectant residual monitoring, when 
required.
     Unprotected cross-connections.
    Finished Water Storage
     Inadequate internal cleaning and maintenance of storage 
tanks.
     Lack of proper screening of overflow pipes, drains, or 
vents.
     Storage tank roofs or covers need repair (e.g., holes or 
hatch of improper construction).
    Pumps, Pump Facilities, and Controls
     Inadequate pump capacity.
     Inadequate maintenance.
     Inadequate/inoperable control system.
    Monitoring, Reporting, and Data Verification
     Failure to properly monitor water quality.
     Failure to meet reporting requirements.
     Inadequate recordkeeping.
    System Management and Operation
     Failure to meet water supply demands/interruptions to 
service (e.g., unreliable water source or lack of auxiliary power).
     Lack of approved emergency response plan.
     Inadequate follow-up to deficiencies noted in previous 
assessment/survey.
    Operator Compliance with State Requirements
     Operator is not certified as required by the State.
     Lack of operator training.
    The State must provide the GWS with written notification, which 
describes any significant deficiencies found, no later than 30 days 
after the State identifies the significant deficiency. The notice may 
be sent to the PWS, or it may be provided on-site either at the time 
the sanitary survey is conducted or the significant deficiency is 
identified. The State may specify appropriate follow-up corrective 
action steps in the notice or may notify the GWS of appropriate 
corrective actions during the consultation period. After receiving the 
written notification, the GWS has 30 days to consult with the State 
regarding corrective actions. However, the State may prescribe 
corrective actions and completion dates, including immediate and/or 
interim corrective actions, in lieu of the consultation process. Under 
this rule, a GWS must complete corrective action or be in compliance 
with a State-approved corrective action plan and schedule within 120 
days of receiving written notice from the State, as described in 
Section IV.C of this preamble. Failure to do so will result in a 
treatment technique violation. This rule requires systems to notify 
customers of uncorrected significant deficiencies. When a significant 
deficiency is identified at a PWS that uses both ground water and 
surface water sources, the GWR treatment technique requirements apply 
except in cases where the State determines that the significant 
deficiency is in a portion of the distribution system that is served by 
surface water (or ground water under the direct influence of surface 
water).
2. What Is EPA's Rationale for the GWR Sanitary Survey Requirements?
    As discussed in the proposed GWR, sanitary surveys enable States 
(and systems) to provide a comprehensive and accurate review of the 
components of water systems, to assess the operating conditions and 
adequacy of the water system, and to determine if past recommendations 
have been implemented effectively. A GWS has the responsibility of 
providing the information necessary to conduct a sanitary survey to the 
State upon request to enable a comprehensive assessment of the system. 
The purpose of the sanitary survey is to evaluate and document the 
capabilities of the water system's sources, treatment, storage, 
distribution network, operation and maintenance, and overall management 
to ensure the provision of safe water. In addition, sanitary surveys 
provide an opportunity for PWS inspectors to visit the water system and 
educate operators about proper monitoring and sampling procedures and 
to provide technical assistance.
    Historically, sanitary surveys have been conducted by State 
drinking water programs as preventative tools for identifying water 
system deficiencies before contamination occurs. In 1976, EPA 
regulations required, as a condition of primacy, that States develop a 
systematic program for conducting sanitary surveys, but EPA did not 
define the scope of sanitary surveys or specify minimum criteria at 
that time. In 1989, the TCR included a provision requiring sanitary 
surveys for systems collecting fewer than five TCR samples per month 
(systems serving fewer than 4,100 people). For those systems, sanitary 
surveys are required under the TCR once every five years for CWSs and 
NCWSs (but once every 10 years for NCWSs that use protected or 
disinfected ground water). However, the TCR did not establish what must 
be evaluated in a sanitary survey or specifically address significant 
deficiencies.
    Consequently, a number of concerns have been raised regarding post-
TCR sanitary survey practices. For example, the GAO investigated 
sanitary survey practices in 1993 and found that many surveys did not 
evaluate one or more of the major components and operations that EPA 
requires be evaluated under the final GWR and that efforts to ensure 
that deficiencies were corrected were often limited (USGAO, 1993). A 
review of State regulations found that many States do not specifically 
require systems to correct deficiencies. These

[[Page 65588]]

factors, coupled with information on contaminant occurrence and 
analysis of microbial waterborne disease outbreak data, indicated that 
public health protection can be strengthened by requiring regular 
sanitary surveys, specifying the scope of surveys, and requiring 
corrective action of significant deficiencies.
    In 1995, EPA and the States (through the Association of State 
Drinking Water Administrators) issued a joint guidance on sanitary 
surveys entitled EPA/State Joint Guidance on Sanitary Surveys (USEPA/
ASDWA, 1995). Recognizing the essential role of sanitary surveys and 
the need to define the broad areas that all sanitary surveys should 
cover, the guidance recommended eight elements for a comprehensive 
sanitary survey. The guidance also recommended the development of 
assessment criteria, proper documentation of results, and thorough 
follow-up, tracking, and enforcement after the survey. The IESWTR, 
(USEPA, 1998b), requires States to address the same eight elements in 
sanitary surveys conducted at surface water systems and at GWUDI 
systems. The GWR incorporates the same eight elements into the sanitary 
survey requirements for GWSs to be consistent with, and as 
comprehensive as, the IESWTR. Based on consultation with the States and 
EPA regions, EPA believes that the majority of States today include the 
eight elements in their sanitary survey programs for both surface water 
and GWSs.
    In addition to requiring these eight elements, the GWR requires the 
State to conduct sanitary surveys no less frequently than every three 
years for CWSs and every five years for NCWSs. This rule provides the 
State with the flexibility to reduce the frequency for CWSs to every 
five years for systems that meet performance criteria (refer to Section 
IV.A.1 for criteria). These frequencies are consistent with the 
recommendations for surface water systems made by the Microbial/
Disinfection Byproducts Federal Advisory Committee, which included 
various stakeholders representing a wide range of sectors in the 
drinking water community. Given this, EPA believes that the same three- 
and five-year interval for conducting sanitary surveys is appropriate 
for GWSs. The GWR requires the first sanitary survey cycle to be 
completed by December 31, 2012 for CWSs, except those that meet 
performance criteria, and December 31, 2014 for all NCWSs and CWSs that 
meet performance criteria. See Section VI of this preamble for 
explanation of initial sanitary survey completion dates.
    As noted earlier, this regulation attempts to build on existing 
State public health programs to the extent possible. Consequently, the 
GWR allows individual elements of a sanitary survey to be conducted on 
a phased review schedule as part of ongoing State assessment programs 
within the established three-or five-year frequency interval. This 
allows States to more efficiently use existing assessment schedules and 
maximize the effective allocation of staff resources and expertise 
across a State in conjunction with other priorities. EPA believes that 
the frequency of sanitary surveys and the required eight sanitary 
survey elements in this rule ensure greater public health protection 
while providing adequate flexibility for States and systems to 
effectively implement the requirements. The GWR requires the initial 
sanitary surveys to be completed six years after rule promulgation for 
CWSs and eight years after rule promulgation for NCWSs. The six to 
eight year time frame for initial sanitary surveys is based on several 
considerations. First, States need time to adopt the rule and obtain 
primacy (two to four years allowed by the SDWA at 1413(a)(1)). In 
addition, systems are given three years to comply with drinking water 
regulations by the SDWA at (1412(b)(10)). Finally, States need three to 
five years to complete the first cycle of sanitary surveys because 
there are many GWSs and States have limited resources.
    A key finding of the GAO report was that deficiencies identified in 
one sanitary survey were often found still uncorrected at the next 
sanitary survey. For example, in a four-State sample of 200 sanitary 
surveys, GAO found approximately 60 percent of the surveys cited 
deficiencies that were also cited in previous surveys. While the report 
indicated that smaller systems (serving 3,300 or fewer people) were in 
the greatest need of improvement, GAO found that, regardless of system 
size, previously identified deficiencies frequently went uncorrected. 
GAO found that some States lacked the authority to ensure that water 
system owners and operators correct documented deficiencies. Additional 
causes for uncorrected deficiencies included a lack of documentation or 
ineffective tracking of survey results. The Agency believes that a 
sanitary survey is an effective tool for identifying significant 
deficiencies. Once identified, it is also essential that such 
deficiencies be corrected in a timely manner. A study of the 
effectiveness of a range of best management practices shows that 
follow-up and correction of sanitary survey deficiencies were 
correlated with lower levels of total coliform, fecal coliform, and E. 
coli (ASDWA, 1998). Thus, this rule requires that systems coordinate 
with the State within 30 days of being notified of the significant 
deficiency and that the systems correct the significant deficiency (or 
be on an enforceable State-prescribed schedule) within 120 days of 
being notified of the significant deficiency. See Section IV.C for 
details on corrective action time frames.
3. What Were the Key Issues Raised by Commenters on the Proposed GWR 
Sanitary Survey Requirements?
    The majority of commenters on the GWR proposal were supportive of a 
sanitary survey requirement for all GWSs. Most commenters supported the 
proposed frequencies of three years for CWSs and five years for NCWSs. 
Several commenters noted that some States conduct surveys at more 
frequent intervals than required in this rule. However, a few 
commenters suggested extending the frequency interval for CWSs, because 
they believed that CWSs would be less likely to have significant 
deficiencies.
    The Agency believes that frequent, comprehensive sanitary surveys 
are an important proactive public health measure and that the minimum 
frequencies of sanitary surveys under this rule balance public health 
protection with State implementation issues. This rule requirement is 
consistent with the frequency required for surface water systems under 
the IESWTR. The GWR provides flexibility in allowing States to perform 
more frequent sanitary surveys or to reduce the frequency for CWSs to 
five years if the CWS meets performance criteria (Section IV.A.1). 
States also have the flexibility to phase-in the evaluation of sanitary 
survey elements within the required frequency interval. The Agency 
believes that a frequency of three years for CWSs and five years for 
NCWSs, combined with flexibility on both timing and implementation, 
appropriately considers limited resource issues while advancing public 
health protection.
    EPA specifically requested comments on ``grandfathering'' sanitary 
surveys conducted under the TCR to satisfy the initial sanitary survey 
requirements of the GWR. The majority of comments favored allowing the 
use of sanitary surveys conducted under the TCR or existing State 
programs to meet the initial sanitary survey requirements of the GWR. 
These comments were largely based on an interest in reducing State

[[Page 65589]]

implementation burden and allowing States to transition their existing 
sanitary survey programs into programs and schedules that meet the 
requirements of the GWR.
    Because of the time frames laid out in the GWR for initial and 
repeat sanitary surveys, grandfathering sanitary surveys is not 
practicable. States must complete their initial CWS sanitary surveys 
six years after rule promulgation for CWSs and eight years for NCWSs. 
The deadline for completing the first round of sanitary surveys is 
longer than the minimum required sanitary survey frequency, so 
grandfathering would not result in a burden reduction for the State. 
For example, if a State were to grandfather a CWS sanitary survey from 
2005, they would be required to complete a second sanitary survey by 
2008 and a third by 2011, whereas a State that completed their first 
sanitary survey in 2009 would not be required to complete their second 
sanitary survey until 2012. As described in Section IV.A.2, the six to 
eight year time frame for initial sanitary surveys is based on several 
considerations. First, States need time to adopt the rule and obtain 
primacy (two to four years allowed under the SDWA at 1413(a)(1)). In 
addition, systems are given three years to comply with drinking water 
regulations by the SDWA at (1412(b)(10)). Finally, States need three to 
five years to complete the first cycle of sanitary surveys because 
there are many GWSs and States have limited resources.
    EPA believes that it is important to reduce State implementation 
burden and that information from existing sanitary surveys and other 
sources is an important resource. Thus, this rule allows States to 
reduce the frequency of sanitary surveys for CWSs that meet performance 
criteria (Section IV.A.1) at any time subsequent to the effective date 
of this rule from every three to every five years. This allows States 
to reduce the implementation burden of sanitary surveys based on 
information collected under the TCR and existing sanitary survey 
programs while still ensuring a minimum sanitary survey frequency of 
five years for both CWSs and NCWSs. Since a significant proportion of 
GWSs are small NCWSs and the GAO report found the greatest need for 
improvement in smaller systems, EPA believes that a reduction in 
frequency for NCWSs would not advance public health protection. EPA 
notes that surveys or elements of sanitary surveys conducted under the 
TCR or as part of site assessment or other State programs may be used 
to meet the GWR requirements if they meet the criteria specified in the 
GWR (i.e., if the minimum eight elements specified in the GWR are 
addressed at the specified GWR frequency).
    EPA received a number of comments on the 30-day time frame that 
States have to notify a system when a significant deficiency is 
identified in the sanitary survey. Some commenters noted that this 
requirement is consistent with current procedures; notice of 
significant deficiencies is often provided to a system much sooner. 
However, other commenters were concerned that this requirement placed 
an unnecessary deadline on the State and that current State policies 
and practices adequately address timely notification of systems with 
significant deficiencies.
    The Agency believes that timely notification of significant 
deficiencies is essential to the timely correction of those 
deficiencies and to the safety of drinking water. EPA believes 
requiring a 30-day maximum notification period in all States is 
reasonable, given the potential public health risk of significant 
deficiencies, and ensures equitable protection of public health across 
the nation.
    EPA also received comments on what constitutes a significant 
deficiency under the GWR. EPA proposed defining significant 
deficiencies as a defect in design, operation, or maintenance, or a 
failure or malfunction of the sources, treatment, storage, or 
distribution system that the State determines to be causing, or has the 
potential for causing, the introduction of contamination into the water 
delivered to consumers. Several commenters urged EPA to go beyond that 
definition and require States to specify a minimum list of significant 
deficiencies under each of the applicable eight sanitary survey 
components set out in the EPA/State Joint Guidance on Sanitary Surveys. 
EPA also received comments regarding specific examples of significant 
deficiencies in each applicable component. Section IV.A.1 of this 
preamble includes specific examples of some significant deficiencies 
provided by commenters.
    The Agency believes that to provide adequate public health 
protection, States must identify and require correction of all 
significant deficiencies. Also, EPA recognizes the importance for the 
State to include additional case-specific deficiencies. This rule 
states that significant deficiencies ``include, but are not limited to, 
defects in design, operation, or maintenance, or a failure or 
malfunction of the sources, treatment, storage, or distribution system 
that the State determines to be causing, or has the potential for 
causing, the introduction of contamination into the water delivered to 
consumers.'' The GWR requires each State, in its primacy application, 
to define and describe at least one specific significant deficiency in 
each of the eight sanitary survey elements. This enables States to work 
within their existing programs to define significant deficiencies as 
part of their primacy application and to define and describe 
significant deficiencies that may be unique to system size, type, 
location, or State requirements. EPA also recognizes that some systems 
may not have all eight components; for example, some TNCWSs may not 
have storage or require certified operators.
    EPA requested comment on having public involvement and/or meetings 
for certain PWSs to discuss the results of sanitary surveys and 
specifically what approaches might be practical and not overly 
burdensome to involve the public in working with water systems to 
address the results of sanitary surveys. Some commenters suggested 
publishing the results in the system's Consumer Confidence Report (CCR) 
or reviewing the results at a public meeting. Others supported 
notifying the public that the results were available and how those 
results could be obtained. Some commenters noted that significant 
deficiencies would be corrected rapidly and that involving or informing 
the public after the correction might not be useful. One commenter 
suggested posting the results of surveys in a public place for non-
community systems.
    EPA believes that adequate opportunities exist for customers to 
obtain information on the complete sanitary survey of their water 
supplier. Results of sanitary surveys and notification from the State 
to the water supplier of significant deficiencies would be available to 
the public upon request from the State or the water supplier. However, 
EPA also believes that the public served by the water system should be 
made aware of significant deficiencies found in sanitary surveys that 
remain uncorrected and be fully informed as to how and when those 
deficiencies will be corrected. This rule requires systems to notify 
customers of such significant deficiencies including the date and 
nature of the significant deficiency, the schedule for correction, any 
interim measures taken, and the progress to date. The State may require 
the system to notify customers of corrected significant deficiencies. 
This requirement is described further in Section IV.D of this preamble.
    EPA received comments suggesting that the sanitary survey 
provisions of

[[Page 65590]]

the TCR are sufficient to address viral and bacterial pathogens in GWSs 
and there is no need for sanitary surveys under the GWR. While EPA 
believes the TCR was a significant step forward for public health 
protection in 1989, the TCR does not require systems to correct 
significant deficiencies or require a minimum frequency of sanitary 
surveys for all systems. Thus, the GWR sanitary survey requirement 
better addresses the potential public health consequences of 
uncorrected significant deficiencies.

B. Source Water Monitoring

    This rule requires ground water source monitoring as an essential 
element in its risk-targeted approach for identifying those GWSs with 
source water fecal contamination that need corrective action. Systems 
targeted for source water monitoring are those with an indication that 
they may be at risk for fecal contamination. Indicators of risk may 
come from total coliform monitoring, hydrogeologic sensitivity 
analyses, or other system-specific data and information. This rule 
requires triggered source water monitoring and provides States with the 
option to require assessment source water monitoring. Source water 
monitoring is not required for any GWS that is already providing at 
least 4-log treatment of viruses.
    A GWS with a distribution system TCR sample that tests positive for 
total coliform is required to conduct triggered source water monitoring 
to evaluate whether the total coliform presence in the distribution 
system is due to fecal contamination in the ground water source. 
Triggered source water monitoring provides a critical ongoing 
evaluation of GWSs.
    As a complement to the triggered source water monitoring provision, 
the GWR gives States the flexibility to require more comprehensive 
assessment source water monitoring on a case-by-case basis. The purpose 
of this optional assessment source water monitoring requirement is to 
target source water monitoring to systems that the State determines are 
at higher risk for fecal contamination. States are in the best position 
to assess which systems are at risk and would most benefit from source 
water monitoring.
    EPA believes that source water monitoring targeted at higher risk 
systems, namely triggered source water monitoring, in conjunction with 
optional assessment source water monitoring, will be effective in 
identifying systems with source water fecal contamination. With 
implementation of the follow-up corrective action requirements outlined 
in Section IV.C, these requirements will provide meaningful 
opportunities to reduce public health risk for a substantial number of 
people served by GWSs.

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BILLING CODE 6560-50-C

[[Page 65592]]

1. What Are the Requirements of This Rule?
    a. Triggered source water monitoring. A GWS must conduct triggered 
source water monitoring within 24 hours of receiving notification that 
a routine sample collected in accordance with Sec.  141.21(a) (TCR) is 
total coliform-positive. A GWS must collect at least one ground water 
source sample from each ground water source (e.g., a well or spring) in 
use at the time the total coliform-positive sample was collected. 
Triggered source water monitoring is required unless: (1) The system 
provides at least 4-log treatment of viruses (using inactivation, 
removal, or a State-approved combination of 4-log virus inactivation 
and removal) before or at the first customer for each ground water 
source; (2) the system is notified that a positive sample collected in 
accordance with Sec.  141.21(a) (TCR) has been invalidated under Sec.  
141.21(c); or (3) the cause of the total coliform-positive collected 
under Sec.  141.21(a) directly relates to the distribution system as 
determined by the system according to State criteria or as determined 
by the State. The State may extend the 24-hour limit on a case-by-case 
basis if the State determines that the system cannot collect the ground 
water source water sample within 24 hours due to circumstances beyond 
its control. In the case of an extension, the State must specify how 
much time the system has to collect the sample.
    Systems are not required to conduct triggered source water 
monitoring if, according to State criteria or a State determination, 
the cause of the total coliform-positive sample collected under Sec.  
141.21(a) directly relates to the distribution system. If the GWS makes 
the decision according to State criteria, the GWS must document the 
decision in writing; if the decision is made by the State, the State 
must document the decision in writing. In the primacy application, the 
State must include criteria that will be used to determine that the 
cause of a total coliform-positive sample collected under Sec.  
141.21(a) is directly related to the distribution system.
    If the State approves the use of E. coli as a fecal indicator for 
triggered source water monitoring, GWSs serving 1,000 people or fewer 
may use a TCR repeat sample collected from a ground water source to 
simultaneously meet the requirements of Sec.  141.21(b) and satisfy the 
GWR's triggered source water monitoring requirements for that ground 
water source only.
    If approved by the State, systems with more than one ground water 
source may conduct triggered source water monitoring at a 
representative ground water source or sources. The State may require 
systems with more than one ground water source to submit for approval a 
triggered source water monitoring plan that the system will use for 
representative sampling. A triggered source water monitoring plan must 
identify ground water sources that are representative of each 
monitoring site in the system's TCR sample siting plan.
    If any initial triggered source water sample is fecal indicator-
positive, the system must collect five additional source water samples 
within 24 hours at that site, unless the State requires immediate 
corrective action to address contamination at that site. The samples 
must be tested for the same fecal indicator for which the initial 
source water sample tested positive.
    Ground water systems that purchase or sell finished drinking water 
(referred to as consecutive or wholesale systems, respectively) must 
comply with triggered source water monitoring provisions for their own 
sources.
    Consecutive and wholesale systems must also comply with other 
triggered source water monitoring requirements. A consecutive GWS that 
has a total coliform-positive sample collected under Sec.  141.21(a) 
(TCR) must notify the wholesale system(s) within 24 hours of being 
notified of the total coliform-positive sample. If a wholesale GWS 
receives notice from a consecutive system it serves that a sample 
collected under Sec.  141.21(a) (TCR) is total coliform-positive, the 
wholesale GWS must conduct triggered source water monitoring. If the 
sample is fecal indicator-positive, in addition to notifying its own 
customers, the wholesale GWS must notify all consecutive systems served 
by that ground water source. The consecutive system is responsible for 
providing any required public notice to the persons it serves.
    b. Assessment source water monitoring. The GWR provides States with 
the option to require systems to conduct assessment source water 
monitoring at any time and require systems to take corrective action. 
See Section IV.B.2.b for EPA's recommendations of when assessment 
source water monitoring may be appropriate and how to structure the 
monitoring program. If the State chooses to use HSAs to determine the 
appropriateness of assessment source water monitoring, then systems 
must comply with State requests for information.
    c. Source water microbial indicators and analytical methods. A 
system that collects a source water sample to comply with this rule 
must analyze the sample for one of the three fecal indicators (E. coli, 
enterococci, or coliphage). Under this rule, GWSs must use one of seven 
specified analytical methods for E. coli, one of three methods 
specified for enterococci, or one of two methods specified for 
coliphage. The system is required to test at least a 100 mL sample 
volume for one of the three fecal indicators (E. coli, enterococci, or 
coliphage). All analyses must be conducted by a laboratory certified by 
the State or EPA.
    d. Invalidation of a fecal indicator-positive ground water source 
sample. This rule allows systems to obtain written State invalidation 
of a fecal indicator-positive ground water source sample under either 
of the following conditions: (1) The system provides the State with 
written notice from the laboratory that improper sample analysis 
occurred; or (2) the State determines and documents in writing that 
there is substantial evidence that a fecal indicator-positive ground 
water source sample is due to a circumstance that does not reflect 
source water quality. If the State invalidates a fecal indicator-
positive ground water source sample, the system must collect another 
ground water source sample within 24 hours of being notified of the 
invalidation by the State and have it analyzed for the same fecal 
indicator. The State may extend the 24-hour limit on a case-by-case 
basis if it determines that the system cannot collect the ground water 
source water sample within 24 hours due to circumstances beyond the 
system's control. In the case of an extension, the State must specify 
how much time the system has to collect the sample.
2. What Is EPA's Rationale for the GWR Source Water Monitoring 
Requirements?
    a. Triggered source water monitoring.
    i. Overall basis for provision. The GWR builds on the public health 
protection provided by the TCR by requiring systems to collect a ground 
water source sample when a TCR distribution system sample is total 
coliform-positive. Because a total coliform-positive sample in the 
distribution system may be caused by either a distribution system 
problem or source water contamination, the GWR triggered source water 
monitoring provision is necessary to distinguish between these two 
possible sources of fecal contamination. Thus, using the total coliform 
indicator is an efficient way to target higher risk systems where 
source water monitoring is warranted to investigate potential fecal

[[Page 65593]]

contamination. EPA believes that the GWR triggered source water 
monitoring provisions provide an effective means for improving public 
health protection.
    Total coliform monitoring in the distribution system is already 
required under the TCR. Thus, total coliform monitoring provides a no-
cost screening for potential fecal contamination and pathogen 
occurrence at the source. Total coliform is a sensitive indicator for 
the presence of potential fecal contamination. In the occurrence 
studies evaluated for the GWR, wells that were monitored with high 
frequency for enterovirus and total coliforms detected both enterovirus 
and total coliform in their source water (i.e., Lieberman et al., 2002; 
Karim et al., 2004; Wisconsin Department of Health, 2000). Total 
coliform presence in source water can also be an indicator of recent 
surface and near surface water inflow to ground water, and pathogens 
originate at or near the surface.
    Triggered source water monitoring provides an ongoing evaluation of 
fecal contamination in the source water of all GWSs. Because well 
conditions and sources of fecal contamination can change over time, EPA 
believes that the ongoing continuous assessment provided by triggered 
source water monitoring is important.
    EPA believes that the triggered source water monitoring 
requirements of the GWR will effectively target higher risk GWSs. EPA's 
analysis indicates that the triggered source water monitoring 
provisions will identify nearly 40 percent of those wells with fecal 
contamination in their source water (See Chapter 6 of USEPA, 2006d). In 
addition, the wells with the highest frequencies of fecal contamination 
occurrence (which EPA believes are the highest risk wells from a public 
health perspective) will likely be captured first and wells with less 
frequent fecal contamination will be identified over time (USEPA, 
2006d).
    ii. Reduced burden for small systems. Under the final GWR, a GWS 
serving 1,000 people or fewer may use a TCR repeat sample to 
simultaneously meet requirements of the TCR and the GWR. Under the TCR, 
when a total coliform sample at a small system (serving 1,000 people or 
fewer) is positive, the TCR requires the system to collect four repeat 
samples (one upstream and proximate to the initial total coliform-
positive, one at the same location, one downstream and proximate to the 
original total coliform-positive, and one at another unspecified 
location). If the State approves the use of E. coli as a fecal 
indicator for ground water source monitoring, the GWR allows these 
small systems to meet the repeat monitoring requirements of Sec.  
141.21(b) (TCR) by collecting their unspecified fourth repeat sample at 
the ground water source, thereby satisfying the GWR's triggered source 
water monitoring requirements for that ground water source at the same 
time. The purpose of this provision is to mitigate the triggered fecal 
indicator source water monitoring burden for small systems and to 
improve upon the diagnostic value of repeat sampling under the TCR.
    The TCR repeat sample can be used for satisfying both the TCR 
repeat sample requirement and the initial source water fecal indicator 
under the GWR because the TCR methods and requirements provide the 
information necessary for complying with the GWR. If the repeat sample 
is negative for total coliform bacteria, then it is also negative for 
E. coli bacteria, and no further testing under the GWR is required. 
Under the TCR, if a repeat sample is positive for total coliform 
bacteria, the sample must then be further analyzed for the presence of 
either E. coli or fecal coliforms. If the sample is analyzed for E. 
coli, that will satisfy the GWR triggered monitoring requirements.
    Total coliform bacteria are a group of bacteria that include E. 
coli. The methods approved for the analysis of the water samples taken 
under the TCR can be found at Sec.  141.21. Most of these methods are 
also approved for E. coli monitoring under the GWR (see Table IV-1 and 
Sec.  141.402(c)). The analytical methods approved for use under the 
TCR listed in Table IV-1 may all be used for both total coliform 
detection, and most can be used for subsequent E. coli detection under 
the GWR. Two of the methods approved under the TCR (and listed with an 
asterix in Table IV-1) can be used for total coliform detection only. 
In these two techniques (one of which is multiple tube fermentation and 
the other of which is membrane filtration using m-Endo medium), total 
coliforms are first cultured and confirmed. The laboratory analyst 
could then proceed to further analyze the total coliform-positive 
culture for either fecal coliforms or E. coli by simply choosing which 
subsequent medium to inoculate. Testing for fecal coliforms requires 
EC-Broth while testing for E. coli requires use of EC-MUG broth. These 
two broths are similar, and require the same incubation temperatures 
and conditions. The only difference between the two media is the 
addition of the substrate 4-methylumbelliferone-[beta]-D-glucuronide 
(MUG) to EC Broth, which is added to detect E. coli. Thus, if the State 
has approved E. coli as the fecal indicator for the GWR, the E. coli 
sample analyzed under the TCR will meet the GWR source water sample 
requirements. For the TCR repeat sample, a PWS must collect a 100 mL 
water sample and analyze it for total coliform bacteria, and further 
analyze it for a fecal indicator if it is total coliform-positive. This 
means that small systems (serving 1,000 people or fewer) have no 
additional sampling burden or costs from the GWR triggered source water 
monitoring requirement for an initial source water sample.

  Table IV-1.--Methods Approved for Detection of Total Coliforms Under the TCR and for the Detection of E. coli
                  Under the GWR (See Sec.   141.402(c) for Details Regarding These Methods) **
----------------------------------------------------------------------------------------------------------------
                                                                            Total
          Method technology type                      Method              coliforms      E. coli       TCR/GWR
                                                                          detected      detected      approval
----------------------------------------------------------------------------------------------------------------
Multiple tube fermentation...............  (LTB/P-A [rarr] BGLB)*.....            X   ............            X
                                           EC-MUG.....................  ............            X             X
                                           NA-MUG.....................  ............            X             X
Enzyme Substrate.........................  Colilert/Colilert-18.......            X             X             X
                                           Colisure...................            X             X             X
                                           E* Colite Test.............            X             X             X
Membrane filtration......................  (m-Endo[rarr]LTB/BGLB)*....            X   ............            X
                                           EC-MUG.....................  ............            X             X
                                           MI Agar....................            X             X             X

[[Page 65594]]

                                           m-ColiBlue 24 Test.........            X             X            X
----------------------------------------------------------------------------------------------------------------
* Methods in parentheses detect total coliforms but not E. coli; if a total coliform sample is determined by
  this method in the source water sample, the analyst can choose the appropriate inoculation medium to analyze
  for E. coli.
** If a total coliform sample is determined negative, no further testing under the GWR is required. If it is
  positive, the analyst can choose the appropriate E. coli method.

    iii. Provision for total coliform-positive result directly related 
to the distribution system. EPA recognizes that some systems may have a 
known problem in their distribution system that causes total coliform-
positive results. In cases when the cause of a total coliform-positive 
result collected under Sec.  141.21(a) is directly related to the 
distribution system according to State criteria or a State 
determination, systems are not required to collect ground water source 
samples to investigate potential fecal contamination in the source 
water. A State must include in its primacy application the criteria it 
will use to determine whether the cause of a total coliform-positive 
sample collected under Sec.  141.21(a) is directly related to the 
distribution system. Systems will use these criteria to determine if 
the cause of a total coliform-positive sample is directly related to 
the distribution system. If the sample meets the criteria, the system 
is not required to do triggered source water monitoring. The State 
needs to determine these criteria as part of their primacy package so 
that GWSs that collect a total coliform-positive sample can decide 
whether they need to collect a source water sample(s) within the 
required 24 hour timeframe. The system must document this determination 
to the State within 30 days so the State can ensure that the criteria 
are used correctly and that no potential public health risk from source 
water contamination has been overlooked. For issues not covered by the 
pre-determined criteria, the State can also make a determination that 
the cause of the total coliform-positive sample directly relates to the 
distribution system.
    iv. Basis for additional fecal indicator sampling following 
triggered source water monitoring. Numerous public comments on the 
proposal expressed concern that a corrective action should not be 
required based on one source water indicator-positive sample, as EPA 
proposed for triggered source water monitoring. The rationale for the 
proposal was that the likelihood of a false positive result occurring 
in both the distribution system sample and the fecal indicator source 
water sample would be small, and therefore it would be likely that the 
source water positive result was caused by true contamination.
    EPA has re-evaluated the use of repeat samples under the triggered 
source water monitoring provisions. Given that total coliform-positives 
in the distribution system can result from either distribution system 
or source water causes, a total coliform-positive in the distribution 
system does not necessarily predict fecal contamination of the source 
water. The possibility of false positives at the source and the 
associated potential for unnecessary follow-up corrective actions, even 
if relatively infrequent, prompted EPA to revise the final rule 
triggered source water monitoring provisions to require five additional 
samples following the initial positive sample before requiring 
corrective action (if one or more additional sample is positive), 
unless the State determines that immediate corrective action is 
necessary. In addition, the potential cost implications for a 
corrective action could be substantial, especially for small systems.
    EPA believes that in most cases these five additional samples 
should capture the fecal contamination event since the samples are 
taken within 24 hours. Discrete contamination releases, such as fecal 
septage, together with discrete precipitation events, become dispersed 
by hydrogeological processes over time. As a result, shorter duration 
events at the original contamination source may become longer duration 
(i.e., days or weeks) but more diluted events at the well. Thus, if an 
initial fecal indicator-positive is detected at the well, that 
occurrence should be detectable again with additional samples within 24 
hours. Nevertheless, since the nature and source of contamination and 
the subsurface condition vary from site to site, prompt resampling 
within 24 hours is needed to capture events that may not be dispersed 
over time. Prompt resampling is particularly important in cases where 
the initial sampling event transpires at the tail-end of the well 
contamination event.
    b. Assessment source water monitoring. As a complement to the 
triggered source water monitoring provision, States have the option of 
requiring systems to conduct assessment source water monitoring. This 
flexible provision gives States the opportunity to target higher risk 
systems for additional source water monitoring and require corrective 
action, if necessary. EPA decided not to include requirements for 
assessment source water monitoring in the GWR for the reasons given in 
Section II.C of the preamble. Rather, EPA decided to give States 
flexibility to require assessment source water monitoring on a case-by-
case basis. The purpose for this optional source water monitoring 
provision is to target systems that the States believe are at high risk 
from fecal contamination for a thorough evaluation of source water 
quality. Also, this allows lower risk GWSs to avoid unnecessary 
sampling (as determined by States).
    While EPA believes that triggered source water monitoring will 
capture many high risk systems, EPA also recognizes that the triggered 
source water monitoring provisions have limitations. Triggered source 
water monitoring under the TCR may not be timely (soon enough) or 
frequent enough to identify systems with intermittent fecal 
contamination. Also, coliforms are not a good indicator in certain 
aquifers in which viruses travel faster and further than bacteria. EPA 
believes that assessment source water monitoring can be an important 
complement to triggered source water monitoring because assessment 
source water monitoring provides a thorough examination of the source 
water at those systems that States deem to be at potentially high risk 
from fecal contamination. The flexibility of this requirement allows 
States to require assessment source water monitoring when and where it 
is needed most. Source water quality can change over time, so it is 
important for States to be

[[Page 65595]]

able to use assessment source water monitoring at any point in time. 
State programs work closely with PWSs on a daily basis and are thus 
knowledgeable about system specific conditions and issues. Therefore, 
EPA believes that the States are in the best position to assess for 
which systems the thorough evaluation of source water quality provided 
by assessment source water monitoring is most appropriate. EPA believes 
that assessment source water monitoring programs within the States' 
discretion will be important to identify fecally contaminated systems 
for which corrective action is necessary to protect public health. EPA 
expects that States may use assessment source water monitoring for 
high-risk systems that are potentially susceptible to fecal 
contamination, especially where contamination is often present but 
intermittent enough to be missed by triggered source water monitoring.
    i. EPA's recommendations for targeting systems for assessment 
source water monitoring. Information on a system's potential 
susceptibility to fecal contamination is available to the States from 
many sources. For example, HSAs, source water assessments, wellhead 
protection plans, past microbial monitoring data particularly triggered 
source water monitoring results and frequency, and sanitary survey 
findings are available to States. In addition to these sources of 
information, EPA recommends that States consider the following risk 
factors in targeting susceptible systems for assessment source water 
monitoring: (1) High population density combined with on-site 
wastewater treatment systems, particularly those in aquifers with 
restricted geographic extent, such as barrier island sand aquifers; (2) 
aquifers in which viruses may travel faster and further than bacteria 
(e.g. alluvial or coastal plain sand aquifers); (3) shallow unconfined 
aquifers; (4) aquifers with thin or absent soil cover; (5) wells 
previously identified as having been fecally contaminated; and (6) 
sensitive aquifers. These factors are described in more detail below.
    Some localities may be at high risk because they serve large, 
sometimes seasonal, populations in areas without centralized sewage 
treatment and their aquifers are of restricted geographic extent, such 
as barrier island sand aquifers and Great Lakes island karst limestone 
aquifers. In these locations, the large population using septic tanks 
can overload the subsurface attenuation capability. Outbreaks have 
occurred in such resort communities (e.g., South Bass Island, OH, Ohio 
EPA, 2005, CDC, 2005; Drummond Island, MI, Ground Water Education in 
Michigan, 1992; Chippewa County Health Department, unpublished report, 
1992) due to overloaded septic tanks.
    Viruses travel faster and further than bacteria in some aquifers. 
In barrier island sand aquifers, traditional bacterial fecal indicator 
organisms such as total coliform and E. coli may not be mobile or 
sufficiently long-lived in the subsurface so as to adequately indicate 
the hazard from longer-lived and more mobile viral pathogens. Thus, a 
system could have fecal contamination and yet not be triggered for 
source water monitoring by TCR monitoring results. In such cases, 
assessment source water monitoring using coliphage would be the best 
means for identifying fecal contaminants because coliphage is a viral 
fecal indicator and thus is more likely to reach the well than 
bacterial indicators such as E. coli and enterococci.
    Shallow, unconfined aquifers are high risk because the vertical 
flow path to the aquifer is short and unrestricted by barriers. 
Pathogens originate at or near the surface and may be more likely to 
contaminate well water when the travel time for infiltrating 
precipitation is short and unhindered.
    Wells previously identified as having been fecally contaminated 
should be considered high risk because such fecal contamination can 
reoccur. For example, wells in this category may include wells 
associated with a previous acute TCR violation related to the source or 
those wells that had an initial fecal indicator-positive triggered 
source water sample but had five negative additional samples 
(especially wells with highly variable source water such as those in 
sensitive aquifers). Wells with highly variable source water may be 
subject to occasional short-lived contamination events. Thus it is 
possible to have a true fecal indicator-positive sample followed by 
true fecal indicator-negative samples. Exposures during intermittent 
contamination events can be significant, so it is important to identify 
such high-risk systems. This is best accomplished through a thorough 
source water evaluation program such as assessment source water 
monitoring.
    Sensitive aquifers (e.g., karst, fractured bedrock, or gravel) can 
have fast (kilometers per day) and direct ground water flow through 
large interconnected openings (void spaces) during which very little 
pathogen attenuation may occur (either by natural inactivation or 
attachment) between a fecal source of contamination and the well. 
Consequently, sensitive aquifers are efficient at transmitting 
pathogens, if present, from surface and near-surface sources to PWS 
wells. Ground water flow in non-sensitive aquifers (such as a sand 
aquifer) tends to be very slow (feet per day), takes a very indirect 
path around a very large number of sand grains, and provides more 
opportunities for pathogen die-off and attachment. The faster flow 
travel time within a sensitive, as opposed to a non-sensitive, aquifer 
enables a much larger contaminant plume from potential fecal 
contamination events (e.g., failing septic systems or a leaking sewer 
line).
    When ground water flow is fast and direct as in sensitive aquifers, 
contamination can be short and intermittent and difficult to capture. 
The frequency by which triggered source water monitoring is prompted 
via detection of a total coliform-positive sample under the TCR may not 
be timely enough to recognize that a well is at risk from fecal 
contamination. First, TCR monitoring at some systems is infrequent. 
Small systems conduct limited total coliform monitoring in the 
distribution system under the TCR and thus intermittent fecal 
contamination of the source could be missed (i.e., these systems may 
conduct triggered source water monitoring infrequently under the GWR). 
Second, the lag time between an initial fecal contamination event and 
total coliform presence in the distribution system may be several days. 
Thus, if the fecal contamination event is of short duration, triggered 
source water monitoring may not capture the initial event.
    Some of the largest reported waterborne disease outbreaks in GWSs 
have occurred among systems drawing water from sensitive aquifers. 
Table IV-2 provides a summary of recent outbreaks reported in sensitive 
aquifers. The number and nature of recent waterborne outbreaks shown in 
the table suggest that additional measures are necessary to protect 
those consuming water from PWS wells in sensitive aquifers. Noteworthy 
among these outbreaks is the South Bass Island, Ohio outbreak. After 
that outbreak in 2004, 16 of the 18 TNCWSs on South Bass Island tested 
positive for fecal indicator organisms (Ohio EPA, 2005; CDC, 2005). 
Thus, the monitoring protections offered by the TCR were inadequate to 
protect the community from experiencing a waterborne disease outbreak 
in this karst limestone aquifer.

[[Page 65596]]

   Table IV-2.--Recent Waterborne Disease Outbreaks (PWSs) Reported in
       Karst Limestone and Fractured Bedrock (Sensitive) Aquifers
------------------------------------------------------------------------
                                                    Number of illnesses/
          Location                  Reference               agent
------------------------------------------------------------------------
                  Outbreaks in Karst Limestone Aquifers
------------------------------------------------------------------------
South Bass Island, OH.......  Ohio EPA, 2005; CDC,  1,450/Norovirus,
                               2005.                 Campylobacter,
                                                     Salmonella.
Walkerton, Ontario, Canada..  Health Canada, 2000;  1,346 cases/E. coli
                               Bopp et al., 2003;    O157:H7 (+
                               Worthington et al.,   Campylobacter); 7
                               2002.                 deaths.
Brushy Creek, TX............  Bergmire-Sweat et     1,300-1,500 cases/
                               al., 1999; Lee et     Cryptosporidium
                               al., 2001.            (not recognized as
                                                     GWUDI until after
                                                     the outbreak).
Reading, PA.................  Moore et al., 1993..  551 cases/
                                                     Cryptosporidium
                                                     (not recognized as
                                                     GWUDI until after
                                                     the outbreak).
Racine, MO..................  MO Department of      28 cases/HAV.
                               Health, unpublished
                               report, 1992.
Drummond Island, MI.........  Ground Water          39 cases/Unknown.
                               Education in
                               Michigan, 1992;
                               Chippewa County
                               Health Department,
                               unpublished report,
                               1992.
Cabool, MO..................  Swerdlow et al.,      243 cases/E. coli
                               1992.                 O157:H7; 4 deaths.
------------------------------------------------------------------------
                 Outbreaks in Fractured Bedrock Aquifers
------------------------------------------------------------------------
Big Horn Lodge, WY..........  Anderson et al.,      35/Norovirus.
                               2003.
Atlantic City, WY...........  Parshionikar et al.,  84/Norovirus.
                               2003.
Couer d'Alene, ID...........  Rice et al., 1999...  117/Arcobacter
                                                     butzleri.
Island Park, ID.............  CDC, 1996...........  82 cases/Shigella.
Northern AZ.................  Lawson et al., 1991.  900 cases/Norwalk
                                                     virus.
------------------------------------------------------------------------

    Where the type of aquifer is unknown, EPA recommends that the State 
conduct an HSA to identify sensitive aquifers and to determine if 
assessment source water monitoring is appropriate. In sensitive 
aquifers, more frequent monitoring could more quickly identify wells 
with fecal contamination. EPA recommends that States use HSAs as a tool 
to determine at-risk GWSs, and EPA intends to provide guidance on how 
to conduct HSAs.
    Several means can be used to evaluate wells without site-specific 
inspections to determine if they are located in sensitive hydrogeologic 
settings. For example, hydrogeologic data are available from published 
and unpublished materials such as maps, reports, and well logs. As 
discussed in more detail in the GWR proposal (USEPA, 2000a), the United 
States Geologic Survey (USGS), U.S. Department of Agriculture's Natural 
Resource Conservation Service, USGS Earth Resources Observation System 
Data Center, the EPA Source Water Assessment Program and Wellhead 
Protection Program, State geological surveys, and universities have 
substantial amounts of regional site-specific information. States can 
also base assessments on available information about the character of 
the regional geology, regional maps, and rock outcrop studies.
    In summary, HSAs can be an effective screening tool for identifying 
GWSs susceptible to fecal contamination for which assessment source 
water monitoring would be appropriate and beneficial.
    ii. EPA's recommendations for assessment source water monitoring 
program. EPA recommends that States require systems that are conducting 
assessment source water monitoring to collect a total of 12 ground 
water source samples that represent each month the system provides 
ground water to the public. The 12 sample minimum is based on several 
considerations:
     The sampling frequency should consider diminishing returns 
on the effectiveness of identifying fecally contaminated wells;
     The sampling should be frequent enough to capture a range 
of conditions that can vary over the course of a year; and
     The sampling frequency should consider ground water source 
monitoring costs incurred by GWSs.
    EPA estimates that about 26 percent of all wells have E. coli 
occurrence at some time, but the periods of such contamination may be 
very short and thus difficult to detect by the triggered source water 
monitoring requirements for some systems. With 12 assessment ground 
water source samples alone (i.e., absent any triggered source water 
monitoring), at least half of the wells with sometime E. coli 
contamination would be expected to test positive at least once. Table 
IV-3 shows that as sampling frequency increases above 12 samples, the 
ability to identify additional wells that have E. coli presence rises 
more slowly and that relatively smaller percentages of additional wells 
with E. coli are identified per additional sample assay. This table 
shows that the sampling with 12 assays (i.e., tests) captures 52 
percent of the wells with sometime E. coli contamination, but sampling 
with 24 assays only captures an additional nine percent.

  Table IV-3.--Number of E. coli Assays and Percent Contaminated Wells
                               Identified
------------------------------------------------------------------------
                                                               Fraction
                                                              identified
                   Number of assays  (N)                       (Mean in
                                                               percent)
------------------------------------------------------------------------
3..........................................................           28
6..........................................................           40
12.........................................................           52
24.........................................................           61
36.........................................................           65
48.........................................................           68
60.........................................................           70
------------------------------------------------------------------------

    The wells that the assessment source water monitoring identifies as 
contaminated tend to be those that have frequent occurrence of E. coli. 
Those wells with highly infrequent E. coli occurrence would be 
difficult to capture even with a significant increase in number of 
samples because the overall period of time of indicator occurrence is 
small relative to when the sampling occurs.
    Considering the costs of additional assays (beyond 12 assessment 
ground water source samples) and the reduced efficiency at identifying 
additional

[[Page 65597]]

contaminated wells, EPA believes that 12 assays are appropriate.
    EPA recommends that the assessment source water monitoring program 
be representative of the system's typical operation. Using a minimum of 
12 samples for assessment source water monitoring would also ensure 
sampling for each month that most systems are in operation, which is 
important because of the impact that seasonal events can have on 
contamination (e.g., heavy rain events). For seasonal systems, EPA 
recommends equally distributing 12 samples or sampling during 
consecutive years.
    The option under the GWR for States to specify assessment source 
water monitoring requirements allows States to initiate a more thorough 
source water monitoring program than that resulting from the triggered 
source water monitoring provisions alone on a case-by-case basis, as 
deemed appropriate. For example, a sanitary survey may indicate that 
there has been a recent development of added source water vulnerability 
that would warrant additional source water sampling to discern whether 
there is potential fecal contamination beyond that which would be 
triggered through the TCR. Additionally, belated recognition of the 
significance of karst limestone after an outbreak (e.g., Walkerton, 
Ontario; South Bass Island, Ohio) suggests that States may choose to 
specify identification of sensitive aquifers combined with assessment 
source water monitoring to enhance multi-barrier protection.
    c. Source Water Samples
    i. Source water microbial indicators. The final GWR requires GWSs 
that are performing triggered source water monitoring to monitor their 
ground water source(s) for one of three fecal indicators (E. coli, 
enterococci, or coliphage). The State must specify which fecal 
indicator the GWSs must test for in their ground water source(s). EPA 
recommends that States use these same requirements for GWSs performing 
assessment source water monitoring.
    In this rule, EPA is authorizing the use of E. coli and enterococci 
as bacterial indicators of fecal contamination. Both of these 
indicators are closely associated with fresh fecal contamination and 
are found in high concentrations in sewage and septage. Approved 
analytical methods for these indicators are commercially available, 
simple, reliable, and inexpensive. E. coli is monitored under the TCR 
and therefore GWSs are familiar with its measurement and 
interpretation. Enterococci are recommended as one of the indicators 
for fecally contaminated recreational waters and therefore have 
widespread use. Enterococci may be a more sensitive fecal indicator 
than E. coli in certain aquifer settings and therefore may be the 
preferred indicator in such locations.
    EPA is also authorizing the use of coliphage as a viral indicator 
of fecal contamination. Coliphage are viruses that infect the bacterium 
E. coli. They are closely associated with fecal contamination because 
they do not tend to infect other non-fecal bacteria. Because they are 
viruses, their stability and transport through soil and certain aquifer 
types are similar to the fate and transport of pathogenic viruses. 
There are two categories of coliphage--somatic coliphage and male-
specific coliphage. Local knowledge of hydrogeological conditions may 
inform which of the indicators may be most effective for identifying 
fecal contamination (USEPA, 2006b). EPA plans to publish a guidance 
manual to help to inform such decisions. This rule gives States the 
discretion to specify use of E. coli, enterococci, or one of the 
coliphage types to monitor for potential presence of fecal 
contamination in ground water sources.
    ii. Basis for requiring one versus more than one fecal indicator. 
EPA's Science Advisory Board (SAB) and the National Drinking Water 
Advisory Council (NDWAC) recommended that EPA require monitoring for 
coliphage and either E. coli or enterococci for source water 
monitoring. The reasons stated by SAB and NDWAC were that (1) Ground 
water occurrence data show that no single indicator can fully capture 
all fecal contamination, (2) coliphage is an important indicator of 
enteric virus contamination in terms of transport and survival 
characteristics, and (3) a significant portion of waterborne disease 
risk is associated with exposure to pathogenic viruses in ground water 
sources utilized by a subset of PWSs (USEPA, 2000h and 2000i).
    EPA had insufficient data to evaluate the effectiveness, on a 
national level, of using both coliphage and either E. coli or 
enterococci as source water indicators of fecal contamination. While 
coliphage data is available for many of the occurrence studies used to 
estimate national occurrence for E. coli, the methods used to measure 
coliphage are often based on high volume analysis and a variety of 
methods different than those specified under the final GWR. Thus, EPA 
could not determine whether SAB's proposal would provide additional 
effectiveness.
    EPA is concerned with the potential increase in sampling burden 
relative to the additional number of fecally contaminated wells that 
would be identified using two indicators compared to the use of one 
indicator. The analytical cost for coliphage (viral fecal indicator) 
monitoring is estimated to be about two to three times the cost for 
bacterial fecal indicator monitoring. Therefore, requiring a GWS to 
monitor for both bacterial and viral fecal indicators would more than 
double the analytical costs for GWSs. Based on the limited data 
available, EPA believes that it is not reasonable to require all GWSs 
to monitor for both a bacterial and a coliphage indicator in their 
source water.
    EPA believes that the most appropriate indicator may vary from 
State to State or site to site. This may be due to regional or site-
specific differences or other reasons that may be identified by the 
State. EPA intends to provide guidance on how to determine which 
indicator may be most appropriate to use.
    For the reasons discussed above, EPA believes that the use of a 
single fecal indicator (E. coli, enterococci, or coliphage) provides a 
cost-effective means for identifying fecally contaminated wells and 
protecting public health.
    iii. Sample volume and analytical methods. This rule requires GWSs 
performing triggered source water monitoring to collect and test at 
least a 100 mL sample volume. EPA recommends that States use this 
requirement for assessment source water monitoring. The final GWR 
requires a minimum sample volume of 100 mL because most utilities are 
familiar with this sample volume for bacterial indicator analysis, and 
the two EPA approved coliphage methods include at least this volume in 
their procedures. EPA believes that specifying a higher minimum sample 
volume would unduly increase the cost per sample (especially due to 
shipping). Furthermore, if a higher minimum sample volume were 
specified in the GWR, small systems would not be able to realize the 
considerable monitoring cost savings from use of TCR repeat sampling 
previously discussed in Section IV.B.2.a.ii.
    With regard to analytical methods used for ground water source 
monitoring under this rule, four of the seven methods for the analysis 
of E. coli in source waters allowed under this rule are consensus 
methods described in Standard Methods for the Examination of Water and 
Wastewater (20th editions) (APHA, 1998). The three E. coli methods that 
are not consensus methods are as follows: MI agar (a membrane filter 
method), the ColiBlue 24 test (a

[[Page 65598]]

membrane filter method), and the E*Colite test (a defined dehydrated 
medium to which water is added). EPA has already evaluated and approved 
these three methods for use under the TCR. In the proposed rule Sec.  
141.403(d), footnotes 4 and 5, the use of MI agar with Membrane 
Filtration Method was allowed. Membrane Filtration Method is an EPA-
approved drinking water method, as indicated in footnote 4, while 
footnote 5 cites a manuscript describing MI agar. Subsequent to the 
proposal of the GWR, EPA developed EPA method 1604 ``Total Coliforms 
and Escherichia coli in Water by Membrane Filtration Using a 
Simultaneous Detection Technique (MI Medium)'' (USEPA, 2002c). This 
method was created to ensure consistency with other EPA microbiological 
methods and was promulgated under the Clean Water Act for use in 
ambient water monitoring July 21, 2003 (68 FR 43272-43283) at 40 CFR 
136.3, Table 1A, footnote 22. Method 1604 is equivalent to both the 
manuscript and the EPA-approved Membrane Filtration Method, and EPA has 
indicated in Section 5.4.2.1.3 of the Manual for the Certification of 
Laboratories Analyzing Drinking Water (USEPA, 2005b) that Method 1604 
is identical. EPA Method 1604 is available on the EPA Web site at 
http://www.epa.gov/microbes. This rule allows EPA Method 1604 because 

the Agency believes it will be easily available to the public.
    Three enterococci methods for the analysis of source water are 
allowed under this rule; two of these are consensus methods in Standard 
Methods (APHA, 1998), and the third (Enterolert) was published in a 
peer-reviewed journal article (Budnick et al., 1996). The description 
for each of the E. coli and enterococci methods explicitly states that 
the method is appropriate for fresh waters or drinking waters. The 
proposed rule, Sec.  141.403(d), footnote 8 of the table, also proposed 
to allow EPA Method 1600 (USEPA, 1997d) as an approved variation of one 
of the two consensus methods, Standard Method 9230C, for enterococci. 
However, subsequent to the proposal of the GWR, EPA slightly modified 
EPA Method 1600 (USEPA, 2002a) and promulgated the new version under 
the Clean Water Act on July 21, 2003 (68 FR 43272-43283), at Sec.  
136.3, Table 1A, Footnote 25. The revised method replaced the 1997 
version on the EPA Web site (http://www.epa.gov/microbes). EPA does not 

regard the changes in the newer version of Method 1600 as substantive 
and, aside from changes in format, contact, and grammar, has indicated 
the differences between the two versions in a memo dated March 12, 2004 
that is included in the Water Docket for the GWR. This rule allows the 
more recent version of EPA Method 1600 because, and in addition to a 
few updates and more clarifications, the Agency believes that it will 
be much more easily available to the public.
    EPA proposed to allow, and continues to allow under this rule, the 
use of the two coliphage methods, U.S. EPA Methods 1601 and 1602 
(USEPA, 2001a, 2001b), for source water testing--a new two-step 
enrichment method (Method 1601) and a single-agar layer method (Method 
1602) recently optimized for ground water samples. These methods have 
been round-robin tested (USEPA, 2003a and b) and the Agency has also 
conducted performance studies, using 10 laboratories, on the two 
proposed methods. A full report of each of the two performance studies 
is available in the Water Docket. They are entitled (1) Results of the 
Interlaboratory Validation of EPA Method 1601 for Presence/Absence of 
Male-specific (F+) and Somatic Coliphage in Water by Two-Step 
Enrichment (USEPA, 2003a), and (2) Results of the Interlaboratory 
Validation of EPA Method 1602 for Enumeration of Male-specific (F+) and 
Somatic Coliphage in Water by Single Agar Layer (SAL) (USEPA, 2003b).
    With regard to method cost, EPA queried seven laboratories that 
participated in the round-robin performance testing of the proposed 
coliphage tests. Based upon this survey, EPA estimates that the 
coliphage tests (not including sampling or shipping costs) will cost 
about $59-$65 per test (DynCorp, 2000). This compares to about $20-25 
for bacterial indicators.
    iv. Invalidation of a fecal indicator-positive ground water source 
sample. This rule allows the State to invalidate a fecal indicator-
positive triggered source water monitoring sample if the system 
provides the State with written notice from the laboratory that 
improper sample analysis occurred, or if the State determines and 
documents in writing that there is substantial evidence that a fecal 
indicator-positive ground water source sample is not related to source 
water quality. These provisions are consistent with the sample 
invalidation criteria under the TCR and provide a necessary flexibility 
to States.
3. What Were the Key Issues Raised by Commenters on the Proposed GWR 
Source Water Monitoring Requirements?
    a. Triggered source water monitoring.
    i. Use of total coliform-positive result as a trigger for source 
water fecal indicator monitoring. Many commenters maintained that a 
single total coliform-positive sample was too sensitive of a trigger to 
prompt a requirement to collect a ground water source sample. Among 
their reasons were that a single total coliform-positive sample in the 
distribution system is not necessarily linked to any source water 
problem or even a public health risk. Some argued that other triggers 
were more suitable, such as an acute MCL violation or a non-acute MCL 
violation under the TCR. A number of commenters were opposed to 
triggered source water monitoring altogether.
    As discussed in Section IV.B.2, EPA believes that triggered source 
water monitoring is an important requirement to protect public health. 
In response to commenters' concerns that a single total coliform-
positive sample in the distribution system is not necessarily linked to 
any source water problem, EPA has added language in the final GWR that 
allows States to determine that the cause of a total coliform-positive 
collected under Sec.  141.21(a) is directly related to the distribution 
system and will thus not be a trigger for fecal indicator source water 
monitoring. Because the time available to make the determination is 
short, the State may develop criteria for systems to use to make the 
determination, which would be followed by a report to the State.
    Unless clearly indicated otherwise, EPA believes that a total 
coliform-positive sample in the distribution system is an indication of 
potential microbial contamination of the GWS that may have originated 
from the ground water source. This is a potentially serious public 
health risk that warrants follow-up action.
    EPA believes that basing triggered source water monitoring on TCR 
MCL violations would not be sensitive enough to identify the majority 
of fecal contamination events at the source. EPA estimated that the 
percentage of fecally contaminated wells that would be identified under 
such a provision would be an order of magnitude less than under the 
requirements of the final rule. Consequently, EPA believes that such a 
requirement would not be adequately protective.
    ii. Consecutive system and wholesale system requirements. EPA 
requested comment on which GWR requirements should apply to consecutive 
systems and specifically who should be responsible for triggered source 
water monitoring after a total coliform-positive sample is found in the 
consecutive system's distribution system. Many commenters recommended 
that the seller (or wholesale) system be responsible for

[[Page 65599]]

ground water source monitoring, not the consecutive system. Others 
suggested the State should decide which system should take the ground 
water source sample. In addition, some commenters maintained that the 
buyer (or consecutive) system should not be responsible for meeting the 
treatment technique requirements (e.g., 4-log treatment) for sources.
    EPA infers that some commenters based their comments on an 
understanding that consecutive systems were only systems that received 
all their finished water from a wholesale system, although that is not 
always correct. Since the GWR proposal, EPA defined ``consecutive 
system'' and ``wholesale system'' in Sec.  141.2 in the Stage 2 
Disinfectants and Disinfection Byproducts Rule (DBPR) (71 FR 388, 
January 4, 2006) (USEPA, 2006g). In those definitions, which apply to 
all requirements in 40 CFR Part 141 (including the GWR), EPA specified 
and clarified that consecutive systems include both systems that 
receive all of their finished water from one or more wholesale systems 
and systems that receive some of their finished water from one or more 
wholesale systems (with the balance coming from a source or sources 
operated and treated, as necessary, by the consecutive system).
    The Agency has added requirements to clarify the responsibilities 
of consecutive and wholesale systems in response to comments received, 
and to facilitate implementation and compliance. EPA believes that 
public health and risk concerns underlying the requirement for 
triggered ground water source monitoring after a total coliform-
positive sample are equally applicable to consecutive systems and 
wholesale systems. EPA also believes that the system that operates the 
ground water source should be responsible for any required triggered or 
assessment source water monitoring and any required corrective actions, 
including 4-log treatment installation, operation, and compliance 
monitoring.
    Without treatment, water quality problems in the wholesale system 
will remain in the water delivered to the consecutive system and thus 
water quality problems in the consecutive system may be related to 
problems in the wholesale system (even if the wholesale system has not 
identified the problems). Therefore, in the GWR, specific triggered 
source water monitoring requirements apply to consecutive systems and 
wholesale systems (as explained in the following paragraphs) unless the 
cause of the total coliform-positive collected under Sec.  141.21(a) 
directly relates to the distribution system as determined by the system 
according to State criteria, or as determined by the State.
    Consecutive systems that have a total coliform-positive sample must 
notify the wholesale system(s) within 24 hours of being notified of the 
total coliform-positive sample so that the wholesale system(s) can 
conduct triggered source water monitoring, since the wholesale system's 
source water may be the cause. Also, a consecutive system with its own 
ground water source(s) that has a total coliform-positive sample under 
the TCR must conduct triggered source water monitoring of its own 
sources, just like any other GWS that must conduct triggered source 
water monitoring. A consecutive system that has no source of its own 
(i.e., it receives all of its finished water from one or more wholesale 
systems) is not required to conduct triggered source water monitoring, 
since it has no source water. Only systems that produce finished ground 
water (i.e., have their own sources) are required to conduct triggered 
source water monitoring.
    Consecutive systems are required to comply with the GWR treatment 
technique requirements only in cases of contamination in the 
consecutive system's own ground water source. Consecutive systems are 
not required to comply with GWR treatment technique requirements if a 
fecal indicator-positive is detected only in the wholesale system's 
ground water source; only the system with the source contamination must 
comply with the GWR treatment technique requirements (in this case, the 
wholesale system). Similarly, wholesale systems are not required to 
comply with GWR treatment technique requirements if a fecal indicator-
positive is detected only in the consecutive system's ground water 
source and not in the wholesale system's source; again, only the system 
with the source contamination must comply with the GWR treatment 
technique requirements (in this case, the consecutive system).
    iii. Repeat samples to confirm initial fecal indicator-positive. 
Several commenters raised concerns that a single positive fecal 
indicator source water sample should not result in a corrective action 
because the indicator sample result may be a false positive. The same 
commenters recommended that repeat samples be taken to confirm the 
initial result before requiring corrective action. In response to 
commenters and based on the discussion in Section IV.B.2, unless the 
State determines that corrective action should be taken following an 
initial fecal indicator-positive source water sample, the final GWR 
requires that the GWS take five additional samples, and that only if 
one of those samples is fecal indicator-positive is corrective action 
required. This prevents systems from incurring costs from the 
application of unnecessary corrective actions. The State may require 
the system to take corrective action after the first fecal indicator-
positive source water sample.
    EPA believes that five additional samples following a positive 
triggered source water monitoring sample provides a reasonable balance 
between ensuring that corrective actions are warranted, avoiding 
excessive re-sampling costs, and avoiding an incorrect conclusion that 
the initial positive was false (i.e., avoiding a situation in which 
corrective action is needed but not taken because of false re-sample 
results). EPA believes that multiple samples, rather than one, are 
needed to ensure that corrective action is taken when necessary. EPA 
proposed using five repeat samples under the routine monitoring 
provisions (65 FR 30230) (USEPA, 2000a). Commenters wanted EPA to use 
repeat samples for the triggered monitoring provisions also because 
they were concerned about false positives and systems taking 
unnecessary corrective actions. They recommended four or five repeat 
samples for triggered monitoring. In response to comments, the final 
GWR requires five repeat samples under the triggered source water 
monitoring provisions.
    iv. Source water monitoring burden. In the final GWR, EPA has 
reduced the sampling burden for small systems serving 1,000 people or 
fewer. Under the TCR, a system that collects one or fewer routine 
samples per month (systems that serve 1,000 people or fewer) with a 
total coliform-positive sample (that has not been invalidated) is 
already required to collect a set of four repeat samples in the 
distribution system within 24 hours of the total coliform-positive 
sample. Under this rule, one of the four repeat samples required under 
the TCR may be used to satisfy the GWR source water monitoring 
requirements if the sample is taken at a ground water source and only 
if the State approves the use of E. coli as a fecal indicator.
    In addition, the final rule reduces sampling burden for systems 
with more than one well (e.g., many large systems). Based on comments 
received, the GWR provides flexibility for systems with more than one 
well. The triggered source water monitoring provision allows systems 
with more than one ground water source, upon State approval, to sample 
a representative ground water source (or sources)

[[Page 65600]]

following any total coliform-positive sample. The State may require 
systems with more than one ground water source to submit for approval a 
triggered source water monitoring plan that the system will use for 
representative sampling. EPA believes that this alternative can be as 
protective of public health as monitoring all wellheads, provided that 
the chosen wells are truly representative of all wellheads. In 
addition, for situations where a particular sample site is 
inaccessible, the State may identify an alternate sampling site that is 
representative of the water quality of the ground water at the 
inaccessible sample site.
    b. Routine Monitoring. Many comments regarding routine source water 
monitoring were related to HSAs. Many commenters suggested State 
discretion on which systems should be considered sensitive and thus be 
required to do routine monitoring.
    EPA has taken public comments on routine monitoring and HSAs into 
consideration, as discussed in Section II.C. The final GWR provides 
State the option to require assessment source water monitoring at GWSs 
that the State determines to be most susceptible to fecal 
contamination. EPA believes that this optional provision is an 
important tool that should be used by States to protect public health.
    EPA recommends HSAs as one way to identify higher risk systems for 
which assessment source water monitoring would be beneficial and 
appropriate. Based on comments received, the final GWR does not require 
HSAs or assessment source water monitoring, except as provided by the 
State (see Section II.C).
    c. Source water microbial indicators and analytical methods. This 
rule allows a State to direct a system to use E. coli, enterococci, or 
coliphage for ground water source monitoring. Regarding coliphage 
testing, one major issue raised by commenters pertained to the 
performance of the two proposed coliphage methods. Many commenters 
questioned method reliability, specificity, sensitivity, false-positive 
rates, and lack of comprehensive field testing. They were also 
concerned about analytical costs and the availability of laboratory 
capacity. As explained earlier, the Agency believes that the results of 
performance studies indicate that both methods have been validated for 
reliable use in drinking water contexts. As discussed in Section 
IV.B.2, EPA recognizes that the analytical costs for coliphage testing 
are more than double the cost for bacterial (E. coli and enterococci) 
analyses. Therefore, EPA believes that many States will specify a 
bacterial fecal indicator for GWR source water monitoring based on 
cost. However, the Agency allows coliphage testing in this rule due to 
awareness that some laboratories are proficient in coliphage analysis 
and that this indicator may be preferred over others, depending on 
site-specific knowledge. While EPA recognizes that limited laboratory 
capacity for coliphage testing may be an issue, this rule provides 
States with discretion in determining which fecal indicators (E. coli, 
enterococci, or coliphage) will be used. EPA expects that one of the 
factors that States may use to decide which fecal indicator to specify 
is laboratory capacity.

C. Corrective Action Treatment Techniques for Systems With Significant 
Deficiencies or Source Water Fecal Contamination

    The final GWR provides for regular, comprehensive sanitary surveys 
of all GWSs and triggered source water and optional assessment source 
water monitoring to determine at-risk GWSs. This rule requires the 
subset of systems with sanitary survey significant deficiencies or 
source water fecal contamination to complete corrective actions in a 
timely manner to ensure public health protection. Failure to complete 
corrective actions within 120 days, including meeting deadlines for 
interim actions and measures, or comply with a State-approved 
corrective action plan and schedule, constitutes a treatment technique 
violation under this rule.

BILLING CODE 6560-50-P

[[Page 65601]]

[GRAPHIC] [TIFF OMITTED] TR08NO06.004

BILLING CODE 6560-50-C
1. What Are the Requirements of This Rule?
    When a system has a significant deficiency, it must consult with 
the State regarding appropriate corrective action within 30 days of 
receiving a written notice of the significant deficiency. When a system 
receives a written notice from a laboratory indicating a fecal 
indicator positive result in one of the five additional triggered 
source water monitoring samples, the system must consult with the State 
regarding appropriate corrective action. When a system receives a 
written notice from a laboratory indicating a fecal indicator

[[Page 65602]]

positive result and the State has determined that corrective action is 
necessary, the system must consult with the State regarding appropriate 
corrective action. Consultation must take place within 30 days. In any 
event, the State may specify corrective action without consultation. In 
the consultation process, the State may approve and/or modify 
corrective actions and completion schedules proposed by the system, or 
the State may specify alternatives. The State may also specify interim 
corrective action measures.
    The GWR rule requires that within 120 days (or earlier if directed 
by the State) of receiving the notification from the State or 
laboratory described in the preceding paragraph, the GWS must either 
(i) Complete appropriate corrective actions in accordance with 
applicable State plan review processes or other State guidance or 
direction, or (ii) be in compliance with a State-approved corrective 
action plan and schedule. If a system is unable to complete corrective 
action within 120 days or on the schedule specified by the State, then 
the system is in violation of the treatment technique requirement.
    Systems must notify the State within 30 days of completing any 
State approved or specified corrective action. As a condition of 
primacy, States must verify that the corrective action has been 
completed within the next 30 days. States may verify that the 
corrective action has been completed and has successfully addressed the 
significant deficiency and/or fecal contamination in the ground water 
source either by a site visit or by written documentation from the 
system, which could consist of the system's notification to the State.
    a. What corrective action alternatives are provided for in this 
rule? When a system has a significant deficiency or a fecal indicator-
positive ground water source sample (either by the initial triggered 
sample, or positive additional sample, as determined by the State), the 
GWS must implement one or more of the following corrective action 
options: (1) Correct all significant deficiencies (e.g., repairs to 
well pads and sanitary seals, repairs to piping tanks and treatment 
equipment, control of cross-connections); (2) provide an alternate 
source of water (e.g., new well, connection to another PWS); (3) 
eliminate the source of contamination (e.g., remove point sources, 
relocate pipelines and waste disposal, redirect drainage or run-off, 
provide or fix existing fencing or housing of the wellhead); or (4) 
provide treatment that reliably achieves at least 4-log treatment of 
viruses (using inactivation, removal, or a State-approved combination 
of 4-log virus inactivation and removal) before or at the first 
customer for each ground water source requiring corrective action.
    b. Compliance monitoring for systems providing at least 4-log 
treatment of viruses. This rule also establishes compliance monitoring 
requirements for GWSs that provide at least 4-log treatment of viruses 
as a corrective action. This rule also establishes compliance 
monitoring requirements for those systems that have notified the State 
that they provide at least 4-log treatment of viruses for their ground 
water sources before the first customer and are therefore not required 
to meet the triggered source water monitoring requirement of this rule.
    Treatment technologies capable of providing at least a 4-log 
treatment of viruses include the following:
     Inactivation, with a sufficient disinfection concentration 
and contact time, through disinfection with chlorine, chlorine dioxide, 
ozone, or through anodic oxidation. Disinfectant concentration and 
contact time (CT) can be based on existing CT tables (USEPA, 1991) or 
State-approved alternatives.
     Removal with membrane technologies with an absolute 
molecular weight cut-off (MWCO), or an alternate parameter that 
describes the exclusion characteristics of the membrane, that can 
reliably achieve at least a 4-log removal of viruses.
     Inactivation, removal or combination of inactivation and 
removal through alternative treatment technologies (e.g., ultraviolet 
radiation (UV)) approved by the State, if the alternative treatment 
technology, alone or in combination (e.g., UV with filtration, 
chlorination with filtration), can reliably provide at least 4-log 
treatment of viruses.
    Under this rule, systems providing 4-log treatment of viruses using 
chemical disinfection must monitor for and must meet and maintain a 
State-determined residual disinfectant concentration (e.g., 4-log 
inactivation of viruses based on CT tables) or State-approved 
alternatives every day the GWS serves from the ground water source to 
the public.
    Systems serving greater than 3,300 people and using chemical 
disinfection (e.g., chlorine) to provide 4-log inactivation must 
continuously monitor the residual disinfectant concentration using 
analytical methods specified in Sec.  141.74(a)(2) (Analytical and 
monitoring requirements) at a location approved by the State, and 
record the lowest residual disinfectant level each day that the GWS 
serves water from the ground water source to the public. The system 
must maintain the State-determined residual disinfectant concentration 
every day the GWS serves from the ground water source.
    Systems serving 3,300 people or fewer that use chemical 
disinfection must monitor the residual disinfectant concentration using 
analytical methods specified in Sec.  141.74(a)(2) (Analytical and 
monitoring requirements) at a location approved by the State either by 
taking at least one grab sample every day the GWS serves water to the 
public or by continuously monitoring the disinfectant residual. Systems 
collecting grab samples must record the disinfectant residual level 
each day that the GWS serves water from the ground water source to the 
public. The system must take a grab sample during the hour of peak flow 
or at another time specified by the State. Systems serving 3,300 people 
or fewer that use continuous residual monitoring equipment must record 
the lowest residual disinfectant level each day that the GWS serves 
water from the ground water source to the public.
    If a GWS taking grab samples has a sample measurement that falls 
below the State-specified residual disinfectant concentration, then the 
system must take follow-up samples at least every four hours until the 
State-specified residual disinfectant level is restored. If a system 
using continuous monitoring equipment fails to maintain the State-
specified disinfectant residual level necessary to achieve 4-log 
inactivation of viruses, the system must restore the disinfectant 
residual level to the State-specified level within four hours. If 
continuous disinfectant monitoring equipment fails, the GWS must take a 
grab sample at least every four hours until the equipment is back on-
line. The system has 14 days to resume continuous monitoring. Failure 
to restore the residual disinfectant level to that required for 4-log 
inactivation of viruses within four hours, using either continuous 
monitoring or grab sampling, is a treatment technique violation.
    Ground water systems that use a membrane filtration treatment 
technology must maintain the integrity of the membrane and monitor and 
operate the membrane filtration system in accordance with State-
specified monitoring and compliance requirements (e.g., membrane 
performance parameters and integrity testing). If a system fails to 
meet these requirements or maintain the integrity of the membrane, it 
must correct the problem within four hours or be in violation of the 
treatment technique requirement.

[[Page 65603]]

    Systems that use a State-approved alternative treatment technology 
must monitor and operate the alternative treatment in accordance with 
all compliance requirements that the State determines to be necessary 
to demonstrate that at least 4-log treatment of viruses is achieved. If 
the system does not comply with these requirements, fails to maintain 
at least 4-log treatment of viruses, and does not restore proper 
operation within four hours, the system is in violation of the 
treatment technique requirement.
    GWSs providing at least 4-log treatment of viruses may discontinue 
treatment if the State determines (e.g., based on source water 
monitoring or replacement of the source) and documents in writing that 
the need for 4-log treatment of viruses no longer exists for that 
ground water source. GWSs that discontinue treatment with State 
approval must comply with the triggered source water requirements of 
this rule. GWSs that provide 4-log treatment of viruses and notify the 
State that they are not subject to the source water monitoring 
requirements of this rule but subsequently discontinue 4-log treatment 
of viruses must have State approval and must comply with the triggered 
source water requirements of this rule.
2. What Is EPA's Rationale for the GWR Treatment Technique 
Requirements?
    EPA believes that fecal contamination in ground water sources of 
undisinfected or minimally disinfected GWSs and significant 
deficiencies demonstrate public health risks that require prompt 
corrective action. Application of corrective actions in cases of source 
water fecal contamination or significant deficiencies provides benefits 
of eliminating existing problems and can also preempt future public 
health risks, such as an outbreak. EPA believes that requiring 
treatment technique provisions to respond to fecally contaminated 
ground water sources and/or significant deficiencies identified by 
sanitary surveys will provide enforcement authority to EPA and States 
to ensure that appropriate corrective actions will be implemented.
    The GAO reported that failure to correct deficiencies identified in 
sanitary surveys is a significant concern (USGAO, 1993). An analysis of 
Best Management Practices (BMPs) (ASDWA, 1998) showed that correction 
of deficiencies was correlated with lower levels of total coliform, 
fecal coliform, and E. coli. Therefore, EPA believes that the treatment 
technique requirements in this rule will result in reduced exposures to 
fecal contamination and associated health risks.
    Findings from a review of the Environmental Law Reporter contained 
in the Baseline Profile Document for the Ground Water Rule (USEPA, 
2000g) indicate that (1) Not all States specifically require systems to 
correct deficiencies, and (2) a number of States may not have the legal 
authority to require systems to correct deficiencies. The treatment 
technique requirements of this rule provide for timely correction, as 
well as public notification, of fecal contamination and significant 
deficiencies. Treatment corrective actions provide for inactivation or 
removal of microbes of public health concern in some ground waters and 
results in reduced exposures and associated health risks. The rule also 
allows non-treatment alternatives such as removing the source of 
contamination or providing an alternate source water, both of which 
also result in reduced exposures and associated health risks.
    To avoid unwarranted action, EPA has added a provision under the 
final rule that allows additional sampling of the source water with the 
initial fecal indicator-positive sample before requiring corrective 
action. If the State determines that corrective action is appropriate 
from the initial fecal indicator-positive finding, then no additional 
sampling would be required. This provision is discussed in Section 
IV.B.2.a.
    a. Corrective Actions and Treatment Technique Requirements. To 
develop the treatment technique requirements, EPA evaluated existing 
State requirements and the measures available to systems to address 
fecal contamination. EPA believes that effective corrective actions 
include correcting significant deficiencies, eliminating the source of 
contamination, providing an alternate source of safe drinking water, or 
providing 4-log treatment of viruses. States and systems have the 
flexibility to take site-specific factors into consideration when 
implementing these corrective actions.
    i. Corrective action technologies. Chemical disinfection 
technologies are commonly used by both ground water and surface water 
systems to provide disinfection prior to distribution of drinking 
water. EPA believes that 4-log inactivation is protective in 
disinfecting GWSs (see Figure III-1). Under the SWTR, EPA requires at 
least 4-log removal and/or inactivation of viruses. Since the frequency 
of viral occurrence and virus concentrations are generally lower in 
ground water supplies than in surface water supplies, EPA believes the 
4-log requirement for GWSs is as protective as the current treatment 
requirements for surface water supplies. Figure III-1 indicates the 
range of protection anticipated from the 4-log requirement for GWSs 
having viral contamination in their source water.
    Numerous studies have investigated the efficacy of chemical 
disinfectants to inactivate viruses. Free chlorine was shown to be able 
to achieve 4-log inactivation of hepatitis A virus (HAV) at a 
temperature of 15 degrees Celsius, a pH of 6-9, and a CT of four mg-
min/L (USEPA, 1991). Chlorine dioxide achieves 4-log inactivation of 
HAV at a temperature of 15 degrees Celsius, a pH of 6-9, and a CT of 
16.7 mg-min/L (USEPA, 1991). Ozone achieves a 4-log inactivation of 
poliovirus at a temperature of 15 degrees Celsius, a pH of 6-9, and a 
CT of 0.6 mg-min/L (USEPA, 1991). Chemical disinfection is a 
demonstrated technology that can achieve 4-log inactivation of viruses. 
The CT value needed to provide 4-log inactivation of viruses is 
dependent on site-specific conditions, including the disinfectant 
demand, water temperature and pH. States and systems may use existing 
inactivation (CT) tables (USEPA, 1991) or State-approved alternatives 
to determine the chemical disinfectant doses required to achieve a 4-
log inactivation of viruses.
    Membrane filtration technologies can achieve 4-log or greater 
removal of viruses, as long as the absolute MWCO of the membrane, or 
alternate parameter that describes the exclusion characteristics of the 
membrane, is smaller than the diameter of viruses. For instance, 
reverse osmosis (RO) can achieve greater than 4-log removal of 
particles (including viruses) larger than 0.5 nm in diameter when the 
absolute MWCO of the RO membrane is less than 0.5 nm (Jacangelo et al., 
1995). In addition, nanofiltration (NF) can achieve greater than 4-log 
removal of particles with a diameter of 0.5 nm or larger when the 
absolute MWCO of the NF membrane is 200-400 Daltons. Viruses range in 
diameter from 20-900 nm. The absolute MWCOs of specific membranes must 
be determined for the specific membranes to meet these conditions. This 
rule also allows for other filtration treatment technologies to be used 
to meet the 4-log treatment requirement.
    The GWR proposal explicitly included UV light in the regulatory 
text as a stand-alone treatment technology that could provide a 4-log 
virus inactivation. However, data published subsequent to the GWR 
proposal indicated that some viruses, particularly adenoviruses, are 
very resistant to UV

[[Page 65604]]

light. The GWR proposal was based on information available at the time 
of the proposal regarding UV doses required to provide a 4-log 
inactivation of HAV and the design doses achieved by available UV 
reactors, which are lower than the UV doses needed to achieve 4-log 
inactivation of adenovirus.
    Further, EPA believes that UV reactors must undergo challenge 
testing to validate the dose level delivered so that effective public 
health protection is provided in systems using UV disinfection. At 
present, EPA is unaware of available challenge testing procedures that 
can be used to validate the performance of UV reactors at dose levels 
needed for a 4-log inactivation of adenovirus.
    The final GWR modifies the proposal by removing the explicit 
reference to UV as a stand-alone technology to achieve 4-log virus 
inactivation. EPA is concerned that fecally-contaminated ground water 
may contain adenoviruses, or other viruses, that are more resistant to 
UV inactivation than HAV, and currently available testing procedures 
cannot validate UV reactor performance at the UV dose levels needed for 
inactivation.
    EPA believes that UV technology can be used in a series 
configuration or in combination with other inactivation or removal 
technologies to provide a total 4-log treatment of viruses to meet this 
rule's requirements. EPA also believes that a UV reactor dose 
verification procedure for 4-log inactivation of a range of viruses may 
be developed in the future. With the future development of UV 
validation procedures, it may become feasible for systems to 
demonstrate that they can achieve 4-log inactivation of viruses with a 
single UV light reactor. Therefore, this rule allows States to approve 
and set compliance monitoring and performance parameters for any 
alternative treatment, including UV light or UV light in combination 
with another treatment technology, that will ensure that systems 
continuously meet the 4-log virus treatment requirements. This 
requirement is both protective of public health and provides systems 
and States with needed flexibility for site-specific decisions. It 
ensures protection against known heath risks associated with waterborne 
viruses; allows systems to make use of technologies that are already in 
place or are more appropriate for the system's size, location, or 
configuration; and provides the opportunity for systems to take 
advantage of future technology developments.
    ii. Corrective action time frame. EPA believes that timely 
correction of source water fecal contamination and significant 
deficiencies in GWSs is an essential component of the public health 
measures presented in this rule.
    EPA has extended the proposed 90-day deadline for completing 
corrective actions to 120 days, which includes additional time for a 
30-day GWS/State consultation period. In the case of source water fecal 
contamination, an investigation into the cause of contamination should 
be conducted during this 30 day period. This consultation allows the 
State, in discussion with the system, to determine the most appropriate 
corrective action for the problem identified to ensure public health 
protection. To reduce burden, the State may specify the corrective 
action in its significant deficiency notice to the system.
    EPA believes that in many situations, a system can complete 
corrective actions within 120 days because many corrective actions are 
easy to implement, such as repairing a well seal. Where this is not the 
case, for example if a system needs to make capital improvements, the 
GWR allows States to determine an alternate schedule. The State is in 
the best position to make these case-by-case determinations of the most 
appropriate schedule to protect public health. The GWR also allows the 
State to require immediate interim corrective action to protect 
consumers while longer-term actions are implemented.
    There may be cases in which systems and States have thoroughly 
investigated and cannot determine the cause of fecal contamination of 
the source water and believe that the source is no longer vulnerable to 
such contamination. If the State determines based on follow-up 
monitoring or other evidence that the contamination is unlikely to 
occur again, the State may consider the source of contamination to be 
eliminated. EPA considers such a system to be high risk and recommends 
that States follow up such a determination with assessment source water 
monitoring as described in Section IV.B.2.b. Commenters supported State 
discretion in making system-specific decisions. EPA is providing this 
interpretation in support of this goal.
    iii. Discontinuing treatment. If the State determines that the need 
for 4-log treatment no longer exists, the State may allow a system to 
discontinue treatment. EPA believes that in certain situations (i.e., 
consolidation, replacement or rehabilitation of ground water sources, 
mitigation of source of contamination), where both corrective action 
has addressed the public health risks and the system has demonstrated 
to the State that corrective action has been successful (e.g., through 
source water monitoring or sanitary surveys), it may be appropriate to 
allow systems to discontinue 4-log treatment of ground water sources. 
If the State allows a system to discontinue 4-log treatment, the system 
is then subject to the source water monitoring requirements of this 
rule.
    b. Monitoring for the Effectiveness and Reliability of Treatment. 
All GWSs that provide treatment must routinely monitor the treatment 
effectiveness to ensure that public health is protected. Because of 
considerations regarding resources and the technical capacities of 
small water systems, this rule includes different monitoring 
requirements for systems of different sizes while still effectively 
ensuring public health protection. The 1996 Amendments to the SDWA 
recognized the importance of considering both the special needs of 
small systems that serve 3,300 people or fewer and the need to ensure 
equal public health protection to consumers served by small and large 
PWSs.
    EPA believes that it is appropriate for disinfecting systems 
serving greater than 3,300 people to install and operate continuous 
disinfection monitoring equipment. These systems will generally have 
the expertise to operate and maintain the necessary equipment, and 
continuous monitoring and recording will alleviate some of the 
monitoring burden for larger systems. Systems serving 3,300 people or 
fewer are provided the flexibility to use either grab sampling or 
continuous monitoring. This option is important because some small 
systems may not have the capacity to purchase, operate, and maintain 
continuous disinfection monitoring equipment. For all systems, the 
monitoring must take place at or prior to the first customer to ensure 
that the required level of treatment has been achieved prior to serving 
water to the public.
    For GWSs that use membrane filtration systems to achieve at least 
4-log removal of viruses, the system must monitor the membrane 
filtration process in accordance with all State-specified monitoring 
requirements. In addition, the system must operate the membrane 
filtration in accordance with all State-specified compliance 
requirements. A GWS that uses membrane filtration is in compliance with 
the 4-log removal requirement for viruses when:
     The membrane has an absolute MWCO, or alternate parameter 
that describes the exclusion characteristics of the membrane, that can 
reliably achieve 4-log removal of viruses;

[[Page 65605]]

     The membrane process is operated in accordance with State-
specified compliance requirements; and
     The integrity of the membrane is intact.

To ensure compliance with the virus removal requirements of the GWR in 
systems that practice membrane filtration, systems must monitor to 
verify that the membrane filtration is operating as specified and that 
the membrane is intact. Without these compliance monitoring 
requirements, failure of membrane filtration may not be detected by the 
system and consumers may be exposed to potentially fecally contaminated 
water. This could result in a failure to maintain at least 4-log 
treatment of viruses.
    In cases where 4-log treatment of viruses is interrupted, the 
requirement that systems must restore 4-log treatment of viruses is 
consistent with requirements for surface water systems under the SWTR 
(USEPA, 1989b) and protects public health while providing flexibility 
for GWSs to address operational issues.
    If the State has not approved compliance criteria for the system to 
use to demonstrate 4-log treatment by the time that the system is 
required to conduct compliance monitoring, the system should comply 
with ground water source monitoring in Sec.  141.402 until the State 
approves compliance criteria for the system to use to demonstrate 4-log 
treatment. EPA is concerned that systems may inadvertently provide 
inadequately treated water (i.e., <  4-log treatment) if they are not 
using State approved compliance criteria.
3. What Were the Key Issues Raised by Commenters on the Proposed GWR 
Treatment Technique Requirements?
    a. State Consultation Versus Approval. EPA received many comments 
related to the State's ability to require the system to implement a 
specific treatment technique in response to significant deficiencies or 
source water fecal contamination. The proposed GWR required the system 
only to consult with the State on the appropriate corrective action 
option for the system. Several commenters expressed concern that with 
only a consultation requirement, a system could implement a treatment 
technique that the State would consider inappropriate or unreliable, 
such as disinfection by a system that is incapable of reliably 
operating a disinfection treatment system. To address these concerns, 
the final GWR requires systems to implement corrective actions in 
accordance with applicable State plan review processes, or other State 
guidance or direction, including interim measures, or be in compliance 
with a State-approved corrective action plan and schedule. EPA believes 
that existing State plan review and permitting activities, such as 
those established in accordance with the primacy requirements at Sec.  
142.10(b)(5), will ensure that systems implement the most appropriate 
corrective action.
    b. UV Disinfection. EPA received comments on the use of UV 
technology to meet the treatment technique requirements of the GWR. The 
GWR proposal included UV as a stand-alone treatment to meet the GWR 
treatment requirements and provided monitoring requirements for systems 
using UV technology, as well as State-determined performance 
requirements for UV technology.
    Commenters requested more information on the use of UV for virus 
inactivation, including UV dose tables and criteria to assist States in 
evaluating UV reactors. Commenters also noted that data published 
subsequent to the GWR proposal indicated that some viruses, in 
particular adenoviruses, are very resistant to UV light. Data show that 
a dose of 186 mJ/cm2 is required to achieve 4-log 
inactivation of adenovirus (68 FR 47713, August 11, 2003) (USEPA, 
2003c). This information suggests that HAV, the virus considered in the 
GWR proposal discussion of UV, may not be an appropriate indicator of 
the virus inactivation performance of UV reactors. EPA agrees that UV 
reactors may need to provide higher doses than those contemplated in 
the GWR proposal to achieve 4-log inactivation of viruses. Moreover, 
there is currently limited information available for States to make 
determinations regarding performance requirements for UV reactors to 
ensure that adequate virus inactivation is being achieved.
    Further, EPA believes that testing of full-scale UV reactors is 
necessary to ensure disinfection performance and a consistent level of 
public health protection. Full-scale testing avoids the significant 
difficulties encountered in predicting UV reactor disinfection 
performance based solely on modeled results or the results of testing 
at a reduced scale. All flow-through UV reactors deliver a distribution 
of doses due to variations in light intensity within the UV reactor and 
the different flow paths of particles passing through the reactor. The 
reactor-delivered dose also varies temporally due to processes such as 
UV lamp aging and fouling, changes in UV absorbance of the water being 
treated, and fluctuations in reactor flow rates.
    A full-scale test typically involves using a surrogate 
microorganism. However, EPA is not aware of an available challenge 
microorganism that allows for full-scale testing of UV reactors to 
demonstrate a 4-log inactivation of adenovirus. EPA believes that 
methodologies for challenge testing at doses necessary to inactivate 
UV-resistant viruses may be developed in the future.
    The final GWR does not include specific performance, monitoring, or 
design requirements related to the use of UV technology. This is based 
on the comments received regarding the use of UV technology to meet the 
GWR requirements, new data regarding UV dosages necessary for virus 
inactivation, and the difficulties in performing full-scale 
demonstrations of 4-log virus inactivation at those doses.
    However, EPA does believe that UV technology may be used in a 
series configuration or in combination with other inactivation or 
removal technologies to provide a total 4-log treatment of viruses to 
meet this rule's requirements. The State has the flexibility to approve 
treatment alternatives not specified in the rule, which could include 
UV disinfection. When using an alternative treatment technology, the 
State must specify monitoring and compliance requirements necessary to 
ensure that the virus treatment requirements of this rule are being 
met. The alternative treatment option in this rule could be applied to 
stand-alone UV disinfection if challenge testing protocols for 4-log 
virus inactivation are developed in the future.
    c. Corrective Action Time Frame. EPA requested comment on the 
appropriateness of the time frame for providing corrective actions. 
Several commenters suggested that the proposed 90-day corrective action 
time frame was too short and that systems would not be able to meet 
this deadline. Some commenters also stated that 90 days would not be 
sufficient for systems seeking an extension of the 90-day deadline for 
completing the corrective action to obtain State approval of a plan and 
schedule within 90 days due to factors outside of the system's control, 
such as the need to obtain competitive bids or to gain the approval of 
the local government. On the other hand, several commenters stated that 
a 90-day corrective action time frame for systems with fecally 
contaminated source water was too long and would place consumers at an 
increased risk.
    EPA received additional comments opposing the requirement on the 
State to approve corrective action plans

[[Page 65606]]

within the same 90 days required for the system to submit the plans 
(for systems seeking an extension of the 90-day deadline for completing 
the corrective action). The commenters pointed out that under the 
proposed rule, systems could potentially submit plans on the 90th day, 
leaving insufficient time for the State to review the plans.
    The final GWR extends the proposed 90-day deadline for completing 
corrective actions from 90 to 120 days, which includes additional time 
for an initial 30-day GWS/State consultation period. This 30-day 
consultation serves a number of purposes. First, GWSs and States can 
investigate the cause of contamination. Second, the GWS and State may 
consult on the most appropriate corrective action. Third, the GWS and 
State may develop a corrective action plan and schedule that could 
extend beyond the 120-day period if necessary. This addresses the 
concerns that GWSs would not be able to complete their corrective 
action or receive an extension. This consultation period provides the 
GWS and State the assurance requested by commenters that they not be 
subject to factors outside of their control. Concerns about corrective 
action taking too long have been addressed by the provision to require 
GWSs to do interim corrective action measures at the State's request. 
In addition, this rule requires States to identify in their primacy 
application their rules or other authorities to demonstrate that they 
can ensure that GWSs take the appropriate corrective action, including 
interim measures, if necessary, pending completion of corrective 
actions.
    EPA believes that the revised process for corrective actions under 
this rule will (1) Allow the State to ensure that the system is held 
accountable in a reasonable time frame for implementing corrective 
actions, and (2) utilize the strengths of existing State plan review 
processes or other State guidance, requirements, or direction. Systems 
and States continue to have the flexibility to complete corrective 
action on a more rapid schedule than 120 days.

D. Providing Notification and Information to the Public

    Section 1414(c)(1) of the 1996 SDWA amendments requires that PWSs 
notify persons served when violations of drinking water standards 
occur. EPA published a revised Public Notification Rule (PNR) in 2000 
(65 FR 25981, May 4, 2000) (USEPA, 2000j). Subsequent EPA drinking 
water regulations that affect public notification requirements 
typically include amendments to the PNR as a part of the individual 
rulemaking. This rule amends the PNR at Sec.  141.202(a) and Sec.  
141.203(a) and requires Tier 1 notice for detection of a fecal 
indicator in a ground water source sample (see Sec.  141.403) and Tier 
2 notice for treatment technique violations (see Sec.  141.404). Also, 
this rule requires Tier 3 notice for monitoring violations (see Sec.  
141.403 or Sec.  141.404(b)). In addition, this rule amends the 
Consumer Confidence Report (CCR) (Sec.  141.153(b) Appendix A to 
subpart O) requirements and includes language to be used when informing 
the public of significant deficiencies and fecal indicator-positive 
results in ground water source samples. Since the CCR only applies to 
CWSs, a special notice requirement for uncorrected significant 
deficiencies is included in the treatment technique section of this 
rule for NCWSs. The language included in this section parallels 
language included in the CCR. Table IV-4 summarizes the GWR 
notification requirements.
    The purpose of public notification is to alert customers of 
potential risks from violations of drinking water standards and to 
inform them of any steps they should take to avoid or minimize such 
risks. A PWS is required to give public notice when it fails to comply 
with existing drinking water regulations, has been granted a variance 
or exemption from the regulations, or is facing other situations posing 
a potential risk to public health. Public water systems are required to 
provide such notices to all persons served by the water system. The PNR 
divides the public notice requirements into three tiers, based on the 
seriousness of the violation or situation.
    Tier 1 is for violations and situations with significant potential 
to have serious adverse effects on human health as a result of short-
term exposure. Notice is required within 24 hours of the violation. 
Drinking water regulation Tier 1 notice violation categories and other 
situations include, but are not limited to, the following:
     An acute violation of the MCL for total coliforms when 
fecal coliform or E. coli are present in the water distribution system, 
or when the water system fails to analyze the sample for fecal 
coliforms or E. coli when any repeat sample tests positive for coliform 
(as specified in Sec.  141.21(e));
     Occurrence of waterborne disease outbreaks, or other 
waterborne emergencies; and
     Other violations or situations with significant potential 
to have serious adverse effects on human health as a result of short-
term exposure, as determined by the State either in its regulations or 
on a case-by-case basis.

The State is explicitly authorized to add other violations and 
situations to the Tier 1 list when necessary to protect public health 
where short-termexposure is a concern.
    Tier 2 is for other violations and situations with the potential to 
have serious adverse effects on human health. Notice is required within 
30 days, with an extension of up to three months permitted at the 
discretion of the State. Violations requiring a Tier 2 notice include 
all MCL and treatment technique violations, except where Tier 1 notice 
is required, and specific monitoring violations when determined by the 
State.
    Tier 3 is for all other violations and situations requiring a 
public notice not included in Tier 1 and Tier 2. Notice is required 
within 12 months of the violation and may be included in the Consumer 
Confidence Report at the option of the water system. Violations 
requiring a Tier 3 notice are principally monitoring and reporting 
violations.
1. What Are the Requirements of This Rule?
    a. GWR violations requiring a Tier 1 notice. A Tier 1 notice is 
required if a GWS has a ground water source sample collected under 
Sec.  141.402(a) or Sec.  141.402(b) that is positive for one of the 
three fecal indicators that are discussed in Section IV.B and is not 
invalidated by the State.
    b. GWR violations requiring a Tier 2 notice. A Tier 2 notice is 
required if:
     A GWS with a significant deficiency or with fecal 
contamination in the ground water source fails to take corrective 
action in accordance with the treatment technique requirements in Sec.  
141.403(a);
     A GWS fails to comply with a State-approved schedule and 
plan, including State-specified interim measures, to correct a 
significant deficiency and/or eliminate fecal contamination in a ground 
water source at any time after State approval or State direction 
pursuant to Sec.  141.403(a)(2); or
     A GWS provides 4-log treatment of viruses but fails to 
maintain 4-log treatment, and the GWS does not restore 4-log treatment 
within four hours.
    c. GWR violations requiring a Tier 3 notice. A Tier 3 public notice 
is required for failure to conduct required ground water source 
monitoring, including source water monitoring when a system has a total 
coliform-positive sample in the distribution system (Sec.  
141.402(a)(2)), source water monitoring following a fecal indicator 
source water positive (Sec.  141.402(a)(3)), and, if required by the 
State, assessment source water monitoring (Sec.  141.402(b)). 
Additionally,

[[Page 65607]]

failure to conduct required compliance monitoring (Sec.  141.403(b)) 
requires a Tier 3 public notice.
    d. Special notice informing the public of significant deficiencies 
and fecal indicator-positives in ground water source samples. In 
addition to the public notice requirements of Sec.  141.202, Sec.  
141.203, and Sec.  141.204, this rule requires PWSs that use ground 
water sources to inform customers of an uncorrected significant 
deficiency and CWSs to inform customers of a fecal indicator-positive 
ground water source sample that is not invalidated by the State. Under 
this rule, the GWS must continue to inform the public annually until 
the significant deficiency is corrected and, in the case of CWSs, the 
fecal contamination in the ground water source is addressed under Sec.  
141.403(a). The State may also direct GWSs to inform the public of 
corrected significant deficiencies.
    The information provided to the public must include the following 
(as applicable to CWSs and NCWSs as described above): (1) The nature of 
the uncorrected significant deficiency or fecal contamination (for 
CWSs), if the source is known, and the date the significant deficiency 
was identified by the State or the date of the fecal indicator-positive 
ground water source sample (for CWSs); (2) for CWSs, if the fecal 
contamination in the ground water source has been addressed under Sec.  
141.403(a) and the date of elimination; (3) the State-approved plan and 
schedule for correction including interim measures, progress to date, 
and any interim measures completed, for any significant deficiency and 
for CWSs, fecal contamination in the ground water source that has not 
been addressed under Sec.  141.403(a); (4) for CWSs, a description of 
the potential health effects using the health effects language of Sec.  
141.153, Appendix A to subpart O, if the system receives notice of a 
fecal indicator-positive ground water source sample that is not 
invalidated by the State; and (5) if directed by the State, 
notification of corrected deficiencies and how and when they were 
corrected.
    To satisfy these special notification requirements, the GWR 
requires a CWS to inform the public served by the water system in the 
CCR. A NCWS must inform the public served by the water system in a 
manner approved by the State (e.g., posting in conspicuous places in 
the area served by the water system for a period of time or 
distributing information directly to the public served by the water 
system) within 12 months of being notified of a significant deficiency. 
Systems must continue to inform the public annually until the 
significant deficiency is corrected and, in the case of CWSs, fecal 
contamination in the ground water source is addressed in accordance 
with Sec.  141.403(a). If a significant deficiency is corrected before 
the next CCR is issued (for CWSs) or within 12 months (for non-CWSs), 
public notification is not required unless directed by the State.

      Table IV-4.--Summary of GWR Public Notification Requirements
------------------------------------------------------------------------
 Systems must comply with the following
  notification requirements when . . .              Reference
------------------------------------------------------------------------
                       Tier 1 Public Notification
------------------------------------------------------------------------
Triggered source water monitoring        Sec.   141.402(g).
 sample or assessment source water
 monitoring sample is positive for E.
 coli, enterococci, or coliphage (and
 is not invalidated).
------------------------------------------------------------------------
                       Tier 2 Public Notification
------------------------------------------------------------------------
A system fails to take corrective        Sec.   141.404(d).
 action following:
    [dec221] State direction to take
     corrective action for a fecal
     indicator-positive sample,
    [dec221] Receipt of laboratory
     notice of fecal indicator-positive
     ground water source sample as a
     result of triggered source water
     monitoring under Sec.
     141.402(a)(3), or
    [dec221] Receipt of State written
     notice of significant deficiency.
A system fails to comply with a State-   Sec.   141.404(d).
 approved schedule and plan (including
 interim measures) related to
 correcting a significant deficiency
 and/or eliminating fecal contamination
 in a ground water source.
A system that elects to provide such     Sec.   141.404(d).
 treatment in lieu of triggered source
 water monitoring fails to maintain 4-
 log treatment of viruses [NOTE: There
 is no violation and public
 notification required if the system
 restores 4-log treatment within four
 hours.].
------------------------------------------------------------------------
                       Tier 3 Public Notification
------------------------------------------------------------------------
A system fails to conduct triggered      Sec.   141.403(d).
 source water monitoring or assessment
 source water monitoring.
A system fails to conduct monitoring to  Sec.   141.403(d).
 demonstrate compliance with 4-log
 treatment requirement.
------------------------------------------------------------------------

[[Page 65608]]

                    Special Notification Requirements
------------------------------------------------------------------------
CWSs:                                    Notice must include:
System has an uncorrected significant    --nature of significant
 deficiency (or corrected significant     deficiency or ground water
 deficiency if directed by the State)     fecal contamination, and date.
 or a source water fecal indicator-      --if the fecal contamination
 positive sample. System must repeat      has been addressed under Sec.
 notice annually until significant         141.403(a), and date.
 deficiency corrected or fecal           --State-approved plan and
 contamination addressed in accordance    schedule, including interim
 with Sec.   141.403(1).                  measures completed (if process
[dec221] Provide notice as part of CCR.   ongoing).
[dec221] If significant deficiency is    --required fecal indicator-
 corrected before the next CCR,           positive language at:
 notification is not required unless     --Sec.   141.403(a)(7)(i).
 directed by the State.
NCWSs:                                   Notice must include:
System has an uncorrected significant    --nature of significant
 deficiency (or corrected significant     deficiency and date.
 deficiency if directed by the State).   --State-approved plan and
 System must repeat notice annually       schedule, including interim
 until significant deficiency             measures completed (if process
 corrected.                               ongoing).
[dec221] Provide notice in manner        --Sec.   141.403(a)(7)(ii).
 approved by the State for significant
 deficiencies (e.g., posting in
 conspicuous places in service area or
 direct distribution of information to
 public served).
[dec221] If significant deficiency is
 corrected within 12 months,
 notification is not required unless
 directed by the State.
------------------------------------------------------------------------

2. What Is EPA's Rationale for the Public Notice Requirements?
    EPA believes that to provide adequate public health protection from 
fecally contaminated ground water, the public must be informed of both 
existing and potential significant problems. EPA recognizes that 
immediate public notification is key to providing effective 
communication when there is an imminent public health risk. In the 
proposed rule, EPA considered requiring Tier 1 notice for all 
violations. The final GWR, however, requires Tier 1 notice only when a 
ground water source sample tests positive for one of the three fecal 
indicators that are discussed in Section IV.B. The presence of a fecal 
indicator in a ground water source sample means that fecal 
contamination is likely to reach consumers and may have significant 
potential for serious adverse health effects from a short-term 
exposure. Other violations of this rule require Tier 2 or Tier 3 
notice, depending on the nature of the violation and potential for 
adverse health effects.
    The Agency believes that it is important for the public to be 
informed when systems are unable to comply with the GWR requirements 
that are established to protect public health. EPA's intent is for the 
public to be informed within an appropriate time frame without 
unnecessary alarm. Under the final GWR, the following treatment 
technique violations have been changed from Tier 1 to Tier 2 notice:
     Failure to correct a significant deficiency and/or 
eliminate fecal contamination in a ground water source;
     Failure to be in compliance with a corrective action 
schedule and plan within 120 days or to comply with the plan and 
schedule after State approval; and
     Failure to restore 4-log treatment of viruses within four 
hours.
    EPA believes that these violations require Tier 2 notice because of 
the potential for serious adverse health effects from fecal 
contamination if treatment technique requirements are not met. Failure 
to conduct ground water source monitoring or compliance monitoring 
under this rule requires a Tier 3 notice public notice. EPA believes 
that the public notification requirements of this rule are protective 
of public health by providing timely and appropriate public 
notification of violations and situations that may affect public 
health.
    Public right-to-know was a key tenet of the 1996 Amendments to the 
SDWA. The final GWR requirements allow the public to become involved in 
any decision-making process for corrective actions taken by the GWS and 
provide information for individual health decisions.
    Consistent with the requirements for the Consumer Confidence Report 
(CCR) to include all detected regulated contaminants, the special 
public information requirements of the GWR require CWSs to include 
information on any fecal contamination of its ground water sources. In 
addition to addressing the requirements for CCRs, EPA believes this 
notice is important in informing individual health decisions. Use of 
the existing CCR public information process for CWSs minimizes the 
burden on CWSs. EPA believes that the Tier 1 notice requirements for 
NCWSs are adequate and appropriate for informing the public of fecal 
contamination of ground water sources and providing information for 
individual health decisions so no additional notice is required for 
fecal contamination at NCWSs.
    EPA also believes that the public must be fully informed of 
uncorrected significant deficiencies because such deficiencies may 
affect their water supply and pose a health risk. In addition, EPA 
believes that this notification of uncorrected significant deficiencies 
will provide an additional incentive to water systems for rapid 
correction of significant deficiencies. To minimize the burden on CWS 
the final GWR requires them to use the CCR to report uncorrected 
significant deficiencies. Because the public served by NCWSs do not 
receive CCRs, this rule requires States to determine the appropriate 
method(s) (e.g., posting in conspicuous places, hand delivery) for 
NCWSs to inform the public of uncorrected significant deficiencies. In 
order to provide the public with complete information on their water 
system, GWSs are required to continue informing the public of 
uncorrected significant deficiencies until corrective actions are 
completed.
    Under the Tier 1 public notice requirements, NCWSs must provide 
public notice of a fecal indicator-positive source water in a form and

[[Page 65609]]

manner designed to reach transient and non-transient users of the PWS. 
This could include conspicuous posting, hand delivery or other methods 
approved by the State. This notice would continue until fecal 
contamination is corrected.
    EPA believes that there may be circumstances when the public should 
be informed of significant deficiencies that have been corrected and 
that States are in the best position to make a decision to require 
notification of the public. These circumstances include significant 
deficiencies that, although corrected, presented a public health risk 
prior to correction; significant deficiencies that were uncorrected for 
long periods of time; and significant deficiencies at systems with 
persistent significant deficiency issues. Notification in these 
circumstances allows the public served by a PWS to become involved in 
any decision-making processes for management, operation, and 
maintenance of the water system and it also provides information for 
individual health decisions. Notification of corrected significant 
deficiencies that had been uncorrected for long periods provides 
closure for the public that has been notified previously of the 
uncorrected significant deficiency. In addition, notification of 
corrected significant deficiencies allows a community to better 
evaluate the management of their system because they will have complete 
information on significant deficiencies at their system.
3. What Were the Key Issues Raised by Commenters on the Proposed GWR 
Public Notification Requirements?
    a. Treatment technique violations. In the proposed GWR, EPA 
considered Tier 1 notice for the following: (1) Detection of a fecal 
indicator-positive in a ground water source sample that is not 
invalidated by the State; (2) failure to correct a State-identified 
significant deficiency or source water fecal contamination within 90 
days or failure to obtain, within the same 90 days, State approval of a 
plan and schedule for meeting the treatment technique requirement; and 
(3) failure to perform source water monitoring. In general, commenters 
responded that Tier 1 notice for failure to correct a significant 
deficiency within 90 days or in accordance with the State-approved time 
frame is not warranted. Other commenters stated that only a confirmed 
fecal indicator-positive sample in the source water of a system that 
does not provide 4-log treatment of viruses should require Tier 1 
notice. A few commenters supported EPA's proposed treatment technique 
violation Tier 1 notice. However, most commenters suggested that Tier 2 
notice, rather than Tier 1 notice, is appropriate for treatment 
technique violations.
    EPA agrees that the public health risk associated with documented 
fecal contamination warrants a Tier 1 notice. EPA agrees that not all 
failures to correct a significant deficiency warrant a Tier 1 notice, 
since not all significant deficiencies will result in an imminent 
danger to public health. For the specific case of a failure to correct 
source water fecal contamination, the existing Tier 1 notification 
requirements allow States to continue to require public notification 
for as long as fecal contamination is present. The final GWR also 
requires that CWSs and NCWSs include notice of uncorrected significant 
deficiencies and that CWSs provide notice of source water fecal 
contamination for as long as significant deficiencies or fecal 
contamination remain uncorrected. CWSs must include this in the CCR, 
and NCWSs will use a form of notification approved by the State.
    b. Monitoring violations. Some commenters responded that failure to 
perform any source water monitoring should not require Tier 1 notice 
but rather Tier 2 notice. Other commenters stated that failure to 
conduct triggered source water monitoring should require a Tier 1 
notice, while failure to conduct assessment source water monitoring 
should require a Tier 2 notice. In general, commenters believed that 
requiring a Tier 1 notice for failure to collect a source water sample 
would unnecessarily alarm the public. Other commenters supported a Tier 
3 notice for failure to conduct source water monitoring so that the GWR 
would be consistent with other monitoring violation notification 
requirements of Sec.  141.204.
    EPA agrees that failure to collect source water samples or conduct 
compliance monitoring may not warrant a Tier 1 notification since lack 
of monitoring data does not indicate there is an imminent danger to 
public health and such notification could unnecessarily alarm the 
public. Consistent with Sec.  141.204, the final GWR requires a Tier 3 
notice for violations of the monitoring requirements, failure to 
collect ground water source samples, or failure to conduct compliance 
monitoring. EPA notes that States continue to have the authority to 
require a Tier 2 notice for monitoring violations if the State 
determines that this level of notification is warranted.
    Some commenters stated that since the TCR governs the quality of 
water provided to a system's customers, it is inappropriate to require 
public notice for failure to conduct source water sampling under the 
GWR. EPA disagrees with the comment and believes that it is appropriate 
to establish public notification requirements for GWSs that fail to 
monitor for fecal contamination in their source water because fecal 
contamination can be a significant health risk. EPA recognizes that the 
TCR protects against distribution system contamination; however, as 
part of the GWR risk-targeting strategy, the Agency believes that 
source water monitoring is an integral component in both assessing 
potential fecal contamination in the source water and eliminating this 
contamination before it reaches the distribution systems.
    c. Special notice informing the public of significant deficiencies 
or a fecal indicator-positive ground water sample. EPA requested 
comment on practicable approaches to involve the public in working with 
their systems to address the results of sanitary surveys or detection 
of source water fecal contamination. Some commenters suggested 
publishing the results in a system's CCR, reviewing the results at a 
public meeting, or posting the results of surveys in a public place for 
NCWSs. Others supported notifying the public that the results were 
available and how those results could be obtained. Some commenters 
noted that significant deficiencies or source water fecal contamination 
would be corrected rapidly and that involving or informing the public 
after the correction might not be useful.
    EPA believes that adequate opportunities exist for customers to 
obtain general information on the sanitary survey of their water 
supplier since the complete sanitary survey report is available from 
both the State and the PWS upon request. EPA believes that the public 
served by a GWS should be made aware of uncorrected significant 
deficiencies and source water fecal contamination. The final GWR uses 
an existing public information process, the CCR, to inform consumers of 
water from CWSs of uncorrected significant deficiencies found during 
sanitary surveys or of source water fecal contamination. NCWSs will use 
a State approved process such as continuous posting in conspicuous 
places and hand-delivered notices to inform consumers of uncorrected 
significant deficiencies. NCWSs will use the State-approved Tier 1 
notification process to notify the public of fecal source water 
contamination. No additional notice of fecal contamination is required 
for

[[Page 65610]]

NCWSs. If directed by the State, GWSs must also provide notification of 
corrected significant deficiencies.

E. What Are the Reporting and Recordkeeping Requirements for Systems?

    The GWR establishes new reporting and recordkeeping requirements 
for GWSs that are necessary to ensure that systems continue to meet the 
requirements of the rule and that States have the information needed to 
perform their oversight responsibilities.
    Specifically, the GWR reporting requirements ensure that States are 
aware of any failure to provide an adequate level of treatment, 
completed corrective actions, and system decisions that triggered 
source water monitoring is not necessary based on State criteria.
    The recordkeeping requirements of this rule ensure that information 
is available to States during sanitary surveys or other instances to 
verify that systems are complying with the requirements of this rule 
for corrective actions, notice to the public, decisions not to conduct 
triggered source water monitoring, and invalidation of fecal indicator-
positive ground water source samples.
    This section discusses the new requirements and the key issues 
raised by commenters.
1. Reporting Requirements
    In addition to the reporting requirements of Sec.  141.31, a GWS 
must provide the following information to the State (see Sec.  
141.405(a)): (1) A GWS conducting compliance monitoring must notify the 
State as soon as possible, but in no case later than the end of the 
next business day, any time the system fails to meet any State-
specified compliance requirements including, but not limited to, 
minimum residual disinfectant concentration, membrane operating 
criteria or membrane integrity, and alternative treatment operating 
criteria, if operation in accordance with the criteria or requirements 
is not restored within four hours; (2) a GWS must notify the State 
within 30 days after completing any corrective action for GWSs with 
significant deficiencies or source water fecal contamination; and (3) 
if a GWS is subject to source water monitoring requirements but is not 
required to monitor its source because it determines using State 
criteria that a total coliform-positive samples is related to 
distribution systems conditions pursuant to Sec.  141.402(a)(5)(ii), 
then the GWS must provide documentation that it met the State criteria 
to the State within 30 days of the total coliform-positive sample.
2. Recordkeeping Requirements
    In addition to the reporting requirements of Sec.  141.31, a GWS 
must maintain the following information in its records (see Sec.  
141.405(b)): (1) Documentation of corrective actions; (2) documentation 
of notice to the public of (a) An uncorrected significant deficiency, 
or (b) a fecal indicator-positive ground water source sample that is 
not invalidated; (3) records of decisions where either (a) The State 
determines, and documents in writing, that the cause of a total 
coliform-positive sample collected under routine coliform sampling is 
directly related to the distribution system, or (b) the GWS determines, 
according to State criteria, that the cause of a total coliform-
positive sample collected under routine coliform sampling directly 
relates to the distribution system; (4) for consecutive systems, 
documentation of notification to the wholesale system(s) of total 
coliform-positive samples that are not invalidated; and (5) for systems 
required to perform compliance monitoring (a) Records of the lowest 
daily residual disinfectant value and records of the date and duration 
of any failure to maintain the State-prescribed minimum residual for a 
period of more than four hours, and (b) records of State-specified 
compliance requirements for membrane filtration and of parameters 
specified by the State for State-approved alternative treatment and 
records of the date and duration of any failure to meet the membrane 
operating, membrane integrity, or alternative treatment operating 
requirements for more than four hours.
3. What Were the Key Issues Raised by Commenters on the Proposed GWR 
Reporting and Recordkeeping Requirements for Systems?
    Most commenters agreed with the system recordkeeping and reporting 
requirements in the proposed rule and that recordkeeping and submittals 
are appropriate for systems that disinfect. Commenters mentioned that 
these requirements should be consistent with those required under other 
regulations, such as the TCR or the Stage 1 DBPR.
    EPA agrees that the recordkeeping and reporting for systems under 
this rule are appropriate and ensure that information is available to 
the State in performing their oversight responsibilities. The records 
must be available for review during sanitary surveys and investigations 
of treatment technique failures. EPA believes that the recordkeeping 
and reporting requirements for systems under this rule are consistent 
with those required under other regulations.
    Commenters also mentioned that systems should keep documentation of 
how the system operators determined the proper disinfectant 
concentration. EPA notes that this is a recordkeeping requirement for 
the State and is required under this rule.
    Others commenters stated that recordkeeping requirements in the 
proposed rule were unrealistic and excessive for extremely small 
systems (such as many NCWSs). EPA notes that many of the recordkeeping 
requirements for systems under this rule are associated with corrective 
actions and compliance monitoring, and that only systems with 
significant deficiencies, source water contamination, or source water 
treatment would be required to keep these records. The records must be 
available for review during sanitary surveys and investigations of 
treatment technique failures.

F. What Are the Special Primacy, Reporting, and Recordkeeping 
Requirements for States?

    The GWR establishes new special primacy, reporting, and 
recordkeeping requirements for States.
    With regards to special primacy requirements, 40 CFR part 142, 
National Primary Drinking Water Regulations Implementation, sets out 
the specific program implementation requirements for States to obtain 
primacy for the Public Water Supply Supervision program as authorized 
under SDWA section 1413. In addition to adopting basic primacy 
requirements, States may be required to adopt special primacy 
provisions pertaining to specific regulations where implementation of 
the rule involves activities beyond general primacy provisions. States 
must include these regulation-specific provisions in an application for 
approval of their program revision.
    The special primacy conditions of this rule (Sec.  142.16(o)) 
ensure (1) That States have the legal authority to require correction 
of significant deficiencies and/or source water fecal contamination, as 
well as the authority to require source water monitoring, (2) that 
States adopt and implement adequate procedures for sanitary surveys, 
and that (3) States develop criteria for source water monitoring and 
treatment technique requirements.
    With regards to reporting and recordkeeping, the SDWA establishes 
requirements that a State or eligible Indian Tribe must meet to assume 
and maintain primacy for its PWSs. Among others, these requirements 
include

[[Page 65611]]

keeping records and making reports available on activities that EPA 
requires by regulation.
    The reporting requirements of this rule ensure that EPA is notified 
when the most recent sanitary survey was completed, the date a system 
completed corrective action, and of systems providing at least 4-log 
treatment of viruses.
    The recordkeeping requirements of this rule ensure that States 
maintain various records to determine compliance with this rule.
    This section discusses these new requirements and the key issues 
raised by commenters on these requirements.
1. Primacy Requirements
    The SDWA established requirements that a State or eligible Indian 
Tribe must meet to assume and maintain primary enforcement 
responsibility (i.e., primacy). These requirements include the 
following:
     Adopting drinking water regulations that are no less 
stringent than Federal drinking water regulations;
     Adopting and implementing adequate procedures for 
enforcement;
     Keeping records on EPA-regulated activities and making 
records available;
     Issuing variances and exemptions (if allowed by the State) 
under conditions no less stringent than allowed under the SDWA; and
     Adopting and being capable of implementing an adequate 
plan for the provision of safe drinking water under emergency 
situations.
    To implement this rule, the State is required to adopt the 
following revisions to 40 CFR part 141:
     Sec.  141.21--Coliform sampling.
     Sec.  141.28--Certified laboratories.
     Sec.  141.153--Content of the reports.
     Sec.  141.202--Tier 1 Public Notice--Form, manner, and 
frequency of notice.
     Sec.  141.203--Tier 2 Public Notice--Form, manner, and 
frequency of notice.
     Sec.  141.204--Tier 3 Public Notice--Form, manner, and 
frequency of notice.
     Subpart O--Regulated contaminants.
     Subpart Q--Public Notification of Drinking Water 
Violations, Appendix A, NPDWR Violations and Other Situations Requiring 
Public Notice.
     Subpart Q--Public Notification of Drinking Water 
Violations, Appendix B, Standard Health Effects Language for Public 
Notification.
     Subpart Q--Public Notification of Drinking Water 
Violations, Appendix C, List of Acronyms Used in Public Notification 
Regulation.
     Subpart S--Ground Water Rule.
    In addition to adopting the basic primacy requirements specified in 
40 CFR part 142, States are required to address special primacy 
conditions pertaining to specific requirements where implementation of 
the rule involves activities beyond general primacy provisions. The 
State must include these regulation-specific provisions in an 
application for approval of their program revision. Under this rule, 
the special primacy conditions are in the following four categories: 
Legal Authority, Sanitary Surveys, Source Water Microbial Monitoring, 
and Treatment Technique Requirements.
    The application for approval of a State program revision that will 
adopt 40 CFR part 141, subpart S, must contain a description of how the 
State will accomplish these four program requirements.
    a. Legal authority. The application for primacy must demonstrate 
that the State has: (i) The authority contained in statute or 
regulation to ensure that GWSs take the appropriate corrective actions, 
including interim measures, if necessary, needed to address significant 
deficiencies; (ii) the authority contained in statute or regulation to 
ensure that GWSs conduct source water monitoring; (iii) the authority 
contained in statute or regulation to ensure that GWSs take the 
appropriate corrective actions, including interim measures, if 
necessary, to address any source water fecal contamination identified 
during source water monitoring; and (iv) the authority contained in 
statute or regulation to ensure that GWSs consult with the State 
regarding corrective action(s).
    b. State practices or procedures for sanitary surveys. In addition 
to the general requirements for sanitary surveys, a primacy application 
must describe how the State will implement a sanitary survey program 
and include an evaluation of the following eight sanitary survey 
components: source; treatment; distribution system; finished water 
storage; pumps, pump facilities, and controls; monitoring, reporting, 
and data verification; system management and operation; and operator 
compliance with State requirements.
    The State must conduct sanitary surveys that address the eight 
sanitary survey components no less frequently than every three years 
for CWSs and every five years for NCWS.
    The State may conduct sanitary surveys once every five years for 
CWSs if the system meets performance criteria (see Section IV.A.1). In 
its primacy application, the State must describe how it will determine 
whether a CWS has an outstanding performance record.
    The State must define and describe in its primacy application at 
least one specific significant deficiency in each of the eight sanitary 
survey elements.
    As a condition of primacy, the State must provide GWSs with written 
notice describing any significant deficiencies no later than 30 days 
after the State identifies the significant deficiency. The notice may 
specify corrective actions and deadlines for completion of corrective 
actions.
    c. State practices or procedures for source water microbial 
monitoring. The State's primacy application must include a description 
of the following: (i) The criteria the State will use for extending the 
24-hour time limit for a system to collect a ground water source sample 
to comply with the source water monitoring requirements; (ii) the 
criteria the State or GWS will use to determine that the cause of a 
total coliform-positive sample is directly related to the distribution 
system; (iii) the criteria the State will use for determining whether 
to invalidate a fecal indicator-positive ground water source sample; 
and (iv) the criteria the State will use to allow systems to conduct 
source water microbial monitoring at a location after treatment.
    d. State practices or procedures for treatment technique 
requirements. As a condition of primacy, the State must verify within 
30 days after the GWS has reported to the State that it has completed 
corrective action that significant deficiencies or source water fecal 
contamination have been addressed either through written confirmation 
from GWSs or a site visit by the State. A GWS's written notice may 
serve as this verification. The State's primacy application must 
include the following: (i) Notification methods that the States will 
require NCWSs to use to inform the public of uncorrected significant 
deficiencies; (ii) the process the State will use to confirm that a GWS 
achieves at least a 4-log treatment of viruses; (iii) the process the 
State will use to determine the minimum residual disinfectant 
concentration; (iv) the State-approved alternative technologies to 
achieve at least 4-log treatment of viruses; (v) the monitoring and 
compliance requirements the State will require for GWSs treating to at 
least 4-log treatment of viruses; (vi) the monitoring, compliance and 
membrane integrity testing requirements the State will require to 
demonstrate virus removal for GWSs using membrane filtration 
technologies; and (vii) the criteria, including public health-based 
considerations and incorporating on-site investigations and source 
water

[[Page 65612]]

monitoring results, the State will use to determine if a GWS may 
discontinue 4-log treatment of viruses.
2. Reporting Requirements
    States are required to report violations, variance and exemption 
status, and enforcement actions to EPA according to the provisions of 
Sec.  142.15. The final GWR adds the following three reporting 
requirements to these provisions (Sec.  142.15(c)(7)): (i) The month 
and year in which the most recent sanitary survey was completed, or for 
a State that uses a phased review process, the date that the last 
element of the applicable eight elements was evaluated for each GWS, 
(ii) the date the GWS completed corrective action, and (iii) all GWSs 
providing at least 4-log treatment of viruses for a ground water 
source.
3. Recordkeeping Requirements
    The regulation at Sec.  142.14 requires States with primacy to keep 
various records. This rule requires States to keep the following 
additional records: (i) Records of written notices of significant 
deficiencies; (ii) Records of corrective action plans, schedule 
approvals, and State-specified interim measures; (iii) Records of 
confirmations that a significant deficiency has been corrected and/or 
the fecal contamination in the ground water source has been addressed; 
(iv) Records of State determinations and records of ground water 
system's documentation for not conducting triggered source water 
monitoring; (v) Records of invalidations of fecal indicator-positive 
ground water source samples; (vi) Records of State approvals of source 
water monitoring plans; (vii) Records of notices of the minimum 
residual disinfection concentrations (when using chemical disinfection) 
needed to achieve at least 4-log virus inactivation before or at the 
first customer; (viii) Records of notices of the State-specified 
monitoring and compliance requirements (when using membrane filtration 
or alternative treatment) needed to achieve at least 4-log treatment of 
viruses (using inactivation, removal, or a State-approved combination 
of 4-log inactivation and removal) before or at the first customer; 
(ix) Records of written notices from the GWS that it provides at least 
4-log treatment of viruses (using inactivation, removal, or a State-
approved combination of 4-log virus inactivation and removal) before or 
at the first customer for each ground water source; and (x) Records of 
written determinations that the GWS may discontinue 4-log treatment of 
viruses (using inactivation, removal, or a State-approved combination 
of 4-log inactivation and removal).
4. What Were the Key Issues Raised by Commenters on the Proposed GWR 
Special Primacy, Reporting, and Recordkeeping Requirements for States?
    Many commenters responded to this request for comment and generally 
indicated that the requirements should be simplified and that a greater 
level of flexibility be afforded to the States.
    Commenters questioned why the States need to identify their 
approach and rationale for determining the fecal indicators to be used 
and commented that States, at their discretion, should be able to use 
any EPA-approved method. Commenters also felt that States should have 
the latitude to allow different indicators if changes in technologies 
or laboratory resources prompt an amendment. EPA agrees with these 
comments, and this rule does not include a requirement regarding 
selection of a fecal indicator.
    Some commenters believe that the GWR should provide specific 
information on how GWSs can achieve 4-log removal of viruses and how 
States should evaluate treatment techniques to assure compliance with 
the rule. In particular, the commenters wanted more information and 
guidance on how States and GWSs would determine what disinfectant 
residual level or operational parameters (in the case of membrane 
filtration or alternative treatment technologies, such as UV) GWSs 
would have to maintain to ensure that the GWS is achieving 4-log 
treatment of viruses. The commenters indicated that describing in their 
primacy package the approach they will use in determining which 
specific treatment option is appropriate in a given circumstance will 
be an arduous task.
    EPA recognizes that selection and approval of a treatment technique 
option is system-specific. This rule does not require States to 
describe in their primacy package the approach they will use in 
determining which specific treatment option is appropriate in a given 
circumstance. This rule does require the States to describe any State-
approved alternative technologies that GWSs may use to meet the 
treatment technique requirements. With regard to specific treatment 
techniques, EPA has recently issued the Membrane Filtration Guidance 
Manual (USEPA, 2005a) and is developing an ultraviolet disinfection 
guidance manual. EPA intends to develop a GWR Corrective Action 
guidance for further information regarding corrective actions and 
treatment techniques for GWSs.
    Commenters indicated that a State should not have to describe ``how 
it will consult'' with water suppliers regarding treatment 
requirements. EPA believes that the process requiring PWS consultation 
with the State prior to implementing corrective action is important in 
ensuring that appropriate corrections occur. EPA recognizes that States 
have a long history of consulting with water systems, so the Agency 
removed this provision from the special primacy requirements in this 
rule. Instead, the GWR requires that States identify the authority that 
they have to ensure consultation, which ensures that corrective actions 
occur, as necessary.

G. Variances and Exemptions

    Section 1415 of the SDWA allows States to grant variances from 
NPDWRs under certain conditions; section 1416 establishes the 
conditions under which States may grant exemptions to MCL or treatment 
technique requirements. These conditions and EPA's view on their 
applicability to the GWR are summarized as follows:
1. Variances
    Section 1415 of the SDWA specifies two provisions under which 
general variances to treatment technique requirements may be granted:
    (1) A State that has primacy may grant a variance to a PWS from any 
requirement to use a specified treatment technique for a contaminant if 
the PWS demonstrates to the satisfaction of the State that the 
treatment technique is not necessary to protect public health because 
of the nature of the PWS's raw water source. EPA may prescribe 
monitoring and other requirements as conditions of the variance 
(section 1415(a)(1)(B)).
    (2) EPA may grant a variance from any treatment technique 
requirement upon a showing by any person that an alternative treatment 
technique not included in such requirement is at least as efficient in 
lowering the level of the contaminant (section 1415(a)(3)).
    EPA does not believe that the variance provision under the SDWA at 
1415(a)(1)(B) is applicable to GWSs under this rule. As discussed 
above, the regulation employs a targeted approach whereby corrective 
action is required only for those systems that have the most risk `` 
those systems that have found fecal contamination in their source water 
as indicated by source water monitoring, or have been found to be 
susceptible to contamination as indicated by a significant deficiency 
from a sanitary survey. Thus, the treatment technique requirements 
account for the nature of the PWS raw

[[Page 65613]]

water source. The GWR does not require the use of disinfection, nor 
does it compel the system to address the raw water source if, for 
example, an alternate source of drinking water is available.
    With respect to the variances authorized under 1415(a)(3), EPA 
notes that this provision is unlikely to be used because the four 
treatment techniques provided in the GWR cover a broad range of options 
and States can approve any alternative treatment technologies. Given 
this broad range of treatment technique options, it is unlikely that a 
system could demonstrate to EPA that an alternative treatment technique 
not included in the regulation is at least as efficient in lowering the 
level of the contaminant of concern.
    Section 1415(e) of the SDWA describes small PWS variances, but 
these cannot be granted for a treatment technique for a microbial 
contaminant. Hence, small PWS variances are not allowed for the GWR.
2. Exemptions
    Under SDWA section 1416(a), a State may exempt any PWS from a 
treatment technique requirement upon a finding that (1) due to 
compelling factors (which may include economic factors such as 
qualification of the PWS as serving a disadvantaged community), the PWS 
is unable to comply with the requirement or implement measures to 
develop an alternative source of water supply; (2) the PWS was in 
operation on the effective date of the treatment technique requirement, 
or for a PWS that was not in operation by that date, no reasonable 
alternative source of drinking water is available to the new PWS; (3) 
the exemption will not result in an unreasonable risk to health; and 
(4) management or restructuring changes (or both) cannot reasonably 
result in compliance with the Act or improve the quality of drinking 
water.
    EPA believes that granting an exemption to the treatment 
requirements of the GWR would result in an unreasonable risk to health. 
As described in section III.C, microbial contamination causes acute 
health effects, which may be severe in sensitive subpopulations. 
Moreover, the additional treatment requirements of the GWR are targeted 
to PWSs with the highest degree of risk. Due to these factors, EPA does 
not support the granting exemptions from the GWR.

V. Explanation of Extent of GWR

A. Mixed Systems

    This rule applies to PWSs (CWSs and NCWSs) that use ground water in 
whole or in part (except GWUDI systems), unless all ground water is 
commingled with surface water before treatment at the surface water 
treatment plant is applied, in which case surface water treatment 
regulations apply. This means that the treatment technique requirements 
of the GWR for significant deficiencies apply to any system using both 
ground water and surface water that has a significant deficiency 
identified past the point of surface water treatment, unless the State 
determines that the significant deficiency is in a portion of the 
system served solely by surface water. EPA believes that the same level 
of public health protection provided by this rule to persons served 
solely by ground water must be provided to persons served by ground 
water supplies in mixed systems.
    EPA received comments regarding the applicability of the proposed 
GWR to systems that serve both ground water and surface water. 
Commenters noted that the requirements for these ``mixed systems'' were 
not explicit for the individual rule components such as sanitary 
surveys and triggered source water monitoring. For example, commenters 
specifically noted that the proposed GWR did not address how to conduct 
the triggered source water monitoring requirement after a total 
coliform-positive under the TCR was detected in systems where ground 
water and surface water are blended in the distribution system.
    EPA has included more explicit regulatory language that describes 
how ``mixed systems'' must comply with individual components of this 
rule to assist PWSs in understanding and implementing the GWR 
provisions. There are approximately 3,700 mixed systems in the U.S. 
This rule explicitly addresses general applicability and the 
applicability of specific GWR components to mixed systems. The 
complexity and variety of configurations and operations in these mixed 
systems do not allow for all the possible scenarios to be addressed 
within a regulatory framework, so States will have the discretion to 
make a site-specific determination whether a significant deficiency is 
in a portion of the system served solely by surface water.
    EPA will provide further information through implementation 
guidance and other non-regulatory approaches to assist States and water 
systems in meeting the intent of this rule, to target GWSs that are at 
risk of fecal contamination and to require these systems to take 
corrective action to protect public health. In some cases, it may be 
possible to identify customers or portions of the distribution system 
in mixed systems served solely by surface water or ground water. In 
other cases, it may not be possible or may be transitory due to complex 
and/or variable system hydraulic conditions.

B. Cross-Connection Control

    EPA is concerned about fecal contamination entering distribution 
systems; however, cross-connection control requirements are not a part 
of this rule, though the proposal contained cross-connection 
consideration. The Stage 2 Microbial and Disinfection Byproducts 
Federal Advisory Committee's Agreement in Principle (65 FR 83015, 
December 2000) (USEPA, 2000b) states that cross-connections and 
backflow in distribution systems represent a significant public health 
risk and that EPA should initiate a process to address cross-connection 
control and backflow prevention requirements as part of the six-year 
review of the TCR. EPA has published its intent to consider such 
requirements as part of the revisions to the TCR (67 FR 19030, April 
17, 2002) (USEPA, 2002b).

VI. Implementation

    This section describes the regulations and other procedures and 
policies that States must adopt, as well as the requirements that 
public GWSs would have to meet to implement this rule. Also discussed 
are the compliance deadlines for these requirements.
    States must continue to meet all other conditions of primacy at 40 
CFR part 142. Section 1413(a)(1) of the 1996 SDWA Amendments provides 
two years (plus more time if the Region approves) after promulgation of 
the final GWR for the State to adopt drinking water regulations that 
are no less stringent than the final GWR in order to obtain primacy for 
the GWR.
    GWSs must continue to meet all other applicable requirements of 40 
CFR part 141. The SDWA as amended in 1996 (see section 1412(b)(10)) 
provides three years after promulgation for compliance with new 
regulatory requirements. Accordingly, the GWR requirements that apply 
to the PWS directly, specifically the requirements found under subpart 
S of 40 CFR part 141 (source water monitoring, corrective actions and 
treatment technique requirements, compliance monitoring, recordkeeping 
and reporting, and public notice and public information), take effect 
three years after promulgation. The State may, in the case of an 
individual system, provide additional time of up to two years for 
capital improvements, if necessary, in accordance with the statute.

[[Page 65614]]

    This rule includes conditions of primacy at 40 CFR part 142 under 
which States will have until December 31, 2012 to complete the initial 
sanitary survey cycle for CWSs, except those meet performance criteria, 
and until December 31, 2014 to complete the initial sanitary survey 
cycle for all NCWSs and CWSs that meet performance criteria (refer to 
Section IV.A.1 for criteria). These sanitary survey implementation 
deadlines provide time for States to adopt the rule and obtain primacy 
(two to four years allowed by the SDWA at 1413(a)(1)). In addition, 
systems are given three years to comply with drinking water regulations 
by the SDWA at (1412(b)(10)). Finally, States need three to five years 
to complete the first cycle of sanitary surveys because there are many 
GWSs and States have limited resources.
    The GWR places the same sanitary survey frequency requirements on 
GWSs as is currently required of surface water systems under 40 CFR 
part 141 subpart H.
    GWSs must comply with all applicable requirements beginning 
December 1, 2009 unless otherwise noted.

VII. Economic Analysis (Health Risk Reduction and Cost Analysis)

    This section summarizes the Health Risk Reduction and Cost Analysis 
(HRRCA) in support of the final GWR. This analysis has been revised and 
updated from the HRRCA prepared for the proposal as required by section 
1412(b)(3)(C) of the SDWA. In addition, under Executive Order 12866, 
Regulatory Planning and Review, EPA must estimate the costs and 
benefits of this rule in an Economic Analysis (EA). EPA has prepared an 
EA (USEPA, 2006d) to comply with the requirements of this order and to 
update the SDWA HRRCA. The EA document for the GWR is available in the 
docket and is also published on the government's Web site http://www.regulations.gov
.

    The HRRCA consists of seven elements as follows: (1) Quantifiable 
and nonquantifiable health risk reduction benefits; (2) quantifiable 
and nonquantifiable health risk reduction benefits from reductions in 
co-occurring contaminants; (3) quantifiable and nonquantifiable costs 
that are likely to occur solely as a result of compliance; (4) 
incremental costs and benefits of rule alternatives; (5) effects of the 
contaminant on the general population and sensitive subpopulations 
including infants, children, pregnant women, elderly, and 
immunocompromised; (6) increased health risks that may occur as a 
result of compliance; and (7) other relevant factors such as 
uncertainties in the analysis. A summary of these elements is provided 
in this section of the preamble, and a complete discussion can be found 
in the GWR EA (USEPA, 2006d).
    Both the benefits and the costs discussed in this section are 
presented as annualized present values in 2003 dollars. This process 
allows comparison of cost and benefit streams that are variable over a 
given time period and differs from the GWR proposal (USEPA, 2000a), 
which only used an annual estimate. The time frame used for both 
benefit and cost comparisons in this rule is 25 years. This time 
interval accounts for early rule implementation activities (e.g., 
States adopting the criteria of the regulation) and the time for 
different types of compliance actions to be realized up through year 25 
following rule promulgation (e.g., identification and correction of 
sanitary survey deficiencies, identification of wells that are fecally 
contaminated and subsequent corrective action). The Agency uses social 
discount rates of both three percent and seven percent to calculate 
present values from the stream of benefits and costs and also to 
annualize the present value estimates. The GWR EA (USEPA, 2006d) also 
shows the undiscounted stream of both benefits and costs over the 25 
year time frame.
    The quantified benefits are calculated based only on endemic, acute 
disease illness, and death from some viral, but not bacterial, 
contamination of PWS wells. EPA was able to monetize only this subset 
of total benefits which were compared to the total costs of this rule. 
The total benefits, both quantified and nonquantified, are estimated 
using illness and death data as well as non-health benefits such as 
avoided costs (e.g., restaurant closures) due to outbreaks. 
Furthermore, the total health benefits are estimated based on a full 
range of health effects, including acute and chronic illness and 
endemic and epidemic disease from both bacteria and virus 
contamination. EPA believes that the quantified benefits for this rule 
underestimate reduction in risk because the Agency was only able to 
calculate a subset of the total benefits; peer reviewers of the GWR 
benefit analysis agree that the quantified benefits are biased low. The 
costs of the rule stem mostly from the sanitary survey and the 
correction of significant deficiencies as well as the triggered source 
water monitoring and corrective action provisions described earlier in 
this preamble.
    This section of the preamble includes 12 elements as follows: (A) 
Rationale for choosing a different alternative from the proposed 
alternative, (B) occurrence and risk analyses that support this rule, 
(C) both quantified and nonquantified benefits, (D) both quantified and 
nonquantified costs, (E) potential impact on households, (F) 
incremental costs and benefits, (G) benefits from simultaneous 
reduction of co-occurring contaminants, (H) increases in risk due to 
other contaminants, (I) effects on the general population and special 
subgroups, (J) uncertainties in risk, benefit, and cost estimates, (K) 
benefit/cost determination, and (L) major comments and responses. 
Section VII.F presents the benefits and costs for the four regulatory 
alternatives that were considered in this rule. Table VII-1 provides a 
summary of monetized benefits and costs for each GWR regulatory 
alternative.

                   Table VII-1.--Monetized Benefits and Costs for GWR Regulatory Alternatives
                                                [Millions, 2003$]
----------------------------------------------------------------------------------------------------------------
                                                         3% Discount rate                7% Discount rate
                                                 ---------------------------------------------------------------
                Rule alternative                                     5th-95th                        5th-95th
                                                       Mean         Percentiles        Mean         Percentiles
----------------------------------------------------------------------------------------------------------------
                                              National GWR Benefits
----------------------------------------------------------------------------------------------------------------
Enhanced COI:
    Risk-Targeted Approach......................           $19.7      $6.5-$45.4           $16.8      $5.5-$38.6
    Sanitary Survey.............................             3.6         0.9-9.3             2.9         0.7-7.5
    Multi-barrier Approach......................            21.3        7.1-48.7            18.2        6.0-41.6

[[Page 65615]]

    Across the Board Disinfection...............            70.2      18.3-177.0            61.9      16.1-156.3
Traditional COI:
    Risk-Targeted Approach......................            10.0        2.2-27.0             8.6        1.9-22.9
    Sanitary Survey.............................             1.9         0.3-5.5             1.5         0.2-4.5
    Multi-barrier Approach......................            10.8        2.5-28.9             9.3        2.1-24.8
    Across the Board Disinfection...............            35.5       6.5-102.4            31.5        5.7-90.8
----------------------------------------------------------------------------------------------------------------
                                               National GWR Costs
----------------------------------------------------------------------------------------------------------------
Risk-Targeted Approach..........................            61.8       45.2-81.4            62.3       46.1-81.6
Sanitary Survey.................................            15.3       11.8-19.2            15.3       11.9-19.0
Multi-barrier Approach..........................            67.9       49.4-89.5            69.4       51.0-90.6
Across the Board Disinfection...................           686.4     636.8-735.4           665.3     612.3-717.0
----------------------------------------------------------------------------------------------------------------

A. How Has the Final Rule Alternative Changed From the Proposed Rule 
Alternative?

    The primary elements of the GWR alternative that EPA proposed were 
sanitary surveys, triggered source water monitoring, hydrogeologic 
sensitivity analyses (HSAs), routine monitoring, corrective action, and 
compliance monitoring. This alternative was termed ``multi-barrier 
approach.'' After the proposal, EPA considered comments received as 
discussed in section II.C of this preamble. This review resulted in the 
Agency choosing a different final rule alternative, Alternative 2, or 
the ``risk-targeted approach.'' EPA believes that the final rule is a 
logical outgrowth of the proposed rule, that it is supported by 
comments, and that it provides public health benefits while 
apportioning costs in a more flexible targeted manner.
    EPA continues to believe that the elements of the multi-barrier 
approach are important. At first, EPA attempted to redesign the multi-
barrier approach to resolve the issues raised by commenters. In this 
redesigned structure, HSAs were optional and routine monitoring 
(renamed assessment source water monitoring) was a required up-front 
monitoring program limited to 1 year of monthly samples. EPA has 
estimated the costs and benefits for this variation of the multi-
barrier approach in the final EA (Alternative 3). However, EPA 
ultimately determined that the structure of this variation of the 
multi-barrier approach was too restrictive to achieve the full 
potential benefits of an assessment source water monitoring program. In 
addition, it did not provide sufficient flexibility to States, which 
was a major theme of the comments EPA received. Therefore, EPA decided 
to redesign the source water monitoring provision by making assessment 
source water monitoring an option that States can require as they see 
fit. The purpose of this optional requirement is to target source water 
monitoring to systems that the States believe are at a higher risk for 
microbial contamination. EPA believes that States are in the best 
position to assess which systems would most benefit from a 
comprehensive source water monitoring program. EPA recommends that 
States use HSAs as one tool to identify high risk systems for 
assessment source water monitoring. The risk-targeted approach of the 
final rule contains sanitary surveys, triggered source water 
monitoring, optional assessment source water monitoring, corrective 
action, and compliance monitoring.
    For the Economic Analysis of the final rule alternative, EPA did 
not include potential costs and benefits of assessment source water 
monitoring. This is because assessment source water monitoring is an 
optional requirement under the final GWR. Thus, the EA considers 
quantified costs and benefits only of sanitary surveys, triggered 
source water monitoring, corrective action, and compliance monitoring. 
Throughout the EA, the final rule alternative is listed as Alternative 
2--the risk-targeted approach. A discussion of the costs and benefits 
for the regulatory alternatives considered may be found in Chapter 8 of 
the EA (USEPA, 2006d).

B. Analyses That Support This Rule

    EPA estimates national viral and fecal indicator occurrence based 
on data from several studies. The following discussion summarizes EPA's 
occurrence and risk analyses that support this rule.
1. Occurrence Analysis
    a. Study selection. As discussed in Section III.C.3 of this 
preamble and in the NODA, EPA examined data from 24 studies of pathogen 
and fecal indicator occurrence in ground water wells that supply PWSs 
(USEPA, 2006e). EPA selected 15 of these studies to use in the risk 
assessment analysis to estimate national viral and fecal indicator 
occurrence in ground water. The Occurrence and Monitoring Document for 
the Final Ground Water Rule (USEPA, 2006b) provides a detailed 
discussion of each occurrence study evaluated.
    To assist study selection and occurrence modeling, EPA convened a 
two-day statistical workshop in May 2005. The core workgroup included 
expert participants from several government agencies and private 
consulting firms working as U.S. government advisors. A summary of the 
workgroup proceedings, including a list of all participants, is 
included in the final docket for this rulemaking. The charge to the 
workgroup was to consider how to improve modeling of viral and 
indicator occurrence. The statisticians strongly recommended that EPA 
make use of all the available data unless there were known quality 
assurance problems with a data set or the well contamination scenario 
was outside the normal operating range of U.S. PWS wells.
    After the workshop, EPA followed through on the workgroup's 
recommendations and used all available data sets having enterovirus and 
fecal indicator occurrence in ground water source(s) from PWS wells in 
the United States with some exceptions. Of the 16 studies described in 
the proposed GWR, EPA did not use data from five studies to inform the 
national occurrence

[[Page 65616]]

estimates for this rule. EPA did not use the data set of alluvial wells 
from Missouri that were substantially affected by severe Mississippi 
River flooding (Vaughn, 1996). Data from a California study (Yates et 
al., 1999) were deleted from further consideration because data were 
available only by well and not by sample, so the probability of viruses 
detected by individual assays could not be assessed. Data from the 
Whittier, California study (Yanko et al., 1999) were not used because 
the study author, in comment on the proposal, suggested that the 
observed somatic coliphage occurrence was not due to fecal 
contamination. EPA did not use data from Honolulu, Hawaii (Fujioka and 
Yoneyama, 2001) because the wells were not sampled for pathogenic 
viruses and because E. coli are endemic in tropical ecosystems and not 
simply indicators of fecal origin. EPA did not use data from the U.S.-
Mexico Border study because the human virus data were never reported in 
written form.
    Of the seven studies that became available since proposal and 
described in the NODA, EPA did not use four studies to inform national 
occurrence estimates. EPA did not use the data from the set of wells 
developed by Karim et al. (2003; 2004), because these 20 wells are also 
included in Abbaszadegan et al. (2003). EPA did not have sufficient 
information to distinguish which of the 20 wells from Karim (2003; 
2004) were the same wells from Abbaszadegan et al. (2003) and, 
therefore, only used the larger data set. EPA did not use the National 
Field Study data (USEPA, 2006f) because the data set includes both PWS 
and domestic wells, and insufficient information is available to 
identify which wells are PWS wells. Also, the National Field Study data 
set (USEPA, 2006f) included virus cell culture measurements using 
smaller sample volumes than all of the other data sets. EPA did not use 
data from La Crosse, Wisconsin (Borchardt et al., 2004) because this 
was a small study of four wells (and two other wells sampled once only) 
in one locality which, although not regulated as GWUDI, were under 
investigation to determine if that regulatory determination was 
correct. EPA did not use data from another small study of two wells in 
Missoula, Montana because of the size of the data set. In addition, EPA 
added one study of 38 wells from Helena, Montana that was submitted to 
EPA in response to the NODA.
    b. Description of occurrence data used to characterize national 
viral and indicator occurrence. Table VII-2 shows the 15 studies used 
to inform national occurrence estimates for viruses and indicators. One 
data set (Lieberman et al., 2002), targeted wells based on presence of 
total coliforms and other indicators of vulnerability to fecal 
contamination. Another data set (Abbaszadegan et al., 2003), targeted a 
representation of wells throughout the United States based on 
hydrogeological conditions, but excluded any wells that were poorly 
constructed, ground water under the direct influence of surface water 
(GWUDI), or without well logs. Other studies sampled a subset of wells 
in a particular State, region, or hydrogeological setting. Most of the 
studies were designed to capture subsets of the total PWS well 
population. EPA excluded data from wells that States had identified as 
being GWUDI. Only a couple of the studies included such wells in their 
sample set (Lieberman et al., 2002, Atherholt et al., 2003). PWS using 
wells with GWUDI are required to meet the same treatment technique 
requirements for pathogens that pertain surface water supplies and are 
not subject to the requirements of this rule. EPA's analysis to develop 
national estimates for virus and indicator frequency of occurrence in 
wells made no attempt to weight any of the studies to compensate for 
any perceived over- or under-representation of the subset as compared 
with the total population.

   Table VII-2.--List of Studies Used in National Occurrence Analysis
------------------------------------------------------------------------

-------------------------------------------------------------------------
Lieberman et al., 2002 (multiple States).
Abbaszadegan, et al., 2003 (multiple States).
Lindsey et al., 2002 (Pennsylvania Non-community Wells).
Francy et al., 2004 (Southeast Michigan).
Atherholt et al., 2003 (New Jersey).
Davis and Witt, 2000 (Missouri Ozark Plateau 1).
Femmer, 2000 (Missouri Ozark Plateau 2).
USEPA et al., 1998d (Wisconsin Migrant Worker Camp).
Doherty, 1998 (New England).
Battigelli, 1999 (Three-State Study: Wisconsin).
Banks et al., 2001 (Three-State Study: Maryland).
Banks and Battigelli, 2002 (Three-State Study: Maryland).
Minnesota DOH, 2000 (Three-State Study: Minnesota).
USEPA, 1998a (EPA Vulnerability Study).
Miller and Meek, 2006 (Montana).
------------------------------------------------------------------------

    Using enterovirus cell culture and E. coli data from the 15 
studies, EPA modeled virus and fecal indicator (E. coli) occurrence in 
ground water. EPA believes that enterovirus cell culture measurements 
provide the best available basis for estimating pathogenic viral 
occurrence since it captures viruses that are alive and infectious. 
However, because the cell culture procedure only captures a portion of 
the types of pathogenic viruses that may actually occur in well water, 
use of this metric underestimates total viral occurrence. EPA did not 
use PWS samples assayed using PCR methods to estimate national viral 
occurrence for this rule because PCR methods cannot discriminate 
between infectious and non-infectious viruses. Three of the 15 studies 
included viral concentration data (Lieberman et al., 2002, 
Abbaszadegan, et al., 2003 and Lindsey et al., 2002). EPA used data 
from these studies to inform national estimates for viral 
concentrations among wells modeled to have viral occurrence. However, 
since the sampling sites from Lieberman et al., 2002 were selected 
because they had a history of total coliform contamination or other 
evidence of vulnerability (whereas the sample sites from the other two 
studies had no such site selection bias), EPA only used viral 
concentration data from Lieberman et al., 2002 for a small portion of 
wells in the U.S.
    EPA used data on the indicator E. coli to inform estimates of fecal 
contamination occurrence. Indicator data is important because illness 
can result from consuming ground water with fecal contamination in the 
absence of identified viruses. EPA chose to use E. coli as the 
indicator organism to inform national fecal contamination occurrence 
for several reasons. First, analysis using two or more indicator 
organisms becomes increasingly complex. Second, substantial variability 
among studies in choice of indicators, indicator assay method, sample 
volumes and, in the case of coliphage, bacterial host and host range, 
adds uncertainty when data sets are combined. Third, for any one 
indicator other than E. coli, the number of assays with consistency of 
measurement is small. Fourth and most important, EPA believes that E. 
coli will be the most likely fecal indicator used when PWS implement 
the GWR and therefore national estimates of E. coli occurrence can be 
used to inform potential cost implications for implementing the GWR.
    c. How data were used to estimate national occurrence of viral and 
fecal contamination. Data from each of 15 studies were combined into 
one single data set used to determine the probabilities of wells having 
anytime viral (indicated by enterovirus cell culture) or fecal 
indicator (indicated by E. coli) contamination. The results of this 
effort led naturally to a combined analysis, which also modeled co-
occurrence of viruses and E. coli. This combined model serves as the 
basis of EPA's national quantitative occurrence estimates.

[[Page 65617]]

    EPA's occurrence model includes four categories of wells:
     Wells with no E. coli occurrence, but some virus 
occurrence,
     Wells with both E. coli and virus occurrence,
     Wells with no virus, but some E. coli occurrence, and
     Wells with neither E. coli nor virus occurrence.
    The fractions of wells falling into these four categories are named 
P1, P2, P3, and P4, respectively. The categories and parameters P1 
through P4 are illustrated in the Venn diagram of Figure VII-1.
[GRAPHIC] [TIFF OMITTED] TR08NO06.005

    Because fecal contamination is intermittent, viruses and E. coli 
will only be present some fraction of time in a contaminated well. 
These fractions will vary from well to well and EPA has modeled these 
different fractions as distributions. One parameter pair describes the 
distribution for viruses and another parameter pair describes the 
distribution for E. coli. These four parameters, together with the 
fractions of wells falling into the four categories, are the parameters 
estimated in the national occurrence model.
    The Economic Analysis for the Final Ground Water Rule describes the 
statistical methods used to estimate model parameters (USEPA, 2006d). 
That document details the statistical model, estimation methods, and 
summary results. The GWR EA also includes a number of Exhibits that 
describe the central estimates (means) and their uncertainties.
    Central estimates for key parameters are as follows:
     P1 = percentage of wells having virus, but no E. coli = 10 
percent
     P2 = percentage of wells having both virus and E. coli = 
16 percent
     P3 = percentage of wells having E. coli, but no virus = 10 
percent
     P4 = percentage of wells having no virus and no E. coli = 
64 percent
     On average, wells with some virus occurrence have 
detectable concentrations 11 percent of the time.
     On average, wells with some E. coli occurrence have 
detectable concentrations 14 percent of the time.
    EPA attempted to evaluate occurrence based on the hydrogeologic 
characteristics of the aquifer. However, because very few data sets 
allowed for differentiation of viral or indicator presence among 
sensitive versus non-sensitive wells, no significant difference in 
viral or indicator presence could be discerned from the limited data. 
Therefore, the same P1, P2, P3, and P4 estimates were assumed for all 
wells, without regard to aquifer sensitivity.
    Although EPA could not stratify the available viral occurrence data 
between wells drawn from sensitive or non-sensitive aquifers, EPA was 
able to discern two classifications of well type according to overall 
vulnerability characteristics (more and less vulnerable wells). The 
data from Lieberman et al., 2002 were used to represent virus 
concentrations in more vulnerable wells and the combined data from 
Abbaszadegan et al., 2003 and Lindsey et al., 2002 were used to 
represent concentrations in less vulnerable wells.
    EPA used acute and non-acute TCR maximum contaminant level (MCL) 
violation data to estimate the percent of wells considered more 
vulnerable. Based on this data, EPA estimated that about 2.5 percent of 
wells in the U.S., which have modeled viral presence, would have viral 
concentrations like the non-GWUDI wells in Lieberman et al., 2002 (more 
vulnerable). Similarly, EPA estimated that about 97.5 percent of the 
wells in the U.S. (100--2.5 percent) which have modeled viral presence 
would have concentrations like those of Abbaszadegan et al. (2003) and 
Lindsey et al. (2002) (less vulnerable).
2. Risk Analyses
    a. Baseline risk estimates. The framework for developing the 
estimates of baseline risk from consumption of contaminated ground 
water is in accordance with the standard framework detailed in the EPA 
Policy for Risk Characterization (USEPA, 1995a), EPA's Guidance for 
Risk Characterization (USEPA, 1995b), and EPA's Policy for Use of 
Probabilistic Analysis in Risk Assessment (USEPA,

[[Page 65618]]

1997c). A complete discussion of EPA's risk analyses in support of this 
rule can be found in the GWR EA (USEPA, 2006d). The discussion below is 
an overview of the analyses, focusing on how information on occurrence, 
exposure, and dose-response is combined to produce estimates of health 
risk.
    EPA's occurrence model predicts the fraction of wells that have 
some degree of viral contamination. The model also predicts degree of 
contamination, in terms of the varying fractions of time that viruses 
can be detected. In the probabilistic risk analysis, Monte Carlo 
techniques are used to simulate large numbers of wells with differing 
fractions of time that virus is present.
    In addition to assigning different fractions of time, the risk 
model also assigns different concentration levels to the simulated 
contaminated wells. Each well is assigned one concentration value and 
this is treated as the well's concentration whenever the well has virus 
present. EPA does this by sampling from the actual virus concentrations 
that were observed in the occurrence studies. Viral concentrations 
among more vulnerable wells are sampled from the measured values of 
non-GWUDI wells in the Lieberman et al., 2002, study. Concentrations in 
less vulnerable wells are sampled from those measured in the 
Abbaszadegan, et al., 2003 and Lindsey et al., 2002 studies.
    EPA's risk model then estimates exposure levels, or doses, for 
consumers of the contaminated well water. A consumer's dose on a day 
when virus is present depends on the virus concentration, the level of 
disinfection employed by the water system, and the volume of tap water 
that the consumer ingests. For systems that do not disinfect, the tap 
water is assumed to have the same virus concentration as the source 
water. In contrast, properly operating systems that disinfect are 
assumed to inactivate 99 percent (2-log) to more than 99.99 percent (4-
log) of viral pathogens, depending on the disinfection practices 
employed. A consumer's daily dose is computed as the product of the tap 
water concentration, the fraction of viral pathogens NOT inactivated 
and the volume of water ingested.
    Next, the consumer's daily dose is translated to risk of infection 
via EPA's dose-response modeling. EPA's risk model applies the 
calculated dose, based on viral cell culture measurement, for both Type 
A and Type B viruses. Daily probabilities of infection are then derived 
on the basis of the daily dose, according to dose-response models. 
Annual probabilities of infection are then derived from the daily 
estimates, based on the number of days per year in which a virus is 
expected to be present.
    Next, morbidity factors (risk of illness given infection), 
secondary spread of illness to other individuals, and mortality factors 
(risk of premature death given an illness), derived from the 
literature, are used to estimate the annual probability for illness and 
premature death. EPA's risk assessment model includes variability and 
uncertainty ranges for morbidity and mortality to account for different 
effects in different subpopulations.
    b. Risk reduction estimates. The methodology for estimating the 
reduction in risk for the regulatory alternatives builds upon the 
approach and assumptions used to establish the baseline risk. The 
primary difference between the modeling for estimating the baseline 
risk model and the modeling for estimating the risk reduction from a 
given regulatory alternative is that the latter incorporates a change 
in the concentration of viral pathogens reaching the finished drinking 
water of the exposed population. These changes reflect either a 
reduction in pathogen concentration between source water and finished 
water due to disinfection or the elimination of the pathogen from other 
non-treatment corrective actions addressing the source water 
contamination. In addition to accounting for the magnitude of pathogen 
exposure reduction, an important component of the risk reduction 
modeling is to account for the timing of when those reductions occur 
over a 25 year analysis timeframe following promulgation of the rule.
    For the baseline risk analysis, each well in the simulation process 
is designated as either having a virus present at some time or never 
having a virus present. For those wells having some viral occurrence, 
values are assigned for the virus concentration and the fraction of 
time that virus occurs. The risk reduction part of the model uses the 
exact same simulated wells as those generated in the baseline risk part 
of the model.
    For the sake of efficiency in implementing the simulation modeling 
process, those wells designated as never having a virus present are 
recognized as having zero risk reduction potential and are counted as 
such in the model outputs, but are not run through the detailed steps 
of the risk reduction model.
    For those wells that do have a virus present, the risk reduction 
model answers the following three questions:
    (1) Is a corrective action performed on this well as a result of 
the regulatory alternative being considered?
    (2) What is the finished water virus concentration following 
corrective action?
    (3) In what year following rule implementation is the corrective 
action performed?
    The risk reduction model then processes the reduced virus 
concentrations through the dose-response functions for infectivity and 
the morbidity and mortality factors as in the baseline risk assessment.
    Estimates of cases avoided, calculated for all of the individual 
wells, are then aggregated across all wells to arrive at the total 
national estimates of risk reduction. In addition, some of the 
assumptions and data used in the risk reduction model are uncertain and 
are therefore input as uncertainty distributions. As a result of the 
uncertainty reflected in those inputs, together with the uncertainty 
reflected in other inputs to the baseline risk model that are also 
carried into the risk reduction model, the output of the model is a 
range of values of cases avoided. The range is used by EPA to determine 
the expected value and the 90 percent confidence bounds on that 
expected value.
    The GWR EA (USEPA, 2006d) describes in more detail the specific 
assumptions and inputs--including considerations of uncertainty--that 
are used to model risk reduction for each of the four rule options at 
the individual well level and the aggregation of those well level 
estimates to obtain the overall national estimates of risk reduction.

C. What Are the Benefits of the GWR?

    The quantified benefits of this rule result from reductions in 
endemic acute viral illness and death from two groups of viruses 
(called Type A and Type B). Type A virus is represented by rotavirus 
and is highly infectious but has essentially only mild health effects. 
Type B virus is represented by enterovirus or echovirus (a member of 
the enterovirus group) and is moderately infectious, but can have 
severe health consequences though the majority of illnesses from Type B 
viruses are also mild. Additionally, the quantified benefits are based 
only on endemic, acute illness that occurs as a result of virus in PWS 
wells under normal operating conditions. Illnesses due to treatment 
interruptions or failures or to distribution system deficiencies are 
not quantified. Bacterial illnesses and deaths avoided are also not 
quantified.

[[Page 65619]]

    As shown in Table VII-3 below, the annualized present value of the 
quantified benefits of this rule are $19.7 million (using a three 
percent discount rate and an enhanced cost-of-illness value that 
includes lost unpaid labor (e.g., household production) and leisure 
time for people within and outside the paid labor force), with a 90 
percent confidence interval of $6.5 to $45.4 million. Using traditional 
cost-of-illness values at the same discount rate, the annualized 
present value of the quantified benefits of the rule are $10.0 million, 
with a 90 percent confidence interval of $2.2 to $27.0 million. At a 
seven percent discount rate and the enhanced cost-of-illness value, the 
annualized present value of the quantified benefits are $16.8 million, 
with a 90 percent confidence interval of $5.5 to $38.6 million. Using 
the traditional cost-of-illness values, the annualized present value of 
the quantified benefits are $8.6 million, with a 90 percent confidence 
interval of $1.9 to $22.9 million at a seven percent discount rate.

                                          Table VII-3.--Summary of Annualized Present Value Quantified Benefits
                                                                   [$Millions, 2003$]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Annualized benefits at three percent       Annualized benefits at seven percent
                                                                                  discount rate                              discount rate
                                                                   -------------------------------------------------------------------------------------
                            System type                                         90 Percent confidence bound                90 Percent confidence bound
                                                                            ----------------------------------         ---------------------------------
                                                                      Mean     Lower  (5th      Upper  (95th     Mean     Lower  (5th      Upper  (95th
                                                                                  %ile)            %ile)                     %ile)            %ile)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Enhanced COI:
    CWSs..........................................................    $16.0             $5.4            $37.0    $13.7             $4.6            $31.6
    NTNCWSs.......................................................      0.9              0.3              2.2      0.8              0.2              1.8
    TNCWSs........................................................      2.7              0.8              6.2      2.3              0.7              5.1
                                                                   -------------------------------------------------------------------------------------
        Total.....................................................     19.7              6.5             45.4     16.8              5.5             38.6
Traditional COI:
    CWSs..........................................................      8.2              1.9             22.3      7.1              1.6             19.1
    NTNCWSs.......................................................      0.5              0.1              1.3      0.4              0.1              1.0
    TNCWSs........................................................      1.3              0.3              3.4      1.1              0.2              2.8
                                                                   -------------------------------------------------------------------------------------
        Total.....................................................     10.0              2.2             27.0      8.6              1.9            22.9
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Estimates are derived from independent model runs and, therefore, detail may not add to total. Values are for endemic viral illnesses and deaths
  avoided over the 25-year period, expressed in annualized dollars. See VII.C.4 for additional rule benefits.

1. Calculation of Baseline Health Risk
    As part of the quantitative analysis to determine the GWR benefits, 
EPA estimated the ``baseline risk'' (pre-GWR)--the number of people 
becoming ill and/or dying each year from Type A (represented by 
rotavirus) and Type B (represented by enterovirus or echovirus) viral 
infection due to consumption of ground water from public water supplies 
(see Table VII-4). The risk analysis uses these two viruses as 
surrogates for waterborne viruses. The annual estimated number of viral 
illnesses from exposure to Type A and Type B viruses ranges from about 
33,000 to 476,000 cases, with a mean of approximately 185,000 cases. 
EPA estimates that about 0.3 to 11 deaths per year (mean of three 
deaths) prior to this rule as a result of exposure to viruses. These 
numbers are the ``baseline'' used to estimate the health risk reduction 
and their associated monetized value of risk reduction due to 
implementation of this rule. As discussed earlier, bacterial illnesses 
and deaths are not considered in the baseline, and only endemic, acute 
viral illnesses from the two surrogate viruses are considered.

   Table VII-4.--Estimates of Baseline Viral Illnesses and Deaths Due to Contamination of Ground Water Systems
----------------------------------------------------------------------------------------------------------------
                                                      Illnesses per year                  Deaths per year
----------------------------------------------------------------------------------------------------------------
                                                                    5th-95th                          5th-95th
                 Virus type                         Mean           Percentiles          Mean         Percentiles
----------------------------------------------------------------------------------------------------------------
Type A (rotavirus)..........................           175,168    32,652-435,381               1.2       0.2-2.9
Type B (enterovirus or echovirus)...........            10,018        501-40,718               2.0       0.0-8.1
                                             -------------------------------------------------------------------
    Total...................................           185,186    33,153-476,099               3.2      0.3-11.0
----------------------------------------------------------------------------------------------------------------

2. Calculation of Avoided Illnesses and Deaths
    The GWR requirements are projected to result in a significant 
reduction in exposure to fecal contamination. EPA used a risk 
assessment model to estimate the avoided viral illnesses and deaths. 
The risk assessment model estimates reductions in baseline incidence 
considering the effects of the sanitary survey and triggered source 
water monitoring. Assessment source water monitoring is optional and is 
not included in this analysis (see Section VII J.10). Table VII-5a 
shows the calculated viral illnesses and deaths avoided due to the GWR. 
The rule is expected to avoid (mean value) approximately 42,000 viral 
illnesses and one viral death annually (averaged over 25 years). 
Details of the assumptions and methodology used in the model are 
described in the GWR EA (USEPA, 2006d). Table VII-5b shows the

[[Page 65620]]

calculated viral illnesses and deaths avoided due to the GWR by system 
type. More detailed information about the GWR benefits assessment and 
all data and analyses used in predicting those benefits can be found in 
the GWR EA (USEPA, 2006d).

                 Table VII-5a.--Summary of Annual Viral Illnesses and Deaths Avoided for the GWR
----------------------------------------------------------------------------------------------------------------
                                                  Illnesses avoided per year          Deaths avoided per year
----------------------------------------------------------------------------------------------------------------
                                                                    5th-95th                          5th-95th
                 Virus type                         Mean           Percentiles          Mean         Percentiles
----------------------------------------------------------------------------------------------------------------
Type A (rotavirus)..........................            39,442     10,093-79,925               0.3       0.1-0.5
Type B (enterovirus or echovirus)...........             2,426         181-8,114               0.5       0.0-1.6
                                             -------------------------------------------------------------------
    Total...................................            41,868     10,274-88,039               0.7      0.1-2.1
----------------------------------------------------------------------------------------------------------------
Note: Details may not add to totals due to independent rounding and independent statistical analyses.
Source: GWR Illness Model.

               Table VII-5b.--Summary of Annual Avoided Viral Illnesses and Deaths by System Type
----------------------------------------------------------------------------------------------------------------
                                                  Illnesses avoided per year          Deaths avoided per year
----------------------------------------------------------------------------------------------------------------
                                                                    5th-95th                          5th-95th
                 System type                        Mean           Percentiles          Mean         Percentiles
----------------------------------------------------------------------------------------------------------------
CWSs........................................            32,031      8,704-68,994               0.6       0.1-1.8
NTNCWSs.....................................             2,094         533-4,308              0.03       0.0-0.1
TNCWSs......................................             7,743      1,037-14,738               0.1      0.01-0.2
                                             -------------------------------------------------------------------
    Total...................................            41,868     10,274-88,039               0.7      0.1-2.1
----------------------------------------------------------------------------------------------------------------
Note: Estimates are derived from independent model runs, and, therefore, detail may not add to total. Values are
  endemic, acute viral illnesses and deaths avoided following full implementation of the GWR and only accounts
  for rotavirus and echovirus.
Source: Derived from GWR model output.

3. Derivation of Quantified Benefits
    EPA quantified the benefits for the GWR based on reductions in the 
risk of endemic, acute viral illness as explained in Section VII.B.2. 
Next, EPA monetized benefits for nonfatal viral illnesses and 
mortalities avoided by the GWR. Table VII-3 shows the estimated 
monetized value for viral illnesses and deaths avoided by the GWR.
    Benefits for nonfatal cases of endemic, acute viral illness were 
calculated using a cost-of-illness (COI) approach. Traditional COI 
valuations focus on medical costs and lost work time and leave out 
significant categories of benefits, specifically, the reduced utility 
from being sick (i.e., lost personal or nonwork time, including 
activities such as child care, homemaking, community service, time 
spent with family, and recreation), although some COI studies also 
include an estimate for unpaid labor (household production) valued at 
an estimated wage rate designed to reflect the market value of such 
labor (e.g., median wage for household domestic labor).
    Ideally, a comprehensive willingness to pay (WTP) estimate would be 
used that includes all categories of loss in a single number. However, 
a review of the literature indicated that the available studies were 
not suitable for valuing acute viral illness; hence, estimates from 
this literature are inappropriate for use in this analysis. Instead, 
EPA presents two COI estimates: a traditional approach that only 
includes valuation for medical costs and lost work time (including some 
portion of unpaid household production) and an enhanced approach that 
also factors in valuations for lost unpaid work time for employed 
people, reduced utility (or sense of well-being) associated with 
decreased enjoyment of time spent in non-work activities, and lost 
productivity at work on days when workers are ill but go to work 
anyway. The first two categories of loss are estimated by multiplying 
the average wage rate by the number of non-work waking hours. The third 
category is estimated by multiplying all waking hours (work and non-
work) by 30 percent of the wage rate for days when subjects are ill but 
report for work anyway.
    The computation of COI involves two broad categories of costs--
direct and indirect medical costs. All costs are updated to a common 
year (2003) used as the starting point for projecting benefits into 
future time periods. For Type A viruses, each cost component has a 
separate estimate made based on age and the health state of the 
individual (healthy or immunocompromised). For Type B viruses, cost 
components have separate estimates based both on age and on the type of 
care required (i.e., no medical care, outpatient care, or inpatient 
care). Chapter 5 of the GWR EA (USEPA, 2006d) has a detailed breakout 
of both Type A and Type B COI estimates.
    For both the Enhanced COI and Traditional COI, the direct cost for 
a case of Type A or Type B viral illness is derived by summing the 
costs of outpatient and inpatient care (in 2003$). Outpatient care 
consists of an initial physician visit ($114.55) and the product of the 
cost of each follow-up visit ($66.18) and the number of follow-up 
visits. Multiplying this sum by the percentage of patients that utilize 
outpatient services yields the weighted unit cost of outpatient care. 
The cost of inpatient care consists of the costs of the initial doctor 
visit in the hospital ($152.87), any follow-up visits ($52.25), and the 
hospital charges (calculated on a per day basis, with costs ranging 
from $1,007 per day for Type A illnesses to $4,870 per day for a severe 
case of Type B illness). As with outpatient costs, multiplying the sum 
of doctor visits and hospital charges by the percentage of patients who 
require inpatient care yields the weighted unit cost of inpatient care.
    The sum of the weighted unit costs of outpatient and inpatient care 
equals the weighted direct costs. The weighted direct medical costs per 
case of Type A viral illness ranges from an average cost of $0 (for 
healthy patients, five years old

[[Page 65621]]

and up requiring no medical care) to $4,486 (for immunocompromised 
patients younger than five years old). The weighted direct medical 
costs per case of Type B viral illness range from an average of $0 (for 
patients requiring no medical care) to $23,431 (for patients less than 
one month old requiring inpatient care).
    Total indirect cost is the sum of the value of patient days lost, 
the value of productivity lost, and the value of care giver days lost. 
For the Enhanced COI, the total indirect cost associated with a case of 
Type A viral illness ranges from an average of $103 (for healthy 
patients 16 years old and older) to $2,136 (for immunocompromised 
patients under two years of age). Indirect costs associated with cases 
of Type B viral illness range from $336 (for patients 16 years old and 
older requiring no medical care) to $2,990 (for patients under 16 years 
of age requiring inpatient care).
    For the Traditional COI, the total indirect cost associated with a 
case of Type A viral illness ranges from an average of $39 (for healthy 
patients 16 years old and older) to $426 (for immunocompromised 
patients two years of age and younger). Indirect costs associated with 
cases of Type B viral illness range from $126 (for patients 16 years 
old and older requiring no medical care) to $596 (for patients 
requiring inpatient care).
    The valuation of children's time presents unique problems. The best 
approach when valuing children's health effects is the use of child-
specific valuations of these effects. For direct costs, EPA has used 
such valuations. Indirect costs, however, prove more challenging. As 
noted in the Children's Health Valuation Handbook (USEPA, 2003c), 
``[children's] time lost to sickness also has value, although no direct 
measure exists for this loss.'' In this instance, the Handbook states 
that, ``as a second-best option, * * * transfer benefit values 
estimated for adults to children.'' The Enhanced COI uses this 
guideline, in conjuncture with Executive Order 13045 (``Protection of 
Children from Environmental Health Risks and Safety Risks''), and 
assumes a day lost due to illness (lost patient day) for the duration 
of illness for patients younger than 16 years to be valued at $199.36 
(based on the median post-tax wage). In contrast, the Traditional COI 
assigns no lost patient day value for children under 16 years of age 
because this approach assigns a monetary value only to lost wages (or 
lost unpaid work time for adults not in the paid labor market). Both 
the Traditional and Enhanced COI approaches assume that a caregiver 
stays home with these children, introducing additional lost caregiver 
days for each lost patient day. The number of days lost entirely to 
illness, either by the adult patient or caregiver, is multiplied by 
$227.79 (for the Enhanced COI) or $85.12 (for the Traditional COI), the 
average value of a lost day.
    In addition, for days when an individual is well enough to work but 
still experiencing symptoms, such as diarrhea, the Enhanced COI 
estimate also includes a 30 percent loss of work and leisure 
productivity (i.e. 30 percent of the wage rate times 16 hours) based on 
a study of giardiasis illness (Harrington et al., 1985). In the 
Traditional COI analysis, productivity losses are not included for 
either work or nonwork time. No productivity losses are assigned to 
children under 16 years of age under either the Traditional or Enhanced 
COI approaches.
    The Agency believes that losses in productivity and lost leisure 
time are unquestionably present and that these categories have positive 
value; consequently, the Traditional COI estimate understates the true 
value of these loss categories. However, using the wage rate to 
estimate the loss of utility during non-work hours may understate or 
overstate the value of this loss, depending on severity of illness and 
other factors. Similarly, using 30 percent of the wage rate to estimate 
the value of lost productivity in work and leisure when a person is 
still experiencing symptoms but is well enough to go to work may 
understate or overstate benefits. EPA notes that these estimates should 
not be regarded as upper and lower bounds. In particular, the Enhanced 
COI estimate may not be an upper bound, because it may not fully 
incorporate the value of pain and suffering.
    As with the avoided mortality valuation, the real wages used in the 
COI estimates were increased by a real income growth factor that varies 
by year, but is the equivalent of about 1.8 percent per year over the 
25-year period. This approach of adjusting for real income growth was 
recommended by the SAB (USEPA, 2000d) because the median real wage is 
expected to grow each year (by approximately 1.8 percent). 
Correspondingly, the real income growth factor of the COI estimates 
increases by the equivalent of 1.8 percent per year (except for medical 
costs, which are not directly tied to wages).
    Reductions in mortalities were monetized using EPA's standard 
methodology for monetizing mortality risk reduction. This methodology 
is based on a distribution of value of statistical life (VSL) estimates 
from 26 labor market and stated preference studies. For this analysis, 
EPA incorporated the Weibell Distribution into the benefit model Monte-
Carlo simulation and updated the VSLs to 2003 dollars. The updated mean 
VSL in 2003 dollars is $7.4 million. A real income growth factor was 
applied to these estimates of approximately 1.8 percent per year for 
the 25-year time span following implementation. Income elasticity for 
VSL was estimated as a triangular distribution that ranged from 0.08 to 
1.00, with a mode of 0.40. VSL values for the 25-year time span are 
shown in the GWR EA in Exhibit B.6 (USEPA, 2006d). A more detailed 
discussion of these studies and the VSL estimate can be found in EPA's 
Guidelines for Preparing Economic Analyses (USEPA, 2000c).
4. Nonquantifiable Benefits
    There are substantial benefits attributable to the GWR that are not 
quantified as part of this rulemaking because of data limitations. The 
GWR quantifies only the endemic, acute illnesses and deaths due to 
rotavirus and enterovirus. By reducing bacterial and other viral 
illnesses and deaths, this rule provides significant health benefits 
beyond the monetized benefit estimates. Chronic illnesses (such as 
diabetes, dilated cardiomyopathy, and reduced kidney function), kidney 
failure, and hypertension (e.g., Garg et al., 2005) resulting from 
waterborne viral and bacterial pathogens are also not quantified but 
provide additional benefits, although such cases are likely to be 
relatively rare. Additional health benefits will accrue from preventing 
outbreaks, reducing periods with insufficient disinfection, and 
minimizing contaminant infiltration into distribution systems.
    This rule will also result in non-health benefits such as avoided 
outbreak response costs, increased information gained through source 
water monitoring that will in turn provide benefits to the systems and 
their customers, and reduced uncertainty regarding drinking water 
safety, which may lead to reduced costs for averting behaviors.
    In addition, the optional assessment source water monitoring 
provision will provide additional benefits similar to those already 
described (i.e. reduction in viral and bacterial illness). However, EPA 
was not able to quantify either the benefits or costs of this program 
because EPA does not know the extent to which States will use the 
option or the manner in which they will implement it. Because this 
provision could potentially

[[Page 65622]]

increase both benefits and cost, a more complete discussion can be 
found in the Section VII.J.10 of this preamble.
    EPA believes that, collectively, these benefits, both health and 
non-health, significantly exceed those which EPA was able to quantify 
and are a major basis for supporting the preferred regulatory 
alternative. A qualitative discussion of these nonquantified benefits 
is included in Section 5.4 of the GWR EA (USEPA, 2006d); a summary of 
this discussion appears below.
    a. Decreased incidence of illness from bacteria. In addition to 
reducing the number of illnesses and deaths due to drinking water 
related to some viral illnesses, the ground water source monitoring and 
corrective actions taken under the GWR will also reduce the number of 
illness and deaths due to bacteria in drinking water. EPA was unable to 
quantify the benefits from preventing bacterial illness; however, EPA 
provides a rough estimate of illnesses and deaths prevented through:
     Estimating potential bacterial illnesses avoided;
     Estimating a mortality rate for waterborne bacterial 
illness; and
     Estimating potential annual deaths avoided by the GWR.
    The first of the analytical steps applies the ratio of waterborne 
disease outbreak incidence rates between bacteria and viruses to the 
quantified viral cases avoided to estimate bacterial cases avoided. The 
second analytical step derives mortality rates for types of bacterial 
illness associated with waterborne disease outbreaks. The third 
analytical step combines the first two steps to devise a rough estimate 
of annual bacterial deaths avoided. EPA estimates that total quantified 
benefits could increase by a factor of five if EPA was able to account 
for additional deaths and hospitalizations caused by bacterial illness 
being avoided (i.e., not even considering the value of reduced non-
fatal non-hospitalization caused bacterial illnesses). More information 
on this calculation can be found in Chapter 5 of the GWR EA (USEPA, 
2006d).
    b. Decreased illness from other viruses. Quantified benefits accrue 
from endemic, acute illnesses associated with rotavirus (a Type A 
virus) and enterovirus or echovirus (a Type B virus) as discussed 
previously. Nonquantified health benefits attributable to viruses 
include decreased incidence of gastroenteritis caused by other Type A 
viruses such as norovirus, astrovirus, and adenovirus; decreased 
incidence of other acute disease endpoints (e.g., hepatitis and 
conjunctivitis) caused by types of viruses not modeled in the 
quantified benefits analysis; and decreased incidence of chronic 
illness associated with Type B virus (e.g., diabetes and dilated 
cardiomyopathy).
    The health effects of norovirus (the most common Type A virus) 
illness include acute onset of nausea, vomiting, abdominal cramps, and 
diarrhea (USEPA, 2006d). EPA believes that nausea and vomiting 
associated with norovirus, typically absent in rotavirus illness, 
suggest that the norovirus disease burden (e.g., number of productive 
days lost) associated with PWS wells is important, especially for 
adults with whom norovirus disease is quite prevalent. EPA believes 
that if norovirus were included in the quantified benefits, there would 
be significantly greater monetized benefits for Type A viruses, because 
monetized rotavirus disease burden (the only Type A virus modeled) 
provides only a small benefit for adults since most adults are immune 
to rotavirus.
    Other acute and chronic viral illnesses can be acquired from 
consuming ground water contaminated with other Type A or Type B 
viruses, but the Agency was unable to quantify or monetize them. These 
include severe, acute illnesses such as hepatitis A; milder, acute 
illnesses such as conjunctivitis; and severe chronic illnesses such as 
diabetes and dilated cardiomyopathy. Most chronic illnesses are costly 
to treat. Lifetime costs associated with a new case of diabetes, for 
example, assuming an average illness duration of 30 years, are 
estimated at $227,032 using a three percent discount rate and $143,733 
using a seven percent discount rate (year 2003 dollars). For dilated 
cardiomyopathy, the lifetime (21 year average) cost is $61,117 (seven 
percent discount rate, year 2003 dollars). These illnesses are 
discussed in further detail in the GWR EA (USEPA, 2006d).
    c. Other nonquantifiable benefits. Other nonquantified health 
benefits include decreased incidence of waterborne disease outbreaks 
and epidemic illness and decreased illness through minimizing treatment 
failures or fewer episodes with inadequate treatment. The nonquantified 
non-health benefits include improved perception of ground water quality 
and perception about reduced risk associated with PWS wells, potential 
reduced use of bottle water and point-of-use devices, reduced time 
spent on averting behavior such as obtaining alternative water 
supplies, and avoided costs associated with outbreak response.
    Pathogenic protozoa can occur in PWS wells, typically when such 
systems are misclassified and are not recognized as GWUDI systems. In 
PWSs with elevated ground water temperatures, Naegleria fowleri can 
colonize the distribution system, well, well gravel-pack, or aquifer. 
N. fowleri is fatal when inhaled (and treatment is not timely) and two 
five-year old boys died in the same week from exposure via a GWS in 
Arizona (Marciano-Cabral et al., 2003). N. fowleri is inactivated by 
disinfection, so corrective action implemented as the result of this 
rule that includes disinfection may prevent death from this organism. 
However, the benefits from avoiding these deaths are nonquantified. 
Cryptosporidiosis and giardiasis outbreaks in sensitive PWS wells have 
also occurred (see Section III.C.2). Sanitary surveys and additional 
monitoring under the GWR combined with existing source water 
assessments and Long Term 2 Surface Water Treatment Rule (LT2ESWTR) (71 
FR 654, January 5, 2006) (USEPA, 2006i) implementation can, in 
combination, minimize the likelihood of misclassification of PWS wells 
(as non-GWUDI) and reduce the likelihood of outbreaks associated with 
such misclassification. This rule only qualitatively considers the 
benefits of identifying misclassified PWS wells.
    Several nonhealth benefits from this rule were also recognized by 
EPA but were not monetized. The nonhealth benefits of this rule include 
avoided outbreak response costs (such as the costs of providing public 
health warnings, boiling drinking water and providing alternative 
supplies, remediation and repair, and testing and laboratory costs). 
Expenses associated with outbreaks can be significant. For example, an 
analysis of the economic impacts of a waterborne disease outbreak in 
Walkerton, Ontario (population 5,000) estimated the economic impact 
excluding medically related costs to be over $43 million in Canadian 
dollars (approximately $32 million in U.S. dollars) (Livernois, 2002). 
The author believed that this was a conservative estimate.
5. How Have the Benefits Changed Since the Proposal?
    The estimated annual quantified benefits for the GWR have changed 
from $205 million (year 2000 dollars, both at 3 percent and 7 percent 
discount rates) to $19.7 million (year 2003 dollars, at 3 percent) 
using enhanced cost-of-illness estimates and $10.0 million (year 2003 
dollars, at 3 percent) using traditional cost-of-illness estimates 
(these are $16.8 and $8.6 using a 7 percent discount rate). The 
proposal only included the enhanced cost-of-illness measure. The change 
in quantified benefits is due to

[[Page 65623]]

changes in both the economic analysis estimates (e.g., interpretation 
of occurrence and other data) and GWR provisions. However, changes in 
the economic analysis estimates are the dominant factor in explaining 
the large change in benefits from the proposal.
    Estimates in the GWR EA that were changed and that most influenced 
the change in the quantified benefit estimate include:
     Frequency and duration of viral occurrence in wells;
     Percentage of wells associated with high versus low viral 
concentrations;
     Efficiency by which virally contaminated wells are 
identified and prescribed corrective action;
     Severity of symptoms associated with predicted illnesses
     Monetized value of illnesses avoided; and
     Using net present values and then annualizing benefits.
    EPA believes that the changes made in the GWR EA since proposal 
substantially improve upon the scientific basis for the quantified 
benefits, a major issue raised by public comments (see Section VII.J of 
this preamble for further discussion of public comments). Chapter 5 of 
the GWR EA describes the basis for the analysis (USEPA, 2006d).
    Changes in the rule provisions also impacted the final benefit 
estimate but these changes are not as significant as the changes made 
in the economic analysis. In addition, the benefits (as well as costs) 
for the optional assessment source water monitoring and additional 
fecal indicator sampling following triggered source water monitoring 
are not included in the final rule analysis. These potential impacts 
are discussed in Section VII.J.10.
    Another major change in the GWR EA since proposal is a more 
thorough analysis of the nonquantified benefits. EPA's analysis of the 
potential benefits from avoided bacterial illness suggests that the 
nonquantified benefits may exceed the quantified benefits by a factor 
of five (see Chapter 5.4 of the GWR EA for a full description of 
nonquantified benefits, USEPA, 2006d).

D. What Are the Costs of the GWR?

1. Summary of Quantified Costs
    In estimating the costs of this rule, the Agency considered impacts 
on public water systems and on States. Table VII-6 summarizes these 
costs in terms of annualized present value: $61.8 million (using a 
three percent discount rate) and $62.3 million (using a seven percent 
discount rate). Most costs occur early in the implementation schedule, 
therefore the values do not differ much using different discount rates.
    To calculate the national costs of compliance, the Agency used a 
Monte-Carlo simulation model specifically developed for the GWR. The 
main advantage of this modeling approach is that in addition to 
providing average compliance costs, it also estimates the range of 
costs within each PWS size and category. It also allows the Agency to 
capture the variability and uncertainty in areas such as PWS 
configuration, current treatment in-place, source water quality, 
existing State requirements, unit costs of treatment technologies, and 
compliance forecasts. The 90 percent confidence bounds shown in Table 
VII-6 reflect the quantified uncertainties.
[GRAPHIC] [TIFF OMITTED] TR08NO06.006

    Table VII-6 shows the estimated annualized present value costs of 
this rule. Drinking water utilities will incur approximately 81 percent 
of the rule's costs. States will incur the remaining costs of the rule. 
In addition to the mean estimates of costs, the Agency calculated 90 
percent confidence intervals by considering, for example, the 
uncertainty in the mean unit technology costs. Table VII-7 shows the 
undiscounted capital costs and all one-time costs for both water 
systems and States. The derivation of these cost numbers can be found 
in Chapter 6 of the GWR EA (USEPA, 2006d). The itemized costs of this 
rule are presented below for systems and States, respectively.

[[Page 65624]]

[GRAPHIC] [TIFF OMITTED] TR08NO06.007

2. Derivation of Quantified Costs
    a. Summary of Baseline Estimate. To quantify the effects of the 
rule, it is necessary to have a baseline against which to compare the 
set of regulatory requirements. The baseline is a characterization of 
the industry and its operations under the conditions expected to exist 
before systems make changes to meet requirements of this rule. As 
discussed in Section IV of this preamble, the regulatory requirements 
can be system, entry point, or well level requirements. These 
requirements, to a large extent, depend upon the levels of existing 
protection from microbial risks, e.g., disinfection levels. Table VII-
8a presents the major baseline information for this rule. The number of 
entry points or wells varies by system size, with larger systems 
generally having more entry points. Chapter 4 of the GWR EA for this 
rule provides a detailed description of the GWR baselines (USEPA, 
2006d).
    b. Rule Implications. To calculate the cost impact of each rule 
alternative on GWSs, the Agency estimated how many systems and their 
associated entry points to distribution systems and wells would be 
affected by the various rule requirements based on national fecal 
indicator occurrence information, as discussed in Section VII.B.1. The 
Agency developed compliance forecast estimates that predict the number 
of systems, entry points, or wells that incur costs to comply with each 
regulatory requirement. Table VII-8b shows these numbers broken down by 
system type and size category. Chapter 6 of the GWR EA for this rule 
provides further description of the estimates of rule implications 
(USEPA, 2006d).
    c. System Costs. This rule is estimated to cost public GWSs $50.0 
million annually using a three percent discount rate ($50.6 million 
annually using a seven percent discount rate). The cost impacts to 
systems complying with the GWR stem from implementing the rule, 
assisting with sanitary surveys, performing source water and compliance 
monitoring, and performing corrective actions. Not every system is 
expected to incur all of these costs because the compliance activities 
for systems depend on the results from sanitary surveys, analysis of 
total coliform samples under the TCR, and source water monitoring.
    The estimated costs for each of the rule requirements are 
summarized in Table VII-8c with a mean, upper bound, and lower bound. 
The mean and confidence bounds are equal for some of the costs because 
EPA derived these costs from point estimates. The total annualized 
costs to systems are presented in Table VII-9 by system size and type. 
The detailed calculation of these cost numbers are presented in Chapter 
6 of the GWR EA (USEPA, 2006d).
    To analyze the different rule components, the Agency had to 
distinguish between correction of significant deficiencies identified 
during sanitary surveys and the corrective actions that result from 
fecal indicator-positive ground water source samples. It was not 
possible to estimate costs for all conceivable corrective actions that 
a system may potentially encounter on a national level due to system-
to-system variability. As a result, the Agency estimated costs for 
representative corrective actions that may be implemented to address 
significant deficiencies identified by sanitary surveys and source 
water fecal contamination, respectively. Table VII-10 shows the 
representative corrective actions.
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BILLING CODE 6560-50-C
    Because the exact timing and distribution of problems among systems 
that may be identified by the sanitary surveys is not known, an average 
annual GWS cost of correcting significant defects is calculated by 
summing the cost of correcting all significant deficiencies over the 
25-year period of analysis and apportioning them evenly over the period 
during which they are performed.
    For entry points with fecal indicator-positive ground water source 
samples (from triggered source water monitoring), systems must perform 
corrective action to comply with the GWR. For cost estimation purposes, 
the model assumes that for every source water positive sample, at least 
one additional sample will also be positive (i.e., corrective action 
ultimately follows every source water positive) (see Chapter 6 of GWR 
EA (USEPA, 2006d) for a complete discussion of this assumption). For 
non-disinfecting systems, the model assigns one representative 
nontreatment corrective action or one disinfection/treatment corrective 
action (Table VII-10). The cost model assigns nondisinfecting entry 
points that need to take corrective actions to the treatment category 
using the current proportion of all entry points providing treatment 
for different size categories. The current proportion is a range of the 
estimated existing percentages of treatment entry points among the 
entry points with less than 4-log disinfection and without 
disinfection.
    For nontreatment corrective actions to comply with the GWR, the 
cost model assigns equal proportions of entry points to high and low 
cost scenarios and then assigns a representative corrective action 
according to the corresponding percentages in that scenario. For entry 
points predicted to use treatment corrective actions, the cost model 
assigns one of the possible treatment technologies based on the 
relative percentage of CWSs currently engaged in those treatment 
practices. Finally, for entry points that require corrective actions 
because of source water fecal contamination (from

[[Page 65629]]

triggered source water monitoring) and already disinfect, but the 
disinfection does not achieve at least a 4-log treatment of viruses 
before or at the first customer, the compliance forecast assigns a 
corrective action that either increases the dose for hypochlorination 
or chlorine gas or adds storage. More information regarding the 
compliance forecasts of corrective actions can be found in Chapter 6 of 
the GWR EA (USEPA, 2006d).

            Table VII-10.--Representative Corrective Actions
------------------------------------------------------------------------
                                 Representative
                               corrective actions           Note
------------------------------------------------------------------------
For Significant Deficiencies  Replace a Sanitary    Low cost option.
 at Source Identified by       Well Seal.
 Sanitary Survey.
                              Rehabilitate an       High cost option.
                               Existing Well.
For Entry Points with a       Non-Treatment         Interim disinfection
 Fecal Indicator-Positive      Options.              is included for
 Ground Water Source Sample.  Rehabilitate an        costing.
                               Existing Well.
                              Drill a New Well....
                              Purchase Water......
                              Eliminate Source of
                               Contamination.
                              Treatment Options...  Chlorine gas and
                              Disinfection           hypochlorite will
                               Alternatives or       be most likely
                               Nanofiltration.       choices for large
                                                     and small systems,
                                                     respectively.
------------------------------------------------------------------------

    In addition to the treatment technique costs, EPA estimated the 
cost for systems to conduct monitoring. It is important to remember 
that triggered source water monitoring applies only to systems that do 
not achieve 4-log treatment of viruses. Compliance monitoring applies 
to systems that currently provide 4-log treatment of viruses, or those 
that install treatment as a result of this rule. Assessment source 
water monitoring is optional and is not included in either the cost or 
benefit estimates (see Section VII.J.10).
    The triggered source water monitoring costs are calculated based on 
the cost of the test and the operator's time to collect and transport 
the sample. GWSs have to collect a ground water source sample and 
analyze it for the selected indicator organism when the system 
experiences a total coliform-positive under the TCR. If the indicator 
sample is positive, the system either takes five additional samples or 
does corrective action immediately. If any of the additional samples is 
positive, the system must implement a corrective action. Specific 
issues regarding the monitoring cost estimate are described in Section 
VII.C.3 of this preamble. The GWR EA has a more detailed discussion of 
the monitoring cost analysis (USEPA, 2006d).
    The cost of compliance monitoring varies with system size. 
Compliance monitoring is required for any system that currently 
provides 4-log treatment of viruses or installs treatment as a result 
of complying with this rule's treatment technique requirements. EPA 
assumes that systems with treatment technology in place prior to the 
GWR promulgation incur minimal additional capital or operation and 
maintenance (O&M) costs for compliance monitoring because GWSs should 
already have a monitoring program in place and has not included them in 
the cost analysis. However, the Agency does include costs for systems 
to notify the State that they achieve at least 4-log treatment of 
viruses or to notify the State in case of system failure.
    For those systems adding a technology that provides 4-log treatment 
of viruses as a corrective action for source water fecal contamination, 
EPA assumes that monitoring equipment will also be installed to perform 
compliance monitoring. The cost varies by system size because the 
monitoring requirements vary by size category. A more detailed 
explanation of compliance monitoring schemes is discussed in Section 
IV.C.
    d. State costs. As indicated in Table VII-6, EPA estimates that 
States will incur less than $11.8 million in annualized costs due to 
the additional sanitary survey requirements in this rule (including 
increased frequency of sanitary surveys), tracking monitoring 
information, reviewing action plans, data management, and other 
activities. Along with system costs, State costs are also summarized in 
Table VII-8c.
    States will incur administrative costs while implementing the GWR. 
These implementation costs are not directly required by specific 
provisions of GWR alternatives, but are necessary for States to ensure 
the provisions of the GWR are properly carried out. States will also be 
required to spend time responding to PWSs whose ground water sources 
are found to be fecally contaminated, or have significant deficiencies. 
These costs include time to review plans and specifications, prepare 
violation letters, and enter data. States will need to allocate time 
for their staff to establish and then maintain the programs necessary 
to comply with the GWR, including developing and adopting State 
regulations, modifying data management systems to track newly required 
system reports to the States, and providing ongoing technical 
assistance to GWSs. For those GWR requirements that include monitoring 
with a laboratory method not currently required by the State, the State 
must devote a portion of its staff time to certifying laboratories for 
the new analytical method. Time requirements for a variety of State 
agency activities and responses are estimated in Chapter 6 of the GWR 
EA (USEPA, 2006d).
    In addition to these one-time costs, States will use resources to 
continue activities for the implementation of the GWR unrelated to any 
specific provision. States with primacy enforcement responsibilities 
have recordkeeping (Sec.  142.14) and reporting (Sec.  142.15) 
requirements associated with primacy enforcement and must coordinate 
with EPA for review of the State primacy program. States must also 
continue to train their personnel and PWS staff, maintain laboratory 
certifications, and report system compliance information to the Safe 
Drinking Water Information System (SDWIS).
3. Nonquantifiable Costs
    Although EPA has quantified the significant costs of the GWR, there 
are some costs that the Agency did not quantify. Overall, EPA believes 
that these nonquantified costs are much smaller than the nonquantified 
benefits. These nonquantified costs result from uncertainties 
surrounding rule assumptions and from modeling assumptions. For 
example, EPA estimated that some systems may need to acquire land if 
they need to build a treatment facility or drill a new well. This was 
not considered for most systems because EPA expects that the majority 
of the technologies that

[[Page 65630]]

systems will use to comply with this rule will fit within the existing 
plant footprint. In addition, if the cost of land is prohibitive, a 
system may choose another lower cost alternative such as connecting to 
another source. EPA has also not quantified costs for systems already 
using disinfection to conduct compliance monitoring because EPA 
believes that such systems are already incurring these costs.
    In addition, the optional assessment source water monitoring 
provision was not included in the quantitative cost analysis. EPA was 
not able to quantify either the benefits or costs of this program. 
Because this provision could potentially increase both benefits and 
cost, a more complete discussion can be found in Section VII.J of this 
preamble. Due to lack of information, EPA was unable to quantify the 
costs (as well as benefits) from the correction of sanitary survey 
deficiencies in distribution systems and treatment plants. This is 
discussed in Section VII.J of this preamble.
    Also, the Agency did not include the costs for taking five 
additional samples following a positive source water sample. However, 
EPA overestimated the cost of triggered source water monitoring because 
it assumed all systems would take an additional sample beyond the 
current TCR requirements. However, many small systems (and most GWSs 
are small) will be able to use one of their TCR repeat samples to also 
comply with the GWR. Overall, the impact of not including the five 
additional sample cost (approximately $200,000 per year) is much 
smaller compared to the overestimate of a few million dollars 
associated with the initial fecal indicator sampling cost already 
conducted for TCR monitoring.
4. How Have the Costs Changed Since the Proposal?
    The estimated annual quantified costs for the GWR have changed from 
$183 million and $199 million (year 2000 dollars at proposal, using 
three and seven percent discount rates, respectively) to $61.8 million 
and $62.3 million (year 2003 dollars, using three and seven percent 
discount rates, respectively). The change in quantified costs is due to 
changes in both the economic analysis estimates (e.g., interpretation 
of occurrence and other data) and GWR provisions. However, changes in 
the economic analysis estimates are the dominant factor in explaining 
the large change in costs from the proposal. The major changes in 
economic analysis estimates include the following:
     The number of significant deficiencies and corrective 
actions in wells from sanitary survey provisions;
     State costs for the incremental changes to existing 
sanitary survey programs;
     The total coliform-positive samples under the TCR and the 
number of triggered source water monitoring samples required under the 
GWR;
     The frequency and duration of fecal indicator occurrence 
in wells;
     The efficiency by which fecally contaminated wells are 
identified and therefore performing a corrective action;
     Compliance forecasts include a higher percentage of non-
treatment corrective actions; and
     Using net present values and then annualizing costs.
    EPA believes that the changes made in the GWR EA since proposal 
substantially improve the basis for quantifying the GWR costs with more 
available data, a major issue raised by public comments (see Section 
VII.L of this preamble for further discussion of major public 
comments).
    Changes in the rule provisions also impacted the final cost 
estimate but these changes are not as significant as the changes made 
in the economic analysis. In addition, the costs (as well as benefits) 
for optional assessment source water monitoring and additional fecal 
indicator sampling following triggered source water monitoring are not 
included in the final rule analysis. These potential impacts are 
discussed in Section VII.J.
    Another major change in the Economic Analysis since the proposed 
GWR is a more thorough analysis of the nonquantified costs. Chapter 6 
of the GWR EA describes the basis for the analysis (USEPA, 2006d). Rule 
changes can be found in Section VII.A of this preamble.

E. What Is the Potential Impact of the GWR on Households?

    This analysis considers the potential increase in a household's 
water bill if a CWS passed the entire cost increase resulting from this 
rule on to their customers. This analysis is a tool to gauge potential 
impacts and should not be construed as a precise estimate of potential 
changes to household water bills.
    The household cost analysis only considers the impact on CWSs. 
State costs and costs to TNCWSs and NTNCWSs are not included in this 
analysis since their costs are not passed through directly to 
households. Table VII-11 presents the mean expected increases in annual 
household costs for all CWSs, including those systems that do not have 
to take corrective action for significant deficiencies or source water 
fecal contamination. Table VII-11 also presents the same information 
for CWSs that must take corrective action. Household costs tend to 
decrease as system size increases, due mainly to the economies of scale 
for the corrective actions.
    As shown in Table VII-11, the mean annual household costs for 
systems (including those that do not add treatment) range from $0.21 to 
$16.54 (systems serving fewer households generally have higher average 
annual household costs). Household costs for the subset of systems that 
take corrective actions range from $0.45 to $52.38. EPA estimates that, 
as a whole, households subject to the GWR face minimal increases in 
their annual costs. The lowest increases in household costs are for 
those served by larger systems due to significant economies of scale 
and because many already disinfect. Approximately 66 percent of the 
households potentially affected by the GWR are customers of systems 
that serve at least 10,000 people. Households served by small systems 
that take corrective actions will face the greatest increases in annual 
costs.

[[Page 65631]]

[GRAPHIC] [TIFF OMITTED] TR08NO06.012

F. What Are the Incremental Costs and Benefits of the GWR?

    The GWR regulatory alternatives achieve increasing levels of 
benefits at increasing levels of costs. The regulatory alternatives for 
this rule, in rank order of increasing costs and benefits are as 
follows:
     Alternative 1: Sanitary Survey and Corrective Action.
     Alternative 2: Risk-Targeted Approach.
     Alternative 3: Multi-Barrier Approach.
     Alternative 4: Across-the-Board Disinfection.
    More information about the alternatives is provided in the GWR EA 
(USEPA, 2006d).
    Incremental costs and benefits are those that are incurred or 
realized in reducing viral illnesses and deaths from one alternative to 
the next more stringent alternative. Estimates of incremental costs and 
benefits are useful in considering the economic efficiency of different 
regulatory alternatives considered by the Agency. Generally, the goal 
of an incremental analysis is to identify the regulatory alternatives 
where net social benefits are maximized. However, the usefulness of 
this analysis is constrained when major benefits and/or costs are not 
quantified or not monetized as in the case with the GWR. Also, as 
pointed out by the Environmental Economics Advisory Committee of the 
Science Advisory Board, efficiency is not the only appropriate 
criterion for social decisionmaking (USEPA, 2000d).
    For the GWR, presentation of incremental quantitative benefit and 
cost comparisons may be unrepresentative of the true net benefits of 
the rule because a significant portion of the rule's potential benefits 
are not quantified, particularly bacterial illness and deaths (see 
Section VII.C.4).
    Table VII-12a and Table VII-12b present the four regulatory 
alternatives in order of increasing level of reduction in waterborne 
pathogens or increasing level of protection from illness. All values 
are annualized mean present values expressed in year 2003 dollars. The 
lower and upper bounds of a 90 percent confidence interval are shown 
below the mean numbers. As shown in Tables VII-12a and b, incremental 
net benefits for all alternatives are negative. The nonquantified 
bacterial illness benefits would add benefits to all alternatives 
without any increase in costs. EPA estimated that the total benefits 
could increase by more than a factor of five by accounting for 
additional deaths and hospitalizations caused by reduced bacterial 
illness alone. These nonquantified benefits have a significant positive 
impact on the incremental benefits and incremental net benefits. Both 
Alternative 3 and Alternative 2 could have positive incremental net 
benefits if the bacterial benefits are considered. The next highest 
alternative, Alternative 4, has such highly negative incremental net 
benefits, and the difference is so substantial, that nonquantified 
benefits would be unlikely to compensate. However, comparisons between 
Alternative 4 and the other alternatives may be between two separate 
sets of benefits, in the sense that they may be distributed to somewhat 
different populations.

[[Page 65632]]

                                       Table VII-12a.--Incremental Net Benefits by Rule Alternative--Enhanced COI
                                                    [Annualized Present Value Mean, $Millions, 2003$]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Annual quantified costs     Annual quantified       Incremental     Incremental     Incremental
                                                                                 benefits (enhanced COI)       costs         benefits*     net benefits*
                   Rule alternatives                   -------------------------------------------------------------------------------------------------
                                                                   A                        B                    C               D            E = D-C
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Three Percent Discount Rate
                                                                      (in dollars)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alternative 1: Sanitary Survey and Corrective Action..         15.3 (11.8-19.2)            3.6 (0.9-9.3)            15.3             3.6           -11.7
Final Rule: Risk-targeted Approach**..................         61.8 (45.2-81.4)          19.7 (6.5-45.4)            46.5            16.1           -30.4
Alternative 3: Multi-Barrier Approach.................         67.9 (49.4-89.5)          21.3 (7.1-48.7)             6.1             1.6            -4.5
Alternative 4: Across-the-Board Disinfection..........      686.4 (636.8-735.4)        70.2 (18.3-177.0)           618.5            48.9          -569.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Seven Percent Discount Rate
                                                                      (in dollars)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alternative 1: Sanitary Survey and Corrective Action..         15.3 (11.9-19.0)            2.9 (0.7-7.5)            15.3             2.9           -12.4
Final Rule: Risk-targeted Approach**..................         62.3 (46.1-81.6)          16.8 (5.5-38.6)            47.0            13.9           -33.1
Alternative 3: Multi-Barrier Approach.................         69.4 (51.0-90.6)          18.2 (6.0-41.6)             7.1             1.4            -5.7
Alternative 4: Across-the-Board Disinfection..........      665.3 (612.3-717.0)        61.9 (16.1-156.3)           595.9            43.8         -552.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Does not include significant nonquantified benefits. See GWR EA Section 5.4 (USEPA, 2006d).
**Benefits and costs are also not included for optional assessment source water monitoring.

                                      Table VII-12b.--Incremental Net Benefits by Rule Alternative--Traditional COI
                                                    [Annualized Present Value Mean, $Millions, 2003$]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Annual quantified costs     Annual quantified       Incremental     Incremental     Incremental
                                                                                  benefits (traditional        costs         benefits*     net benefits*
                   Rule alternatives                   -------------------------           COI)          -----------------------------------------------
                                                                                -------------------------
                                                                   A                        B                    C               D            E = D-C
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Three Percent Discount Rate
                                                                      (in dollars)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alternative 1: Sanitary Survey and Corrective Action..         15.3 (11.8-19.2)            1.9 (0.3-5.5)            15.3             1.9           -13.5
Final Rule: Risk-targeted Approach**..................         61.8 (45.2-81.4)          10.0 (2.2-27.0)            46.5             8.2           -38.3
Alternative 3: Multi-Barrier Approach.................         67.9 (49.4-89.5)          10.8 (2.5-28.9)             6.1             0.8            -5.3
Alternative 4: Across-the-Board Disinfection..........      686.4 (636.8-735.4)         35.5 (6.5-102.4)           618.5            24.7          -593.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Seven Percent Discount Rate
                                                                      (in dollars)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alternative 1: Sanitary Survey and Corrective Action..         15.3 (11.9-19.0)            1.5 (0.2-4.5)            15.3             1.5           -13.8
Final Rule: Risk-targeted Approach**..................         62.3 (46.1-81.6)           8.6 (1.9-23.0)            47.0             7.1           -39.9
Alternative 3: Multi-Barrier Approch..................         69.4 (51.0-90.6)           9.3 (2.1-24.8)             7.1             0.7            -6.4
Alternative 4: Across-the-Board Disinfection..........      665.3 (612.3-717.0)          31.5 (5.7-90.8)           595.9            22.2         -573.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Does not include significant nonquantified benefits. See GWR EA Section 5.4 (USEPA, 2006d).
**Benefits and costs are also not included for optional assessment source water monitoring.
Notes: The Traditional COI only includes valuation for medical costs and lost work time (including some portion of unpaid household production and
  caregiver time for sick children). The Enhanced COI also factors in valuations for lost personal time (non-worktime) such as child care and homemaking
  (to the extent not covered by the traditional COI), time with family, and recreation, and lost productivity at work on days when workers are ill but
  go to work anyway.
Source: Chapter 8 of the GWR EA (USEPA, 2006d). Ranges in parentheses are the 90 percent confidence bounds.

[[Page 65633]]

G. Are There Any Benefits From Simultaneous Reduction of Co-Occurring 
Contaminants?

    As discussed in Section VII.B.2, the GWR is expected to reduce not 
only viral illnesses and deaths (the monetized rule benefit) but also 
bacterial illnesses and deaths. This rule is also expected to decrease 
the risk of outbreaks that would reduce illnesses and deaths and other 
outbreak-related costs. Additional health benefits of this rule include 
the reduction in illnesses and deaths associated with reduced incidence 
of upsets or failures among disinfecting supplies and reduced incidence 
of distribution system contamination among disinfecting and non-
disinfecting systems. EPA anticipates reductions in disease incidence 
in these areas to result from the sanitary survey provisions and the 
treatment and monitoring provisions pertaining to disinfected supplies.
    If a system chooses to install treatment, it may choose a 
technology that would also address other drinking water contaminants. 
If a system had an iron or manganese problem, for example, the addition 
of an oxidant and filtration could treat this problem as well as fecal 
contamination. Also, some membrane technologies installed to remove 
bacteria or viruses can reduce or eliminate many other drinking water 
contaminants, including arsenic. EPA recognizes that some systems will 
choose these more expensive treatment technologies. EPA has included 
them in the decision tree in the cost analysis, but no estimate of the 
additional benefit from reducing co-occurring contaminants has been 
made.

H. Is There Any Increase in Risk From Other Contaminants?

    It is unlikely that the GWR will result in a significant increase 
in risk from other contaminants, although adding disinfection to 
currently non-disinfecting systems could result in some increased risk. 
When disinfection is first introduced into a previously undisinfected 
system, the disinfectant can react with pipe scale, causing increased 
risk from some contaminants and other water quality problems. 
Contaminants that could be released include lead, copper, and arsenic. 
It could also possibly lead to a temporary discoloration of the water 
as the scale is loosened from the pipe. These risks can be addressed by 
gradually phasing in disinfection to the system, by targeted flushing 
of distribution system mains, and by maintaining a proper corrosion 
control program.
    Using a chemical disinfectant could also result in an increased 
risk from disinfection byproducts (DBPs). Risk from DBPs has already 
been addressed in the Stage 1 Disinfection Byproducts Rule (DBPR) 
(USEPA, 1998c) and additional consideration of DBP risk has been 
addressed in the recently published final Stage 2 DBPR (USEPA, 2006g). 
In general, GWSs are less likely to experience high levels of DBPs than 
surface water systems because they have lower levels of naturally 
occurring organic materials (generally represented by total organic 
carbon (TOC)) that contribute to DBP formation. For the most part, GWSs 
with high levels of TOC in their ground water source are located in 
States that already require GWSs to disinfect, therefore decreasing the 
chance that significant disinfection byproduct problems would result 
from this rule.

I. What Are the Effects of the Contaminant on the General Population 
and Groups Within the General Population That Are Identified as Likely 
To Be at Greater Risk of Adverse Health Effects?

    EPA estimates that the average annual baseline illnesses and deaths 
associated with viruses in ground water are about 185,000 and 3, 
respectively (Table VII-4). The general population typically 
experiences GI illness when exposed to waterborne viral and bacterial 
pathogens, although other severe diseases such as kidney failure can 
also occur. Sensitive subpopulation exposure to these pathogens can 
result in more severe illness than in the general population, and 
sometimes death.
    Examples of sensitive subpopulations include pregnant women, 
infants, elderly (over 65), cancer patients, and AIDS patients (Gerba 
et al., 1996). Gerba estimates that these groups represent almost 20 
percent of the U.S. population. The purpose of this section is to 
discuss the potential health effects associated with sensitive 
population groups, especially children, pregnant women, and the 
elderly.
1. Risk of Acute Viral Illness to Children and Pregnant Women
    The risk of acute illness and death due to viral contamination of 
drinking water depends on several factors, including the age of the 
exposed individual. Infants and young children have higher rates of 
infection and disease from enteroviruses than other age groups (USEPA, 
1999). Several enteroviruses that can be transmitted through water can 
have serious health consequences in children. Enteroviruses (which 
include poliovirus, coxsackievirus, and echovirus) have been implicated 
in cases of flaccid paralysis, myocarditis, encephalitis, hemorrhagic 
conjunctivitis, and diabetes mellitis (CDC, 1997; Modlin, 1997; 
Melnick, 1996; Cherry, 1995; Berlin et al., 1993; Smith, 1970; Dalldorf 
and Melnick, 1965). Women may be at increased risk from enteric viruses 
during pregnancy (Gerba et al., 1996). Enterovirus infections in 
pregnant women can also be transmitted to the unborn child late in 
pregnancy, sometimes resulting in severe illness in the newborn (USEPA, 
2000e).
    a. Children's Environmental Health. To comply with Executive Order 
13045, EPA calculated the baseline risk and reduction of risk from 
waterborne viral illness and death for children as a result of this 
rule. To address the disproportionate risk of waterborne viral illness 
and death affecting children, EPA used age-specific morbidity data in 
the risk assessment. The risk assessment first estimated the proportion 
of the population that falls into several age categories for which data 
are available for two model viruses: Type A (represented by rotavirus 
data) and Type B (represented by enterovirus or echovirus data).
    While bacterial illnesses are not addressed in the quantified 
benefits analysis, EPA believes that the nonquantified benefits 
associated with consumption of undisinfected bacterially contaminated 
PWS well water could be significant in sensitive subpopulations. In an 
alternative analysis to the quantified benefits calculation, EPA 
estimated that roughly 16,805 bacterial illnesses and 11 bacterial 
deaths annually could be avoided in the general population. See Section 
5.4.3 of the GWR EA for details of the analysis (USEPA, 2006d). 
Children and the elderly are particularly vulnerable to kidney failure 
(hemolytic uremic syndrome) caused by the bacterium E. coli O157:H7. 
Waterborne outbreaks due to E. coli O157:H7 have caused kidney failure 
in children and the elderly as the result of disease outbreaks from 
consuming ground water in Cabool, Missouri (Swerdlow et al., 1992); 
Alpine, Wyoming (Olsen et al., 2002); Washington County, New York (NY 
State DOH, 2000); and Walkerton, Ontario, Canada (Health Canada, 2000).
    Type A viruses of high infectivity (Type A, e.g., rotavirus) 
disproportionately affect children less than three years of age. Thus, 
the age categories used in the hazard analysis were less than three 
years of age and greater than three years of age. Based on rotavirus 
data, it was assumed that 10 to

[[Page 65634]]

88 percent of children less than three years old would become ill once 
infected with high infectivity viruses and that 10 to 50 percent of the 
population over three years of age would become ill.
    For viruses of low-to-medium infectivity (Type B, e.g., echovirus), 
children are again disproportionately at risk of becoming ill once 
infected. For this virus type, the age categories used in the hazard 
analysis were less than five years of age, five to 19 years of age, and 
greater than 19 years of age. Based on echovirus data, EPA estimated 
that 50 to 78 percent of children less than five years old would become 
ill once infected with low-to-medium infectivity viruses, 12 to 57 
percent of children five to 19 years of age and 12 to 33 percent of 
people over 19 years of age would become ill once infected.
    In addition to illness, EPA also considered child mortality 
attributable to waterborne viral illness. For viruses of high 
infectivity (Type A), EPA estimates 0.00057 to 0.00073 percent of the 
ill population (including children) will die (Tucker et al., 1998). 
This value, based on rotavirus data from children less than five years 
of age (20 deaths from 2,730,000 to 3,500,000 illnesses), was applied 
to individuals of all ages because data for older individuals are not 
available. For low-to-medium infectivity viruses (Type B), EPA 
estimates that 0.92 percent of children less than one month of age who 
become ill will die based on data from Jenista et al. (1984), Modlin 
(1986) and Kaplan et al. (1983). For those individuals greater than one 
month in age, 0.02 percent who become ill will die based on the EPA 
assumption that one percent of enterovirus illnesses are severe and two 
percent of severe illnesses result in death. The low-to-medium 
infectivity viruses result in a higher mortality rate than the high 
infectivity viruses because they can cause more serious health effects.
    To estimate the benefits to children from this rule, the Agency 
calculated the number of endemic, acute viral illnesses and deaths 
avoided after rule implementation for children less than five years old 
and for children ages five through 15 years old. Table VII-13 shows the 
estimates for annual illnesses avoided in young children due to this 
rule. Overall, this rule will result in about 2,780 fewer endemic, 
acute viral illnesses per year caused by Type A (represented by 
rotavirus data) and Type B (represented by enterovirus or echovirus 
data) viruses and 0.06 deaths in children less than five years of age. 
For older children aged five to 15 years of age, this rule will result 
in 4,856 fewer acute illnesses per year (see Chapter 5 of the GWR EA 
(USEPA, 2006d)). In addition to endemic, acute viral illnesses avoided, 
EPA estimates that there will be fewer deaths (less than one death) in 
children of all ages.
    Of the total annual avoided gastrointestinal illnesses predicted as 
the result of this rule, approximately 18 percent (7,636) of the mean 
annual illnesses avoided occur in children aged 15 years or younger. 
Children are disproportionately represented in the average annual 
number of illnesses avoided. Because children are often likely to be 
exposed via exposure pathways other than water in schools and day care 
centers (including fomites, respiratory, dermal, and person-to-person), 
the waterborne proportion probably does not dominate in total exposure 
but it may represent a significant fraction. More serious waterborne 
illnesses, such as hemolytic uremic syndrome (kidney failure), 
disproportionately affect children but this calculation only considers 
gastrointestinal illness.

                      Table VII-13.--Annual Viral Illnesses Avoided by the GWR in Children, the Elderly, and the Immunocompromised
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Infants and
              Virus type                     Health effect      young children    Elderly adults >65     Immunocompromised (all       Total sensitive
                                                                 < 5 years old          years old                  ages)                  subgroups
--------------------------------------------------------------------------------------------------------------------------------------------------------
Type A (Rotavirus)....................  Illness...............           2,588  Illness: 5,559........  Illness: 126............  Illness: 8,465.
                                        Death.................            0.02
Type B (Enterovirus or Echovirus).....  Illness...............             191  Deaths: 0.10..........  Deaths: 0.002...........  Deaths: 0.15.
                                        Death.................            0.04
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Detail may not sum due to independent statistical analyses and rounding. The figures presented represent only the quantifiable benefits of the
  GWR. The nonquantified benefits are expected to comprise a significant portion of the overall benefits of the GWR and are presented in Section 5.4 of
  the GWR EA (USEPA, 2006d). The immunocompromised population includes bone marrow transplant recipients, AIDS patients, and organ transplant patients.
Source: Number of Illnesses Avoided, Deaths Avoided, and Annual Benefits from GWR Model Output.

2. Risk of Viral Illness to the Elderly and Immunocompromised
    The elderly are particularly at risk from diarrheal diseases (Glass 
et al., 2000), such as those associated with waterborne microbial 
pathogens. Fifty-three percent of diarrheal deaths occur among those 
older than 74 years of age, and 77 percent of diarrheal deaths occur 
among those older than 64 years of age. In Cabool, Missouri (Swerdlow 
et al., 1992), a waterborne E. coli O157:H7 outbreak in a GWS resulted 
in four deaths, all among the elderly. One death occurred from 
hemolytic uremic syndrome (kidney failure); the others from 
gastrointestinal illness. Table VII-13 shows that this rule's estimates 
for avoided viral illnesses and deaths per year in the elderly 
population (> 65 years old) are approximately 5,559 and 0.1, 
respectively.
    Most epidemiological studies focus on nursing homes because the 
cluster of individuals improves data collection. Nursing home 
populations are typically, but not exclusively, elderly. Gerba et al. 
(1996) compiled data to show that, for the various waterborne microbial 
pathogens, nursing home mortality rates are significantly higher than 
in the general population. In Gideon, Missouri, a waterborne Salmonella 
typhimurium outbreak (Angulo et al., 1997) resulted in seven deaths 
from gastrointestinal illness, all among nursing home residents.
    Hospitalizations due to diarrheal disease are higher in the elderly 
(Glass et al., 2000). Average hospital stays for individuals older than 
74 years of age due to diarrheal illness are 7.4 days compared to 4.1 
days for individuals aged 20 to 49 (Glass et al., 2000).
    For another significant sensitive subpopulation, the 
immunocompromised, Gerba et al. (1996) summarized the literature and 
reported that enteric adenovirus and rotavirus are the two waterborne 
viruses most commonly isolated in the stools of AIDS patients. For 
patients undergoing bone-marrow transplants, several

[[Page 65635]]

studies cited by Gerba et al. (1996) reported mortality rates greater 
than 50 percent among patients infected with enteric viruses. Table 
VII-13 shows that this rule's estimates for avoided illnesses and 
deaths in the immunocompromised groups (all ages) are approximately 126 
and 0.002, respectively.
    Overall, this rule will provide protection from waterborne viral 
and bacterial illness to both the general population and sensitive 
subpopulations. To capture the impact of the rule on both populations, 
the Agency considered the different severities of illness when valuing 
reductions in illness that will result from this rule.

J. What Are the Uncertainties in the Risk, Benefit, and Cost Estimates 
for the GWR?

    Many uncertain values are used to derive estimates of baseline 
risk, risk reductions, and costs of this rule. Most, but not all, of 
these are mathematically modeled so that a ``realization'' is selected 
for them in each ``uncertainty iteration'' of EPA's probabilistic 
economic analysis. These uncertainties then propagate through the 
derivation of final estimates so the total uncertainty of those final 
estimates can be understood. Each of those uncertainties, or the 
assumption that is made by not modeling it mathematically, is 
summarized in Sections 5.6 (for benefits) and 6.7 (for costs) in the 
GWR EA (USEPA, 2006d) for its importance and tendency to contribute 
systematically to an over-or understatement of the final estimate. The 
paragraphs that follow discuss the most important of these uncertain 
quantities.
1. The Baseline Numbers of Ground Water Systems, Populations Served, 
and Associated Disinfection Practice
    The baseline number of systems is uncertain because of data 
limitations in the Safe Drinking Water Information System (SDWIS). For 
example, some systems use both ground and surface water, but because of 
other regulatory requirements, they are labeled in SDWIS as surface 
water systems. In addition, the SDWIS data on NCWSs do not reflect a 
consistent reporting convention for population served. Some States may 
report the population served by TNCWSs over the course of a year, while 
others may report the population served on an average day. For example, 
a State park may report the population served yearly instead of daily. 
Thus, SDWIS data may, in some cases, overestimate the daily population 
served. Also, SDWIS does not require States to provide information on 
current disinfection practices, resulting in uncertainty in the 
percentage of disinfecting systems providing 4-log or greater virus 
treatment. Although these different factors influencing the baseline 
estimates are uncertain, EPA believes that their relative degree of 
uncertainty in influencing the estimates within the GWR EA is small 
compared to other uncertain components of the Economic Analysis, so 
these are not treated probabilistically in the analysis.
2. The Numbers of Wells Designated as More Versus Less Vulnerable
    For the purposes of the GWR EA, contaminated wells are classified 
as more or less vulnerable, which determines the assumptions used for 
the concentrations of virus as discussed in Section VII.B.1.c of this 
preamble. The numbers of systems falling into these two categories is 
uncertain and is also modeled as an uncertain variable.
3. The Baseline Occurrence of Viruses and E. coli in Ground Water Wells
    EPA's occurrence analysis is based on monitoring data from over 
1,200 public drinking water supply wells that were tested for 
culturable virus, E. coli, or both. Compiled from 15 ground water 
surveys that were designed for different purposes, these wells are 
believed to be representative of ground water wells. Although the 
number of wells is large, the number of assays per well is small, and 
most wells were sampled only once for either virus or E. coli. Because 
of the limited amount of data, these data do not provide precise 
occurrence estimates. EPA's analysis recognizes the limitations of the 
data, producing a large ``uncertainty sample'' of estimates that are 
consistent with the data. This uncertainty sample is an input to the 
probabilistic economic analysis, where these uncertainties are combined 
with the uncertainties of other inputs to portray total uncertainty in 
the GWR cost and benefit estimates. EPA's occurrence model includes 
concentration differences between more and less vulnerable wells, but 
applies the same hit rate model to both types of wells. Also, because 
of data limitations, EPA was unable to make an assessment of aquifer 
sensitivity as part of the final rule and, therefore, no difference in 
hit rates or concentration levels between sensitive and nonsensitive 
wells is assumed. The GWR EA addresses uncertainty about these 
assumptions in a qualitative discussion (USEPA, 2006d).
4. For the Sanitary Survey Provisions, the Percentage of Systems 
Identified as Having Significant Deficiencies, the Percentage of These 
Deficiencies That Are Corrected, and State Costs for Conducting Surveys
    For the sanitary survey provisions, EPA estimated the impacts 
associated with well deficiencies. EPA used data from the 1998 ASDWA 
survey to estimate the percentage of wells with deficiencies (ASDWA, 
1997). To estimate benefits, EPA assumed that if a correction of a well 
defect occurred at a virally contaminated well, some, but not all of 
these virally contaminated wells would no longer have viral 
contamination. EPA used an uncertainty distribution for this estimate.
    To estimate costs for significant deficiencies detected at or near 
the source, EPA chose two representative corrective actions to use in 
the cost model: replacement of a sanitary well seal or rehabilitation 
of an existing well. Because the corrections of significant 
deficiencies are dependent upon the deficiencies defined as significant 
by States and the conditions of specific systems, both of which are 
highly variable, EPA used a high and low scenario to bound the cost 
estimates. The low-cost scenario assumes a greater percentage of the 
systems with significant deficiencies will have deficiencies that are 
less expensive to correct (e.g., more systems will have to replace 
their sanitary well seal than will have to perform a complete 
rehabilitation of their well). This high/low bounding provides an 
estimate of the uncertainty with respect to the percentages of each 
type of defect to be corrected.
    While the sanitary survey provisions will also result in 
identification and correction for deficiencies associated with 
treatment or distribution system deficiencies, due to insufficient 
data, EPA did not quantify either costs or benefits for these types of 
deficiencies. In the GWR EA, EPA qualitatively discusses these impacts 
(USEPA, 2006d).
    Finally, EPA assumes that most States are already conducting 
sanitary surveys that include the eight required elements, and that 
many States are already conducting sanitary surveys for GWSs that meet 
the frequency requirements in the GWR, so EPA estimated incremental 
costs for these activities in only a relatively small subset of States.

[[Page 65636]]

5. The Predicted Rates at Which Virally Contaminated (and Non-
Contaminated) Wells Will Be Required To Take Action After Finding E. 
coli Ground Water Sources
    EPA's occurrence model estimates the percentage of wells that have 
only virus present, both E. coli and virus present, or only E. coli 
present. The occurrence model also includes parameters that describe 
how often contaminated wells actually have the contaminant present. For 
example, some contaminated wells have E. coli present less than one 
percent of the time, while others have E. coli present more than 10 
percent of the time (some of which will also have sometime viral 
presence). When E. coli-contaminated wells are tested for the first 
time, those with frequent E. coli occurrence are the most likely to be 
identified as contaminated. As these problems are addressed and 
corrected, there should be fewer and fewer wells with frequent E. coli 
occurrence (as well as viral occurrence since a fraction of E. coli 
wells will also have sometime viral presence; see Section III.C.2 for 
further elaboration). This diminishing rate of fecal contamination 
identification is included in the GWR EA (USEPA, 2006d). Uncertainty 
about the diminishing rate is due to uncertainty about the EPA's 
estimates of how often E. coli occurs in contaminated wells. As with 
other key uncertain inputs, this uncertainty is represented by an 
uncertainty sample of the relevant parameters. Again, EPA assumes no 
difference based on vulnerability or sensitivity. The GWR EA 
qualitatively discusses uncertainty of this assumption (USEPA, 2006d).
    Undisinfected wells are subjected to triggered source water 
monitoring. The rate at which triggered source water monitoring 
identifies a well as fecally-contaminated depends on both the fraction 
of time that E. coli is present in the well and the frequency at which 
the well is sampled. Data verification (DV) data on total coliform 
occurrence in distribution systems provide the basis for estimates of 
sampling frequency in different types and sizes of systems. Although 
the data are limited, EPA has not modeled these as uncertain estimates. 
Compared to other uncertain parameters, these have relatively little 
uncertainty and are expected to make only minor contributions to the 
total uncertainty in the GWR EA.
    EPA also did not consider the cost impacts of additional fecal 
indicator sampling following triggered source water monitoring on 
corrective action costs. The analysis assumes that for every triggered 
source water monitoring positive, at least one additional fecal 
indicator sample will also be positive, resulting in corrective action. 
The rationale for this assumption is explained in Chapter 6 of the GWR 
EA. However, it is possible that some systems will not have a positive 
additional fecal indicator sample and will therefore not incur costs 
for corrective action. Accounting for this would reduce the costs of 
the rule associated with corrective actions and, to the extent that 
these systems actually do have viral or bacterial pathogens present, 
would reduce the benefits of the rule as well.
    EPA assumes that the occurrence of fecal contamination will remain 
constant throughout the implementation of the rule. However, this might 
not be the case if increased development results in fecal contamination 
of a larger number of aquifers in areas served by GWSs or if other 
rules, such as Concentrated Animal Feeding Operations (CAFO) and Class 
V Underground Injections Control (UIC) Well regulations, result in 
decreased fecal contamination. This uncertainty is not mathematically 
modeled in the GWR Economic Analysis.
6. The Infectivity of Echovirus and Rotavirus Used To Represent Viruses 
That Occur in Ground Water
    EPA does not have dose-response data for all viruses associated 
with previous ground water disease outbreaks. For viral illness, the 
Agency used echovirus and rotavirus as surrogates for all pathogenic 
viruses from fecal contamination that can be found in ground water. By 
using these two viruses, the Agency is capturing the effects of both 
high infectivity (Type A) viruses that cause mild illness and low-to-
medium infectivity (Type B) viruses that may cause more severe illness 
but not the range of infectivity within each type. Further, there is 
additional uncertainty in the dose-response functions used, even for 
these two viruses. The dose-response relationship was modeled in two 
steps. First, infectivity, or the percentage of people in the different 
age groups who become infected after exposure to a given quantity of 
water with a given concentration of viruses, was estimated. Then 
morbidity, or the percentage of infected people who actually become 
ill, was estimated. EPA models uncertainty for morbidity within 
different age categories and differences in morbidity across different 
age categories (variability).
7. The Costs of Illnesses Due to Ingestion of Contaminated Ground Water
    There is also uncertainty in the valuation of risk reduction 
benefits. For this analysis, EPA used a cost of illness (COI) approach 
based on the direct medical care costs as well as the indirect costs of 
becoming ill. However, there is uncertainty in these estimates and 
variability in the COI across populations and geographic regions.
8. The Costs of Taking Action After Finding E. coli in Ground Water 
Sources
    EPA recognizes that there are both variability and uncertainty in 
unit cost estimates for treatment. Variability is expected in the 
actual costs that will be experienced by different water systems with 
similar flows installing the same treatment technology. Otherwise 
similar systems may experience different capital and/or O&M costs due 
to site-specific factors. Inputs to unit costs such as water quality 
conditions, labor rates, and land costs can be highly variable and 
increase the system-to-system variability in unit costs. In developing 
the unit cost estimates, there is insufficient information to fully 
characterize what the distribution of this variability will be on a 
national scale for all of the treatments and all possible conditions.
    The unit costs for the GWR EA are developed as average or 
representative estimates of what these unit costs will be nationally. 
That is, in developing unit costs, design criteria for the technologies 
were selected to represent typical, or average, conditions for the 
universe of systems. As a result, there is uncertainty inherent in 
these unit cost estimates since they are based on independent 
assumptions with supporting data and vendor quotes, where available, 
rather than on a detailed aggregation of State, regional, or local 
estimates based on actual field conditions. EPA quantifies the 
uncertainty in these national average unit cost factors for specific 
technologies. The percentage uncertainty bounds used to characterize 
unit costs were developed based on input from engineering professionals 
and reflect recommendations from the National Drinking Water Advisory 
Council (NDWAC, 2001) in its review of the national cost estimation 
methodology for the Arsenic Rule. EPA believes that the uncertainties 
in capital and O&M costs for a given treatment technology are 
independent of one another and that uncertainties across all 
technologies are independent.

[[Page 65637]]

9. Nonquantifiable Benefits
    A major uncertainty concerns the number of baseline bacterial 
illnesses caused by ground water contamination. The bacterial risk 
could not be modeled because of the lack of occurrence and dose-
response data; therefore, the Agency was unable to include these 
benefits in the primary analysis. Many other nonquantifiable endpoints 
(as discussed in Section VII.C.4 of this preamble and in the GWR EA 
Chapter 5 (USEPA, 2006d) cause further uncertainty. In summary, the 
quantified benefits may be small as compared with the total benefits. 
EPA's analysis of benefits from avoided bacterial illnesses and deaths 
suggests that these benefits could exceed the monetized benefits by a 
factor of five.
10. Optional Assessment Source Water Monitoring
    The Agency was not able to estimate the benefits or costs resulting 
from the optional assessment source water monitoring program. States 
can determine which systems they deem most vulnerable to fecal 
contamination and require these systems to conduct assessment source 
water monitoring. Systems would incur additional costs from monitoring 
and reporting results as well as any corrective action associated with 
fecal indicator-positives. States would incur additional costs for 
determining what systems would be required to monitor, assisting 
systems with corrective action decisions, and recordkeeping. The types 
of illnesses avoided would be similar to those already described in 
this preamble such as reduced viral and bacterial illness.
11. Corrective Actions and Significant Deficiencies
    The Agency also did not develop costs for corrective actions for 
all conceivable significant deficiencies that a system may encounter. 
Instead, representative actions that span the range of low cost to 
expensive actions were used as shown in Table VII-10. The corrective 
actions that are a result of significant deficiencies identified during 
sanitary surveys do not include the ones performed within the treatment 
plant or in the distribution system due to lack of adequate data. 
Exclusion of these costs from the cost analysis results in an 
underestimate of potential rule costs, though the magnitude of the 
underestimate is unknown. Data limitations also exclude quantifying any 
benefits that may be realized from these corrective actions. More 
information regarding these costs and benefits can be found in the GWR 
EA (USEPA, 2006d) (see Chapter 6.6 for cost and Chapter 5.4.7 and 5.4.8 
for benefits).
12. Uncertainty Summary
    Overall, EPA recognizes that there is uncertainty in various parts 
of its estimates. The Agency has, however, been careful to use the best 
available data to account for uncertainty quantitatively when possible, 
and to avoid any consistent biases in assumptions and the use of data. 
The primary known bias is that some benefits and costs have not been 
quantified, and therefore are not included in the quantitative 
comparison of regulatory alternatives. However, as explained above and 
in the EA, EPA believes that the nonquantified benefits are 
significantly greater than the quantified benefits. In summary, EPA 
believes that the analyses presented represent a solid foundation for 
the decisions made for this rule.

K. What Is the Benefit/Cost Determination for the GWR?

    As required by the SDWA, at the time of proposal, the Agency 
determined that the benefits of this rule justify the costs. In making 
this determination, EPA considered both quantified and nonquantified 
benefits and costs as well as the other components of the HRRCA 
outlined in section 1412 (b)(3)(C) of the SDWA.
    For the final rule, as shown in Table VII-14, for the regulatory 
alternative being finalized in this rule, the annualized mean 
quantified benefits are approximately $20 million ($10 million using 
traditional cost-of-illness values) and the annualized mean quantified 
costs are approximately $62 million using a three percent discount rate 
($17/$9 million and $62 million, respectively, using a seven percent 
discount rate). Overall, the GWR will reduce the risk of fecal 
contamination reaching the consumer. The monetized costs of these 
provisions were compared to the monetized benefits that result from the 
reduction in some viral illnesses and deaths. In addition, other non-
monetized benefits further justify the costs of this rule. For example, 
including bacterial illness would significantly increase the benefits 
without any increases in costs.
    Table VII-15 shows the net benefits for this rule as well as the 
three regulatory alternatives considered. The net benefits include only 
the monetized values (i.e., nonquantified costs and benefits are not 
considered). The nonquantified benefits are likely to be significantly 
greater than the quantified benefits (and also much greater that the 
nonquantified costs). Thus, the net benefits of each of the options may 
be higher than shown in these estimates. Nonquantified costs are also 
not included.

                                       Table VII-14.--Estimated Annualized National Benefits and Costs for the GWR
                                                                   [$Millions, 2003$]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         3% Discount rate                                7% Discount rate
                                                         -----------------------------------------------------------------------------------------------
                                                                            90 percent confidence bound                     90 percent confidence bound
                                                                         --------------------------------                -------------------------------
                                                               Mean         Lower (5th      Upper (95th        Mean         Lower (5th      Upper (95th
                                                                               %ile)           %ile)                           %ile)           %ile)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Enhanced COI:
    Benefits............................................           $19.7            $6.5           $45.4           $16.8            $5.5           $38.6
    Costs...............................................            61.8            45.2            81.4            62.3            46.1            81.6
    Net Benefits........................................           -42.1          Note 1          Note 1           -45.5          Note 1          Note 1
Traditional COI:
    Benefits............................................            10.0             2.2            27.0             8.6             1.9            22.9
    Costs...............................................            61.8            45.2            81.4            62.3            46.1            81.6
    Net Benefits........................................           -51.8          Note 1          Note 1           -53.7          Note 1          Note 1
    Nonquantified Benefits..............................  Decreased incidence of other acute viral disease endpoints.
                                                          Decreased incidence of bacterial illness and death.
                                                          Decreased incidence of chronic bacterial or viral illness sequellae.

[[Page 65638]]

                                                          Decreased incidence of waterborne disease outbreaks and epidemic illness.
                                                          Decreased illness through minimizing treatment failures or fewer episodes with inadequate
                                                          treatment.
                                                          Potential decreased use of bottled water and point-of-use devices (material costs).
                                                          Decreased time spent on averting behavior.
                                                          Avoided costs associated with outbreak response.
                                                          Perceived improvement in drinking water quality and reduction in risk associated with
                                                          ingestion.
                                                          Benefits from optional Assessment Source Water Monitoring.
                                                          Benefits from correction of sanitary survey deficiencies identified in the distribution
                                                          systems and treatment plant.
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Nonquantified Costs.................................  Costs for optional Assessment Source Water Monitoring.
                                                          Costs from correction of sanitary survey deficiencies identified in the distribution systems
                                                          and treatment plant.
                                                          Some land costs depending on the treatment technology.
                                                          Cost for five additional samples but this is small compared to the overestimate of cost for
                                                          the initial fecal-indicator sample that systems would take.
                                                          Costs for compliance monitoring at some systems that already disinfect.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note 1: Because benefits and costs are calculated using different model modules, bounds are not calculated on net benefits.
Note 2: The Traditional COI only includes valuation for medical costs and lost work time (including some portion of unpaid household production). The
  Enhanced COI also factors in valuations for lost personal time (non-worktime) such as child care and homemaking (to the extent not covered by the
  traditional COI), time with family, and recreation, and lost productivity at work on days when workers are ill but go to work anyway.

 Table VII-15.--Annualized Net Benefits ($Millions, 2003$) by Regulatory
                               Alternative
------------------------------------------------------------------------
                                             Annualized value
                                 ---------------------------------------
        Rule alternative           3% discount rate    7% discount rate
                                       (dollars)           (dollars)
------------------------------------------------------------------------
Enhanced COI:
    Alternative 1...............   -11.7............   -12.4
    Final Rule..................   -42.1............   -45.5
    Alternative 3...............   -46.6............   -51.2
    Alternative 4...............   -616.2...........   -603.4
Traditional COI:
    Alternative 1...............  -13.5.............  -13.8
    Final Rule..................   -51.8............   -53.7
    Alternative 3...............   -57.1............   -60.1
    Alternative 4...............   -650.9...........   -633.8
    Nonquantified Benefits......  Decreased incidence of other acute
                                   viral disease endpoints.
                                  Decreased incidence of bacterial
                                   illness and death.
                                  Decreased incidence of chronic
                                   bacterial or viral illness sequellae.
                                  Decreased incidence of waterborne
                                   disease outbreaks and epidemic
                                   illness.
                                  Decreased illness through minimizing
                                   treatment failures or fewer episodes
                                   with inadequate treatment.
                                  Potential decreased use of bottled
                                   water and point-of-use devices
                                   (material costs).
                                  Decreased time spent on averting
                                   behavior.
                                  Avoided costs associated with outbreak
                                   response.
                                  Perceived improvement in drinking
                                   water quality and reduction in risk
                                   associated with ingestion.
                                  Benefits from optional Assessment
                                   Source Water Monitoring.
                                  Benefits from correction of sanitary
                                   survey deficiencies identified in the
                                   distribution systems and treatment
                                   plant.
    Nonquantified Costs.........  Costs for optional Assessment Source
                                   Water Monitoring.
                                  Costs from correction of sanitary
                                   survey deficiencies identified in the
                                   distribution systems and treatment
                                   plant.
                                  Some land costs depending on the
                                   treatment technology.
                                  Cost for five additional samples but
                                   this is small compared to the
                                   overestimate of cost for the initial
                                   fecal-indicator sample that systems
                                   would take.
                                  Cost for compliance monitoring at some
                                   systems that already disinfect.
------------------------------------------------------------------------

[[Page 65639]]

    In addition to examining the net benefits of this rule, the Agency 
used several other techniques to compare benefits and costs. For 
example, Table VII-16 shows the cost of the rule per viral illness 
avoided. This cost effectiveness measure is another way of examining 
the benefits and costs of the rule but should not be used to compare 
alternatives because an alternative with the lowest cost per illness 
avoided may not result in the greatest net benefits. The cost 
effectiveness analysis, as with the net benefits, is limited because 
the Agency was able to only partially quantify and monetize the 
benefits of the GWR. This rule achieves the lowest cost per viral 
illness avoided. Additional information about this analysis and other 
methods used to compare benefits and costs can be found in Chapter 8 of 
the GWR EA (USEPA, 2006d).

    Table VII-16.--Cost Per Case of Viral Illness or Death Avoided by
                         Regulatory Alternative
                                 [2003$]
------------------------------------------------------------------------
                                          Cost per viral illness avoided
            Rule alternative             -------------------------------
                                           3% (dollars)    7% (dollars)
------------------------------------------------------------------------
Alternative 1...........................           2,045           2,044
Final Rule..............................           1,476           1,488
Alternative 3...........................           1,495           1,527
Alternative 4...........................           4,420           4,284
------------------------------------------------------------------------
Note: Calculated using mean costs of illness avoided.

    Overall, the measures described above are very close for the Final 
Rule and Alternative 3 and EPA believes that the nonquantified benefits 
of the rule would result in positive net benefits for either option. 
The Final Rule allows States to implement the assessment source water 
monitoring provision, which would have been mandatory if EPA had chosen 
Alternative 3, on a voluntary basis. The final GWR is more flexible, 
targeted, and protective than Alternative 3 (see Section VII.A of this 
preamble and Chapter 8 of the GWR EA (USEPA, 2006d) for more details). 
The level at which additional costs will be incurred and benefits 
realized under the voluntary provision is dependent on the rate at 
which States elect to adopt the provisions, and thus is not quantified 
as part of the Economic Analysis.

L. What Were Some of the Major Comments Received on the Economic 
Analysis and What Are EPA's Responses?

1. Costs
    EPA requested comment on all aspects of cost analysis for the 
proposed GWR, particularly on the flow estimate for NTNCWSs and TNCWSs 
and handling mixed systems. In addition to these two issues, EPA also 
received numerous comments on the following analyses: sanitary survey 
costs, estimate of treatment baseline, costs of corrective actions, and 
compliance costs for small systems or NCWSs.
    a. Flow estimate for NTNCWSs and TNCWSs. EPA received a few 
comments on NTNCWS and TNCWS flow estimates. Some commenters indicated 
that the alternative approach described in the preamble of the proposed 
rule would lead to greater disparities from the true values. The other 
commenters supported using the alternative approach. For this rule, EPA 
continues to apply the CWS regression equations to NCWSs, recognizing 
that this may overestimate flow and, therefore, costs. This 
overestimate is addressed as part of the uncertainties, which is 
discussed in Chapter 4 of the GWR EA (USEPA, 2006d). Further discussion 
of the alternative approach is also presented there.
    b. Mixed systems. EPA received comments that regulatory impacts on 
mixed systems were not adequately characterized because either their 
costs were underestimated or the methodology for deriving the costs was 
unclear. Since the available data was insufficient to directly account 
for ground water entry points in mixed systems, EPA based the cost 
estimate for mixed systems on the primarily ground water mixed system 
inventory report. Primarily ground water mixed systems are systems 
using ground water for more than 50 percent of their source water; the 
remainder of their source water is surface water. The primarily ground 
water-mixed CWSs identified by this calculation were added to the 
solely GWS inventory to produce the total baseline number of GWSs used 
in the economic analysis. Because NTNCWSs and TNCWSs are typically a 
single building or located in a small area, a simplifying assumption 
was made for this analysis that all NCWSs draw from a single source 
water type.
    The total baseline number of GWSs is treated as ground water-only 
systems throughout subsequent analyses. This methodology, treating 
mixed systems as ground water-only systems, may overestimate costs and 
benefits (i.e., some surface water entry points are now counted as 
ground water entry points). However, the ground water entry points in 
the excluded mixed surface water inventory (those mixed systems using 
less than 50 percent ground water) are not included in the analysis, 
potentially underestimating costs and benefits. The contrasting over- 
and under-accounting for ground water entry points are expected to 
offset one another to some extent in the cost and benefit analyses. 
Data are not available to quantify the direction or magnitude of the 
final effect on overall national cost estimates, but the effect is 
expected to be small. Chapter 4 of the GWR EA (USEPA, 2006d) contains a 
detailed description of the methodology for impact analysis of mixed 
systems.
    c. Sanitary survey costs. EPA received comments that the sanitary 
survey costs were inadequately estimated because of lack of 
considerations of the surveys currently performed by States and travel 
times needed for conducting surveys. The sanitary survey cost estimates 
used in this rule analysis have been updated based on data that became 
available after the proposed GWR. For the proposed GWR, EPA used the 
same unit costs as the ones used in a previous economic analysis 
(IESWTR) for estimating costs of full sanitary surveys. Fifty percent 
of full survey costs was applied to all systems as the incremental 
costs resulting from the GWR sanitary survey provision. This percentage 
was used to account for the more comprehensive survey coverage (i.e., 
evaluation of eight elements) under the GWR than under existing 
requirements of the TCR.
    For the final rule, EPA revised its cost analysis for conducting 
sanitary surveys

[[Page 65640]]

based on new information from States. First, EPA revised its estimates 
for conducting full sanitary surveys specifically for GWSs with and 
without treatment. Second, EPA estimated the number of additional full 
sanitary costs (including travel time costs) that would result from the 
higher frequency of sanitary surveys required under the GWR, over the 
number that is currently being implemented. This number of additional 
sanitary surveys was multiplied by the sanitary survey unit costs to 
estimate national costs for this effect.
    Third, for those sanitary surveys already being conducted, EPA 
estimated the percentage of systems for which sanitary surveys would 
need to be increased in scope to ensure that all 8 elements were being 
implemented. Because all States currently have sanitary surveys in 
place under the IESWTR, TCR, or other State programs, most States are 
now conducting sanitary surveys at the frequencies and scope required 
by the GWR. The revised sanitary survey costs thus assume no 
incremental unit costs in most States and are substantially lower than 
the estimates costed for the proposed GWR. Chapter 6 of the GWR EA 
(USEPA, 2006d) contains a detailed discussion of sanitary survey 
costing assumptions.
    d. Treatment baseline. EPA received comments that the percentage of 
disinfecting systems currently achieving 4-log virus inactivation was 
overestimated. For the proposed rule, EPA based the estimate of systems 
achieving 4-log inactivation (77 percent) on the data from the AWWA 
disinfection survey for community GWSs. EPA recognizes the limited data 
resources; AWWA data was the only source available on a national level 
and the disinfection rate estimate used in the proposed rule is likely 
to bias high due to relatively small sample size and question 
complexity for the survey.
    In the final GWR EA, EPA re-evaluated the AWWA data and made a 
conservative assumption that those community GWSs providing 
insufficient information for the CT calculation in the AWWA survey are 
not currently achieving 4-log virus inactivation. As a result, the 4-
log disinfection rate was revised downward to 52 percent. A similar 
change was made for NCWSs. Chapter 4 of the GWR EA (USEPA, 2006d) 
provides the detailed discussion of current disinfection rates.
    e. Corrective action costs. EPA received comments that corrective 
action costs were underestimated, especially the costs for installing 
disinfection units. The commenters questioned the cost estimates of the 
additional land required and the addition of storage tanks for 
achieving sufficient CT values for 4-log virus inactivation. EPA 
believes that the unit costs of technologies provided in the Technology 
and Cost Document for the Final Ground Water Rule (USEPA, 2006h) (T&C 
document) are adequate to derive the costs for complying with the GWR 
corrective action provisions because the costs were derived using the 
best available published data, vendor estimates and best professional 
judgment.
    EPA understands that some technologies used to comply with this 
rule will not fit within the existing plant footprints for some 
systems. When land costs become expensive, systems have the flexibility 
to consider other non-treatment options such as well rehabilitation or 
purchasing water. EPA further recognizes the land costs as part of 
nonquantified costs in the GWR EA (USEPA, 2006d).
    The T&C document presents the unit costs of disinfection apart from 
the unit costs for storage tanks because consultation with the field 
experts indicates that some systems have existing storage tanks or 
certain lengths of pipes before the first costumers. Systems that do 
not have existing storage tanks will need to consider the costs for 
them in cases when they would need to meet the CT values for 4-log 
inactivation of viruses. The detention times in existing facilities 
could be sufficient for achieving the 4-log CT values with disinfectant 
doses within a typical range. For these cases, EPA assumes that no 
additional storage will be required for installing disinfection or that 
an increase of disinfectant doses will be feasible for increasing viral 
disinfection levels to 4-logs.
    EPA also recognizes that disinfection and conducting compliance 
monitoring may not be preferred by some systems (particularly for small 
systems) because of distribution system size and configuration or 
operational complexity (including compliance monitoring) and costs. 
After further consultation with State representatives, EPA revised the 
compliance forecasts for this rule by lowering the percentages of 
systems taking treatment actions (and raising percentages of systems 
taking non-treatment actions) and adding a range of estimates to 
quantify the uncertainty around the compliance forecasts. The 
consultation also resulted in the addition of interim disinfection for 
systems taking corrective actions due to a fecal indicator-positive 
ground water source sample. This is because some immediate protection 
measures may have to be in place prior to completing corrective 
actions. Chapter 6 of the GWR EA (USEPA, 2006d) contains a detailed 
discussion of the corrective action costs.
    f. Compliance costs for small systems or NCWSs. Some commenters 
questioned whether EPA appropriately considered the costs to small 
systems. As part of the GWR regulatory development process, EPA 
participated in extensive consultations with small system 
representatives to develop risk-based rule requirements that would 
minimize the time and financial burden on small systems. To address 
concerns over the potential cost of additional monitoring for small 
systems, the GWR leverages the existing TCR monitoring framework to the 
extent possible (e.g., by using the results of the TCR monitoring to 
determine if triggered source water monitoring is required and by 
allowing small systems to use TCR repeat samples to satisfy GWR 
requirements). In addition, the implementation schedule for the 
sanitary survey requirement is staggered (e.g., every three to five 
years for CWSs and every five years for NCWSs), providing some relief 
for small systems since there are many more small NCWSs than CWSs. In 
addition to the targeted requirements for minimizing small systems 
burden, financial assistance to small systems may be available from 
programs administered by EPA or other Federal agencies (http://www.epa.gov/safewater/dwsrf/index.html
).

    Some commenters noted that systems may break into smaller units to 
fall below SDWA regulatory thresholds. Specifically, they noted that if 
a system is no longer classified as a PWS, it would be able to opt out 
of the GWR requirements. However, EPA believes that systems would most 
likely consolidate with other systems to defray costs rather than split 
up and lose economies of scale and put the public health at risk. 
Systems would also have to consider the transaction costs associated 
with dissolving into smaller units such as drilling new wells and 
separating distribution systems.
    EPA also received a number of comments questioning if the Agency 
considered the costs to NCWSs (i.e., NTNCWSs and TNCWSs). EPA did 
consider the costs to NTNCWSs and TNCWSs. The baseline number of 
systems subject to GWR requirements was derived from all CWSs, NTNCWSs, 
and TNCWSs listed in the SDWIS inventory. The new occurrence database 
also includes NCWSs. Costs were estimated by system size and type 
corresponding to applicable GWR requirements and schedules and typical 
operating characteristics (e.g., population served, treatment in place,

[[Page 65641]]

flows, etc.). Detailed descriptions of all costing procedures are 
presented in the GWR EA (USEPA, 2006d). More specifically, NTNCWS and 
TNCWS cost estimates are presented by system size in Exhibit 6.40 of 
the GWR EA.
2. Benefits
    a. Use of occurrence data in risk assessment. Some commenters 
questioned the basis for EPA using the data from the Lieberman et al. 
(2002) and Abbaszadegan (Abbaszadegan, 2002 and Abbaszadegan et al., 
1999a-c and 2003) studies to represent national microbial occurrence in 
the risk assessment. Issues raised included use of the studies to 
represent all CWSs and NCWSs on a national level, use of the 
Abbaszadegan et al. data set to represent ``properly constructed 
wells,'' and use of the Lieberman data set to represent ``poorly 
constructed wells.''
    Upon re-examination of all available occurrence data, EPA has made 
several changes to the occurrence analysis used to support the risk 
assessment. The Agency has made changes to achieve better 
representation of viral and fecal indicator occurrence among all PWS 
wells in the U.S. as described in Section VII.B.
    Data from all the studies used in the occurrence analysis of the 
GWR EA were cited in the NODA (USEPA, 2006e) and made publicly 
available. EPA believes that use of occurrence data from the cited 
studies in Section VII.A rather than using only the two studies used in 
the GWR EA under the proposal (Lieberman et al., 2002; Abbaszadegan, 
2002 and Abbaszadegan et al., 1999a-c and 2003) provides a better 
national estimate of intermittent enterovirus occurrence in support of 
the GWR risk assessment.
    Under the proposed rule, EPA used the Lieberman et al. (2002) data 
set to estimate enteric virus occurrence for poorly constructed wells 
and the Abbaszadegan (Abbaszadegan, 2002; Abbaszadegan et al., 1999a-c 
and 2003) data set to estimate enteric virus occurrence in properly 
constructed wells. In this rule, due to data limitations, EPA assumes 
the same enterovirus occurrence and percent time of viral presence (as 
described in Section VII.B of this preamble) for all wells.
    In this rule, EPA uses the terminology ``more vulnerable'' and 
``less vulnerable'' wells as categories for differing enteric virus 
concentration assumptions in differing groups of wells. Since the wells 
sampled from the Lieberman et al. (2002) data were selected because of 
likely vulnerability to fecal contamination, the enteric virus 
concentration data from Lieberman et al. (2002) is assumed to be 
characteristic of ``more vulnerable'' wells. Since the wells from the 
Abbaszadegan et al. (2002) and Lindsey et al. (2002) studies were not 
selected with a bias toward greater likelihood of fecal contamination, 
enteric viral concentrations from these two studies were assumed to be 
characteristic of ``less vulnerable'' wells. A more complete 
description of this analysis is available in Chapters 4 and 5 of the 
GWR EA (USEPA, 2006d).
    b. Variability and uncertainty. Some commenters suggested that EPA 
could do more to address uncertainty and variability when calculating 
the benefits of this rule. As a result of these comments, EPA re-
evaluated the data used to support the proposed GWR and the newer data 
published since the proposal. EPA determined that the values and/or 
analysis used in the proposed rule should be revised to better capture 
variability and uncertainty. The following discussion describes the 
significant changes that were made in the analysis supporting this rule 
as a result of the public comments and EPA's re-analysis.
    EPA has significantly revised its modeling of virus and indicator 
(E. coli) occurrence in ground water sources of drinking water in 
response to public comments. Section VII.B describes additional surveys 
and their use to produce a national assessment of occurrence. The 
modeling framework features probabilistic treatments of both 
variability and uncertainty.
    In this rule, EPA modified the mathematical expression that 
describes the human challenge studies with infectious rotavirus 
(infectivity of the virus). The purpose of the challenge study was to 
determine the rotavirus dose required to cause infection in humans. 
Previously, EPA used an approximation to the exact Beta-Poisson 
distribution in describing the dose-response data to simplify the 
Monte-Carlo simulation computational requirements. EPA's primary 
analysis now recognizes that the approximation is poor for some 
combinations of dose and parameter values and when used to predict low 
dose risk. As a result, EPA is using the exact expression for this 
rule. In an alternative analysis, EPA utilizes only data from the 
lowest dose used in the study. That dose (0.9 infectious units) is 
nearest the most relevant environmental number ingested: exactly one 
infectious unit. An exponential dose-response model is applied in the 
alternative analysis and the small number of subjects (seven exposed at 
this dose) results in considerable uncertainty about the model 
parameter.
    In this rule, EPA maintains as its primary analysis a Beta-Poisson 
dose-response model (Pareto approximation) utilizing the full echovirus 
data set but now includes an alternative analysis in which an 
exponential model is utilized with data from all but the two highest 
dose levels. Subjects who were not infected at the high dose levels 
demonstrate that different individuals have different levels of 
susceptibility (a feature of the Beta-Poisson model), but without the 
high dose data, the remaining subjects appear equally susceptible (a 
feature of the exponential model). The alternative analysis predicts 
significantly lower risk at environmental exposure levels. EPA's two 
analyses demonstrate considerable uncertainty with respect to model and 
data selection.
    In this rule, EPA revised the morbidity value for rotavirus illness 
in adults. The Agency now recognizes that the variability in this value 
is considerable and has included a range of uncertainty in the 
morbidity estimate. Because of limited data on common source rotavirus 
outbreaks involving adults, under the proposal, EPA had assumed that 
most adults remain immune due to multiple repeat infections, or if 
infected, do not often become ill. Under the proposal, EPA used a low 
value for the adult rotavirus morbidity rate (0.10). However, EPA re-
examined the Ward et al. (1986) data and concluded that one-half of the 
subjects in the dose-response study became ill after infection. Also, 
since the proposal, Griffin et al. (2002) analyzed previous outbreaks 
and identified one rotavirus genotype that is associated with outbreaks 
involving adults in the U.S. This new knowledge suggests that the 
morbidity value for adults can be much more variable than previously 
believed depending on which rotavirus genotype is consumed. EPA now 
uses a range in the rotavirus adult morbidity value from 0.10-0.50 and 
a uniform distribution. The distribution selected reflects the 
variability among rotavirus genotypes.
    EPA obtained additional echovirus (Type B) morbidity data to 
improve the analysis described in the proposal. The proposal used only 
Echovirus type 30 morbidity data from the Seattle Virus Watch Study 
(Hall et al., 1970) based on the assumption that data from a single 
strain would minimize variability among the general population. In this 
rule, EPA uses multiple echovirus serotype data from both the Seattle 
and New York Virus Watch Studies (Kogon et al., 1969) to determine the 
range of

[[Page 65642]]

morbidity rates in the general population.
    c. Are the benefits and the data used to estimate the benefits of 
the GWR sufficient to justify regulatory action? EPA received several 
comments that addressed the calculation of benefits. Most commenters 
questioned whether the GWR benefits are sufficient to justify 
regulatory action. In particular, comments suggested that the 
probability of an outbreak is low and there is no linkage between 
undisinfected ground water and waterborne disease. EPA also received 
several comments about the overall lack of information suitable for 
estimating health benefits.
    In general, EPA recognizes that the health effects data available 
for use in calculating GWR benefits are limited because there are no 
national epidemiological studies to identify waterborne disease from 
ground water nor is there any national system for reporting waterborne 
disease once it is identified.
    EPA has substantially revised its benefits analysis to use a 
combination of measured data, calculated values, and reasonable 
assumptions to make predictions about benefits. The benefits determined 
for the GWR are based on measurement of pathogenic enteric viruses in 
public drinking water wells, so these data are directly applicable to 
making predictions about possible avoided illnesses due to elimination 
of these pathogens from the drinking water supply. Furthermore, it 
should be recognized that, in the benefits calculation, EPA does not 
assume that pathogen occurrence automatically results in illness in all 
individuals consuming water from that drinking water supply well. EPA 
used dose-response data from human feeding studies to determine the 
probability that an individual would become infected by consuming water 
with a range of pathogen concentrations. For echovirus (one of the 
enteroviruses), illness rates and ranges were determined from 
epidemiology studies on the general population. For rotavirus, illness 
rates and ranges were determined from epidemiology studies on the 
general population and from the symptomatic response to infection in 
human challenge studies.
    d. Transparency of regulatory impact analysis. Some commenters 
expressed that the Regulatory Impact Analysis for the proposed GWR 
(USEPA, 2000f) did not provide a clear description of the critical 
assumptions underlying the cost and benefit analysis.
    EPA believes that it has made the GWR EA for the final rule more 
transparent than the analysis done for the proposal. Changes include 
(1) Expanded text on the basis for most of the assumptions used in the 
analysis, (2) expanded text and new diagrams describing how the 
different steps in the analysis are combined to produce an aggregate 
analysis, and (3) expanded text on how the nonquantified benefits 
complement the quantified benefits analysis.
3. Risk Management
    a. What is EPA's response to comments that EPA chose the wrong 
option and that the benefits do not justify the cost or that the rule 
is not cost-effective? Consistent with EPA's statutory requirements, 
the Agency carefully considered benefits and costs in proposing and 
promulgating the GWR. The Agency's decision for the final rule is 
described in VII.A. The Agency believes that this rule provides 
benefits at a cost that is justified. In making decisions for the final 
rule, EPA considered both quantified and nonquantified benefits and 
costs as well as the other components of the Health Risk Reduction and 
Cost Analysis (HRRCA) outlined in section 1412(b)(3)(C) of the SDWA.
    In the proposal, the Multi-Barrier approach (Regulatory Alternative 
3) had net benefits similar to the proposed regulatory Alternative 2, 
Sanitary Survey and Triggered Monitoring. However, the Multi-Barrier 
approach provided a greater reduction in illnesses and deaths, 
especially to children. After an exhaustive review of the benefits and 
cost estimates used in the proposal resulting from public comments, 
peer review, and the NDWAC Arsenic Review panel, the Agency updated 
both the benefit and cost analysis for each rule option. The risk-
targeted approach, which was selected for the final rule, has lower net 
benefits than Alternative 1, but more than Alternatives 3 and 4. EPA 
believes that the additional benefits realized under Alternative 2 
justify its selection over Alternative 1, despite the lower net 
benefits.
    Other commenters noted that the proposed rule is not cost-
effective. The mean cost per viral illness avoided for the final rule 
ranges from $1,476 to $1,488, at three percent and seven percent 
discount rates respectively. These represent the lowest values of all 
alternatives considered and are much lower than either Alternative 1 or 
Alternative 4. Thus, Alternative 2 is the most cost-effective rule 
alternative by this measure.
    b. Did the Agency consider that some systems may have negative net 
benefits, and did the Agency conduct an incremental analysis by system 
size and type? Some commenters noted that the costs may exceed benefits 
for smaller size systems. EPA agrees that for some drinking water 
regulations the costs may exceed the benefits because the populations 
served by these systems are much smaller. Generally, large systems 
benefit from economies of scale which eases the relative impact on 
these systems. In addition, many GWR benefits remain nonquantified.
    Other commenters suggested that EPA should exclude or set different 
standards for small systems based on benefit and cost analysis, 
including incremental analysis, by system size or type. However, the 
SDWA does not generally provide a basis for establishing tailored 
drinking water standards as these commenters suggest. Rather, the SDWA 
is designed to ensure uniform levels of public health protection across 
the country (except as specifically provided for in variances from the 
standard).
    Thus EPA disagrees with the suggestion that the level of the final 
standard be altered to address system size or type. However, as 
discussed in detail in the preamble of this rule, the rule provides 
flexibility that reduces burden on small systems and reflects 
individual system conditions. Financial and technical assistance is 
also available through various funding authorities. Regarding 
affordability, variances based on affordability are not allowed by the 
SDWA for regulations addressing microbial contamination, and as a 
result EPA did not conduct an affordability analysis. However, EPA has 
considered the SAB review of the Arsenic Rule and the suggestions of 
the NDWAC Arsenic Cost Working Group regarding the further 
disaggregation of the analyses. The NDWAC group recommended calculation 
and presentation of cost information in multiple size categories, which 
is done in the GWR EA (USEPA, 2006d).
    In addition, the Agency took many steps to reduce the burden on 
small systems where possible. More information regarding this effort 
can be found in Chapter 6 of the GWR EA (USEPA, 2006d).

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), 
this action is a ``significant regulatory action''. Accordingly, EPA 
submitted this action to the Office of Management and Budget (OMB) for 
review under EO 12866 and any changes made in

[[Page 65643]]

response to OMB recommendations have been documented in the docket for 
this action.
    In addition, EPA has prepared an analysis of the potential costs 
and benefits associated with this action. This analysis is contained in 
the Economic Analysis for the Final Ground Water Rule (USEPA, 2006d). A 
copy of the analysis is available in the docket for this action and the 
analysis is briefly summarized in Section VII of this preamble.

B. Paperwork Reduction Act

    The Office of Management and Budget (OMB) has approved the 
information collection requirements contained in this rule under the 
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and 
has assigned OMB control number 2040-0271.
    The information collected as a result of this rule will allow the 
States and EPA to make decisions and evaluate compliance with the rule. 
For the first three years after the promulgation of the GWR, the major 
information requirements are for States and PWSs to prepare for 
implementation of the rule. The information collection requirements are 
described in 40 CFR part 141, for systems, and part 142, for States, 
and are mandatory. The information collected is not confidential.
    EPA estimates that the annual burden on PWSs and States for 
reporting and recordkeeping will be 385,264 hours. This annual burden 
is based on an estimate that 57 States and territories will each need 
to provide one response each year with an average of 2,193 hours per 
response, and that 49,110 systems will each provide two responses each 
year with an average of 2.6 hours per response. The total reporting and 
recordkeeping cost over the three-year period of the Information 
Collection Request is $30,274,266 (labor costs) (USEPA, 2006a). It 
should be noted, however, that much of the paperwork burden of the rule 
will be incurred only after the three-year time horizon covered in this 
analysis. Subsequent ICR submissions will address future burden for 
activities such as triggered and compliance monitoring. There are no 
operation, maintenance or capital costs estimated for the first three 
years. The labor burden is estimated for the following activities: 
reading and understanding the rule, planning, training, and meeting 
primacy requirements. Burden means the total time, effort, or financial 
resources expended by persons to generate, maintain, retain, or 
disclose or provide information to or for a Federal agency. This 
includes the time needed to review instructions; develop, acquire, 
install, and utilize technology and systems for the purposes of 
collecting, validating, and verifying information, processing and 
maintaining information, and disclosing and providing information; 
adjust the existing ways to comply with any previously applicable 
instructions and requirements; train personnel to be able to respond to 
a collection of information; search data sources; complete and review 
the collection of information; and transmit or otherwise disclose the 
information.
    An Agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9. In addition, EPA is 
amending the table in 40 CFR part 9 of currently approved OMB control 
numbers for various regulations to list the regulatory citations for 
the information requirements contained in this rule.

C. Regulatory Flexibility Act (RFA)

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    The RFA provides default definitions for each type of small entity. 
Small entities are defined as: (1) A small business as defined by the 
Small Business Administration's (SBA) regulations at 13 CFR 121.201; 
(2) a small governmental jurisdiction that is a government of a city, 
county, town, school district or special district with a population of 
less than 50,000; and (3) a small organization that is any ``not-for-
profit enterprise which is independently owned and operated and is not 
dominant in its field.'' However, the RFA also authorizes an agency to 
use alternative definitions for each category of small entity, ``which 
are appropriate to the activities of the agency'' after proposing the 
alternative definition(s) in the Federal Register and taking comment. 5 
U.S.C. 601(3)-(5). In addition, to establish an alternative small 
business definition, agencies must consult with SBA's Chief Counsel for 
Advocacy.
    For purposes of assessing the impacts of the final GWR on small 
entities, EPA considered defining ``small entities'' in its regulatory 
flexibility assessments under the RFA to be public water systems 
serving 10,000 or fewer persons. As required by the RFA, EPA proposed 
using this alternative definition in the Federal Register (63 FR 7620, 
February 13, 1998), requested public comment, consulted with the Small 
Business Administration (SBA), and finalized the alternative definition 
in the Consumer Confidence Reports regulation (63 FR 44511, August 19, 
1998). As stated in that Final Rule, the alternative definition applies 
to this regulation as well.
    Pursuant to section 603 of the RFA, EPA prepared an initial 
regulatory flexibility analysis (IRFA) for the proposed rule (see 65 FR 
30193, May 10, 2000) and convened a Small Business Advocacy Review 
Panel to obtain advice and recommendations of representatives of the 
regulated small entities (USEPA, 2000a). A detailed discussion of the 
Panel's advice and recommendations is found in the Panel Report (docket 
number EPA-HQ-OW-2002-0061; document number W-98-23-I.E-2). A summary 
of the Panel's recommendations is presented in the GWR proposal at 65 
FR 30253, May 10, 2000 (USEPA, 2000a).
    As required by section 604 of the RFA, we also prepared a final 
regulatory flexibility analysis (FRFA) for the final GWR. The FRFA 
addresses the issues raised by public comments on the IRFA, which was 
part of the proposal of this rule. The FRFA is available for review in 
the docket and is summarized below.
    EPA is issuing this final rule to comply with section 1412(b)(8) of 
the SDWA, which directs EPA to ``promulgate national primary drinking 
water regulations requiring disinfection as a treatment technique for 
all public water systems, including surface water systems and, as 
necessary, ground water systems.'' The need for this final rule is 
based upon the substantial likelihood that fecal contamination of 
ground water supplies is occurring at frequencies and levels that 
present public health concern. Fecal contamination refers to the 
contaminants, particularly the microorganisms, contained in human or 
animal feces. These microorganisms may include bacterial and viral 
pathogens, which can cause illnesses in the individuals that consume 
them. The objective of the final GWR is to identify those systems with 
fecal contamination and undertake corrective action to eliminate or 
address that contamination.
    Two significant issues were raised in comments on the IRFA for the 
proposed rule. First, several commenters wrote

[[Page 65644]]

that small water systems lack the customer base to defray the costs of 
installing new treatment, such as disinfection, or the cost of a new 
source. EPA notes that the final GWR does not mandate disinfection, but 
rather is a flexible regulation, targeting those high-risk systems or 
sources that are vulnerable to contamination. EPA also notes that 
financial assistance is available to small systems through programs 
such as the Drinking Water State Revolving Fund, the Loan and Grant 
program of the U.S. Department of Agriculture's Rural Utilities 
Services (RUS) and the Community Development Block Grant Program of the 
Department of Housing. The second significant issue raised in comments 
on the IRFA was a recommendation that EPA allow the States flexibility 
to consider competing fiscal impacts on small systems when implementing 
the rule. EPA believes the final rule has greater flexibility and is 
less burdensome for States and small systems than the proposal. For 
example, a GWS serving 1,000 people or fewer may use a repeat sample 
collected from a ground water source to meet the TCR to satisfy the GWR 
triggered source water monitoring requirements if the State approves 
the use of E. coli as a fecal indicator for ground water source 
monitoring.
    EPA assessed the potential impact of the final GWR on small 
entities. There are 147,330 CWSs, NTNCWSs, and TNCWSs providing potable 
ground water to the public; 145,580 (99 percent) are classified by EPA 
as small entities. EPA has determined that all small systems are 
impacted by the sanitary survey requirement and a substantial number 
these systems will be impacted by additional requirements of the final 
GWR, including the triggered source water monitoring requirements and 
the corrective action requirements.
    In addition, in the final GWR there are a number of recordkeeping 
and reporting requirements for all GWSs (including small systems). To 
minimize the burden with these provisions, the final rule uses a risk-
based regulatory strategy, whereby the monitoring requirements are 
based on system characteristics and not directly related to system 
size. In this manner, the rule takes a system-specific approach to 
regulation.
    To prevent conflict and overlap with other Federal rules, this 
final rule leverages the existing TCR monitoring framework to the 
extent possible (e.g., by using the results of the routine TCR 
monitoring to determine if source water monitoring is required). GWSs 
that do not reliably treat to 4-log inactivation or removal of viruses 
are required to collect a source water sample following a total 
coliform-positive sample in the distribution system. Additionally, 
systems may utilize one of the follow-up monitoring samples required 
under the TCR to meet the triggered source water sampling requirements 
of this final rule.
    As a result of the input received from stakeholders, the EPA 
workgroup, and other interested parties, EPA constructed four 
regulatory options: The sanitary survey option, the sanitary survey and 
triggered monitoring option, the multi-barrier option, and the across-
the-board disinfection option. In developing this final rule, EPA 
considered the recommendations to minimize the cost impact to small 
systems. A risk-targeted approach, based on sanitary surveys and 
triggered source water monitoring (which only requires corrective 
action if the GWS has a sanitary survey significant deficiency or 
source water fecal contamination), was selected as the option to 
protect public health and to reduce burden. Assessment source water 
monitoring, part of the preferred proposal option (the multi-barrier 
option), has been finalized as a discretionary requirement as 
determined by the State, allowing further flexibility and burden 
reduction.
    To mitigate the associated compliance cost increases across water 
systems, this final rule also provides States with considerable 
flexibility when implementing other requirements of the rule. This 
flexibility will allow States to consider the characteristics of 
individual systems when determining an appropriate corrective action. 
For example, States have the flexibility to allow systems to fix 
existing wells, drill a new well, obtain a new source, or use any 
disinfection treatment technology that achieves 4-log inactivation or 
removal of viruses. States may also determine that the source of 
contamination has been eliminated if, after thorough investigation by 
the State and the system, the State concludes that contamination is 
unlikely to reoccur.
    As required by section 212 of the Small Business Regulatory 
Enforcement Fairness Act (SBREFA), EPA also is preparing a Small Entity 
Compliance Guide to help small entities comply with this rule. This 
guide will be available on EPA's Web site at http://www.epa.gov/safewater/
[fxsp0]disinfection/gwr/index.html or by calling the Safe 

Drinking Water Hotline at (800) 426-4791.

D. Unfunded Mandates Reform Act (UMRA)

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub. 
L. 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and Tribal 
governments and the private sector. Under section 202 of UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and Tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including Tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    EPA has determined that this rule does not contain a Federal 
mandate that may result in expenditures of $100 million or more for 
State, local, or Tribal governments in the aggregate, or the private 
sector in any one year (see Table VIII-1). The rule is estimated to 
cost State, local and Tribal governments $41.5 to $41.9 million. Public 
water systems that are privately owned will incur total costs of $20.3 
to $20.4 million per year. A more detailed description is presented in 
the Economic Analysis for the Final Ground Water Rule (USEPA, 2006d), 
which is available in the water docket. Thus, this rule is not subject 
to the requirements of sections 202 and 205 of the UMRA.

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[GRAPHIC] [TIFF OMITTED] TR08NO06.013

    In developing this rule, EPA consulted with small governments 
pursuant to its interim plan established under section 203 of the UMRA 
to address impacts of regulatory requirements in the rule that might 
significantly or uniquely affect small governments. EPA held four 
public meetings for all stakeholders. Because of the GWR's impact on 
small entities, the Agency convened a Small Business Advocacy Review 
(SBAR) Panel in accordance with the Regulatory Flexibility Act (RFA) as 
amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) to address small entity concerns, including small local 
governments specifically. EPA consulted with small entity 
representatives prior to convening the Panel to get their input on the 
GWR. Of the 22 small entity participants, five represented small 
governments. EPA also made presentations on the GWR to the national and 
some local chapters of the American Water Works Association, the Ground 
Water Foundation, the National Ground Water Association, the National 
Rural Water Association, and the National League of Cities.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    This final rule does not have Federalism implications. It will not 
have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. This rule does not contain a 
``significant Federal government mandate'' under section 202 of the 
UMRA, nor does it have a significant impact on small governments. Thus, 
Executive Order 13132 does not apply to this rule.
    Although Section 6 of Executive Order 13132 does not apply to this 
rule, EPA did consult with State and local officials in developing this 
rule (65 FR 30203 and 30263, May 10, 2000) (USEPA, 2000a). A summary of 
the concerns raised during that consultation and EPA's response to 
those concerns are provided in the proposal. In the spirit of Executive 
Order 13132, and consistent with EPA policy to promote communications 
between EPA and State and local governments, EPA specifically solicited 
comment on the proposed rule from State and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000), 
requires EPA to develop ``an accountable process to ensure meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' Under Executive Order 13175, 
EPA may not issue a regulation that has Tribal implications, that 
imposes substantial direct compliance costs, and that is not required 
by statute, unless the Federal government provides the funds necessary 
to pay the direct compliance costs incurred by Tribal governments, or 
EPA consults with Tribal officials early in the process of developing 
the proposed regulation and develops a Tribal summary impact statement.
    EPA has concluded that this final rule may have Tribal implications 
because it may impose substantial direct compliance costs on Tribal 
governments and the Federal government will not provide the funds 
necessary to pay those costs. This rule will significantly affect 
communities of Tribal governments because 87 percent of PWSs in Indian 
Country are GWSs. Accordingly, EPA provides the following Tribal 
summary impact statement as required by section 5(b).
    EPA consulted with Tribal officials early in the process of 
developing this regulation to permit them to have meaningful and timely 
input into its development (see the proposed rule, 65 FR 30259, May 10, 
2000) (USEPA, 2000a). Two consultations took place at national 
conferences; one for the National Indian Health Board and the other for 
the National Tribal Environmental Council. A third consultation was 
conducted in conjunction with the Inter-Tribal Council of Arizona, Inc. 
EPA received one comment on the proposed rule from a Tribal 
organization. The organization is concerned that the GWR will have a 
negative impact on their ability to provide infrastructure improvements 
by taking funding resources away from new water supply construction 
programs and applying these funds to cover compliance costs for 
existing water systems. EPA recognizes that the GWR will increase the 
compliance burden for some Tribal PWSs, however, EPA believes that the 
GWR will provide public health benefits that justify the increase in 
burden. To offset some of this burden, EPA has provided flexibility for 
small systems through various mechanisms. For a detailed discussion, 
please see Section IV of this preamble.

[[Page 65646]]

    As required by section 7(a), EPA's Tribal Consultation Official has 
certified that the requirements of this Executive Order have been met 
in a meaningful and timely manner. A copy of the certification is 
included in the docket for this rule.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045: ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies 
to any rule that: (1) Is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that EPA has reason to believe may 
have a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    While this final rule is not subject to the Executive Order because 
it is not economically significant as defined under Executive Order 
12866, we nonetheless have reason to believe that the environmental 
health or safety risk addressed by this action may have a 
disproportionate effect on children. As a matter of EPA policy, we 
therefore assessed the environmental health or safety effects of 
viruses on children. The results of this assessment are contained in 
Section VII.I.1 of the preamble of this rulemaking as well as in the 
final GWR EA (USEPA, 2006d).

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This rule is not a ``significant energy action'' as defined in 
Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355 
(May 22, 2001)) because it is not likely to have a significant adverse 
effect on the supply, distribution, or use of energy.
1. Energy Supply
    The GWR does not regulate power generation, either directly or 
indirectly. The public and private PWSs that the GWR regulates do not, 
in general, generate power. Further, the cost increases borne by 
customers of PWSs as a result of the GWR represent a small percentage 
of the total cost of water, except for a very few small systems that 
will need to spread the cost of installing advanced technologies over a 
narrow customer base. Therefore, the customers that are power 
generation utilities are unlikely to face any significant effects as a 
result of the GWR. In summary, the GWR does not regulate the supply of 
energy, does not generally regulate the utilities that supply energy, 
and is unlikely to significantly affect the customer base of energy 
suppliers. Thus, the GWR will not adversely affect the supply of 
energy.
2. Energy Distribution
    The GWR does not regulate any aspect of energy distribution. PWSs 
that are regulated by the GWR already have electrical service. The rule 
is projected to increase peak electricity demand at PWSs by only 0.001 
percent (see below). Therefore, EPA assumes that the existing 
connections are adequate and that the GWR has no discernable adverse 
effect on energy distribution.
3. Energy Use
    Some PWSs are expected to add treatment technologies that use 
electrical power. This potential impact of the GWR on the use of energy 
was evaluated. The analyses that underlay the estimation of costs are 
national in scope and do not identify specific plants or systems that 
may install treatment in response to the GWR. As a result, no analysis 
of the effect on specific energy suppliers is possible with the 
available data. Further data are required to evaluate the effect on 
specific energy suppliers. The approach used to estimate the impact of 
energy use, therefore, focuses on national-level impacts. In this 
approach, EPA estimates the additional energy use due to the GWR and 
compares that to the national levels of power generation in terms of 
average and peak loads.
    The first step is to estimate the energy used by the technologies 
or corrective action expected to be installed as a result of the GWR. 
Energy use is not directly estimated in the Technology and Cost 
Document for the Final Ground Water Rule (USEPA, 2006h), but the annual 
cost of energy for each technology and corrective action addition or 
upgrade necessitated by the GWR is provided. An estimate of plant-level 
energy use is derived by dividing the total energy cost per plant for a 
range of flows by an average national cost of electricity of $0.076 per 
kilowatt hour per year (kWh/y) (USDOE EIA, 2002). The energy use per 
plant for each flow range and technology or corrective action is then 
multiplied by the number of plants predicted to install each technology 
in a given flow range. The energy requirements for each flow range are 
then added to produce a national total. No electricity use is 
subtracted to account for the technologies that may be replaced by new 
technologies, resulting in a conservative estimate of the increase in 
energy use. An incremental national annual energy usage of 4,521 
megawatt hours (mWh) was calculated.
    The total increase in energy usage by water systems as a result of 
the GWR is predicted to be approximately 4.5 million kWh/y, which is 
less than one-ten-thousandth of one percent of the total energy 
produced in 2003. While the rule may have some adverse energy effects, 
EPA does not believe that this constitutes a significant adverse effect 
on the energy supply. See the Economic Analysis for the Final Ground 
Water Rule (USEPA, 2006d) for further detail.

I. National Technology Transfer and Advancement Act

    As noted in the proposed rule, Section 12(d) of the National 
Technology Transfer and Advancement Act of 1995 (``NTTAA''), Public Law 
104-113, 12(d) (15 U.S.C. 272 note) directs EPA to use voluntary 
consensus standards in its regulatory activities unless to do so would 
be inconsistent with applicable law or otherwise impractical. Voluntary 
consensus standards are technical standards (e.g., materials 
specifications, test methods, sampling procedures, and business 
practices) that are developed or adopted by voluntary consensus 
standards bodies. The NTTAA directs EPA to provide Congress, through 
OMB, explanations when the Agency decides not to use available and 
applicable voluntary consensus standards.
    This rulemaking involves technical standards. EPA has identified 
some consensus standards and developed or modified methods for the 
remaining methods requirements. These methods are listed in Sec.  
141.402(c).
    Most of the methods that EPA is approving for the detection of E. 
coli in source waters are consensus methods described in Standard 
Methods for the Examination of Water and Wastewater (20th Edition) 
(APHA, 1998). The three E. coli methods that are not consensus methods 
are newly developed: MI agar (a membrane filter method), the ColiBlue 
24 test (a membrane filter method) and the E*Colite test (a defined 
dehydrated medium to which water is added). EPA has already evaluated 
and approved these three methods for use under the TCR. Of the three 
enterococci methods EPA is approving in this rule, two are consensus 
methods in Standard Methods; the third (Enterolert) was described in a 
peer-reviewed journal article (Budnick et al., 1996).

[[Page 65647]]

    The two methods EPA proposed for the detection of coliphage in 
source water are not consensus methods. For the coliphage tests, EPA is 
approving the use of two methods: EPA Method 1601 (Two-Step Enrichment 
Presence-Absence Procedure) (USEPA, 2001a) and EPA Method 1602 (Single 
Agar Layer Procedure) (USEPA, 2001b). EPA Method 1601 is a new method 
optimized for the detection of a single coliphage in a small (100-1,000 
mL) water sample. EPA did not use the consensus method for coliphage in 
Standards Methods (20th edition) (Method 9211D) (APHA, 1998) rather, 
EPA modified and optimized Method 9211D to improve its sensitivity and 
versatility.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 establishes a Federal policy for 
incorporating environmental justice into Federal Agency missions by 
directing agencies to identify and address disproportionately high and 
adverse human health or environmental effects of its programs, 
policies, and activities on minority and low-income populations.
    The Environmental Justice Executive Order requires the Agency to 
consider environmental justice issues in the rulemaking and to consult 
with minority and low-income stakeholders. The Agency has considered 
environmental justice issues concerning the potential impacts of this 
action and has consulted with minority and low-income stakeholders. The 
GWR applies to all PWSs (CWSs, NTNCWSs, and NTCWSs) that use ground 
water as their source water. Consequently, the health protection 
benefits provided by this rule are equal across all income and minority 
groups served by these systems. Existing regulations such as the SWTR, 
IESWTR, and LT2ESWTR provide similar health benefit protection to 
communities that use surface water or ground water under the direct 
influence of surface water.
    Nonetheless, the Agency held a stakeholder meeting on March 12, 
1998, to address various components of pending drinking water 
regulations and how they may impact sensitive sub-populations, minority 
populations, and low-income populations. See the discussion of this 
meeting in the proposed rule for further information (65 FR 30261, May 
10, 2000) (USEPA, 2000a).

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is a ``major rule'' as defined by 5 U.S.C. 
804(2). This rule will be effective January 8, 2007.

L. Analysis of the Likely Effect of Compliance With the GWR on the 
Technical, Financial, and Managerial Capacity of Public Water Systems

    Section 1420(d)(3) of SDWA, as amended, requires that in 
promulgating an NPDWR, the Administrator shall include an analysis of 
the likely effect of compliance with the regulation on the technical, 
managerial, and financial capacity of public water systems. This 
analysis can be found in the GWR Economic Analysis (USEPA, 2006d). 
Analyses reflect only the impact of new requirements, as established by 
the GWR; the impacts of previously established requirements on system 
capacity are not considered.

IX. Consultation With Science Advisory Board, National Drinking Water 
Advisory Council, and the Secretary of Health and Human Services; and 
Peer Review

    In accordance with sections 1412(d) and 1412(e) of the SDWA, the 
Agency consulted with the Science Advisory Board, the National Drinking 
Water Advisory Council (NDWAC), and the Secretary of Health and Human 
Services.
    In addition, this rule was supported by influential scientific 
information. Therefore, the Agency conducted a peer review in 
accordance with OMB's Final Information Quality Bulletin for Peer 
Review (OMB, December 15, 2004). EPA developed charge questions related 
to the statistical approach used to characterize national occurrence of 
viral pathogens and fecal indicators; risk characterization including 
dose-response modeling; characterization of morbidity, mortality, and 
severity for Type A and Type B viruses; characterization of 
nonquantified benefits; and national risk reduction (benefits) and 
costs for the GWR. The Peer Review Report is located in the docket for 
this rule.

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Modlin, J.F. 1997. Enteroviruses: coxsackievirus, echoviruses and 
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Moore, A.C., B.L. Herwaldt, G.F. Craun, R. L. Calderon, A.K. 
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SBI[fxsp0]--EPA.pdf.
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OMB. 2004. Final Information Quality Bulletin for Peer Review. 
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inforeg/peer2004/[fxsp0]peer--bulletin.pdf.
Parshionikar, S.U., S. Willian-True, G.S. Fout, D.E. Robbins, S.A. 
Seys, J.D. Cassady, and R. Harris. 2003. Waterborne outbreak of 
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Environmental Microbiology. 69(9):5263-5268.
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Tanner. 1999. Isolation of Arcobacter butzleri from ground water. 
Letters in Applied Microbiology. 28:31-35.
Rose, J.B. 1997. Environmental ecology of Cryptosporidium and public 
health implications. Annual Rev Public Health. 18:135-161.
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Swerdlow, D.L., B.A. Woodruff, R.C. Brady, P.M. Griffin, S. Tippen, 
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K.D. Greene, M. Bright, N.H. Bean, and P.A. Blake. 1992. A 
waterborne outbreak in Missouri of Escherichia coli O157:H7 
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Szewzyk, U., Szewzyk, R., Manz, W. and Schleifer, K.-H. 2000. 
Microbiological safety of drinking water. Annual Review of 
Microbiology. 54:81-127.
Tucker, A.W., A.C. Haddix, J.S. Bresee, et al. 1998. Cost-
effectiveness analysis of a rotavirus immunization program for the 
United States. JAMA. 279(17):1371-1376.
U.S. Department of Energy, Energy Information Administration. 2002. 
Table 7.1 Electricity Overview (Billion Kilowatthours). http://www.eia.doe.gov/
[fxsp0]emeu/mer/txt/mer7-1

USEPA. 2006a. Information Collection Request for National Primary 
Drinking Water Regulations: Final Ground Water Rule. EPA-815-R-06-
011.
USEPA. 2006b. Occurrence and Monitoring Document for the Final 
Ground Water Rule. EPA-815-R-06-012.
USEPA. 2006c. Public Comment and Response Document for the Final 
Ground Water Rule. EPA-815-R-06-013.
USEPA. 2006d. Economic Analysis for the Final Ground Water Rule. 
EPA-815-R-06-014.
USEPA. 2006e. National Primary Drinking Water Regulations; Ground 
Water Rule; Notice of Data Availability. 71 FR 15105, March 27, 
2006.
USEPA. 2006f. National Field Study for Coliphage Detection in 
Groundwater: Method 1601 and 1602 Evaluation in Regional Aquifers. 
EPA-822-R-06-002.
USEPA. 2006g. National Primary Drinking Water Regulations: Stage 2 
Disinfectants and Disinfection Byproducts Rule; Final Rule. 71 FR 
388, January 4, 2006.
USEPA. 2006h. Technology and Cost Document for the Final Ground 
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USEPA. 2006i. National Primary Drinking Water Regulations: Long Term 
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FR 654, January 5, 2006.
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EPA 815-R-06-009.
USEPA. 2005b. Manual for the Certification of Laboratories Analyzing 
Drinking Water. Fifth Edition, January, 2005. EPA 815-R-05-004.
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USEPA. 2003b. Results of the Interlaboratory Validation of EPA 
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[[Page 65650]]

Enumeration of Malespecific (F+) and Somatic Coliphage in Water by 
Single Agar Layer (SAL). July, 2003. EPA-821-R-03-016.
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EPA 100-R-01-002.
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Announcement of the Results of EPA's Review of Existing Drinking 
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17, 2002.
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030.
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002.
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2000.
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Final Draft. July, 2000.
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Proposal for the Ground Water Rule. June 30, 2000. EPA-SAB-DWC-LTR-
00-005.
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Recommendations. May 11, 2000.
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Unpublished report prepared by International Consultants, Inc. for 
the Office of Ground Water and Drinking Water, 29 pp.
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December 16, 1998.
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December 16, 1998.
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1997.
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Microbial Contamination of Ground Water Systems--July 10-11, 1996--
Proceedings Report. September 1996.
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21, 1995.
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1990.
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June 29, 1989.
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1990. SAB-EC-90-021.
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Vaughn, J.M. 1996. Sample Analyses. Attachment, unpublished letter 
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the Southern Ontario Section of the Canadian Geotechnical Society. 
Pp. 1081-1086.
Yanko, W.A., J.L. Jackson, F.P. Williams, A.S. Walker, and M.S. 
Castillo. 1999. An unexpected temporal pattern of coliphage 
isolation in ground waters sampled from wells at varied distance 
from reclaimed water recharge sites. Water Resource. 33:53-64.
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Detecting Enteroviruses in Water: Comparing Infectivity, Molecular, 
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International Symposium on Waterborne Pathogens, Milwauke, WI.

List of Subjects

40 CFR Part 9

    Reporting and recordkeeping requirements.

40 CFR Part 141

    Environmental protection, Chemicals, Indians-lands, Incorporation 
by reference, Intergovernmental relations, Radiation protection, 
Reporting and recordkeeping requirements, Water supply.

40 CFR Part 142

    Environmental protection, Administrative practice and procedure, 
Chemicals, Indians-lands, Radiation protection, Reporting and 
recordkeeping requirements, Water supply.

    Dated: October 11, 2006.
Stephen L. Johnson,
Administrator.
    For the reasons set forth in the preamble, title 40 chapter I of 
the Code of Federal Regulations is amended as follows:

[[Page 65651]]

PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT

0
1. The authority citation for part 9 continues to read as follows:

    Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003, 
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33 
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330, 
1342, 1344, 1345 (d) and (e), 1361; Executive Order 11735, 38 FR 
21243, 3 CFR, 1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 
300f, 300g, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 
300j-2, 300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-
7671q, 7542, 9601-9657, 11023, 11048.

0
2. In Sec.  9.1 the table is amended by adding entries Sec.  141.401-
141.405'', Sec.  142.14(d)(17)'', Sec.  142.15(c)(7)'' and Sec.  
142.16(o)'' in numerical order, as follows:

Sec.  9.1  OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------
                                                            OMB control
                     40 CFR citation                            No.
------------------------------------------------------------------------

                              * * * * * * *
------------------------------------------------------------------------
               National Primary Drinking Water Regulations
------------------------------------------------------------------------

                              * * * * * * *
------------------------------------------------------------------------
141.401-141.405.........................................       2040-0271

                              * * * * * * *
------------------------------------------------------------------------
       National Primary Drinking Water Regulations Implementation
------------------------------------------------------------------------

                              * * * * * * *
------------------------------------------------------------------------
142.14(d)(17)...........................................       2040-0271

                              * * * * * * *
------------------------------------------------------------------------
142.15(c)(7)............................................       2040-0271

                              * * * * * * *
------------------------------------------------------------------------
142.16(o)...............................................       2040-0271
------------------------------------------------------------------------

* * * * *

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

0
3. The authority citation for part 141 continues to read as follows:

    Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.

0
4. Section 141.21 is amended by adding paragraph (d)(3) to read as 
follows:

Sec.  141.21  Coliform sampling.

* * * * *
    (d) * * *
    (3) Sanitary surveys conducted by the State under the provisions of 
Sec.  142.16(o)(2) of this chapter may be used to meet the sanitary 
survey requirements of this section.
* * * * *
0
5. Section 141.28 is amended by revising paragraph (a) to read as 
follows:

Sec.  141.28  Certified laboratories.

    (a) For the purpose of determining compliance with Sec.  141.21 
through 141.27, 141.30, 141.40, 141.74, 141.89 and 141.402, samples may 
be considered only if they have been analyzed by a laboratory certified 
by the State except that measurements of alkalinity, calcium, 
conductivity, disinfectant residual, orthophosphate, pH, silica, 
temperature and turbidity may be performed by any person acceptable to 
the State.
* * * * *

0
6. Section 141.153 is amended by adding a new paragraph (h)(6) to read 
as follows:

Sec.  141.153  Content of the reports.

* * * * *
    (h) * * *
    (6) Systems required to comply with subpart S. (i) Any ground water 
system that receives notice from the State of a significant deficiency 
or notice from a laboratory of a fecal indicator-positive ground water 
source sample that is not invalidated by the State under Sec.  
141.402(d) must inform its customers of any significant deficiency that 
is uncorrected at the time of the next report or of any fecal 
indicator-positive ground water source sample in the next report. The 
system must continue to inform the public annually until the State 
determines that particular significant deficiency is corrected or the 
fecal contamination in the ground water source is addressed under Sec.  
141.403(a). Each report must include the following elements.
    (A) The nature of the particular significant deficiency or the 
source of the fecal contamination (if the source is known) and the date 
the significant deficiency was identified by the State or the dates of 
the fecal indicator-positive ground water source samples;
    (B) If the fecal contamination in the ground water source has been 
addressed under Sec.  141.403(a) and the date of such action;
    (C) For each significant deficiency or fecal contamination in the 
ground water source that has not been addressed under Sec.  141.403(a), 
the State-approved plan and schedule for correction, including interim 
measures, progress to date, and any interim measures completed; and
    (D) If the system receives notice of a fecal indicator-positive 
ground water source sample that is not invalidated by the State under 
Sec.  141.402(d), the potential health effects using the health effects 
language of Appendix A of subpart O.

[[Page 65652]]

    (ii) If directed by the State, a system with significant 
deficiencies that have been corrected before the next report is issued 
must inform its customers of the significant deficiency, how the 
deficiency was corrected, and the date of correction under paragraph 
(h)(6)(i) of this section.
* * * * *

0
7. Appendix A to subpart O is amended by adding a new entry ``Fecal 
Indicators (enterococci or coliphage)'' to read as follows:

                                               Appendix A to Subpart O of Part 141--Regulated Contaminants
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Traditional MCL in    To convert for                                             Major sources in     Health effects
       Contaminant (units)               mg/L          CCR, multiply by    MCL in CCR units          MCLG           drinking water         language
--------------------------------------------------------------------------------------------------------------------------------------------------------
Microbiological Contaminants:

                                                                      * * * * * * *
Fecal Indicators (enterococci or  TT................  ..................  TT................  N/A...............  Human and animal    Fecal indicators
 coliphage).                                                                                                       fecal waste.        are microbes
                                                                                                                                       whose presence
                                                                                                                                       indicates that
                                                                                                                                       the water may be
                                                                                                                                       contaminated with
                                                                                                                                       human or animal
                                                                                                                                       wastes. Microbes
                                                                                                                                       in these wastes
                                                                                                                                       can cause short-
                                                                                                                                       term health
                                                                                                                                       effects, such as
                                                                                                                                       diarrhea, cramps,
                                                                                                                                       nausea,
                                                                                                                                       headaches, or
                                                                                                                                       other symptoms.
                                                                                                                                       They may pose a
                                                                                                                                       special health
                                                                                                                                       risk for infants,
                                                                                                                                       young children,
                                                                                                                                       some of the
                                                                                                                                       elderly, and
                                                                                                                                       people with
                                                                                                                                       severely
                                                                                                                                       compromised
                                                                                                                                       immune systems.

                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * *
TT=Treatment Technique.

0
8. Section 141.202 is amended by redesignating entry (8) in Table 1 in 
paragraph (a) as entry (9); and adding a new paragraph (8) to read as 
follows:

Sec.  141.202  Tier 1 Public Notice--Form, manner, and frequency of 
notice.

    (a) * * *
Table 1 to Sec.  141.202--Violation Categories and Other Situations 
Requiring a Tier 1 Public Notice
* * * * *
    (8) Detection of E. coli, enterococci, or coliphage in source water 
samples as specified in Sec.  141.402(a) and Sec.  141.402(b).
* * * * *

0
9. Section 141.203 is amended by adding entry (4) to Table 1 in 
paragraph (a) to read as follows:

Sec.  141.203  Tier 2 Public Notice--Form, manner, and frequency of 
notice.

    (a) * * *
Table 1 to Sec.  141.203--Violation Categories and Other Situations 
Requiring a Tier 2 Public Notice
* * * * *
    (4) Failure to take corrective action or failure to maintain at 
least 4-log treatment of viruses (using inactivation, removal, or a 
State-approved combination of 4-log virus inactivation and removal) 
before or at the first customer under Sec.  141.403(a).
* * * * *

0
10. Appendix A to Subpart Q of Part 141 is amended to read as follows:
0
a. Adding I.A.11;
0
b. Redesignating entry IV.F as entry IV.G; and
0
c. Adding a new entry IV.F in alphabetical order:

     Appendix A to Subpart Q of Part 141--NPDWR Violations and Other Situations Requiring Public Notice \1\
----------------------------------------------------------------------------------------------------------------
                                                    MCL/MRDL/TT violations \2\        Monitoring and testing
                                                 --------------------------------      procedure violations
                                                                                 -------------------------------
                   Contaminant                    Tier of public                  Tier of public
                                                      notice         Citation         notice         Citation
                                                     required                        required
----------------------------------------------------------------------------------------------------------------
                   I. Violations of National Primary Drinking Water Regulations (NPDWR): \3\
                                         A. Microbiological Contaminants
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
11. Ground Water Rule violations................               2         141.404               3     141.402(h).
                                                                                                     141.403(d).

[[Page 65653]]

                                                 * * * * * * *
                               IV. Other Situations Requiring Public Notification
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
F. Source Water Sample Positive for GWR Fecal                  1      141.402(g)             N/A             N/A
 indicators: E. coli, enterococci, or coliphage.

                                                 * * * * * * *
----------------------------------------------------------------------------------------------------------------
\1\ Violations and other situations not listed in this table (e.g., failure to prepare Consumer Confidence
  Reports) do not require notice, unless otherwise determined by the primacy agency. Primacy agencies may, at
  their option, also require a more stringent public notice tier (e.g., Tier 1 instead of Tier 2 or Tier 2
  instead of Tier 3) for specific violations and situations listed in this Appendix, as authorized under Sec.
  141.202(a) and Sec.   141.203(a).
\2\ MCL--Maximum contaminant level, MRDL--Maximum residual disinfectant level, TT--Treatment technique.
\3\ The term Violations of National Primary Drinking Water Regulations (NPDWR) is used here to include
  violations of MCL, MRDL, treatment technique, monitoring, and testing procedure requirements.

* * * * *

0
11. Appendix B of Subpart Q of Part 141 is amended by adding entries 
A.1.c and A.1.d in numerical order to read as follows:

          Appendix B to Subpart Q of Part 141--Standard Health Effects Language for Public Notification
----------------------------------------------------------------------------------------------------------------
                                                                                       Standard health effects
            Contaminant                   MCLG \1\ mg/L           MCL \2\ mg/L           language for public
                                                                                             notification
----------------------------------------------------------------------------------------------------------------
                              National Primary Drinking Water Regulations (NPDWR)
                                         A. Microbiological Contaminants
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
1c. Fecal indicators (GWR):          Zero..................  TT....................  Fecal indicators are
i. E. coli                           None..................  TT....................   microbes whose presence
ii. enterococci                      None..................  TT....................   indicates that the water
iii. coliphage                                                                        may be contaminated with
                                                                                      human or animal wastes.
                                                                                      Microbes in these wastes
                                                                                      can cause short-term
                                                                                      health effects, such as
                                                                                      diarrhea, cramps, nausea,
                                                                                      headaches, or other
                                                                                      symptoms. They may pose a
                                                                                      special health risk for
                                                                                      infants, young children,
                                                                                      some of the elderly, and
                                                                                      people with severely
                                                                                      compromised immune
                                                                                      systems.
1d. Ground Water Rule (GWR) TT       None..................  TT....................  Inadequately treated or
 violations.                                                                          inadequately protected
                                                                                      water may contain disease-
                                                                                      causing organisms. These
                                                                                      organisms can cause
                                                                                      symptoms such as diarrhea,
                                                                                      nausea, cramps, and
                                                                                      associated headaches.

                                                 * * * * * * *
----------------------------------------------------------------------------------------------------------------
\1\ MCLG--Maximum contaminant level goal.
\2\ MCL--Maximum contaminant level.

* * * * *

0
12. Appendix C to Subpart Q is amended by adding the following 
abbreviations in alphabetical order:

Appendix C to Subpart Q of Part 141--List of Acronyms Used in Public 
Notification Regulations

* * * * *
GWR Ground Water Rule
* * * * *

0
13. A new subpart S is added to read as follows:
Subpart S--Ground Water Rule
Sec.
141.400 General requirements and applicability.
141.401 Sanitary surveys for ground water systems.
141.402 Ground water source microbial monitoring and analytical 
methods.
141.403 Treatment technique requirements for ground water systems.
141.404 Treatment technique violations for ground water systems.
141.405 Reporting and recordkeeping for ground water systems.

Subpart S--Ground Water Rule

Sec.  141.400  General requirements and applicability.

    (a) Scope of this subpart. The requirements of this subpart S 
constitute National Primary Drinking Water Regulations.
    (b) Applicability. This subpart applies to all public water systems 
that use ground water except that it does not apply to public water 
systems that combine all of their ground water with surface water or 
with ground water under the direct influence of surface water prior to 
treatment under subpart

[[Page 65654]]

H. For the purposes of this subpart, ``ground water system'' is defined 
as any public water system meeting this applicability statement, 
including consecutive systems receiving finished ground water.
    (c) General requirements. Systems subject to this subpart must 
comply with the following requirements:
    (1) Sanitary survey information requirements for all ground water 
systems as described in Sec.  141.401.
    (2) Microbial source water monitoring requirements for ground water 
systems that do not treat all of their ground water to at least 99.99 
percent (4-log) treatment of viruses (using inactivation, removal, or a 
State-approved combination of 4-log virus inactivation and removal) 
before or at the first customer as described in Sec.  141.402.
    (3) Treatment technique requirements, described in Sec.  141.403, 
that apply to ground water systems that have fecally contaminated 
source waters, as determined by source water monitoring conducted under 
Sec.  141.402, or that have significant deficiencies that are 
identified by the State or that are identified by EPA under SDWA 
section 1445. A ground water system with fecally contaminated source 
water or with significant deficiencies subject to the treatment 
technique requirements of this subpart must implement one or more of 
the following corrective action options: correct all significant 
deficiencies; provide an alternate source of water; eliminate the 
source of contamination; or provide treatment that reliably achieves at 
least 4-log treatment of viruses (using inactivation, removal, or a 
State-approved combination of 4-log virus inactivation and removal) 
before or at the first customer.
    (4) Ground water systems that provide at least 4-log treatment of 
viruses (using inactivation, removal, or a State-approved combination 
of 4-log virus inactivation and removal) before or at the first 
customer are required to conduct compliance monitoring to demonstrate 
treatment effectiveness, as described in Sec.  141.403(b).
    (5) If requested by the State, ground water systems must provide 
the State with any existing information that will enable the State to 
perform a hydrogeologic sensitivity assessment. For the purposes of 
this subpart, ``hydrogeologic sensitivity assessment'' is a 
determination of whether ground water systems obtain water from 
hydrogeologically sensitive settings.
    (d) Compliance date. Ground water systems must comply, unless 
otherwise noted, with the requirements of this subpart beginning 
December 1, 2009.

Sec.  141.401  Sanitary surveys for ground water systems.

    (a) Ground water systems must provide the State, at the State's 
request, any existing information that will enable the State to conduct 
a sanitary survey.
    (b) For the purposes of this subpart, a ``sanitary survey,'' as 
conducted by the State, includes but is not limited to, an onsite 
review of the water source(s) (identifying sources of contamination by 
using results of source water assessments or other relevant information 
where available), facilities, equipment, operation, maintenance, and 
monitoring compliance of a public water system to evaluate the adequacy 
of the system, its sources and operations and the distribution of safe 
drinking water.
    (c) The sanitary survey must include an evaluation of the 
applicable components listed in paragraphs (c)(1) through (8) of this 
section:
    (1) Source,
    (2) Treatment,
    (3) Distribution system,
    (4) Finished water storage,
    (5) Pumps, pump facilities, and controls,
    (6) Monitoring, reporting, and data verification,
    (7) System management and operation, and
    (8) Operator compliance with State requirements.

Sec.  141.402  Ground water source microbial monitoring and analytical 
methods.

    (a) Triggered source water monitoring.--(1) General requirements. A 
ground water system must conduct triggered source water monitoring if 
the conditions identified in paragraphs (a)(1)(i) and (a)(1)(ii) of 
this section exist.
    (i) The system does not provide at least 4-log treatment of viruses 
(using inactivation, removal, or a State-approved combination of 4-log 
virus inactivation and removal) before or at the first customer for 
each ground water source; and
    (ii) The system is notified that a sample collected under Sec.  
141.21(a) is total coliform-positive and the sample is not invalidated 
under Sec.  141.21(c).
    (2) Sampling Requirements. A ground water system must collect, 
within 24 hours of notification of the total coliform-positive sample, 
at least one ground water source sample from each ground water source 
in use at the time the total coliform-positive sample was collected 
under Sec.  141.21(a), except as provided in paragraph (a)(2)(ii) of 
this section.
    (i) The State may extend the 24-hour time limit on a case-by-case 
basis if the system cannot collect the ground water source water sample 
within 24 hours due to circumstances beyond its control. In the case of 
an extension, the State must specify how much time the system has to 
collect the sample.
    (ii) If approved by the State, systems with more than one ground 
water source may meet the requirements of this paragraph (a)(2) by 
sampling a representative ground water source or sources. If directed 
by the State, systems must submit for State approval a triggered source 
water monitoring plan that identifies one or more ground water sources 
that are representative of each monitoring site in the system's sample 
siting plan under Sec.  141.21(a) and that the system intends to use 
for representative sampling under this paragraph.
    (iii) A ground water system serving 1,000 people or fewer may use a 
repeat sample collected from a ground water source to meet both the 
requirements of Sec.  141.21(b) and to satisfy the monitoring 
requirements of paragraph (a)(2) of this section for that ground water 
source only if the State approves the use of E. coli as a fecal 
indicator for source water monitoring under this paragraph (a). If the 
repeat sample collected from the ground water source is E.coli 
positive, the system must comply with paragraph (a)(3) of this section.
    (3) Additional Requirements. If the State does not require 
corrective action under Sec.  141.403(a)(2) for a fecal indicator-
positive source water sample collected under paragraph (a)(2) of this 
section that is not invalidated under paragraph (d) of this section, 
the system must collect five additional source water samples from the 
same source within 24 hours of being notified of the fecal indicator-
positive sample.
    (4) Consecutive and Wholesale Systems. (i). In addition to the 
other requirements of this paragraph (a), a consecutive ground water 
system that has a total coliform-positive sample collected under Sec.  
141.21(a) must notify the wholesale system(s) within 24 hours of being 
notified of the total coliform-positive sample.
    (ii) In addition to the other requirements of this paragraph (a), a 
wholesale ground water system must comply with paragraphs (a)(4)(ii)(A) 
and (a)(4)(ii)(B) of this section.
    (A) A wholesale ground water system that receives notice from a 
consecutive system it serves that a sample collected under Sec.  
141.21(a) is total coliform-positive must, within 24 hours of being 
notified, collect a sample from its ground water source(s) under 
paragraph (a)(2) of this section and analyze it for

[[Page 65655]]

a fecal indicator under paragraph (c) of this section.
    (B) If the sample collected under paragraph (a)(4)(ii)(A) of this 
section is fecal indicator-positive, the wholesale ground water system 
must notify all consecutive systems served by that ground water source 
of the fecal indicator source water positive within 24 hours of being 
notified of the ground water source sample monitoring result and must 
meet the requirements of paragraph (a)(3) of this section.
    (5) Exceptions to the Triggered Source Water Monitoring 
Requirements. A ground water system is not required to comply with the 
source water monitoring requirements of paragraph (a) of this section 
if either of the following conditions exists:
    (i) The State determines, and documents in writing, that the total 
coliform-positive sample collected under Sec.  141.21(a) is caused by a 
distribution system deficiency; or
    (ii) The total coliform-positive sample collected under Sec.  
141.21(a) is collected at a location that meets State criteria for 
distribution system conditions that will cause total coliform-positive 
samples.
    (b) Assessment Source Water Monitoring. If directed by the State, 
ground water systems must conduct assessment source water monitoring 
that meets State-determined requirements for such monitoring. A ground 
water system conducting assessment source water monitoring may use a 
triggered source water sample collected under paragraph (a)(2) of this 
section to meet the requirements of paragraph (b) of this section. 
State-determined assessment source water monitoring requirements may 
include:
    (1) Collection of a total of 12 ground water source samples that 
represent each month the system provides ground water to the public,
    (2) Collection of samples from each well unless the system obtains 
written State approval to conduct monitoring at one or more wells 
within the ground water system that are representative of multiple 
wells used by that system and that draw water from the same 
hydrogeologic setting,
    (3) Collection of a standard sample volume of at least 100 mL for 
fecal indicator analysis regardless of the fecal indicator or 
analytical method used,
    (4) Analysis of all ground water source samples using one of the 
analytical methods listed in the in paragraph (c)(2) of this section 
for the presence of E. coli, enterococci, or coliphage,
    (5) Collection of ground water source samples at a location prior 
to any treatment of the ground water source unless the State approves a 
sampling location after treatment, and
    (6) Collection of ground water source samples at the well itself 
unless the system's configuration does not allow for sampling at the 
well itself and the State approves an alternate sampling location that 
is representative of the water quality of that well.
    (c) Analytical methods. (1) A ground water system subject to the 
source water monitoring requirements of paragraph (a) of this section 
must collect a standard sample volume of at least 100 mL for fecal 
indicator analysis regardless of the fecal indicator or analytical 
method used.
    (2) A ground water system must analyze all ground water source 
samples collected under paragraph (a) of this section using one of the 
analytical methods listed in the following table in paragraph (c)(2) of 
this section for the presence of E. coli, enterococci, or coliphage:

             Analytical Methods for Source Water Monitoring
------------------------------------------------------------------------
      Fecal indicator \1\             Methodology        Method citation
------------------------------------------------------------------------
E. coli.......................  Colilert \3\..........  9223 B.\2\
                                Colisure \3\..........  9223 B.\2\
                                Membrane Filter Method  EPA Method
                                 with MI Agar.           1604.\4\
                                m-ColiBlue24 Test \5\.  ................
                                E*Colite Test \6\.....  ................
                                EC-MUG \7\............  9221 F.\2\
                                NA-MUG \7\............  9222 G.\2\
Enterococci                     Multiple-Tube           9230B.\2\
                                 Technique.
                                Membrane Filter         9230C.\2\
                                 Technique.
                                Membrane Filter         EPA Method
                                 Technique.              1600.\8\
                                Enterolert \9\........  ................
Coliphage.....................  Two-Step Enrichment     EPA Method
                                 Presence-Absence        1601.\10\
                                 Procedure.
                                Single Agar Layer       EPA Method
                                 Procedure.              1602.\11\
------------------------------------------------------------------------
Analyses must be conducted in accordance with the documents listed
  below. The Director of the Federal Register approves the incorporation
  by reference of the documents listed in footnotes 2-11 in accordance
  with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the documents may be
  obtained from the sources listed below. Copies may be inspected at
  EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW.,
  EPA West, Room B102, Washington DC 20460 (Telephone: 202-566-2426); or
  at the National Archives and Records Administration (NARA). For
  information on the availability of this material at NARA, call 202-741-
  6030, or go to: http://www.archives.gov/[fxsp0]federal--register/

  [fxsp0]code--of--federal--[fxsp0]regulations/ibr--locations.html.
\1\ The time from sample collection to initiation of analysis may not
  exceed 30 hours. The ground water system is encouraged but is not
  required to hold samples below 10[deg]C during transit.
\2\ Methods are described in Standard Methods for the Examination of
  Water and Wastewater 20th edition (1998) and copies may be obtained
  from the American Public Health Association, 1015 Fifteenth Street,
  NW., Washington, DC 20005-2605.
\3\ Medium is available through IDEXX Laboratories, Inc., One IDEXX
  Drive, Westbrook, Maine 04092.
\4\ EPA Method 1604: Total Coliforms and Escherichia coli in Water by
  Membrane Filtration Using a Simultaneous Detection Technique (MI
  Medium); September 2002, EPA 821-R-02-024. Method is available at
  http://www.epa.gov/[fxsp0]nerlcwww/1604sp02.pdf or from EPA's Water

  Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington,
  DC 20460.
\5\ A description of the m-ColiBlue24 Test, ``Total Coliforms and E.
  coli Membrane Filtration Method with m-ColiBlue24[reg] Broth,'' Method
  No. 10029 Revision 2, August 17, 1999, is available from Hach Company,
  100 Dayton Ave., Ames, IA 50010 or from EPA's Water Resource Center
  (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460.
\6\ A description of the E*Colite Test, ``Charm E*Colite Presence/
  Absence Test for Detection and Identification of Coliform Bacteria and
  Escherichia coli in Drinking Water, January 9, 1998, is available from
  Charm Sciences, Inc., 659 Andover St., Lawrence, MA 01843-1032 or from
  EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW.,
  Washington, DC 20460.
\7\ EC-MUG (Method 9221F) or NA-MUG (Method 9222G) can be used for E.
  coli testing step as described in Sec.   141.21(f)(6)(i) or (ii) after
  use of Standard Methods 9221 B, 9221 D, 9222 B, or 9222 C.

[[Page 65656]]

\8\ EPA Method 1600: Enterococci in Water by Membrane Filtration Using
  membrane-Enterococcus Indoxyl-[beta]-D-Glucoside Agar (mEI) EPA 821-R-
  02-022 (September 2002) is an approved variation of Standard Method
  9230C. The method is available at http://www.epa.gov/[fxsp0]nerlcwww/

  1600sp02.pdf or from EPA's Water Resource Center (RC-4100T), 1200
  Pennsylvania Avenue, NW., Washington, DC 20460. The holding time and
  temperature for ground water samples are specified in footnote 1
  above, rather than as specified in Section 8 of EPA Method 1600.
\9\ Medium is available through IDEXX Laboratories, Inc., One IDEXX
  Drive, Westbrook, Maine 04092. Preparation and use of the medium is
  set forth in the article ``Evaluation of Enterolert for Enumeration of
  Enterococci in Recreational Waters,'' by Budnick, G.E., Howard, R.T.,
  and Mayo, D.R., 1996, Applied and Environmental Microbiology, 62:3881-
  3884.
\10\ EPA Method 1601: Male-specific (F+) and Somatic Coliphage in Water
  by Two-step Enrichment Procedure; April 2001, EPA 821-R-01-030. Method
  is available at http://www.epa.gov/[fxsp0]nerlcwww/1601ap01.pdf or

  from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue,
  NW., Washington, DC 20460.
\11\ EPA Method 1602: Male-specific (F+) and Somatic Coliphage in Water
  by Single Agar Layer (SAL) Procedure; April 2001, EPA 821-R-01-029.
  Method is available at http://www.epa.gov/[fxsp0]nerlcwww/1602ap01.pdf

  or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania
  Avenue, NW., Washington, DC 20460.

    (d) Invalidation of a fecal indicator-positive ground water source 
sample. (1) A ground water system may obtain State invalidation of a 
fecal indicator-positive ground water source sample collected under 
paragraph (a) of this section only under the conditions specified in 
paragraphs (d)(1)(i) and (ii) of this section.
    (i) The system provides the State with written notice from the 
laboratory that improper sample analysis occurred; or
    (ii) The State determines and documents in writing that there is 
substantial evidence that a fecal indicator-positive ground water 
source sample is not related to source water quality.
    (2) If the State invalidates a fecal indicator-positive ground 
water source sample, the ground water system must collect another 
source water sample under paragraph (a) of this section within 24 hours 
of being notified by the State of its invalidation decision and have it 
analyzed for the same fecal indicator using the analytical methods in 
paragraph (c) of this section. The State may extend the 24-hour time 
limit on a case-by-case basis if the system cannot collect the source 
water sample within 24 hours due to circumstances beyond its control. 
In the case of an extension, the State must specify how much time the 
system has to collect the sample.
    (e) Sampling location. (1) Any ground water source sample required 
under paragraph (a) of this section must be collected at a location 
prior to any treatment of the ground water source unless the State 
approves a sampling location after treatment.
    (2) If the system's configuration does not allow for sampling at 
the well itself, the system may collect a sample at a State-approved 
location to meet the requirements of paragraph (a) of this section if 
the sample is representative of the water quality of that well.
    (f) New Sources. If directed by the State, a ground water system 
that places a new ground water source into service after November 30, 
2009, must conduct assessment source water monitoring under paragraph 
(b) of this section. If directed by the State, the system must begin 
monitoring before the ground water source is used to provide water to 
the public.
    (g) Public Notification. A ground water system with a ground water 
source sample collected under paragraph (a) or (b) of this section that 
is fecal indicator-positive and that is not invalidated under paragraph 
(d) of this section, including consecutive systems served by the ground 
water source, must conduct public notification under Sec.  141.202.
    (h) Monitoring Violations. Failure to meet the requirements of 
paragraphs (a)-(f) of this section is a monitoring violation and 
requires the ground water system to provide public notification under 
Sec.  141.204.

Sec.  141.403  Treatment technique requirements for ground water 
systems.

    (a) Ground water systems with significant deficiencies or source 
water fecal contamination.
    (1) The treatment technique requirements of this section must be 
met by ground water systems when a significant deficiency is identified 
or when a ground water source sample collected under Sec.  
141.402(a)(3) is fecal indicator-positive.
    (2) If directed by the State, a ground water system with a ground 
water source sample collected under Sec.  141.402(a)(2), Sec.  
141.402(a)(4), or Sec.  141.402(b) that is fecal indicator-positive 
must comply with the treatment technique requirements of this section.
    (3) When a significant deficiency is identified at a Subpart H 
public water system that uses both ground water and surface water or 
ground water under the direct influence of surface water, the system 
must comply with provisions of this paragraph except in cases where the 
State determines that the significant deficiency is in a portion of the 
distribution system that is served solely by surface water or ground 
water under the direct influence of surface water.
    (4) Unless the State directs the ground water system to implement a 
specific corrective action, the ground water system must consult with 
the State regarding the appropriate corrective action within 30 days of 
receiving written notice from the State of a significant deficiency, 
written notice from a laboratory that a ground water source sample 
collected under Sec.  141.402(a)(3) was found to be fecal indicator-
positive, or direction from the State that a fecal indicator'positive 
collected under Sec.  141.402(a)(2), Sec.  141.402(a)(4), or Sec.  
141.402(b) requires corrective action. For the purposes of this 
subpart, significant deficiencies include, but are not limited to, 
defects in design, operation, or maintenance, or a failure or 
malfunction of the sources, treatment, storage, or distribution system 
that the State determines to be causing, or have potential for causing, 
the introduction of contamination into the water delivered to 
consumers.
    (5) Within 120 days (or earlier if directed by the State) of 
receiving written notification from the State of a significant 
deficiency, written notice from a laboratory that a ground water source 
sample collected under Sec.  141.402(a)(3) was found to be fecal 
indicator-positive, or direction from the State that a fecal indicator-
positive sample collected under Sec.  141.402(a)(2), Sec.  
141.402(a)(4), or Sec.  141.402(b) requires corrective action, the 
ground water system must either:
    (i) Have completed corrective action in accordance with applicable 
State plan review processes or other State guidance or direction, if 
any, including State-specified interim measures; or
    (ii) Be in compliance with a State-approved corrective action plan 
and schedule subject to the conditions specified in paragraphs 
(a)(5)(ii)(A) and (a)(5)(ii)(B) of this section.
    (A) Any subsequent modifications to a State-approved corrective 
action plan and schedule must also be approved by the State.
    (B) If the State specifies interim measures for protection of the 
public health pending State approval of the corrective action plan and 
schedule or pending completion of the corrective action plan, the 
system must comply with these interim measures as well as

[[Page 65657]]

with any schedule specified by the State.
    (6) Corrective Action Alternatives. Ground water systems that meet 
the conditions of paragraph (a)(1) or (a)(2) of this section must 
implement one or more of the following corrective action alternatives:
    (i) Correct all significant deficiencies;
    (ii) Provide an alternate source of water;
    (iii) Eliminate the source of contamination; or
    (iv) Provide treatment that reliably achieves at least 4-log 
treatment of viruses (using inactivation, removal, or a State-approved 
combination of 4-log virus inactivation and removal) before or at the 
first customer for the ground water source.
    (7) Special notice to the public of significant deficiencies or 
source water fecal contamination. (i) In addition to the applicable 
public notification requirements of Sec.  141.202, a community ground 
water system that receives notice from the State of a significant 
deficiency or notification of a fecal indicator-positive ground water 
source sample that is not invalidated by the State under Sec.  
141.402(d) must inform the public served by the water system under 
Sec.  141.153(h)(6) of the fecal indicator-positive source sample or of 
any significant deficiency that has not been corrected. The system must 
continue to inform the public annually until the significant deficiency 
is corrected or the fecal contamination in the ground water source is 
determined by the State to be corrected under paragraph (a)(5) of this 
section.
    (ii) In addition to the applicable public notification requirements 
of Sec.  141.202, a non-community ground water system that receives 
notice from the State of a significant deficiency must inform the 
public served by the water system in a manner approved by the State of 
any significant deficiency that has not been corrected within 12 months 
of being notified by the State, or earlier if directed by the State. 
The system must continue to inform the public annually until the 
significant deficiency is corrected. The information must include:
    (A) The nature of the significant deficiency and the date the 
significant deficiency was identified by the State;
    (B) The State-approved plan and schedule for correction of the 
significant deficiency, including interim measures, progress to date, 
and any interim measures completed; and
    (C) For systems with a large proportion of non-English speaking 
consumers, as determined by the State, information in the appropriate 
language(s) regarding the importance of the notice or a telephone 
number or address where consumers may contact the system to obtain a 
translated copy of the notice or assistance in the appropriate 
language.
    (iii) If directed by the State, a non-community water system with 
significant deficiencies that have been corrected must inform its 
customers of the significant deficiencies, how the deficiencies were 
corrected, and the dates of correction under paragraph (a)(7)(ii) of 
this section.
    (b) Compliance monitoring--(1) Existing ground water sources. A 
ground water system that is not required to meet the source water 
monitoring requirements of this subpart for any ground water source 
because it provides at least 4-log treatment of viruses (using 
inactivation, removal, or a State-approved combination of 4-log virus 
inactivation and removal) before or at the first customer for any 
ground water source before December 1, 2009, must notify the State in 
writing that it provides at least 4-log treatment of viruses (using 
inactivation, removal, or a State-approved combination of 4-log virus 
inactivation and removal) before or at the first customer for the 
specified ground water source and begin compliance monitoring in 
accordance with paragraph (b)(3) of this section by December 1, 2009. 
Notification to the State must include engineering, operational, or 
other information that the State requests to evaluate the submission. 
If the system subsequently discontinues 4-log treatment of viruses 
(using inactivation, removal, or a State-approved combination of 4-log 
virus inactivation and removal) before or at the first customer for a 
ground water source, the system must conduct ground water source 
monitoring as required under Sec.  141.402.
    (2) New ground water sources. A ground water system that places a 
ground water source in service after November 30, 2009, that is not 
required to meet the source water monitoring requirements of this 
subpart because the system provides at least 4-log treatment of viruses 
(using inactivation, removal, or a State-approved combination of 4-log 
virus inactivation and removal) before or at the first customer for the 
ground water source must comply with the requirements of paragraphs 
(b)(2)(i), (b)(2)(ii) and (b)(2)(iii) of this section.
    (i) The system must notify the State in writing that it provides at 
least 4-log treatment of viruses (using inactivation, removal, or a 
State-approved combination of 4-log virus inactivation and removal) 
before or at the first customer for the ground water source. 
Notification to the State must include engineering, operational, or 
other information that the State requests to evaluate the submission.
    (ii) The system must conduct compliance monitoring as required 
under Sec.  141.403(b)(3) of this subpart within 30 days of placing the 
source in service.
    (iii) The system must conduct ground water source monitoring under 
Sec.  141.402 if the system subsequently discontinues 4-log treatment 
of viruses (using inactivation, removal, or a State-approved 
combination of 4-log virus inactivation and removal) before or at the 
first customer for the ground water source.
    (3) Monitoring requirements. A ground water system subject to the 
requirements of paragraphs (a), (b)(1) or (b)(2) of this section must 
monitor the effectiveness and reliability of treatment for that ground 
water source before or at the first customer as follows:
    (i) Chemical disinfection--(A) Ground water systems serving greater 
than 3,300 people. A ground water system that serves greater than 3,300 
people must continuously monitor the residual disinfectant 
concentration using analytical methods specified in Sec.  141.74(a)(2) 
at a location approved by the State and must record the lowest residual 
disinfectant concentration each day that water from the ground water 
source is served to the public. The ground water system must maintain 
the State-determined residual disinfectant concentration every day the 
ground water system serves water from the ground water source to the 
public. If there is a failure in the continuous monitoring equipment, 
the ground water system must conduct grab sampling every four hours 
until the continuous monitoring equipment is returned to service. The 
system must resume continuous residual disinfectant monitoring within 
14 days.
    (B) Ground water systems serving 3,300 or fewer people. A ground 
water system that serves 3,300 or fewer people must monitor the 
residual disinfectant concentration using analytical methods specified 
in Sec.  141.74(a)(2) at a location approved by the State and record 
the residual disinfection concentration each day that water from the 
ground water source is served to the public. The ground water system 
must maintain the State-determined residual disinfectant concentration 
every day the ground water system serves water from the ground water 
source to the public. The ground water system must take a daily grab 
sample during the hour of peak flow or at another time specified by the 
State. If any daily grab sample

[[Page 65658]]

measurement falls below the State-determined residual disinfectant 
concentration, the ground water system must take follow-up samples 
every four hours until the residual disinfectant concentration is 
restored to the State-determined level. Alternatively, a ground water 
system that serves 3,300 or fewer people may monitor continuously and 
meet the requirements of paragraph (b)(3)(i)(A) of this section.
    (ii) Membrane filtration. A ground water system that uses membrane 
filtration to meet the requirements of this subpart must monitor the 
membrane filtration process in accordance with all State-specified 
monitoring requirements and must operate the membrane filtration in 
accordance with all State-specified compliance requirements. A ground 
water system that uses membrane filtration is in compliance with the 
requirement to achieve at least 4-log removal of viruses when:
    (A) The membrane has an absolute molecular weight cut-off (MWCO), 
or an alternate parameter that describes the exclusion characteristics 
of the membrane, that can reliably achieve at least 4-log removal of 
viruses;
    (B) The membrane process is operated in accordance with State-
specified compliance requirements; and
    (C) The integrity of the membrane is intact.
    (iii) Alternative treatment. A ground water system that uses a 
State-approved alternative treatment to meet the requirements of this 
subpart by providing at least 4-log treatment of viruses (using 
inactivation, removal, or a State-approved combination of 4-log virus 
inactivation and removal) before or at the first customer must:
    (A) Monitor the alternative treatment in accordance with all State-
specified monitoring requirements; and
    (B) Operate the alternative treatment in accordance with all 
compliance requirements that the State determines to be necessary to 
achieve at least 4-log treatment of viruses.
    (c) Discontinuing treatment. A ground water system may discontinue 
4-log treatment of viruses (using inactivation, removal, or a State-
approved combination of 4-log virus inactivation and removal) before or 
at the first customer for a ground water source if the State determines 
and documents in writing that 4-log treatment of viruses is no longer 
necessary for that ground water source. A system that discontinues 4-
log treatment of viruses is subject to the source water monitoring and 
analytical methods requirements of Sec.  141.402 of this subpart.
    (d) Failure to meet the monitoring requirements of paragraph (b) of 
this section is a monitoring violation and requires the ground water 
system to provide public notification under Sec.  141.204.

Sec.  141.404  Treatment technique violations for ground water systems.

    (a) A ground water system with a significant deficiency is in 
violation of the treatment technique requirement if, within 120 days 
(or earlier if directed by the State) of receiving written notice from 
the State of the significant deficiency, the system:
    (1) Does not complete corrective action in accordance with any 
applicable State plan review processes or other State guidance and 
direction, including State specified interim actions and measures, or
    (2) Is not in compliance with a State-approved corrective action 
plan and schedule.
    (b) Unless the State invalidates a fecal indicator-positive ground 
water source sample under Sec.  141.402(d), a ground water system is in 
violation of the treatment technique requirement if, within 120 days 
(or earlier if directed by the State) of meeting the conditions of 
Sec.  141.403(a)(1) or Sec.  141.403(a)(2), the system:
    (1) Does not complete corrective action in accordance with any 
applicable State plan review processes or other State guidance and 
direction, including State-specified interim measures, or
    (2) Is not in compliance with a State-approved corrective action 
plan and schedule.
    (c) A ground water system subject to the requirements of Sec.  
141.403(b)(3) that fails to maintain at least 4-log treatment of 
viruses (using inactivation, removal, or a State-approved combination 
of 4-log virus inactivation and removal) before or at the first 
customer for a ground water source is in violation of the treatment 
technique requirement if the failure is not corrected within four hours 
of determining the system is not maintaining at least 4-log treatment 
of viruses before or at the first customer.
    (d) Ground water system must give public notification under Sec.  
141.203 for the treatment technique violations specified in paragraphs 
(a), (b) and (c) of this section.

Sec.  141.405  Reporting and recordkeeping for ground water systems.

    (a) Reporting. In addition to the requirements of Sec.  141.31, a 
ground water system regulated under this subpart must provide the 
following information to the State:
    (1) A ground water system conducting compliance monitoring under 
Sec.  141.403(b) must notify the State any time the system fails to 
meet any State-specified requirements including, but not limited to, 
minimum residual disinfectant concentration, membrane operating 
criteria or membrane integrity, and alternative treatment operating 
criteria, if operation in accordance with the criteria or requirements 
is not restored within four hours. The ground water system must notify 
the State as soon as possible, but in no case later than the end of the 
next business day.
    (2) After completing any corrective action under Sec.  141.403(a), 
a ground water system must notify the State within 30 days of 
completion of the corrective action.
    (3) If a ground water system subject to the requirements of Sec.  
141.402(a) does not conduct source water monitoring under Sec.  
141.402(a)(5)(ii), the system must provide documentation to the State 
within 30 days of the total coliform positive sample that it met the 
State criteria.
    (b) Recordkeeping. In addition to the requirements of Sec.  141.33, 
a ground water system regulated under this subpart must maintain the 
following information in its records:
    (1) Documentation of corrective actions. Documentation shall be 
kept for a period of not less than ten years.
    (2) Documentation of notice to the public as required under Sec.  
141.403(a)(7). Documentation shall be kept for a period of not less 
than three years.
    (3) Records of decisions under Sec.  141.402(a)(5)(ii) and records 
of invalidation of fecal indicator-positive ground water source samples 
under Sec.  141.402(d). Documentation shall be kept for a period of not 
less than five years.
    (4) For consecutive systems, documentation of notification to the 
wholesale system(s) of total-coliform positive samples that are not 
invalidated under Sec.  141.21(c). Documentation shall be kept for a 
period of not less than five years.
    (5) For systems, including wholesale systems, that are required to 
perform compliance monitoring under Sec.  141.403(b):
    (i) Records of the State-specified minimum disinfectant residual. 
Documentation shall be kept for a period of not less than ten years.
    (ii) Records of the lowest daily residual disinfectant 
concentration and records of the date and duration of any failure to 
maintain the State-prescribed minimum residual disinfectant 
concentration for a period of more than

[[Page 65659]]

four hours. Documentation shall be kept for a period of not less than 
five years.
    (iii) Records of State-specified compliance requirements for 
membrane filtration and of parameters specified by the State for State-
approved alternative treatment and records of the date and duration of 
any failure to meet the membrane operating, membrane integrity, or 
alternative treatment operating requirements for more than four hours. 
Documentation shall be kept for a period of not less than five years.

PART 142--NATIONAL PRIMARY DRINKING WATER REGULATIONS 
IMPLEMENTATION

0
14. The authority citation for part 142 continues to read as follows:

    Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.

0
15. Section 142.14 is amended by adding paragraph (d)(17) to read as 
follows:

Sec.  142.14  Records kept by States.

* * * * *
    (d) * * *
    (17) Records of the currently applicable or most recent State 
determination, including all supporting information and an explanation 
of the technical basis of each decision, made under the following 
provisions of 40 CFR part 141, subpart S and 40 CFR part 142.
    (i) Section 142.16(o)(2)(v). Records of written notices of 
significant deficiencies.
    (ii) Section 141.403(a)(5)(ii) of this chapter. Records of 
corrective action plans, schedule approvals, and State-specified 
interim measures.
    (iii) Section 142.16(o)(4). Records of confirmations under Sec.  
141.403(a) of this chapter that a significant deficiency has been 
corrected or the fecal contamination in the ground water source has 
been addressed.
    (iv) Section 141.402(a)(5) of this chapter. Records of State 
determinations and records of ground water system's documentation for 
not conducting triggered source water monitoring.
    (v) Section 141.402(d) of this chapter. Records of invalidations of 
fecal indicator-positive ground water source samples.
    (vi) Section 141.402(a)(2)(ii) of this chapter. Records of State 
approvals of source water monitoring plans.
    (vii) Section 142.16(o)(4)(ii). Records of notices of the minimum 
residual disinfection concentration (when using chemical disinfection) 
needed to achieve at least 4-log virus inactivation before or at the 
first customer.
    (viii) Sections 142.16(o)(4)(iv) and 142.16(o)(4)(v) Records of 
notices of the State-specified monitoring and compliance requirements 
(when using membrane filtration or alternative treatment) needed to 
achieve at least 4-log treatment of viruses (using inactivation, 
removal, or a State-approved combination of 4-log inactivation and 
removal) before or at the first customer.
    (ix) Sections 141.403(b)(1) and 141.403(b)(2) of this chapter. 
Records of written notices from the ground water system that it 
provides at least 4-log treatment of viruses (using inactivation, 
removal, or a State-approved combination of 4-log virus inactivation 
and removal) before or at the first customer for a ground water source.
    (x) Section 142.16(o)(4)(vi). Records of written determinations 
that the ground water system may discontinue 4-log treatment of viruses 
(using inactivation, removal, or a State-approved combination of 4-log 
inactivation and removal).
* * * * *

0
16. Section 142.15 is amended by adding paragraph (c)(7) to read as 
follows:

Sec.  142.15  Reports by States.

* * * * *
    (c) * * *
    (7) Ground water rule. (i) Sanitary surveys. The month and year in 
which the most recent sanitary survey was completed or, for a State 
that uses a phased review process, the date the last element of the 
applicable eight elements was evaluated under Sec.  142.16(o)(2) for 
each ground water system.
    (ii) Corrective action requirements. For any corrective action 
under Sec.  141.403(a) of this chapter, the date the ground water 
system completed corrective action.
    (iii) Compliance monitoring. All ground water systems providing at 
least 4-log treatment of viruses (using inactivation, removal, or a 
State-approved combination of 4-log virus inactivation and removal) 
before or at the first customer for any ground water source(s).
* * * * *

0
17. Section 142.16 is amended as follows:
0
a. Revise paragraph (a)(2)(iii), and
0
b. Add paragraph (o) to read as follows:

Sec.  142.16  Special primacy requirements.

    (a) * * *
    (2) * * *
    (iii) Table 1 of 40 CFR 141.202(a) (Items (5), (6), and (9))--To 
require public water systems to give a Tier 1 public notice (rather 
than a Tier 2 or Tier 3 notice) for violations or situations listed in 
Appendix A of Subpart Q of Part 141 of this chapter;
    (o) Requirements for States to adopt 40 CFR part 141, subpart S. In 
addition to the general primacy requirements specified elsewhere in 
this part, including the requirement that State regulations are no less 
stringent than the Federal requirements, an application for approval of 
a State program revision that adopts 40 CFR part 141, subpart S, must 
contain the information specified in this paragraph (o).
    (1) Legal authority. The application for primacy must demonstrate 
the State has:
    (i) The authority contained in statute or regulation to ensure that 
ground water systems conduct source water monitoring under Sec.  
141.402(a)(2), Sec.  141.402(a)(3) and Sec.  141.402(a)(4)(ii)(A) of 
this chapter.
    (ii) The authority contained in statute or regulation to ensure 
that ground water systems take the appropriate corrective actions 
including interim measures, if necessary, needed to address significant 
deficiencies.
    (iii) The authority contained in statute or regulation to ensure 
that ground water systems take the appropriate corrective actions, 
including interim measures if necessary, to address any source water 
fecal contamination identified during source water monitoring under 
Sec.  141.402 of this chapter.
    (iv) The authority contained in statute or regulation to ensure 
that ground water systems consult with the State regarding corrective 
action(s).
    (2) State practices or procedures for sanitary surveys. In addition 
to the general requirements for sanitary surveys contained in Sec.  
142.10(b)(2), a primacy application must describe how the State will 
implement a sanitary survey program that meets the requirements of 
paragraph (o)(2)(i) of this section. A ``sanitary survey,'' as 
conducted by the State, includes but is not limited to, an onsite 
review of the water source(s) (identifying sources of contamination by 
using results of source water assessments or other relevant information 
where available), facilities, equipment, operation, maintenance, and 
monitoring compliance of a public water system to evaluate the adequacy 
of the system, its sources and operations and the distribution of safe 
drinking water.
    (i) The State must conduct sanitary surveys that address the eight 
sanitary survey components listed in this section no less frequently 
than every three years

[[Page 65660]]

for community water systems, except as provided in paragraph 
(o)(2)(iii) of this section, and every five years for non-community 
water systems. The State may conduct more frequent sanitary surveys for 
any system. The initial sanitary survey for each community water system 
must be conducted by December 31, 2012, unless the system meets the 
requirements of paragraph (o)(2)(iii) of this section. The initial 
sanitary survey for each community water system that meets the 
requirements of paragraph (o)(2)(iii) of this section and for each non-
community water system must be conducted by December 31, 2014. The 
sanitary survey must include an evaluation of each of the following 
elements as applicable:
    (A) Source,
    (B) Treatment,
    (C) Distribution system,
    (D) Finished water storage,
    (E) Pumps, pump facilities, and controls,
    (F) Monitoring, reporting, and data verification,
    (G) System management and operation, and
    (H) Operator compliance with State requirements.
    (ii) The State may use a phased review process to meet the 
requirements of (o)(2)(i) of this section if all the applicable 
elements of paragraphs (o)(2)(i)(A) through (o)(2)(i)(H) of this 
section are evaluated within the required interval.
    (iii) The State may conduct sanitary surveys once every five years 
for community water systems if the system either provides at least 4-
log treatment of viruses (using inactivation, removal, or a State-
approved combination of 4-log inactivation and removal) before or at 
the first customer for all its ground water sources, or if it has an 
outstanding performance record, as determined by the State and 
documented in previous sanitary surveys and has no history of total 
coliform MCL or monitoring violations under Sec.  141.21 of this 
chapter since the last sanitary survey. In its primacy application, the 
State must describe how it will determine whether a community water 
system has an outstanding performance record.
    (iv) The State must define and describe in its primacy application 
at least one specific significant deficiency in each of the eight 
sanitary survey elements in paragraphs (o)(2)(i)(A) through 
(o)(2)(i)(H) of this section. Significant deficiencies include, but are 
not limited to, defects in design, operation, or maintenance, or a 
failure or malfunction of the sources, treatment, storage, or 
distribution system that the State determines to be causing, or have 
potential for causing, the introduction of contamination into the water 
delivered to consumers.
    (v) As a condition of primacy, the State must provide ground water 
systems with written notice describing any significant deficiencies no 
later than 30 days after the State identifies the significant 
deficiency. The notice may specify corrective actions and deadlines for 
completion of corrective actions. The State may provide the written 
notice at the time of the sanitary survey.
    (3) State practices or procedures for source water microbial 
monitoring. The State's primacy application must include a description 
of the following:
    (i) The criteria the State will use under Sec. Sec.  
141.402(a)(2)(i) and 141.402(d)(2) of this chapter for extending the 
24-hour time limit for a system to collect a ground water source sample 
to comply with the source water monitoring requirements.
    (ii) The criteria the State will use under Sec. Sec.  
141.402(a)(5)(i) and 141.402(a)(5)(ii) of this chapter to determine 
whether the cause of the total coliform-positive sample taken under 
Sec.  141.21(a) of this chapter is directly related to the distribution 
system.
    (iii) The criteria the State will use for determining whether to 
invalidate a fecal indicator-positive ground water source sample under 
Sec.  141.402(d)(1)(ii) of this chapter.
    (iv) The criteria the State will use to allow source water 
microbial monitoring at a location after treatment under Sec.  
141.402(e)(1) of this chapter.
    (4) State practices or procedures for treatment technique 
requirements. As a condition of primacy, the State must verify that 
significant deficiencies or source water fecal contamination have been 
addressed. The State must verify within 30 days after the ground water 
system has reported to the State that it has completed corrective 
action. The State must verify either through written confirmation from 
the ground water system or a site visit by the State. Written notice 
from the ground water system under Sec.  141.405(a)(2) of this chapter 
may serve as this verification. The State's primacy application must 
include the following:
    (i) The process the State will use to determine that a ground water 
system achieves at least a 4-log treatment of viruses (using 
inactivation, removal, or a combination of inactivation and removal) 
before or at the first customer for a ground water source for systems 
that are not subject to the source water monitoring requirements of 
Sec.  141.402(a) of this chapter because the ground water system has 
informed the State that it provides at least 4-log treatment of 
viruses.
    (ii) The process the State will use to determine the minimum 
residual disinfectant concentration the system must provide prior to 
the first customer for systems using chemical disinfection.
    (iii) The State-approved alternative technologies that ground water 
systems may use alone or in combination with other approved 
technologies to achieve at least 4-log treatment of viruses (using 
inactivation, removal, or a State-approved combination of 4-log 
inactivation and removal) before or at the first customer for a ground 
water source.
    (iv) The monitoring and compliance requirements the State will 
require for ground water systems treating to at least 4-log treatment 
of viruses (using inactivation, removal, or a State-approved 
combination of inactivation and removal) before or at the first 
customer for State-approved alternative treatment technologies.
    (v) The monitoring, compliance and membrane integrity testing 
requirements the State will require to demonstrate virus removal for 
ground water systems using membrane filtration technologies.
    (vi) The criteria, including public health-based considerations and 
incorporating on-site investigations and source water monitoring 
results the State will use to determine if a ground water system may 
discontinue 4-log treatment of viruses (using inactivation, removal, or 
a State-approved combination of inactivation and removal) before or at 
the first customer.
* * * * *

[FR Doc. 06-8763 Filed 11-7-06; 8:45 am]

BILLING CODE 6560-50-P