[Federal Register Volume 65, Number 91 (Wednesday, May 10, 2000)]
[Proposed Rules]
[Pages 30194-30274]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-10763]



[[Page 30193]]

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Part II





Environmental Protection Agency





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40 CFR Parts 141 and 142



National Primary Drinking Water Regulations: Ground Water Rule; 
Proposed Rules

  Federal Register / Vol. 65, No. 91 / Wednesday, May 10, 2000 / 
Proposed Rules  

[[Page 30194]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 141 and 142

[WH-FRL-6584-4]
RIN 2040-AA97


National Primary Drinking Water Regulations: Ground Water Rule

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking.

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SUMMARY: EPA is proposing to require a targeted risk-based regulatory 
strategy for all ground water systems. The proposed requirements 
provide a meaningful opportunity to reduce public health risk 
associated with the consumption of waterborne pathogens from fecal 
contamination for a substantial number of people served by ground water 
sources.
    The proposed strategy addresses risks through a multiple-barrier 
approach that relies on five major components: periodic sanitary 
surveys of ground water systems requiring the evaluation of eight 
elements and the identification of significant deficiencies; 
hydrogeologic assessments to identify wells sensitive to fecal 
contamination; source water monitoring for systems drawing from 
sensitive wells without treatment or with other indications of risk; a 
requirement for correction of significant deficiencies and fecal 
contamination (by eliminating the source of contamination, correcting 
the significant deficiency, providing an alternative source water, or 
providing a treatment which achieves at least 99.99 percent (4-log) 
inactivation or removal of viruses), and compliance monitoring to 
insure disinfection treatment is reliably operated where it is used.
    EPA believes that the combination of these components strikes an 
appropriate regulatory balance which tailors the intensity or burden of 
protective measures and follow-up actions with the risk being 
addressed. In addition to proposing requirements for ground water 
systems, EPA requests comment on ways to address the problem of 
transient providers of water who furnish drinking water to large 
numbers of people for a limited period of time. One possible solution 
is to adopt alternative definitions for ``public water systems'' which 
is currently defined as ``one that serves 25 or more people or has 15 
or more service connections and operates at least 60 days per year. EPA 
is only requesting comment on this issue. The Agency is not today 
proposing to change the definition of ``public water system ,'' or 
modify related provisions. If EPA decides to take action on this issue, 
EPA will publish a proposal at a later date.

DATES: The EPA must receive comments on or before July 10, 2000.

ADDRESSES: References, supporting documents and public comments (and 
additional comments as they are provided) are available for review at 
EPA's Drinking Water Docket #W-98-23: 401 M Street, SW, Washington, DC 
20460 from 9 a.m. to 4 p.m., Eastern Time, Monday through Friday, 
excluding Federal holidays.
    You may submit comments by mail to the docket at: 1200 Pennsylvania 
Ave., NW, Washington, DC 20460 or by sending electronic mail (e-mail) 
to [email protected]. Hand deliveries should be delivered to: EPA's 
Drinking Water Docket at 401 M Street, SW, Washington, DC 20460.
    For access to docket materials, please call 202/260-3027 to 
schedule an appointment and obtain the room number.

FOR FURTHER INFORMATION CONTACT: For general information, contact the 
Safe Drinking Water Hotline, telephone (800) 426-4791. The Safe 
Drinking Water Hotline is open Monday through Friday, excluding Federal 
holidays, from 9 a.m. to 5:30 p.m. Eastern Time. For technical 
inquiries, contact the Office of Ground Water and Drinking Water (MC 
4607), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., 
N.W. Washington, DC 20460; telephone (202) 260-3309.

SUPPLEMENTARY INFORMATION:

Regulated Entities

    Entities potentially regulated by the Ground Water Rule are public 
water systems using ground water. Regulated categories and entities 
include:

------------------------------------------------------------------------
                                                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 this table could also be regulated. To determine whether 
your facility is regulated by this action, you should carefully examine 
the applicability criteria in Sec. 141.400(b) of this proposed rule. If 
you have questions regarding the applicability of this action to a 
particular entity, consult the person listed in the preceding section 
entitled FOR FURTHER INFORMATION CONTACT.

Abbreviations Used in This Notice

AWWA: American Water Works Association
ASDWA: Association of State Drinking Water Administrators
AWWARF: American Water Works Association Research Foundation
BMP: Best Management Practice
CDC: Centers for Disease Control and Prevention
CT: The residual concentration of disinfectant multiplied by the 
contact time
CWS: community water system
CWSS: Community Water System Survey
DBP: disinfection byproducts
ELR: Environmental Law Reporter
EPA: Environmental Protection Agency
FR: Federal Register
GAO: Government Accounting Office
GWR: Ground Water Rule
GWS: ground water system
HAA5: Haloacetic acids consisting of the sum of mono-, di-, and 
trichloroacetic acids, and mono-and dibromoacetic acids
HAV: Hepatitis A Virus
ICR: Information Collection Rule
IESWTR: Interim Enhanced Surface Water Treatment Rule
IT: UV irradiance multiplied by the contact time
m: meter
ml: milliliters
MCL: maximum contaminant level
MCLG: maximum contaminant level goal
mg/L: milligrams per liter
MPN: most probable number
MWCO: molecular weight cut-off
NCWS: non-community water system
NTNCWS: non-transient non-community water system
PCR: polymerase chain reaction
PWS: public water system
RO: reverse osmosis
RT-PCR: reverse-transcriptase, polymerase chain reaction
SBREFA: Small Business Regulatory Enforcement Fairness Act
SDWA: Safe Drinking Water Act
SDWIS: Safe Drinking Water Information System
Stage 1 DBPR: Stage 1 Disinfectants/Disinfection Byproducts Rule
Stage 2 DBPR: Stage 2 Disinfectants/Disinfection Byproducts Rule
SWAPP: Source Water Assessment and Protection Program
SWTR: Surface Water Treatment Rule
TCR: Total Coliform Rule
TNCWS: transient non-community water system
TTHM: total trihalomethanes
UIC: Underground Injection Control
USGS: United States Geological Survey
US EPA: United States Environmental Protection Agency
UV: ultraviolet radiation
WHP: Wellhead Protection

Table of Contents

I. Introduction and Background

A. Statutory Authority

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B. Existing Regulations
    1. Total Coliform Rule
    2. Surface Water Treatment Rule and Interim Enhanced Surface 
Water Treatment Rule
    3. Information Collection Rule
    4. Stage 1 Disinfectants/Disinfection ByProducts Rule
    5. Underground Injection Control Program
    6. Source Water Assessment and Protection Program (SWAPP) and 
the Wellhead Protection (WHP) Program
C. Industry Profile--Baseline Information
    1. Definitions and Data Sources
    2. Alternate Definition of ``Public Water System'' and the 
Problem of Short-term Water Providers
    3. Number and Size of Ground Water Systems
    4. Location of Ground Water Systems
    5. Ownership of Ground Water Systems
D. Effectiveness of Various Best Management Practices in Ground 
Water Systems
    1. EPA Report on State Ground Water Management Practices
    2. ASDWA Analysis of BMPs for Community Ground Water Systems
    3. EPA Report on Ground Water Disinfection and Protective 
Practices
E. Outreach Activities
    1. Public Meetings
    2. Review and Comment of Preliminary Draft GWR Preamble

II. Public Health Risk

A. Introduction
B. Waterborne Disease Outbreak Data
C. Ground Water Occurrence Studies
    1. Abbaszadegan et al. (1999) (AWWARF Study)
    2. Lieberman et al. (1994, 1999) (EPA/AWWARF Study)
    3. Missouri Ozark Aquifer Study #1
    4. Missouri Ozark Aquifer Study #2
    5. Missouri Alluvial Aquifer Study
    6. Wisconsin Migrant Worker Camp Study
    7. EPA Vulnerability Study
    8. US-Mexico Border Study
    9. Whittier, California, Coliphage Study
    10. Oahu, Hawaii Study
    11. New England Study
    12. California Study
    13. Three State PWS Study (Wisconsin, Maryland and Minnesota)
D. Health Effects of Waterborne Viral and Bacterial Pathogens
E. Risk Estimate
    1. Baseline Risk Characterization
    2. Summary of Basic Assumptions
    3. Population Served by Untreated Ground Water Systems
    4. Pathogens Modeled
    5. Microbial Occurrence and Concentrations
    6. Exposure to Potentially Contaminated Ground Water
    7. Pathogenicity
    8. Potential Illnesses
    10. Request for Comments
F. Conclusion

III. Discussion of Proposed GWR Requirements

A. Sanitary Surveys
    1. Overview and Purpose
    2. General Accounting Office Sanitary Survey Investigation
    3. ASDWA/EPA Guidance on Sanitary Surveys
    4. Other Studies
    5. Proposed Requirements
    6. Reporting and Record Keeping Requirements
    7. Request for Comments
B. Hydrogeologic Sensitivity Assessment
    1. Overview and Purpose
    2. Hydrogeologic Sensitivity
    3. Hydrogeologic Barrier
    4. Alternative Approaches to Hydrogeologic Sensitivity 
Assessment
    5. Proposed Requirements
    6. Request for Comments
C. Cross Connection Control
D. Source Water Monitoring
    1. Overview and Purpose
    2. Indicators of Fecal Contamination
    3. Proposed Requirements
    4. Analytical Methods
    5. Request for Comments
E. Treatment Techniques for Systems with Fecally Contaminated Source 
Water or Uncorrected Significant Deficiencies
    1. Overview and Purpose
    2. Proposed Requirements
    3. Public Notification
    4. Request for Comments

IV. Implementation

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

A. Overview
B. Quantifiable and Non-Quantifiable Costs
    1. Total Annual Costs
    2. System Costs
    3. State costs
    4. Non-Quantifiable Costs
C. Quantifiable and Non-Quantifiable Health and Non-Health Related 
Benefits
    1. Quantifiable Health Benefits
    2. Non-quantifiable Health and Non-Health Related Benefits
D. Incremental Costs and Benefits
E. Impacts on Households
F. Cost Savings from Simultaneous Reduction of Co-Occurring 
Contaminants
G. Risk Increases From Other Contaminants
H. Other Factors: Uncertainty in Risk, Benefits, and Cost Estimates
I. Benefit Cost Determination
J. Request for Comment
    1. NTNC and TNC Flow Estimates
    2. Mixed Systems

VI. Other Requirements

A. Regulatory Flexibility Act (RFA)
    1. Background
    2. Use of Alternative Definition
    3. Initial Regulatory Flexibility Analysis
    4. Small Entity Outreach and Small Business Advocacy Review 
Panel
B. Paperwork Reduction Act
C. Unfunded Mandates Reform Act
    1. Summary of UMRA Requirements
    2. Written Statement for Rules With Federal Mandates of $100 
Million or More
    3. Impacts on Small Governments
D. National Technology Transfer and Advancement Act
    1. Microbial Monitoring Methods
    E. Executive Order 12866: Regulatory Planning and Review
    F. Executive Order 12898: Environmental Justice
    G. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
    1. Risk of Viral Illness to Children and Pregnant Women
    2. Full Analysis of the Microbial Risk Assessment
H. Consultations with the Science Advisory Board, National Drinking 
Water Avisory Council, and the Secretary of Health and Human 
Services
I. Executive Orders on Federalism
J. Executive Order 13084: Consultation and Coordination With Indian 
Tribal Governments
K. Plain Language

VII. Public Comment Procedures

A. Deadlines for Comment
B. Where to Send Comment
C. Guidelines for Commenting

VIII. References

I. Introduction and Background

    The purpose of this section is to provide background on existing 
regulations that affect ground water systems and current state 
practices.

A. Statutory Authority

    This section discusses the Safe Drinking Water Act (SDWA) 
requirements which EPA must meet in developing the Ground Water Rule 
(GWR).
    EPA has the responsibility to develop a GWR which not only 
specifies the appropriate use of disinfection but, just as important, 
addresses other components of ground water systems to ensure public 
health protection. Section 1412(b)(8) states that EPA develop 
regulations specifying the use of disinfectants for ground water 
systems ``as necessary.'' Under these provisions, EPA has the 
responsibility to develop a ground water rule which specifies the 
appropriate use of disinfection, and, in addition, addresses other 
components of ground water systems to ensure public health protection.

B. Existing Regulations

    This section briefly describes the existing regulations that apply 
to ground water systems. These rules are the baseline for developing 
the GWR. The regulations that will be discussed include the Total 
Coliform Rule (TCR)(US EPA, 1989a), Surface Water Treatment Rule 
(SWTR)(US EPA, 1989b), Interim Enhanced Surface Water Treatment Rule 
(IESWTR)(US EPA 1998d), Information Collection Rule (ICR)(US EPA, 
1996b), Stage 1 Disinfectant/Disinfection Byproducts Rule (Stage 1 
DBPR)(US EPA, 1998e), Underground Injection Control Program (US EPA, 
1999g) and the Source Water Assessment and Protection Program/Wellhead 
Protection Program.

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1. Total Coliform Rule
    The Total Coliform Rule (TCR), promulgated on June 29, 1989 (54 FR 
27544)(US EPA,1989a) covers all public water systems. The rule protects 
public water supplies from disease-causing organisms (pathogens), and 
it is the most important regulation applicable to drinking water from 
ground water systems.
    Total coliforms are a group of closely related bacteria that are 
generally free-living in the environment, but are also normally present 
in water contaminated with human and animal feces. They generally do 
not cause disease (there are some exceptions). Specifically, coliforms 
are used as a screen for fecal contamination, as well as to determine 
the efficiency of treatment and the integrity of the water distribution 
system. The presence of total coliforms in drinking water indicates 
that the system is either fecally contaminated or vulnerable to fecal 
contamination.
    The TCR requires systems to monitor their distribution system for 
total coliforms at a frequency that depends upon the number of people 
served and whether the system is a community water system (CWS) or non-
community water system (NCWS). The monitoring frequency ranges from 480 
samples per month for the largest systems to once annually for some of 
the smallest systems. If a system has a total coliform-positive sample, 
it must (1) test that sample for the presence of fecal coliform or E. 
coli, (2) collect three repeat samples (four, if the system collects 
one routine sample or fewer per month) within 24 hours and analyze them 
for total coliforms (and then fecal coliform or E. coli, if positive), 
and (3) collect at least five routine samples in the next month of 
sampling regardless of system size.
    Under the TCR, a system that collects 40 or more samples per month 
(generally systems that serve more than 33,000 people) violates the 
maximum contaminant level (MCL) for total coliforms if more than 5.0% 
of the samples (routine + repeat) it collects per month are total 
coliform-positive. A system that collects fewer than 40 samples per 
month violates the MCL if two samples (routine or repeat samples) 
during the month are total coliform-positive. For any size system, if 
two consecutive total coliform-positive samples occur at a site during 
a month, and one is also fecal coliform/E. coli-positive, the system 
has an acute violation of the MCL, and must provide public notification 
immediately. The presence of fecal coliforms or E. coli indicates that 
recent fecal contamination is present in the drinking water.
    The TCR also requires a sanitary survey every five years (ten years 
for a protected, disinfected, ground water system) for every system 
that takes fewer than five samples per month (the monitoring frequency 
for systems serving 4,100 people or fewer, which is approximately 97% 
of GWS). Other provisions of the TCR include criteria for invalidating 
a positive or negative sample and a sample siting plan to ensure that 
all parts of the distribution system are monitored over time.
2. Surface Water Treatment Rule and Interim Enhanced Surface Water 
Treatment Rule
    The Surface Water Treatment Rule, promulgated in June 29, 1989 (54 
FR 27486)(40 CFR Part 141, Subpart H)(US EPA 1989b), covers all systems 
that use surface water or ground water under the direct influence of 
surface water. It is intended to protect against exposure to Giardia 
lamblia, viruses, and Legionella, as well as many other pathogens. The 
rule requires all such systems to reduce the level of Giardia by 99.9% 
(3-log reduction) and viruses by 99.99% (4-log reduction). Under this 
rule, all surface water systems must disinfect. The vast majority must 
also filter, unless they meet certain EPA-specified filter avoidance 
criteria that define high source water quality. More specifically, the 
SWTR requires: (1) A 0.2 mg/L disinfectant residual entering the 
distribution system, (2) maintenance of a detectable disinfectant 
residual in all parts of the distribution system; (3) compliance with a 
combined filter effluent performance standard for turbidity (i.e., for 
rapid granular filters, 5 nephelometric turbidity units (NTU) maximum; 
0.5 NTU maximum for 95% of measurements (taken every 4 hours) during a 
month); and 4) watershed protection and other requirements for 
unfiltered systems. The SWTR set a maximum contaminant level goal 
(MCLG) of zero for Giardia, viruses, and Legionella. The MCLG is a non-
enforceable level based only on health effects.
    On December 16, 1998, EPA promulgated the Interim Enhanced Surface 
Water Treatment Rule (IESWTR) (63 FR 69478)(US EPA, 1998d). The IESWTR 
covers all systems that use surface water, or ground water under the 
direct influence of surface water, that serve 10,000 people or greater. 
Key provisions include: a 2-log Cryptosporidium removal requirement for 
filtered systems; strengthened combined filter effluent turbidity 
performance standards (1 NTU maximum; 0.3 NTU maximum for 95% of 
measurements during a month); individual filter turbidity provisions; 
disinfection benchmark provisions to ensure continued levels of 
microbial protection while facilities take the necessary steps to 
comply with new disinfection byproduct (DBP) standards; inclusion of 
Cryptosporidium in the definition of ground water under the direct 
influence of surface water and in the watershed control requirements 
for unfiltered public water systems; requirements for covers on new 
finished water reservoirs; sanitary surveys for all surface water 
systems regardless of size; and an MCLG of zero for Cryptosporidium. In 
a parallel rulemaking, EPA has proposed a companion microbial 
regulation for surface water systems serving less than 10,000 people, 
the Long Term 1 Enhanced Surface Water Treatment Rule.
3. Information Collection Rule
    The Information Collection Rule, promulgated on May 14, 1996 (61 FR 
24368)(40 CFR part 141, Subpart M)(US EPA, 1996b), is a monitoring and 
data reporting rule. The data and information provided by this rule 
will support development of the Stage 2 Disinfection Byproducts Rule 
and a related microbial rule, the Long Term 2 Enhanced SWTR, scheduled 
for promulgation in May 2002.
    The ICR applied to large water systems serving at least 100,000 
people, and ground water systems serving at least 50,000 people. About 
300 systems operating 500 treatment plants were involved. The ICR 
required systems to collect source water samples, and in some cases 
finished water samples, monthly for 18 months, and test them for 
Giardia, Cryptosporidium, viruses, total coliforms, and either fecal 
coliforms or E. coli. The ICR also required systems to determine the 
concentrations of a range of disinfectant and disinfection byproducts 
in different parts of the system. These disinfection byproducts form 
when disinfectants used for pathogen control react with naturally 
occurring total organic compounds (TOC) already present in source 
water. Some of these byproducts are toxic or carcinogenic. The rule 
also required systems to provide specified operating and engineering 
data to EPA. The required 18 months of monitoring under the ICR ended 
in December 1998.
    As noted earlier, the only ground water systems affected by the ICR 
were those that served at least 50,000 people. These systems had to 
conduct treatment study applicability monitoring (by measuring TOC 
levels) and, in some

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cases, studies to assess the effectiveness of granular activated carbon 
or membranes to remove DBP precursors. In addition, ground water 
systems serving at least 100,000 people had to obtain disinfectant and 
DBP occurrence and treatment data. EPA is still processing the ICR 
data, and has not used this information in developing the GWR.
4. Stage 1 Disinfectants/Disinfection Byproducts Rule
    The Stage 1 Disinfectants/Disinfection Byproducts Rule (Stage 1 
DBPR) (63 FR 69389; December 16, 1998) (US EPA, 1998e) sets maximum 
residual disinfection level limits for chlorine, chloramines, and 
chlorine dioxide, and MCLs for chlorite, bromate, and two groups of 
disinfection byproducts: total trihalomethanes (TTHMs) and haloacetic 
acids (HAA5). TTHMs consist of the sum of chloroform, 
bromodichloromethane, dibromochloromethane, and bromoform. HAA5 consist 
of the sum of mono-, di-, and trichloroacetic acids, and mono- and 
dibromoacetic acids. The rule requires water systems that use surface 
water or ground water to remove specified percentages of organic 
materials, measured as total organic carbon (TOC), that may react with 
disinfectants to form DBPs. Under the rule, precursor removal will be 
achieved through a treatment technique (enhanced coagulation or 
enhanced softening) unless a system meets alternative criteria.
    The Stage 1 DBPR applies to all CWSs and non-transient NCWSs, both 
surface water systems and ground water systems, that treat their water 
with a chemical disinfectant for either primary or residual treatment. 
In addition, certain requirements for chlorine dioxide apply to 
transient water systems.
    A ground water system that disinfects with chlorine or other 
chemical disinfectant must comply with the Stage 1 DBPR by December 
2003. Sampling frequency will depend upon the number of people served. 
Ground water systems not under the direct influence of surface water 
that serve 10,000 people or greater must take one sample per quarter 
per treatment plant, and analyze for TTHMs and HAA5; systems that serve 
fewer than 10,000 people must take one sample per year per treatment 
plant during the month of warmest water temperature, and analyze for 
the same chemicals. Systems must monitor for chlorine or chloramines at 
the same location and time that they monitor for total coliforms. 
Additional monitoring for other chemicals is required for systems that 
use ozone or chlorine dioxide.
    5. Underground Injection Control Program
    In 1980, EPA established an Underground Injection Control (UIC) 
Program (US EPA, 1999g) to prevent injection practices which 
contaminate sources of drinking water. The UIC Program protects both 
underground sources of drinking water and ground water under the direct 
influence of surface water, which includes at least 41 percent of the 
streams and rivers in the U.S. during dry periods. Injection is a 
common and long-standing method of placing fluids underground for 
disposal, storage, replenishment of ground water, enhanced recovery of 
oil and gas, and mineral recovery. These fluids often contain 
contaminants. The EPA sets minimum requirements for effective State 
programs to ensure that injection practices, or ``injection wells'' as 
they are called in the UIC Program, are operated safely. EPA or the 
appropriate State regulatory agency may impose on any injection well, 
requirements for siting, construction, corrective action, operation, 
maintenance, monitoring, reporting, plugging and abandonment, and 
impose penalties on violators. The UIC Program regulations are designed 
to recognize varying geologic, hydrologic or historic conditions among 
different States or areas within a State.
    The UIC Program regulations are found under Title 40 of the Code of 
Federal Regulations (CFR), Parts 124, and 144-148. Section 144.6 
divides injection practices into five categories or classes of wells. 
Classes I, II, and III are wells which inject fluids beneath and away 
from aquifers used by ground water systems into confined geologic 
formations. These wells are associated with municipal or industrial 
waste disposal, hazardous waste or radioactive waste sites, oil and gas 
production, and extraction of minerals. Class IV and most of Class V 
are wells which inject contaminants, into or above aquifers which may 
be used by ground water systems. Class IV wells inject hazardous or 
highly radioactive wastes and are banned by all States and EPA. Class V 
wells include storm water and agricultural drainage wells, dry wells, 
floor drains and similar types of shallow disposal systems which 
discharge directly or indirectly to ground water, but in any case, must 
not endanger the ground water resources. However, Class V wells which 
may pose the greatest potential threat to ground water systems include 
poorly-designed or malfunctioning large-capacity septic tanks, leach 
fields and cesspools associated with solely sanitary wastewater 
disposal. Malfunctioning septic systems can result in the release of 
disease-causing microorganisms including enteric viral and bacterial 
pathogens to surface and ground water. Multi-family, commercial, 
manufacturing, recreational, and municipal facilities, particularly 
those located in unsewered areas sometimes dispose both sanitary waste 
and process wastewater containing harmful chemicals in Class V wells. 
This combination can increase the risk of contamination to aquifers 
used by ground water systems. Approximately half of the States have 
adopted primary enforcement authority for the regulation in whole or 
part and, therefore, have primary enforcement responsibility (primacy). 
State enforcement activities range from notices of improper activities 
to penalties and well closures. For those States which do not have 
primacy, the EPA Regional Offices perform the enforcement duties. 
(Note: the UIC Program does not regulate individual or single family 
residential septic systems and cesspools which inject solely sanitary 
wastewater) (40 CFR 144.1(g)(1)(2)). EPA has finalized banning large 
capacity cesspools in ground water source water protection areas (64 FR 
234, December 7, 1999)(USEPA, 1999g).
6. Source Water Assessment and Protection Program (SWAPP) and the 
Wellhead Protection (WHP) Program
    The Wellhead Protection Program (WHP Program) in SDWA section 1428 
requires every State to develop a program that protects ground water 
sources of public drinking water. The intended result of the WHP 
Program are local pollution prevention programs that reduce or 
eliminate the threats of contamination to ground water sources of 
drinking water. To do this, States delineate wellhead protection areas 
(WHPA) in which sources of contamination are managed to minimize ground 
water contamination. WHPA boundaries are determined based on factors 
such as well pumping rates, time-of-travel of ground water flowing to 
the well, aquifer boundaries, and degree of aquifer protection by the 
overlying geology. These hydrogeologic characteristics have a direct 
effect on the likelihood and extent of contamination. Currently, 48 
States and two territories have a WHP Program in place.
    A new Source Water Assessment and Protection Program (SWAPP) was 
incorporated into SDWA section 1453 and requires each State to 
establish a SWAPP that describes how the State will: (1) Delineate 
source water

[[Page 30198]]

protection areas; (2) inventory significant contaminants in these 
areas; and (3) determine the susceptibility of each public water supply 
to contamination. This program builds upon the WHP Program; however, it 
addresses both ground water and surface water sources of public 
drinking water. The States' SWAPP were approved by EPA by November, 
1999. Under the SWAPP, the State must complete source water assessments 
for all PWSs by November 6, 2001, although EPA may grant an extension 
to May 6, 2003. A summary of the results of the source water 
assessments must then be made available to the public in CWSs' Consumer 
Confidence Reports. The 1996 Amendments to the SDWA do not require 
States to protect water sources after the assessments are completed.
    EPA seeks, in today's proposed GWR, to incorporate the States' 
SWAPP and WHP Programs into an overall Agency program for protecting 
ground water sources of public drinking water by encouraging States to 
use information gathered through these programs in site-specific 
sanitary surveys and hydrogeologic sensitivity assessments where 
appropriate.

C. Industry Profile--Baseline Information

1. Definitions and Data Sources
    Outlined in the following section are data sources relied upon by 
the Agency to develop baseline information for the GWR. The baseline 
information is important to understanding how various regulatory 
options might affect risk reduction and the cost to small public water 
systems. The information shows that there is a large number of systems 
which solely utilize ground water, over 156,000. In addition, most of 
the ground water systems are small, with 97% serving 3,300 or fewer 
people. However, 55% of the people served by ground water sources get 
their drinking water from systems which serve 10,000 or more persons 
(one percent of the systems).
    A public water system (PWS) is one that serves 25 or more people or 
has 15 or more service connections and operates at least 60 days per 
year. The following discussion of PWSs is based on the current 
definition of PWS (i.e., operating at least 60 days a year). A PWS can 
be publicly owned or privately owned. EPA classifies PWSs as community 
water systems (CWSs) or non-community water systems (NCWSs). CWSs are 
those that serve at least 15 service connections used by year-round 
residents or regularly serves at least 25 year-round residents. NCWSs 
do not have year-round residents, but serve at least 15 service 
connections used by travelers or intermittent users for at least 60 
days each year, or serving an average of 25 individuals for at least 60 
days a year. NCWSs are further classified as either transient or non-
transient. A non-transient non-community water system (NTNCWS) serves 
at least 25 of the same persons over six months per year (e.g., 
factories and schools with their own water source). Transient non-
community water systems (TNCWS) do not serve at least 25 of the same 
persons over six months per year (e.g., many restaurants, rest stops, 
parks). The majority of ground water systems are NCWSs, with 60% 
(93,618) transient and 12% (19,322) non-transient. CWSs make up the 
remaining 28% (44,910) of all ground water systems. Although there are 
far more NCWSs, CWSs serve a far larger number of people.
    Over 88 million people are served by CWSs that use ground water and 
20 million people are served by NCWSs that use ground water. An overlap 
occurs because most people are served by both types of systems which 
may also include a combination of ground and surface water. For 
example, a person may be served by a surface water community water 
system (CWS) at home and by a ground water non-community water system 
(NCWS) at work.
    EPA uses two primary sources of information to characterize the 
universe of ground water systems: the Safe Drinking Water Information 
System (SDWIS) and the Community Water System Survey (CWSS) (US EPA, 
1997c). EPA's SDWIS contains data on all PWSs as reported by States and 
EPA Regions. This data reflects both mandatory and optional reporting 
components. States must report the location of the system, system type 
(CWS, TNCWS, or NTNCWS), primary raw water source (ground water, 
surface water or ground water under the direct influence of surface 
water), and violations. States may also report, at their option, type 
of treatment and ownership type. EPA does not have complete data on the 
discretionary items (such as treatment) in SDWIS for every system; this 
is especially common for NCWSs.
    The second source of information, CWSS, is a detailed survey of 
surface and ground water CWSs conducted by EPA in 1995 (US EPA, 1997c). 
The CWSS includes information such as the number of system operators, 
revenues, expenses, treatment practices, source water protection 
measures, and capacity (i.e., the amount of water the system is 
designed to deliver). The CWSS contains data from 1,980 water systems, 
and is stratified to represent CWSs across the U.S. Of the 1,980 water 
systems that were surveyed by CWSS, 1,020 are ground water systems; 510 
are surface water systems; and 450 represent purchased water systems. 
Among the ground water systems represented, approximately 17% were from 
systems serving 100 persons or less; 20% were from systems serving 101-
500 persons; 13% were from systems serving 501-1,000 persons; 14% were 
from systems serving 1,001-3,300 persons; 15% were from systems serving 
3,301-10,000 persons; 10% were from systems serving 10,001-50,000 
persons; and 11% were from systems serving 50,001 or more persons.
    Baseline profile data for ground water systems from SDWIS and CWSS 
are summarized later. The data on system ownership, treatment, and 
operator information is from the CWSS.
2. Alternate Definition of ``Public Water System'' and the Problem of 
Short-Term Water Providers
    EPA is not today proposing to change the definition of ``public 
water supply,'' nor proposing additional requirements for short-term 
water providers. If EPA decides to take either action, EPA will publish 
a proposal at a later date. However, EPA requests comment on the 
following issues.
    A PWS is one that serves 25 or more people or has 15 or more 
service connections and operates at least 60 days per year. EPA 
requests comment on the definition of ``public water system'' 
specifically, shortening the time period within the regulatory 
definition (Sec. 141.2). Section 1401(4)(A) of the SDWA defines public 
water system as one that ``regularly serves at least twenty-five 
individuals.'' EPA by regulation defined the minimum time period that a 
system ``regularly'' serves as 60 days. See 40 FR 59566, December 24, 
1975 for a discussion of the definition. The current definition applies 
after a minimum of 1,500 consumer servings (60 days multiplied by 25 
individuals). However, some drinking water providers serve far more 
people during just a few events. For example, out-door public events 
may occur at a site just a few days a year but may draw thousands of 
people to each event. Such drinking water providers thus can affect the 
public health of a similar number of persons in a short period of time 
as a system that serves fewer people for a longer period. EPA wants to 
provide the same public health protection in these situations. Only

[[Page 30199]]

contaminants that cause adverse health effects through small volumes or 
short exposure (e.g., acute contaminants such as microbes, nitrate and 
nitrite) are of concern at these short term events. Therefore, EPA is 
considering changing the definition of ``public water system'' by 
reducing the 60 day time frame to 30 days and including events drawing 
many people on one or just a few days, specifically by adding the 
phrase, ``or serves at least 750 people for one or more days'' to the 
end of the current definition of ``public water system.'' In other 
words, for short-term providers, the term ``regularly serves'' would be 
defined in terms of the number of persons served rather than days of 
service, but the minimum number of persons served would be equivalent 
to the number of servings for longer-term systems. EPA requests comment 
on this issue. Rather than the simple total of 750 (30 days times 25 
people), should EPA include a minimum of persons served days 
(calculated by multiplying the average number of individuals served by 
the number of days the system serves water)? What should that number 
be? Should there be a sliding scale (e.g., for a system operating one 
day and serving more than 10,000 consumers, and systems operating more 
than 30 days and serving 2,000 consumers)? EPA requests comments on 
defining/identifying systems, implementation, public notice, training, 
monitoring and record keeping and reporting issues for these systems if 
they were included.
    As an alternate to changing the definition EPA is also considering 
and requesting comments on requiring under section 1431 of the SDWA or 
other appropriate authorities that transient water providers or other 
types of drinking water systems (including those not currently defined 
as public water systems) monitor for acute contaminants prior to 
providing water to the public and requiring that any such provider that 
finds acute contaminants at a level above the MCL not be allowed to 
serve drinking water until it is corrected. Currently, transient public 
water systems must currently monitor for total coliforms, nitrate and 
nitrite. In addition, transient public water systems using surface 
water or ground water under the direct influence of surface water must 
comply with the treatment technique requirements of the SWTR. EPA is 
also considering proposing requiring any non-community water system 
that is not operated year round monitor for: fecal coliforms, nitrate 
and nitrate, and that monitoring required to show treatment technique 
compliance (e.g., Cryptosporidium) no more than 30 days prior to 
beginning operation for that season. EPA requests comment on what time 
frame the monitoring should be completed prior to beginning operation 
(i.e., 10 or 15 days).
3. Number and Size of Ground Water Systems
    Nationally, SDWIS indicates that there are approximately157,000 
public water systems that use ground water solely (SDWIS, 1997). 
Slightly more than 13,000 additional systems use surface water. SDWIS 
only describes any system that uses any amount of surface water as a 
surface water system. SDWIS therefore, does not have information on the 
number of systems that mix ground water and surface water. Under the 
SDWA and for purposes of the Regulatory Flexibility Act (RFA) analysis, 
EPA defines a small system as serving fewer than 10,000 people. 
According to SDWIS (1997), 96.6% of the 42,413 CWSs and virtually all 
of the NCWSs that use ground water serve fewer than 10,000 persons and 
thus are ``small.'' Collectively, 99% of systems serve fewer than 
10,000 people. About 97% of the systems (152,555) serve 3,300 people or 
fewer (totaling over 31 million people nationally). The purpose of 
these requirements would be to prevent any endangerment to public 
health that might occur if these short-term, high volume providers 
dispense drinking water that is untested and potentially contaminated.
4. Location of Ground Water Systems
    Ground water systems are located in all 50 States, many tribal 
lands and most United States territories. The number of ground water 
systems varies substantially by State. The largest numbers of ground 
water systems are in the States of Wisconsin, Michigan, Pennsylvania, 
New York and Minnesota. These five States, each with over 8,000 ground 
water systems, account for over 50,698 ground water systems--one third 
of the total number in the U.S. By contrast, Hawaii (126), Kentucky 
(287), Rhode Island (430), and the United States territories (254) have 
the fewest ground water systems (See Table I-1).
5. Ownership of Ground Water Systems
    For ground water CWSs, 36% are publicly operated, 35% are owned and 
operated by private entities whose primary business is providing 
drinking water, and 29% are ancillary water systems which are operated 
by entities whose primary business is not providing drinking water, but 
do so to support their primary business (e.g., mobile home park 
operators). The distribution of ownership type, however, varies 
significantly with the size of the system. For example, over 90% of the 
ground water systems serving less than 100 people are privately owned 
or are ancillary systems. For systems serving over 100,000 people, only 
16% are privately owned and none are ancillary systems.

                               Table I-1.--Number of Ground Water Systems and Populations Served by State and System Type
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               CWSs                        TNCWSs                      NTNCWSs
                                                                  --------------------------------------------------------------------------------------
                         State/territory                            Number of     Population     Number of     Population     Number of     Population
                                                                     systems        served        systems        served        systems        served
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alabama..........................................................          345       1,283,469          123          11,170           46          21,182
Alaska...........................................................          511         342,722          906          97,647            0               0
American Samoa...................................................           10          48,692            0               0            0               0
Arizona..........................................................          783       1,308,843          602         120,126          216         100,317
Arkansas.........................................................          480       1,003,145          442          22,521           57          13,528
California.......................................................        2,831      14,223,977        3,698       1,301,671        1,018         359,096
Colorado.........................................................          548         927,917        1,061         153,454          133          34,884
Commonwealth of the Northern Marianas............................           30          50,769            7             620            6           3,039
Connecticut......................................................          537         311,771        3,360       2,980,181          641         121,664
Delaware.........................................................          225         173,460          215          57,634           86          24,840
District of Columbia.............................................            0               0            0               0            0               0
Florida..........................................................        2,019      13,132,468        3,660         304,865        1,119         286,055
Georgia..........................................................        1,465       1,484,860          663         127,661          291          80,240
Guam.............................................................            6          20,220            0               0            2             770

[[Page 30200]]

 
Hawaii...........................................................          109       1,247,315            3           1,125           14           7,437
Idaho............................................................          658         579,778        1,033         125,873          265          68,195
Illinois.........................................................        1,255       2,606,104        3,715         413,000          446         142,655
Indiana..........................................................          806       1,826,820        2,984         327,229          693         158,102
Iowa.............................................................        1,033       1,239,902          639          78,653          133          35,715
Kansas...........................................................          601         747,169          110           4,481           67          23,602
Kentucky.........................................................          124         271,630           83           9,374           80          21,620
Louisiana........................................................        1,211       2,707,805          482         115,804          234          88,070
Maryland.........................................................          448         519,289        2,509          93,757          495         142,171
Massachusetts....................................................          360       1,396,430          863         209,476          229          67,650
Michigan.........................................................        1,185       1,602,792        8,930       1,187,331        1,718         344,654
Minnesota........................................................          919       2,074,843        6,963         252,602          672          49,514
Mississippi......................................................        1,253       2,586,680          169          28,006          126          89,416
Missouri.........................................................        1,194       1,638,152        1,040         138,894          227          76,360
Montana..........................................................          554         267,597        1,011         140,745          215          38,504
Nebraska.........................................................          616         811,112          584          22,241          189          26,219
Nevada...........................................................          250         187,509          273          55,792           91          28,497
New Hampshire....................................................          621         262,371        1,012         181,949          421          77,505
New Jersey.......................................................          516       2,339,500        2,955         346,484        1,009         274,758
New Mexico.......................................................          600       1,235,920          506          74,256          149          38,101
New York.........................................................        1,940       4,396,557        5,742         853,533          693         248,223
North Carolina...................................................        1,900       1,271,804        5,373         542,400          655         198,136
North Dakota.....................................................          258         239,874          215          16,910           22           2,349
Ohio.............................................................        1,129       3,555,876        3,545         533,921        1,116         276,441
Oklahoma.........................................................          556         671,287          302          34,172          123          20,419
Oregon...........................................................          677         622,157        1,390         233,477          332          67,531
Pennsylvania.....................................................        1,788       1,567,696        7,017         922,336        1,251         480,328
Puerto Rico......................................................          207         623,958            4             765           43          36,426
Rhode Island.....................................................           59         127,854          300          48,875           71          25,246
South Carolina...................................................          550         671,878          577          54,837          248          71,239
South Dakota.....................................................          367         250,742          243          42,949           25           3,072
Tennessee........................................................          193       1,312,996          503          61,504           58          11,010
Texas............................................................        3,613       6,150,001        1,378         245,171          748         253,468
Tribes...........................................................          685         330,466            0               0           82          20,833
Utah.............................................................          335         583,506          439          79,371           52          20,969
U.S. Virgin Islands..............................................            0               0            0               0            0               0
Vermont..........................................................          346         154,521          718         523,079            1              25
Virginia.........................................................        1,199         584,779        1,911         443,920          772         312,422
Washington.......................................................        2,092       2,299,340        1,498         283,735          287          70,009
West Virginia....................................................          297         304,888          644          47,313          182          39,318
Wisconsin........................................................        1,117       1,947,016        9,704         731,781        1,049         214,561
--------------------------------------------------------------------------------------------------------------------------------------------------------

D. Effectiveness of Various Best Management Practices in Ground Water 
Systems

    There are numerous sanitation practices, called best management 
practices (BMPs), to prevent, identify and correct contamination in a 
water supply. These practices relate to well siting, well construction, 
distribution system design and operations. Examples of BMPs that form a 
barrier to ground water contamination include drilling into a protected 
aquifer; siting a well away from sources of contamination; identifying 
and controlling contamination sources; and disinfection. BMPs that form 
a barrier to well contamination include well casing, well seals, and 
grouting the well. Distribution system BMPs include disinfection; 
maintaining positive pressure; flushing water mains; and adopting cross 
connection control programs. Surveillance BMPs such as sanitary surveys 
are conducted to identify weaknesses in the barriers.
    EPA recognizes that BMPs can and do contribute significantly to the 
safety of drinking water; however, the effectiveness of each individual 
practice can be difficult to measure. Two studies, State Ground Water 
Management Practices--Which Practices are Linked to Significantly Lower 
Rates of Total Coliform Rule Violations? (US EPA, 1997d) and the 
Analysis of Best Management Practices for Community Ground Water 
Systems (Association of State Drinking Water Administrators, or ASDWA, 
1998), were conducted to examine the relative effectiveness of BMPs in 
reducing microbial contamination of ground water systems. The EPA study 
compared BMP implementation at the State level to total coliform MCL 
violation rates of community ground water systems over a four year 
period. The ASDWA study compared BMP implementation to detections of 
both total and fecal coliform in community ground water systems over a 
two year period.
    A third study was conducted by EPA, Ground Water Disinfection and 
Protective Practices in the United States, (US EPA, 1996a) to review 
State practices and requirements for the protection of drinking water 
that has ground water as its source.
1. EPA Report on State Ground Water Management Practices
    In the EPA study, State Ground Water Management Practices--Which

[[Page 30201]]

Practices are Linked to Significantly Lower Rates of Total Coliform 
Rule Violations? (US EPA, 1997d), 12 BMPs were compared to the MCL 
violation rate for total coliform in community water systems by State. 
The 12 State BMPs were taken from the EPA report Ground Water 
Disinfection and Protective Practices in the United States (US EPA, 
1996a). The study used total coliform MCL violation data in SDWIS for 
community water systems for Fiscal Years 1993 through 1996. In the 
study, pairwise and stepwise linear regression analyses were used to 
determine if there was a statistically significant difference in the 
TCR MCL violation rates between those States that practice a particular 
BMP and those that do not. From this perspective, BMPs associated with 
lower violation rates are considered effective. The 12 BMPs included in 
the study were well construction codes, well/pump disinfection 
requirements, sanitary surveys, disinfection of new/repaired mains, 
cross connection controls, operator certification, minimum setback 
distances, EPA approved State Wellhead Protection Programs, periodic 
flushing of mains, wellhead monitoring, hydrogeologic criteria, and 
disinfection.
    Six of the 12 State management practices were unsuitable for 
pairwise analysis because these practices were present in nearly all 
States. Therefore, a comparison of TCR MCL violation rates in States 
with and without these practices could not be made. The BMPs for which 
analysis were not done were: well construction codes, well/pump 
disinfection requirements, sanitary surveys, disinfection of new/
required mains, cross connection controls, and operator certification. 
However, these six management practices were evaluated as part of the 
1998 Best Management Practices Survey conducted by ASDWA.
    Using a pairwise statistical analysis, two of the remaining six 
practices, disinfection and hydrogeologic criteria, showed a 
significant statistical relationship (at a .01 and a .05 level of 
confidence, respectively) in lowering the statewide median TCR 
violation rates, with disinfection showing the strongest relationship. 
In this analysis, disinfection is defined as the maintenance of at 
least a chlorine residual or its equivalent at the entry point or in 
the distribution system. The report focused its analysis on 
disinfection practices among 20 States, comparing the 10 highest 
disinfecting States with the 10 lowest disinfection States. 
Specifically, the 10 States with the highest percentage of disinfected 
CWSs had an average MCL violation rate of 16% over the four year 
period, versus a 33% violation rate for the ten States with the lowest 
disinfection rates. States that require hydrogeologic criteria for well 
siting and construction decisions had significantly lower median MCL 
violation rates than States that do not use these criteria (15.4% vs. 
24.6%). The other four practices, minimum setback distances from 
pollution sources, EPA approved Wellhead Protection Programs, periodic 
flushing of the distribution system, and wellhead monitoring, did not 
show a significant relationship in lowering TCR violation rates at the 
State level. The report does not provide information on the statistical 
significance of these results.
    The four year time frame for the statistical analyses was chosen as 
a more accurate reflection of the effectiveness of statewide management 
practices given the high degree of variability in the TCR violation 
rate from year to year. Different trends emerge when annual rates are 
compared. There is not enough data to determine if the year to year 
variability, shown in the FY 96 data, correlates to a change in State 
management practices.
    In a second analysis, stepwise linear regression was used on the 
six best management practices to further explain the variability among 
States in their reported TCR MCL violation rates. This analysis 
examines both the simultaneous effect of several BMPs on the State TCR 
MCL violation rate and evaluates which of the practices may explain the 
variability in the TCR violation rate among States. Ascertaining how 
much of the State-to-State variability can be explained by each of the 
practices is an important question given that the TCR requirements are 
the same for all States. The results of this analysis indicate that 
disinfection is the single largest factor in explaining the difference 
in the TCR violation rate among States. In general, the higher the rate 
of disinfection, the lower the rate of TCR MCL violations.
    Uncertainties associated with this analysis were: (1) Whether a 
State's BMP requirements are fully implemented at the system level; (2) 
what effect the six State BMPs not analyzed had on violation rates; (3) 
the degree of voluntary implementation of BMPs; and (4) the effect of 
not including State practices required only under certain 
circumstances. Nonetheless, this data on State management practices 
indicates that there is a significant association between disinfection 
and a lower TCR MCL violation rate.
2. ASDWA Analysis of BMPs for Community Ground Water Systems
    In the ASDWA study, The Analysis of Best Management Practices for 
Community Ground Water Systems (ASDWA, 1998), a working group selected 
28 BMPs that represent four major areas of plant operations and 
developed and distributed a survey to all 50 State drinking water 
programs. Each State was asked to select eight systems in each of the 
three following categories: (1) Systems with no detections of total 
coliform; (2) systems with total coliform detections only; and (3) 
systems with both total coliform and fecal coliform (or E. coli) 
detections. For each system, the State was asked to report which of 28 
BMPs listed were used by the system during a two year period (1995 and 
1996). Thirty-six States responded to the survey, each completing up to 
24 individual system surveys, providing data for 812 systems.
    The survey results were analyzed using both descriptive statistics 
and two statistical models--pairwise and logistical regression. The 
descriptive statistics illustrate the characteristics of a system but 
cannot isolate the effect of a particular BMP from the effects of other 
BMPs. The statistical models were used to describe the relationship 
between implementation of individual or a group of BMPs and a reduction 
in total or fecal coliform detections.
    A pairwise association analysis (i.e., comparing a system that 
implements a particular BMP to one that does not) was used to determine 
if the use of a BMP reduced the percentage of positive total coliform 
samples. The analysis determined that a significant association was 
found between 21 of the 28 BMPs and systems with no total coliform 
detections. The two BMPs with the strongest correlation to fewer total 
coliform detections were correction of deficiencies identified by the 
sanitary survey and operator certification (ASDWA, 1998).
    Using pairwise analysis for systems with fecal coliform (based only 
on those systems with at least one positive total coliform sample), the 
study found a significant association for eight of the twenty-eight 
BMPs. These eight BMPs include: system wells constructed according to 
State regulations, routine disinfection after well or pump repair, 
treatment for purposes other than disinfection, system maintaining 
acceptable pressure at all times, water distribution tanks are designed 
according to State requirements, systems are in compliance with State 
permitting requirements, systems have corrected deficiencies noted by 
the State

[[Page 30202]]

and system and operators receive routine training and education. 
According to the results, fewer BMPs are found to be significant in 
this analysis than the total coliform analysis. These results are 
expected given that the analysis of fecal coliform and E. coli only 
evaluate systems with at least one total coliform positive detection. 
Fecal coliform and E. coli tests are more specific to organisms found 
in human and animal feces, whereas total coliform tests indicate the 
presence of a broader class of enteric organisms. For this reason, 
there are fewer data points to model the association of BMPs with fecal 
coliform. Therefore, this analysis sets apart only the BMPs significant 
in preventing or eliminating fecal contamination.
    Using the logistical regression technique, three BMPs were 
associated with a significant reduction of total coliform-positive 
samples: (1) Maintaining a disinfectant residual; (2) operator 
training; and (3) correcting deficiencies identified by the State as 
part of a sanitary survey. The two BMPs associated with a significant 
reduction of fecal coliform/E. coli-positive samples were treatment for 
purposes other than disinfection, e.g., iron removal, and operator 
training. Another analysis was constructed using Logit models for four 
categories of BMPs to consider the effects of BMPs in groups rather 
than individually. Out of the four categories (Source Protection/
Construction, Treatment, Distribution System, and Management and 
Oversight), the Management and Oversight category showed the most 
significant association with reduced coliform detections.
    The ASDWA survey also evaluated the effectiveness of BMPs with 
regard to system size. For systems serving less than 500 persons, 
correction of deficiencies identified by the State, and regular 
training and education of operators were the most significant in 
reducing microbial contamination. Routine disinfection after well or 
pump repair had the greatest significance among systems serving between 
501 and 3,300 persons, while maintaining a disinfection residual had 
the greatest significance among systems serving between 3301 and 10,000 
persons.
    Overall, this study found that the percentage of systems 
implementing BMPs is highest among systems with no total coliform 
detections. In addition, systems that routinely educate and train their 
operators were more likely to implement other BMPs than systems with no 
regular training. Similarly, those systems that practice disinfection 
(contact time or maintain disinfection residual) were more likely to 
implement other BMPs than systems that do not disinfect. Observations 
about the implementation of BMPs suggests that many BMPs are 
interrelated, therefore, it is difficult to isolate the effect of an 
individual BMP.
3. EPA Report on Ground Water Disinfection and Protective Practices
    The purpose of the EPA study, Ground Water Disinfection and 
Protective Practices in the United States, (US EPA, 1996a) was to 
compile and assess State regulations, guidance, codes, and other 
materials pertaining to protection of public health from microbial 
contamination in public water systems using ground water.
    The information compiled included the following:
     Wellhead/ground water protection information;
     Ground water disinfection requirements;
     Well siting and construction requirements/guidelines;
     Sanitary survey requirements/guidelines;
     Distribution system protection requirements/guidelines; 
and
     Operator certification requirements.
    The study found that there are widespread, but diverse requirements 
for the protection of drinking water that has ground water as its 
source. Few of these protective practices are used by all States and 
there is a variety of interpretations of the same practice. For 
example, 47 States specify minimum setback distances from sources of 
microbial contamination but show a wide range of setback distances for 
the same type of contaminant source; 49 States drinking water programs 
require disinfection of some sort, but when and where disinfection is 
required varies considerably; and of the 48 States that have well 
construction codes, 21 States do not require consideration of 
hydrogeological criteria in the approval of the siting of a well.
    Overall, the study found that although many States appear to 
require similar BMPs, the nature, scope, and detail of these 
requirements varies considerably at the national level.

E. Outreach Activities

1. Public Meetings
    As part of the 1986 amendments to the Safe Drinking Water Act 
(SDWA) Section 1412(b)(8), Congress directed EPA to promulgate a 
national primary drinking water regulation (NPDWR) requiring 
disinfection as a treatment technique for all public water systems, 
including those served by surface water and ground water. In 1987, EPA 
began developing a rule to cover ground water systems. This effort 
included a preliminary public meeting on the issues in 1990 (see 55 FR 
21093, May 22, 1990, US EPA, 1990a). In 1992, EPA circulated a strawman 
draft for comment (see 57 FR 33960, July 31, 1992) (US EPA, 1992a).
    From 1990 to 1997, EPA conducted technical discussions on a number 
of issues, primarily to establish a reasonable means of establishing 
whether a ground water source was vulnerable to fecal contamination and 
thus pathogens. This effort was accomplished through 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 addition, technical meetings 
were held in Irvine, California in July 1996, (US EPA, 1996c) and in 
Austin, Texas in March 1997 (US EPA, 1997e).
    The SDWA was amended in August 1996, and as a result, several 
statutory provisions were added establishing new drinking water 
requirements. Specifically, Congress required under section 1412(b)(8) 
that EPA develop regulations specifying the use of disinfectants for 
ground water systems ``as necessary.'' These amendments established a 
new regulatory framework that required EPA to set criteria for States 
to determine whether ground water systems need to disinfect. In 
December 1997, EPA held its first of a series of stakeholder meetings 
to present a summary of the findings resulting both from technical 
discussions held since 1990 and from information generated by internal 
EPA working groups with the intention of developing disinfection 
criteria for ground water systems.
    EPA held a preliminary Ground Water Rule meeting on December 18 and 
19, 1997, in Washington, DC for the purpose of engaging all interested 
stakeholders in the analysis of data to support the GWR. The two day 
meeting covered discussions on the implications of the data, solicited 
further data from stakeholders, and reviewed EPA's next steps for rule 
development, data analysis and stakeholder involvement.
    Since December 1997, EPA has held GWR stakeholder meetings in 
Portland, OR, Madison, WI, Dallas, TX, Lincoln, NE, and Washington, DC 
along with three early involvement meetings with State representatives. 
In addition, EPA has received valuable input from small system 
operators as part of an Agency outreach initiative under the Small 
Business Regulatory Enforcement Fairness Act. See section VI for more

[[Page 30203]]

information on the SBREFA process. Taken together, these stakeholder 
meetings have been crucial both in obtaining feedback and getting 
additional information as well as in guiding the Agency's consideration 
and development of different regulatory components.
    The Agency's goal in developing the GWR is to reduce the risk of 
illness caused by microbial contamination in public water systems 
relying on ground water. The series of GWR stakeholder meetings were 
beneficial in assisting EPA in understanding how State strategies fit 
together as part of a national strategy. For more information see the 
(Stakeholders Meeting Summary, Resolve, July 27, 1998).
Portland, OR, GWR Stakeholder Meeting
    There were four different regulatory approaches presented in the 
first of a series of stakeholder meetings held in Portland, OR, in May 
1998: the Barrier Assessment Approach, the Existing State Practices 
Approach, the Setback Approach, and the Checklist Approach (Stakeholder 
Meetings Summary, Resolve, July 27, 1998). All approaches address, to 
varying degrees, three main areas: minimum program requirements or 
baseline measures, identification of high risk wells, and corrective 
action. Discussions on the potential approaches centered around 
determining triggers that could place a well in a high priority 
category and which minimum set of BMPs should be implemented at high 
risk wells.
Madison, WI GWR Stakeholder Meeting
    There were three approaches presented in a June 9, 1998, GWR 
stakeholder meeting held in Madison, WI: Status Quo Approach, Baseline 
Approach, and Disinfection Approach. Regulatory approaches were revised 
in response to stakeholder input from the earlier GWR stakeholder 
meetings, representing a continuum of requirements, from Existing 
Status Quo to mandatory disinfection for all ground water systems. EPA 
emphasized that existing occurrence data does not appear to support 
mandatory disinfection across the board, but that the Agency would 
still appreciate stakeholder input on a range of options. The 
approaches presented were based on monitoring, inspections, BMPs and 
disinfection.
Dallas, TX GWR Stakeholder Meeting
    A third GWR meeting on June 25, 1998 in Dallas, TX, provided slight 
modifications to the regulatory approaches, but for the most part the 
regulatory approach remained unchanged from the Madison meeting held in 
early June. EPA continued to emphasize the need to identify and 
strengthen the potential barriers to contamination. Among the three 
approaches, (Status Quo, Progressive and Universal Disinfection) the 
Progressive approach was considered the more viable regulatory option 
to ensure public health protection among public water systems.
Early Involvement Meetings
    ASDWA held three early involvement meetings (EIMs) on the GWR. The 
first EIM followed the May 5, 1998 stakeholder meeting in Portland, OR. 
The second EIM meeting was held in Washington, DC on July 14 and 15, 
1998 and the third meeting was held in Chicago, IL on April 7 and 8, 
1999. Representatives from 12 States, four EPA Regions, ASDWA and EPA 
Headquarters participated in the May 6 and 7, 1998 meeting in Portland, 
OR. The second EIM involved 10 State representatives, ASDWA, and EPA 
Headquarters. The third EIM included one Region, seven State 
representatives, ASDWA and EPA Headquarters. The purpose of the 
meetings was to review the findings and comments from the stakeholder 
meetings and to work together to further refine GWR regulatory options. 
EPA and States discussed a range of issues including risk, exposure, 
strategies for identifying high risk systems, occurrence data, and 
regulatory implementation barriers.
2. Review and Comment of Preliminary Draft GWR Preamble
    EPA developed a preliminary draft preamble reflecting a wide range 
of input from numerous stakeholders across the country including four 
public meetings, three EIMs with State representatives, in addition to 
valuable input received from small system operators as part of the 
outreach process established by SBREFA.
    To facilitate the rule development process, the preliminary draft 
preamble was made available to the public via the Internet through 
EPA's website site on February 3, 1999. Approximately 300 copies were 
mailed to participants of the public meetings or to those who requested 
a copy. EPA welcomed any comments, suggestions, or concerns reviewers 
had on either the general direction or the technical basis of the 
proposal. EPA closed the email box on February 23, 1999 and continued 
to receive written comments through the mail through March 17, 1999. 
Because this was an informal process, EPA did not prepare a formal 
response to the comments. Nonetheless, the Agency carefully reviewed 
and evaluated all comments and technical suggestions and greatly 
appreciated the input and feedback provided by these outreach efforts.
    Eighty individual comment letters were received. Commenters 
included: State and local government representatives, trade 
associations, academic institutions, businesses and other Federal 
agencies. Microbial monitoring received the most individual comments. 
Sanitary survey, sensitivity assessment and treatment issues were next, 
respectively.

II. Public Health Risk

    The purpose of this section is to discuss the health risk 
associated with pathogens in ground waters. More detailed information 
about pathogens may be found in three EPA drinking water criteria 
documents for viruses (US EPA 1985a; 1999b; 1999c), three EPA criteria 
documents for bacteria (US EPA 1984a, b; 1985b) and the GWR Occurrence 
and Monitoring Document (US EPA, 1999d). EPA requests comment on all 
the information presented in this section, and the potential impact of 
proposed regulatory provisions on public health risk.

A. Introduction

    Enteric viral and bacterial pathogens are excreted in the feces of 
infected individuals. Many bacterial pathogens can infect both humans 
and animals. Bacterial pathogens that infect humans can also be found 
in animal feces. In contrast, enteric viruses that are human pathogens 
generally only infect humans, and thus are only found in human feces. 
These organisms are able to survive in sewage and leachate derived from 
septic tanks (septage) and sewer lines. When sewage and septage are 
released into the environment, they are a source of fecal 
contamination. Fecal contamination is a very general term that includes 
all of the organisms found in feces, both pathogenic and non-
pathogenic, as well as chemicals.
    Fecal contamination of ground water can occur by several routes. 
First, fecal contamination can reach the ground water source from 
failed septic systems, leaking sewer lines, and from land discharge by 
passage through soils and fissures. Twenty-five million households in 
the United States use conventional onsite wastewater treatment systems, 
according to the 1990 Census. These systems include systems with septic 
systems and leach fields. A national estimate for failure rates of 
these systems is not available; however, a National Small Flows 
Clearinghouse survey reports that in

[[Page 30204]]

1993 alone, 90,632 failures were reported. (USEPA, 1997f). 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. Third, fecal contamination may also enter the distribution 
system when cross connection controls fail or when negative pressure in 
a leaking pipe allows contaminant infiltration.
    Biofilms in distribution systems may harbor bacterial pathogens, 
especially the opportunistic pathogens that cause illness primarily in 
individuals with weakened immune systems. These bacterial pathogens may 
have entered the distribution system as part of fecal matter from 
humans or other animals. Biofilms may also harbor viral pathogens 
(Quignon et al., 1997), but, unlike some bacterial pathogens, viruses 
do not grow in the biofilm. However, a biofilm may protect the viruses 
against disinfectants and help them survive longer.
    Although not the basis for today's proposed rule, there are 
additional waterborne pathogens that EPA is currently evaluating. These 
include bacterial pathogens that may be free-living in the environment, 
and thus not necessarily associated with fecal contamination. These 
pathogens include Legionella (causes Legionnaires Disease and Pontiac 
Fever), Pseudomonas aeruginosa, and Mycobacterium avium-intracellulare. 
Many of these bacteria can colonize pipes of the distribution system 
and plumbing systems and may play a role in causing waterborne disease 
that is currently under study. EPA recognizes the potential risk of 
such organisms, but believes that more research needs to be conducted 
before they can be considered for regulation. Also, the Agency is aware 
that Giardia and Cryptosporidium have occurred in ground water systems 
(GWSs) (Hancock et al., 1998), causing outbreaks in such systems (Solo-
Gabriele and Neumeister, 1996). However, by definition under Sec. 141.2 
ground waters with significant occurrence of large diameter pathogens 
such as Giardia or Cryptosporidium are considered ground water under 
the direct influence of surface water and are already subject to the 
SWTR and IESWTR. The Agency is also not addressing in the GWR the 
important issue of toxic or carcinogenic chemicals in the GWR. This 
issue is instead covered in other regulations that address chemicals.
    In order to assess the public health risk associated with drinking 
ground water, EPA has evaluated information and conducted analysis in a 
number of important areas discussed in more detail later. These 
include: (1) Recent waterborne disease outbreak data; (2) dose-response 
data and other health effects data from a range of pathogens; (3) 
occurrence data from ground water studies and surveys; (4) an 
assessment of the current baseline ground water protection provided by 
existing regulations; and (5) an analysis of risk.

B. Waterborne Disease Outbreak Data

    The purpose of this section is to present a detailed review of 
waterborne disease outbreaks associated with ground waters. Outbreak 
characterization is useful for indicating relative degrees of risk 
associated with different types of source water and systems.
    The Centers for Disease Control and Prevention (CDC) maintains a 
database of information on waterborne disease outbreaks in the United 
States. The database is based upon responses to a voluntary and 
confidential survey form that is completed by State and local public 
health officials. CDC defines a waterborne disease outbreak as 
occurring when at least two persons experience a similar illness after 
ingesting a specific drinking water (Kramer et al., 1996). Data from 
the CDC database appears in Tables II-1, II-2, II-3, and II-4.
    The National Research Council strongly suggests that the number of 
identified and reported outbreaks in the CDC database (both for surface 
and ground waters) represents a small percentage of actual waterborne 
disease outbreaks (Safe Water From Every Tap, National Research 
Council, 1997; Bennett et al., 1987; Hopkins et. al., 1985 for Colorado 
data). In practice, most waterborne outbreaks in community water 
systems are not recognized until a sizable proportion of the population 
is ill (Perz et al., 1998; Craun 1996), perhaps 1% to 2% of the 
population (Craun, 1996). Some of the reasons for the lack of 
recognition and reporting of outbreaks, most of which were noted by the 
National Research Council (1997), are as follows:
     Some States do not have active disease surveillance 
systems. Thus, States that report the most outbreaks may not be those 
in which the most outbreaks occur.
     Even in States with effective disease surveillance 
systems, health officials may not recognize the occurrence of small 
outbreaks. In cities, large outbreaks are more likely to be recognized 
than sporadic cases or small outbreaks in which ill persons may consult 
different physicians. Even so, health authorities did not recognize the 
massive outbreak (403,000 illnesses) of waterborne cryptosporidiosis 
that occurred in Milwaukee, WI, in 1993, until the disease incidence 
was near or at its peak (MacKenzie et al., 1994). The outbreak was 
recognized when a pharmacist noticed that the sale of over-the-counter 
diarrheal medicine was very high and consequently notified health 
authorities.
     Most cases of waterborne disease are characterized by 
general symptoms (diarrhea, vomiting, etc.) that cannot be 
distinguished from other sources (e.g., food).
     Only a small fraction of people who develop diarrheal 
illness seek medical assistance.
     Many public health care providers may not have sufficient 
information to request the appropriate clinical test.
     If a clinical test is ordered, the patient must comply, a 
laboratory must be available and proficient, and a positive result must 
be reported in a timely manner to the health agency.
     Not all outbreaks are effectively investigated. Outbreaks 
are included in the CDC database only if water quality and/or 
epidemiological data are collected to document that drinking water was 
the route of disease transmission. Monitoring after the recognition of 
an outbreak may be too late in detecting intermittent or a one-time 
contamination event.
     Some States do not always report identified waterborne 
disease outbreaks to the CDC. Reporting outbreaks is voluntary.
     The vast majority of ground water systems are non-
community water systems (NCWSs). Outbreaks associated with NCWSs are 
less likely to be recognized than those in community water systems 
because NCWSs generally serve nonresidential areas and transient 
populations.
    There is also the issue of endemic waterborne disease. Endemic 
waterborne disease may be defined as any waterborne disease not 
associated with an outbreak. A more precise definition is the normal 
level of waterborne disease in a community. Under this definition, an 
outbreak would represent a spike in the incidence of disease. Based on 
this definition, the level of endemic waterborne disease in a community 
may be quite high. For example, 14%-40% of the normal gastrointestinal 
illness in a community in Quebec was associated

[[Page 30205]]

with drinking treated water from a surface water source (Payment et 
al., 1997). Significant levels of endemic disease could also be 
associated with ground waters. Because endemic waterborne disease may 
be a significant and substantially preventable source of health risk, 
under the directive of the 1996 SDWA Amendments, EPA is jointly 
pursuing with CDC a multi-city study of waterborne disease occurrence 
in an effort to provide greater understanding of this risk. EPA 
believes that some meaningful percentage of the nationwide occurrence 
of endemic waterborne disease is in ground water systems (GWSs). EPA 
believes that the prudent policy of prevention embodied in this 
proposal with regard to identified sources of substantial microbial 
risk to GWSs gains further justification as a counter to the endemic 
occurrence of waterborne disease. EPA solicits comment and any data 
that can increase knowledge of these endemic risks, in particular any 
studies on such risk in GWSs.
CDC Waterborne Disease Outbreak Data
    Outbreak data collected by CDC are presented in Tables II-1, II-2 , 
II-3, and II-4. Table II-1 provides outbreak data for all public water 
systems (surface and ground water). Table II-2 shows sources of 
waterborne disease outbreaks for GWSs. Table II-3 identifies the 
etiology of waterborne outbreaks in GWSs. Table II-4 shows causes 
associated with waterborne disease outbreaks and illnesses in GWSs.
    According to CDC, between 1971 and 1996 a total of 643 outbreaks 
and 571,161 cases of illnesses were reported (see Table II-1); however, 
the total includes 403,000 cases from a single surface water outbreak 
caused by Cryptosporidium in Milwaukee, WI in 1993. Excluding the 
Milwaukee outbreak from the data set, 642 outbreaks and 168,161 cases 
of illness were reported during the same period of time. Ground water 
sources were associated with 371 (58%) of the total outbreaks and 16% 
of the associated illness (54% of the illness if the Milwaukee outbreak 
is excluded). In comparison, surface water sources were associated with 
216 (33%) of the total outbreaks and 82% of the associated illness (40% 
of the illness if the Milwaukee outbreak is excluded). Although the 
data in Table II-1 indicate that NCWSs using ground water had twice as 
many outbreaks as CWSs using ground water, this may reflect the fact 
that there are over twice as many NCWSs as CWSs.
    The outbreak data indicate that the major deficiency in ground 
water systems was source water contamination--either untreated or 
inadequately treated ground water (see Table II-2). Contaminated source 
water was the cause of 86% of the outbreaks in ground water systems. 
Contamination due to source water was the cause of 68% of the outbreaks 
for CWSs, while for NCWSs it was 92%. Distribution system deficiencies 
were associated with 29% of the outbreaks in CWSs and in five percent 
of the NCWSs.
    Of the 371 outbreaks in ground water systems, 91 (25%) were 
associated with specific viral or bacterial pathogens, while 22 (6%) 
were associated with chemicals (see Table II-3). Etiologic agents were 
not identified in 232 (63%) outbreaks. The diversity of disease agents 
is similar to that of surface water, with a variety of protozoa, 
viruses, and bacteria. As stated previously, a ground water with 
Cryptosporidium or Giardia is, by definition, a ``ground water under 
the direct influence of surface water'', and is thus subject to the 
microbial treatment requirements of a surface water system (i.e., SWTR 
or IESWTR). According to CDC's data, bacterial pathogens were 
responsible for more outbreaks (57) than were viral pathogens (34). 
However, EPA suspects that many, perhaps a majority, of the outbreaks 
where an agent was not determined (232) were virus-caused, given the 
fact that it is generally more difficult to analyze for viral pathogens 
than bacterial pathogens. The fecal bacterial pathogen, Shigella, 
caused far more reported outbreaks (eight percent) than any other 
single agent.
    Table II-4 shows outbreak data since 1991, the year in which the 
TCR became effective. Untreated ground water and inadequate treatment 
were collectively associated with 73% of the outbreaks in ground water 
systems between 1991-1996.
    Large outbreaks are rarely associated with ground water systems 
because most ground water systems are small. However, one large 
outbreak occurred in Georgetown, TX, in 1980 (Hejkal et al., 1982) 
where 7,900 people became ill. Coxsackievirus and hepatitis A virus 
were found in the raw well water in a karst hydrogeologic setting; the 
outbreak was the result of source water contamination. Another occurred 
in 1965, in Riverside, CA, where about 16,000 illnesses resulted from 
exposure to Salmonella typhimurium in the source water (Boring, 1971).
    Most of the outbreaks were caused by agents of gastrointestinal 
illness. Normally, the disease is self-limiting and the patient is well 
within one week or less. However, in some cases, deaths have occurred. 
In 1989, four deaths (243 illnesses) occurred in Cabool, MO, as a 
result of distribution system contamination by E. coli 0157:H7 
(Swerdlow et al., 1992; Geldreich et al., 1992). In 1993, seven deaths 
(650 illnesses) occurred in Gideon, MO, as a result of distribution 
system contamination by Salmonella typhimurium (Angulo, 1997). Both 
cases involved ground water systems. Waterborne disease in ground water 
systems has also caused serious illness such as hemolytic uremic 
syndrome (six reported cases in two outbreaks), which includes kidney 
failure, especially in children and the elderly. Two cases of hemolytic 
uremic syndrome were reported during the Cabool outbreak, the affected 
individuals being three and 79 years of age. Deep wells are not immune 
from contamination; for example, an outbreak of gastroenteritis caused 
by the Norwalk virus (900 illnesses) was associated with a 600-foot 
well (Lawson et al., 1991).
    Collectively, the data indicate that outbreaks in ground water 
systems are a problem and that source contamination and inadequate 
treatment (or treatment failures) are responsible for the great 
majority of outbreaks. The outbreaks are caused by a variety of 
pathogens, most of which cause short term gastrointestinal disease.

        Table II-1.--Comparison of Outbreaks and Outbreak-Related Illnesses From Ground Water and Surface Water for the Period 1971-1996 \1\ \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Outbreaks in    Outbreaks in
           Water source                Total outbreaks\1\         Cases of  illnesses          CWSs            NCWSs       Total CWS\4\    Total NCWS\4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ground...........................  371 (58%)                   90,815 (16%)                          113             258          43,908         112,940
Surface..........................  216 (33%)                   469,721\2\ (82%)                      142              43          10,760           2,848
Other............................  56 (9%)                     10,625 (2%)                            29              19  ..............  ..............

[[Page 30206]]

 
All Systems\3\...................  643 (100%)                  571,161 (100%)                        284             320          54,668        115,788
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Modified from Craun and Calderon, 1994, plus 1995-1996 data.
\2\ Includes 403,000 cases of illness from a single outbreak in Milwaukee, Wisconsin, 1993.
\3\ Includes outbreaks in CWSs + NCWSs + Private wells.
\4\ Safe Drinking Water Information System, 1998.


                            Table II-2.--Sources of Waterborne Disease Outbreaks, Public Ground Water Systems, 1971-1996 1,2.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Percent of                      Percent of                      Percent of
                  Type of contamination                        Total           total           CWSs            total           NCWSs           total
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Source..............................................             274              86              53              68             221              92
    Untreated...........................................             150              47              20              26             130              54
    Disinfected.........................................             122              38              31              40              91              38
    Filtered............................................               2               1               2               3               0               0
Distribution System.....................................              35              11              23              29              12               5
Unknown Cause...........................................               9               3               2               3               7               3
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................             318             100              78             100             240            100
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Source water could not be identified for 29 CWSs and 19 NCWSs with outbreaks, and thus these systems are not included in the table.
\2\ Excludes outbreaks caused by protozoa and chemicals.


  Table II-3.--Etiology of Outbreaks in Ground Water Systems, 1971-96,
                             CWSs and NCWSs
------------------------------------------------------------------------
               Causative agent                   Outbreaks      Percent
------------------------------------------------------------------------
Undetermined................................             232  63
Chemical....................................              22  6
Giardia.....................................          \1\ 21  6
Cryptosporidium.............................           \1\ 4  1
E. histolytica..............................               1  1
Total Protozoa..............................              26  7
Hepatitis A.................................              18  5
Norwalk Agent...............................              16  5
Total Virus.................................              34  9
Shigella....................................              30  8
Campylobacter...............................              10  3
Salmonella, non-typhoid.....................              10  3
E. coli.....................................               4  1
S. typhi....................................               1  1
Yersinia....................................               1  1
Plesiomonas shigelloides....................               1  1
                                             ---------------------------
Total Bacteria..............................              57  15
                                             ===========================
Total.......................................             371  100
------------------------------------------------------------------------
\1\ Ground waters with Giardia and Cryptosporidium are regulated under
  the SWTR and IESWTR. These systems would likely not be considered
  ground water systems for purposes of this rule.


                       Table II-4.--Causes of Outbreaks in Ground Water Systems, 1991-1996
----------------------------------------------------------------------------------------------------------------
                                                                                                    Percent of
                                                                     Number of       Cases of        outbreak-
                              Cause                                  outbreaks        illness         related
                                                                                                     illnesses
----------------------------------------------------------------------------------------------------------------
Untreated Ground Water..........................................              18            2924              51
Distribution System Deficiency..................................               6             944              17
Treatment Deficiency............................................              17            1260              22
Miscellaneous, Unknown Cause....................................               3             568              10
                                                                 -----------------------------------------------
    Total.......................................................              44            5696            100
----------------------------------------------------------------------------------------------------------------
\1\ Excludes protozoa and chemicals.


[[Page 30207]]

C. Ground Water Occurrence Studies
    The purpose of this section is to present data on the occurrence of 
waterborne pathogens and indicators of fecal contamination in ground 
water supplying PWS wells. These data are important to GWR development 
because they provide insight on: (1) The extent to which ground water 
may be contaminated; (2) possible fecal indicators for source water 
monitoring under the GWR; and (3) a national estimate of ground water 
pathogen occurrence. In addition, determining the occurrence of 
microbial contaminants in ground water sources of drinking water is 
necessary to yield a quantified national estimate of public health 
risk.
    EPA has reviewed data from13 recent or on-going studies of pathogen 
and/or fecal indicator occurrence in ground waters that supply PWSs. 
While most of these studies were not designed to yield a nationally 
representative sample of ground water systems, one of the studies 
(Abbaszadegan et al., 1999, or the ``AWWARF study'') was later expanded 
to include a nationally representative range of hydrogeologic settings. 
This study was used as the basis of EPA's quantitative assessment of 
baseline risk from viral contamination of ground water, which is also a 
component of the quantitative benefits assessment for the proposed 
rule. Short narratives on each of the studies are provided in the next 
sections. The study design and results for each study are summarized in 
Table II-6, at the end of the narratives. The Agency decided not to 
combine the data from these studies, because of the different method 
protocols and scopes.
    Each occurrence study investigated a combination of different 
pathogenic and/or indicator viruses and bacteria. Indicator viruses and 
bacteria may be non-pathogenic but are associated with fecal 
contamination and are transmitted through the same pathways as 
pathogenic viruses and bacteria. The samples analyzed in each study 
were tested for viral pathogens such as enteroviruses (a group of human 
viruses also referred to as ``total cultureable viruses'') and/or 
bacterial pathogens such as Legionella and Aeromonas. Several studies 
used the polymerase chain reaction (PCR) as part of the method for 
determining the presence of pathogenic viruses. Bacterial indicators of 
fecal contamination tested included enterococci (or fecal streptococci, 
which are closely related), and fecal coliforms (or E. coli, which is 
closely related), and Clostridium perfringens. Most studies tested for 
total coliforms, which are not considered a direct fecal indicator 
since they also include coliforms that live in soil. Viral indicators 
of fecal contamination were all bacteriophage, which are viruses that 
infect bacteria. Among the bacteriophage tested were somatic coliphage 
and/or male-specific coliphage, both of which infect the bacterium E. 
coli. Bacteroides phage were tested in two studies and Salmonella phage 
in one study.
    While this section presents a summary of each study, a more 
detailed explanation of one study (Abbaszadegan et al., 1999) (AWWARF 
Study) is provided, as it is the broadest study in scope. The 
hydrogeology of individual wells is mentioned in addition to the 
microbial results, because EPA considers hydrogeology an important 
factor in source water contamination. Hydrogeology is discussed in 
greater detail in section III.B.
1. Abbaszadegan et al. (1999) (AWWARF Study)
    Of the 13 studies, the AWWARF study sampled the largest number of 
wells, examined the widest array of well and system characteristics, 
and tested sites in 35 States across the U.S., located in hydrogeologic 
settings representative of national hydrogeology. The objectives of the 
AWWARF study were to: (1) Determine the occurrence of virus 
contamination in source water of public ground water systems; (2) 
investigate water quality parameters and occurrence of microbial 
indicators in ground water and possible correlation with human viruses; 
and (3) develop a statistically-based screening method to identify 
wells at risk of fecal contamination. A summary of AWWARF results are 
presented in Tables II-5 and II-6.
    Many of the initial sites were selected to evaluate the 
effectiveness of a method based on the reverse-transcriptase, 
polymerase chain reaction (RT-PCR) technique to detect pathogenic 
viruses in ground water. Sites for this portion of the study were 
selected based on the following criteria: (1) Ground water sites with 
high concentrations of minerals, metals, or TOC; (2) sites with a 
previous detection of any virus or bacteria in the ground water source; 
(3) sites with potential exposure to contaminants due to agricultural 
activities near the well, industrial activities near the well, or 
septic tanks near the well; and (4) sites with different pH values, 
temperatures, depths, production capacities and aquifer types. Sites 
were selected for the virus occurrence project based upon their 
geological characteristics to balance out the range of geologies so 
that the sites in aggregate more closely matched the national geologic 
profile of ground water sources. Sites for the virus occurrence study 
were selected from an initial mailing to 500 utilities that currently 
disinfect their water; 160 utilities with 750 wells volunteered to be 
included in the study. In total, 448 wells were sampled for the study. 
AWWARF excluded sites from the investigation if: (1) It was known to be 
under the influence of surface water; (2) the well log records were not 
available; or (3) it was considered poorly constructed.
    EPA subsequently compared nitrate concentrations from a national 
database of nitrate concentrations in ground water (Lanfear, 1992) with 
nitrate data measured in the AWWARF study wells. The purpose of the 
comparison was to determine if there was any statistically significant 
difference between the nitrate levels in the AWWARF wells as compared 
with the national distribution of nitrate concentration data. Nitrate 
was chosen for this comparison because there is a large, national 
database available. Each data set contained 216 samples selected so 
that proportionately, wells of equal depth were analyzed in each 
comparison. The national data were selected randomly from a database of 
more than 100,000 wells; all available AWWARF data were used. In 
analyzing the data, EPA noted that the national data is biased by 
multiple sampling of many shallow monitoring wells in farming regions 
leading to a few wells having exceptionally high nitrate levels. In 
order to minimize the impact of these wells on the analysis, EPA chose 
a small random subset comparable in size to the sample in the AWWARF 
study. Thus, the data are not directly comparable with PWS wells. 
Census data were used to divide the national nitrate database into 
urban and rural components. The analysis showed that the AWWARF wells 
had nitrate concentrations that were not significantly different from 
the national data or from the urban and rural components. Thus, using 
nitrate concentration as a surrogate, EPA concludes that, by this 
measure, the AWWARF wells are nationally representative.
    All samples were collected by the systems. AWWARF provided a sample 
kit containing all needed equipment and a video illustrating the 
details of appropriate sampling and storage procedures. A total of 539 
samples were collected from 448 sites in 35 States. The preliminary 
results indicate that of the 448 wells sampled, about 64% were located 
in unconsolidated aquifers, 27% in consolidated aquifers including 
consolidated sedimentary strata, and 9% in unknown geology. 
Unconsolidated aquifers are made of

[[Page 30208]]

loosely packed (uncemented) particles, such as sand grains or gravel, 
while consolidated aquifers are comprised of compacted (cemented) 
particles or crystalline rock (e.g., granite, limestone). As discussed 
further in section III.B., the degree and type of consolidation may 
affect the transport of pathogens from a source of fecal contamination 
to the well. The percentages of sites sampled from these geologic 
settings are similar to those of national ground water production from 
unconsolidated and consolidated hydrogeologic settings (modified by 
AWWARF, from United States Geological Survey (USGS) Circular 1081, 
1990). The data indicate that 174 sites (39%) were within 150 feet of a 
known sewage source, and an additional 127 sites (28%) were within 550 
feet of a known sewage source. There is no comparable data on the 
distribution nationally of wells relative to sewage sources. EPA notes 
however, that the proximity to these sources is not inconsistent with 
State standards across the country. For example, 41 States have setback 
distances (the minimum distance between a source of contamination and a 
well) that are less than or equal to 100 feet for sources of microbial 
contaminants. Only five States appear to require setback from all 
sewage sources of more than 200 feet. The preliminary results also 
indicated that a total of 25 sites were sampled more than once. Most 
sites were from systems that serve greater than 3,300 people, and 
almost all systems maintain a disinfectant residual.
    In the study, systems collected at least 400 gallons (1,512 liters) 
of water and concentrated it using a filter-adsorption and elution 
method. The concentrated samples were then sent to the researchers for 
analysis. The presence of enteroviruses was determined by two 
procedures: a cell culture assay and a procedure using the RT-PCR 
technique. The RT-PCR technique was also used to determine the presence 
of hepatitis A virus, rotavirus, and Norwalk virus. The researchers 
also tested each well for total coliforms, enterococci, Clostridium 
perfringens, somatic coliphage, and male-specific coliphage to 
establish their relationship with enterovirus and to get a better 
indication of the percentage of fecally contaminated wells.
    Preliminary results indicated that fecal contamination occurs in a 
subset of PWS wells (see Table II-5). The investigators detected 
pathogenic viruses, either by cell culture or RT-PCR analyses, in a 
significant percentage of samples.

            Table II-5.--Preliminary Results of AWWARF Study
------------------------------------------------------------------------
                                             Percent of wells positive
                  Assay                      (number positive/samples
                                                     analyzed)
------------------------------------------------------------------------
Enteroviruses (cell culture)............  4.8% (21/442)
Bacterial Indicators....................  15.1%
    Total coliforms.....................  9.9% (44/445)
    enterococci.........................  8.7% (31/355)
    Clostridium perfringen spores.......  1.8% (1/57)
Coliphage Indicators....................  20.7%
    Male-specific coliphage (Salmonella   9.5% (42/440)
     WG-49 host).
    Somatic coliphage (E. coli C host)..  4.1% (18/444)
    Somatic and male-specific coliphage   10.8% (48/444)
     (E. coli C-3000 host).
PCR.....................................  31.5%
    Norwalk viruses (PCR)...............  0.96% (3/312)
    Enteroviruses (PCR).................  15.9% (68/427)
    Rotaviruses (PCR)...................  14.6% (62/425)
    Hepatitis A viruses (PCR)...........  7.2% (31/429)
------------------------------------------------------------------------

2. Lieberman et al., (1994, 1999) (EPA/AWWARF Study)
    The study objectives included the following: (1) develop and 
evaluate a molecular biology (PCR) monitoring method; (2) obtain 
occurrence data for human enteric viruses and Legionella (a bacterial 
pathogen) in ground water; and (3) assess the microbial indicators of 
fecal contamination. These objectives were accomplished by sampling 
vulnerable wells nominated by States to confirm the presence of fecal 
indicators (Phase I) and then choosing a subset of these for monthly 
sampling for one year (Phase II).
    In Phase I, well vulnerability was established using historical 
microbial occurrence data and waterborne disease outbreak history, 
known sources of human fecal contamination in close proximity to the 
well, and sensitive hydrogeologic features (e.g., karst). Ninety-six of 
the 180 potentially vulnerable wells were selected for additional 
consideration. Selected wells were located in 22 States and 2 US 
territories. Additional water quality information was then successfully 
obtained for 94 of the wells through use of a single one liter grab 
sample which was subsequently tested for several microbial indicators 
(see Table II-6). The wells from Phase I served as the well selection 
pool for Phase II sampling.
    In Phase II, 23 of the Phase I wells were selected for monthly 
sampling for one year. Seven additional wells were selected from a list 
of state-nominated wells for a total of 30 wells, located in 17 States 
and 2 US territories. The additional seven wells were based on other 
criteria, including historical water quality data, known contaminant 
sources in proximity to the well, hydrogeologic character or to replace 
wells that were no longer available for sampling. Samples were analyzed 
for enteroviruses, Legionella, enterococci, E. coli, Clostridium 
perfringens, total coliforms, somatic coliphage, male-specific 
coliphage and Bacteroides phage. For each sample analyzed for enteric 
viruses and bacteriophages, an average of approximately 6,000 liters of 
water were filtered and analyzed by cell culture.
    Twenty samples from seven wells were enterovirus positive and were 
speciated by serotyping. Coxsackievirus and echovirus, as well as 
reovirus, were identified. The range in virus concentration in 
enterovirus-positive samples was 0.9-212 MPN/100 liters (MPN, or most 
probable number, is an estimate of concentration).
    The hydrogeologic settings for the seven enterovirus-positive wells 
were

[[Page 30209]]

karst (3), a gravel aquifer (1), fractured bedrock (2), and a sandy 
soil and alluvial aquifer (1). The karst wells were all positive more 
than once. The gravel aquifer was also enterovirus-positive more than 
once, with 4 of 12 monthly samples positive.
3. Missouri Ozark Aquifer Study #1
    The purpose of this study was to determine the water quality in 
recently constructed community public water system wells in the Ozark 
Plateau region of Missouri. This largely rural region is characterized 
by carbonate aquifers, both confined and unconfined, with numerous 
karst features throughout. A confining layer is defined in this study 
as a layer of material that is not very permeable to ground water flow 
and that overlays an aquifer and acts to prevent water movement into 
the aquifer.
    The US Geological Survey, working with the Missouri Department of 
Natural Resources, selected a total of 109 wells, in both unconfined 
and confined aquifers (Davis and Witt, 1998, 1999). In order to 
eliminate poorly constructed wells from the study, most of the selected 
wells had been constructed within the last 15 years. Wells were also 
selected to obtain good coverage of the aquifer and to reflect the 
variability in land use. All wells were sampled twice, in summer and 
winter. Evidence of fecal contamination was found in a number of wells. 
Thirteen wells had samples that were PCR-positive for enterovirus.
4. Missouri Ozark Aquifer Study #2
    The purpose of this study is to determine the water quality in 
older (pre-1970) CWS wells in the Ozark Plateau region of Missouri to 
supplement the Missouri Ozark Aquifer Study #1, by Davis and Witt 
(1998, 1999). This largely rural region is characterized by carbonate 
aquifers, both confined and unconfined, with numerous karst features 
throughout.
    The US Geological Survey, working with the Missouri Department of 
Natural Resources, sampled a total of 106 wells (Femmer, 1999), in both 
unconfined and confined aquifers. Wells (all of which were constructed 
before 1970) were selected for monitoring to obtain good coverage of 
the aquifer, and to reflect the variability in land use. Priority was 
given to wells that had completion records, well operation and 
maintenance history and wells currently being used. Each well was 
sampled once (during the spring). No wells were enterovirus-positive by 
cell culture.
5. Missouri Alluvial Aquifer Study
    The purpose of this study was to determine water quality in wells 
located in areas that were subjected to recent flooding. The wells are 
located primarily in the thick, wide alluvium of the Missouri and 
Mississippi rivers. Sampling (117 samples) occurred during the period 
of March through June 1996. Twelve wells served as control wells 
(uncontaminated) and were sited in ``deep rock'' aquifers or upland 
areas. A total of 64 wells were sampled.
    Many of the wells had been flooded. Fifty-five were affected by a 
flood in 1995. In addition, some of the wells sampled had been flooded 
around the surface well casing prior to the sampling event, and several 
were flooded at the time of sampling (Vaughn, 1996).
6. Wisconsin Migrant Worker Camp Study
    The purpose of this study was to determine the quality of drinking 
water in the 21 public ground water systems serving migrant worker 
camps in Wisconsin (US EPA, 1998a). These transient, non-community 
water systems are located in three geographic locations across the 
State. Each well was sampled monthly for six months, from May through 
November, 1997. The study conducted sampling for male-specific 
coliphage, total coliforms and E. coli. When detections of coliforms 
occurred, the specific type of coliform was further identified 
(speciated). One total coliform positive sample was identified to 
contain Klebsiella pneumoniae. Along with the microbial indicators, 
nitrate and pesticides were also measured.
    Other factors were compared to the microbial and chemical sampling 
results of the study. Well construction records were available for 14 
of the wells. The mean casing depth was 109 feet (range 40 to 282 feet) 
and the mean total well depth was 155 feet (range 44 to 414 feet). Most 
of these 14 wells are also reported to terminate in a sand or sandstone 
formation.
    Investigators detected male-specific coliphage in 20 of 21 wells 
during the six-month sampling period, but never detected E. coli. In 
addition, four wells had nitrate levels that exceeded the EPA MCL for 
nitrate.
7. EPA Vulnerability Study
    The purpose of this study was to conduct a pilot test of a new 
vulnerability assessment method by determining whether it could predict 
microbial monitoring results (U.S. EPA 1998b). The vulnerability 
assessment assigned low or high vulnerability to wells according to 
their hydrogeologic settings, well construction and age, and distances 
from contaminant sources. A total of 30 wells in eight States were 
selected to represent ten hydrogeologic settings. Selection was based 
on the following criteria: (1) Wells representing a variety of 
conditions relevant to the vulnerability predictions; (2) wells with 
nearby sources of potential fecal contamination; and (3) wells with 
sufficient well and hydrogeologic information available.
    Samples were taken and tested for enteroviruses (both by cell 
culture and PCR), hepatitis A virus (HAV) (by PCR), rotavirus (by PCR), 
Norwalk virus (by PCR), and several indicators (total coliforms, 
enterococci, male-specific coliphage, and somatic coliphage). The only 
positive result was one PCR sample positive for HAV.
8. US-Mexico Border Study
    The purpose of this study was to determine water quality in wells 
sited in alluvium along the Rio Grande River between El Paso, Texas and 
the New Mexico border (U.S. EPA, in preparation). The 17 wells selected 
were perceived to be the most vulnerable, based on well depth, chloride 
concentration and proximity to contamination sources, especially the 
Rio Grande River.
    The wells tested are relatively shallow and all serve less than 
10,000 people. One well serves 8,000 people, while seven wells serve 
fewer than 100 people. Well depths range from 65 feet to 261 feet, but 
most are about 150 feet deep. This signifies that water was collected 
from the middle aquifer, a shallow but potable aquifer. Wells shallower 
than 65 feet contain chloride concentrations prohibitively high for 
drinking water.
    Samples were collected from each well and tested for enteroviruses 
(by cell culture), somatic coliphage, and male-specific coliphage. None 
of the sites were positive for any of the viruses tested.
9. Whittier, CA, Coliphage Study
    The purpose of this study was to determine the presence of fecal 
contamination in all wells located within 500 feet down-gradient of a 
water recharge infiltration basin (Yanko et al., 1999). The 23 wells 
were sampled once per month for six months.
    The wells are sited in similar hydrogeologic settings, although 
they vary in age and depth. The hydrogeologic setting is primarily a 
thick layer of unconsolidated sand, with lesser amounts of other sized 
grains. About 30% of the recharge volume to

[[Page 30210]]

the wells is reclaimed water. Wells were all constructed between 1919 
and 1989 and produce water from depths ranging from 60-888 feet.
    The wells were sampled monthly for a six month period. The samples 
were tested for total coliforms and indicators of fecal contamination, 
including male specific coliphage, somatic coliphage, and E. coli. 
Coliphage were found in all wells, and repeatedly in 20 of the 23 
wells.
10. Oahu, HI Study
    The purpose of this study was to establish a water quality 
monitoring program to assess the microbial quality of deep ground water 
used to supply Honolulu (Fujioka and Yoneyama, 1997). A total of 71 
wells were sampled, 32 of which were sampled for viruses and 39 of 
which were sampled for bacteria. The wells are located in carbonate or 
basalt aquifers.
    Each of the wells was tested for several pathogens and indicators 
of fecal contamination. Bacterial samples taken from 39 wells (79 
samples) were tested for total coliforms, fecal streptococci, 
Clostridium perfringens, heterotrophic bacteria (by m-HPC), and 
Legionella (by PCR). Sample volumes were 100 mL for C. perfringens and 
heterotrophic bacteria, and both 100 mL and 500 mL for coliforms and 
fecal streptococci. For FRNA coliphage (male-specific coliphage), one 
liter samples from 32 wells (35 samples) were tested by membrane 
adsorption-elution method, while 24 wells (24 samples) were tested by 
an enrichment technique developed by Yanko. None of the wells were 
coliphage-positive, and only one sample each was positive for E. coli 
and fecal streptococci.
11. New England Study
    The purpose of this study was to: (1) Determine the prevalence of 
enteric pathogens in New England's public water supply wells; (2) 
assess the vulnerability of different systems; and (3) evaluate various 
fecal indicators.
    Wells were selected based on the following criteria: (1) Must have 
constant withdrawal throughout the year; (2) must be near septic 
systems, (3) should have, if possible, a history of violations of the 
MCL for total coliforms or elevated nitrate levels; and (4) must not 
have direct infiltration by surface water (Doherty, 1998).
    Wells were nominated, characterized, selected and sampled by 
regulatory staff of Connecticut, Maine, Massachusetts, New Hampshire, 
Rhode Island, and Vermont. The selection process considered wells in 
different hydrogeologic settings. Of the 124 total wells, 69 (56%) were 
located in unconfined aquifers, 31 (25%) were located in bedrock 
aquifers, 10 (8%) were located in confined aquifer hydrogeologic 
settings, and 14 (11%) were located in unknown aquifer settings. Each 
well was sampled quarterly for one year. Enterococci were identified in 
20 of 124 wells (16%) and in 6 of 31 (19%) bedrock aquifer wells. Two 
wells were enterovirus-positive using cell culture methods, both in 
unconsolidated aquifers. One of these two wells is 38 feet deep and the 
other well is 60 feet deep. Final results from this study are not yet 
available.
12. California Study
    The purpose of this research is two-fold: (1) To assess the 
vulnerability of ground water to viral contamination through repeated 
monitoring, and (2) to assess the potential for bacteria and coliphages 
to serve as indicators of the vulnerability of ground water to viral 
contamination (Yates 1999).
    Eighteen wells were tested monthly for human enteroviruses (by cell 
culture (direct RT-PCR, Immunomagnetic separation reverse transcriptase 
(IMS-RT-PCR) and integrated cell culture RT-PCR) and PCR), HAV (by 
PCR), rotaviruses (by PCR), somatic and male-specific coliphage, and 
total coliforms and fecal streptococci. The depth of the wells is 
variable, but is on the order of about 200 feet (the deeper the well, 
the less likely contamination). There are some intermittent confining 
layers.
    Of the 230 samples tested for enteroviruses, 6 samples from 6 of 
the 18 wells were cell culture positive for enteroviruses. Final 
results from this study are not yet available.
13. Three State PWS Study (Wisconsin, Maryland and Minnesota)
    The purpose of the three-state study is to characterize the extent 
of viral contamination in PWS wells by testing wells in differing 
hydrogeologic regions and considering contamination over time 
(Battigelli, 1999). Wells were sampled quarterly for one year in 
Wisconsin (25 wells), Minnesota (25 wells), and will be sampled in 
Maryland (up to 35 wells).
    Three wells in Wisconsin were positive for enteroviruses by cell 
culture. Final results for this study are not yet available.

                         Table II-6.--Ground Water Microbial Occurrence Studies/Surveys
----------------------------------------------------------------------------------------------------------------
                                                                                             Pathogenic viruses,
                                                                      Indicators monitored   Legionella (number
                                Number of PWS    Sampling frequency/     (number of POS.    of POS. wells/number
            Study               wells sampled          volume            wells/number of       of wells total,
                                 and location                          wells total, unless    unless otherwise
                                                                      otherwise indicated)       indicated)
----------------------------------------------------------------------------------------------------------------
1. AWWARF Study..............  448 wells; 35    Sampled once (25      Male-sp. coliphage,   Cell Culture:
                                States.          wells sampled         host Salmonella WG-   Enterovirus (21/
                                                 twice); 539 samples   49 (42/440);          442); PCR:
                                                 total, not all        Somatic coliphage,    Rotavirus (62/425),
                                                 analyses conducted    host E. coli C (18/   Hepatitis A virus
                                                 on all samples.       444); Coliphage,      (31/429), Norwalk
                                                 Sampling volumes:     host E. coli C-3000   virus (3/312),
                                                 1512L eluated for     (48/444); Total       Enterovirus (68/
                                                 virus analyses (5     coliform (44/445);    427).
                                                 liter equivalent      enterococci (31/
                                                 for RT-PCR, 600L      355); C.
                                                 for cell culture),    perfringens (1/57).
                                                 Coliphage 15L,
                                                 Bacteria 200 mL.
2a. EPA/AWWARF Phase I Study.  94 wells; 22     One sample, 1 L.....  Somatic coliphage 5/  ....................
                                States plus PR                         94; 1*; Total
                                and USVI.                              coliform 31/94; 9*;
                                                                       E. coli 18/94; 5*;
                                                                       enterococci 17/94;
                                                                       3*; C. perfringens
                                                                       4/94; 0*;
                                                                       *indicates number
                                                                       of wells positive
                                                                       in Phase I which
                                                                       were not positive
                                                                       or not sampled in
                                                                       Phase II.

[[Page 30211]]

 
2b. EPA/AWWARF--Phase II       30, of which 23  Monthly for one       Somatic coliphage     Cell Culture:
 Study.                         were from        year; Average         (16/30); Male         Enterovirus (7/30);
                                Phase I; 17      volume filtered:      specific coliphage    PCR: polio, entero,
                                States plus PR   6,037 L;              (6/30); Bacteroides   Hepatitis A,
                                and USVI.        Microscopic           bacteriophage (6/     Norwalk, rota
                                                 Particulate           30); Somatic          (results not
                                                 Analysis (MPA) data   Salmonella            available), (300+
                                                 available for each    bacteriophage (6/     samples from 30
                                                 well.                 30); Total coliform   wells; several
                                                                       (24/30);              wells cell culture
                                                                       enterococci (21/      positive multiple
                                                                       30); C.               times); Legionella
                                                                       perfringens(10/30);   sp. (14/30),
                                                                       E. coli (15/30); E.   Legionella
                                                                       coli H7:O157 (0/7).   pneumophila (6/30).
3. Missouri Ozark Plateau      109 wells......  Two samples/well, 25  Somatic coliphage (1/ Cell Culture:
 Study #1 (Davis and Witt,                       wells sampled once    109); Male specific   Enterovirus (0/
 1999).                                          for tritium, 200-     coliphage (10/109);   109); PCR:
                                                 300 L ground water    Fecal streptococci    Enterovirus (13/
                                                 filtered at the       (1/109); Fecal        109).
                                                 well head.            coliform (2/109);
                                                                       E. coli (0/109).
4. Missouri Ozark Plateau      106 wells......  One sample, 200-300   Somatic coliphage (3/ Study in progress;
 Studies #2 (Femmer, 1999)                       L filtered at the     106); Male specific   Cell Culture:
 (pre-1970 wells).                               well head.            coliphage (3/106);    Enterovirus (0/
                                                                       Fecal streptococci    106).
                                                                       (8/106); Fecal
                                                                       coliform (8/106);
                                                                       E. coli (9/106).
5. Missouri Alluvial Study...  64 wells.......  Sampling occurred     Somatic coliphage (1/ Cell Culture:
                                                 during a four month   81); Male specific    Enterovirus (1//
                                                 period. Some          coliphage (1/81);     81).
                                                 sampling done         Bacteroides
                                                 during flooding.      bacteriophage (1/
                                                                       81); Total coliform
                                                                       (33/81); Fecal
                                                                       coliform (5/81);
                                                                       Fecal streptococci
                                                                       (12/81).
6. Wisconsin Migrant Worker    21 wells.......  Monthly: Bacteria--6  Male specific         ....................
 Camp Study.                                     mos.; Phage--5        coliphage (20/21);
                                                 mos.; Bacteria--100   Total coliform (14/
                                                 mL; Phage--1L.        21); E. coli (0/
                                                                       21); K. pneumoniae
                                                                       (1/21).
7. EPA Vulnerability Study...  30 wells in 8    Each well visited     Male specific         Cell Culture:
                                States.          once. Two 1L grab     coliphage (0/30);     enterovirus (0/30);
                                                 samples and 1500-L    Somatic coliphage     PCR: HAV (1/30),
                                                 sample Equiv. vol.    (2/24; large          Rota (0/30),
                                                 650L for              volume); Total        Norwalk (0/30),
                                                 enterovirus, 100 mL   coliform (4/30);      enterovirus (0/30).
                                                 for bacteria, 10 mL   enterococci (0/30).
                                                 to 100L for
                                                 coliphage, PCR?.
8. US-Mexico Border Study (TX  17 wells.......  3 (300-1000 gallon)   Male specific         Cell Culture:
 and NM).                                        samples/well.         coliphage (0/17);     Enterovirus (0/17).
                                                                       Somatic coliphage
                                                                       (0/17).
9. Whittier, CA, Coliphage     23 wells.......  Once a month for 6    Male specific         ....................
 Study.                                          months; 4L samples.   coliphage (18/23);
                                                                       Somatic coliphage
                                                                       (23/23); Total
                                                                       coliform (4/23); E.
                                                                       coli (0/23).
10. Oahu, Hawaii Study.......  Virus--32 wells  Each well sampled 1-  Male specific         Legionella sp. (PCR;
                                Bacteria--39     4 times; total 79     coliphage (0/32);     15/26), Legionella
                                wells.           samples, Virus--1-    Somatic coliphage     pneumophila (PCR; 1/
                                                 L; C. perfringens,    (0/32); Total         27).
                                                 HPC--0.1L;            Coliform (3/39); E.
                                                 Coliforms, fecal      coli (1/39); Fecal
                                                 strep--0.1L and       Streptococci (1/
                                                 0.5L.                 39); C. perfringens
                                                                       (0/39).
11. New England Study........  124 wells; 6     Each well sampled     Study in progress;    Study in progress;
                                States.          four times over one   Male specific         Cell Culture:
                                                 year; Up to 1500-L    coliphage (4/79);     Enterovirus (2/
                                                 sample for virus.     Somatic coliphage     122); PCR:
                                                                       (1/70); Total         Enterovirus
                                                                       coliform (27/124);    (results not
                                                                       Aeromonas             available).
                                                                       hydrophila (19/
                                                                       122); C.
                                                                       perfringens (6/
                                                                       119); E. coli (0/
                                                                       124); enterococci
                                                                       (20/124).
12. California Study.........  18 wells.......  14 of 18 wells        Study in progress;    Study in progress;
                                                 sampled 12 to 22      Male specific         Cell Culture:
                                                 times (monthly);      coliphage: (hosts     enterovirus (6/18);
                                                 Average sample        E. coli FAMP, S.      PCR: HAV (0/18),
                                                 volume 1784 L         typhimurium WG-49)    Rota (0/18),
                                                 (range 240-3331 L)    (4/18); Somatic       enterovirus (direct
                                                 1 l grab sample for   coliphage: host E.    RT-PCR) (6/18), IMS-
                                                 indicators;           coli 13706 (13/18);   RT-PCR (10/18),
                                                 (Coliphage analyzed   Total coliform (7/    Integrated Cell
                                                 using 10 mL grab      18); Fecal            Culture PCR
                                                 samples, 1-L          streptococci (0/18).  enterovirus (4/
                                                 enrichment samples,                         18)).
                                                 IMDS filter eluates
                                                 and filter
                                                 concentrates).
13. Three-State Study          50 wells (25     Each well sampled     Study in progress;    Study in progress;
 (Wisconsin, Maryland,          from MN, 25      four times over one   Somatic coliphage;    Cell Culture:
 Minnesota).                    from WI,         year.                 Male specific         enterovirus (3/25).
                                additional                             coliphage; Total
                                wells from MD).                        coliform;
                                                                       enterococci; C.
                                                                       perfringens; E.
                                                                       coli.
----------------------------------------------------------------------------------------------------------------


[[Page 30212]]

D. Health Effects of Waterborne Viral and Bacterial Pathogens

    To assess the public health risk associated with a waterborne 
pathogen, or group of pathogens, both occurrence data and health 
effects data are needed. The previous section discussed the occurrence 
in ground water of pathogens and indicators of fecal contamination. 
This section discusses the health effects associated with waterborne 
pathogens, first viral agents and then bacterial.
Viral Pathogens
    Table II-7 and II-8 list viral and bacterial pathogens that have 
caused waterborne disease in ground waters. Unlike some bacterial 
pathogens, viruses cannot reproduce or proliferate outside a host cell. 
Viruses that infect cells lining the human gut are enteric viruses. 
With a few exceptions, viruses that can infect human cells typically 
cannot infect the cells of other animals and vice versa. This contrasts 
with many bacterial pathogens, which often have a broader host range. 
Some enteric viral pathogens associated with water may infect cells in 
addition to those in the gut, thereby causing mild or serious secondary 
effects such as myocarditis, conjunctivitis, meningitis or hepatitis. 
There is also increasing evidence that the human body reacts to foreign 
invasion by viruses in ways that may also be detrimental. For example, 
one hypothesis for the cause of adult onset diabetes is that the human 
body, responding to coxsackie B5 virus infection, attacks pancreatic 
cells in an auto-immune reaction as a result of similarities between 
certain pancreas cells and the viruses (Solimena and De Camilli, 1995).
    When humans are infected by a virus that infects gut cells, the 
virus becomes capable of reproducing. As a result, humans shed viruses 
in stool, typically for only a short period (weeks to a few months). 
Shedding often occurs in the absence of any signs of clinical illness. 
Regardless of whether the virus causes clinical illness, the viruses 
being shed may infect other people directly (by person-to-person 
spread, contact with infected surfaces, etc.) and is referred to as 
secondary spread. Waterborne viral pathogens thus may infect others via 
a variety of routes.

       Table II-7.--Some Illnesses Caused by Fecal Viral Pathogens
------------------------------------------------------------------------
             Enteric virus                           Illness
------------------------------------------------------------------------
Poliovirus.............................  Paralysis.
Coxsackievirus A.......................  Meningitis, fever, respiratory
                                          disease.
Coxsackievirus B.......................  Myocarditis, congenital heart
                                          disease, rash, fever,
                                          meningitis, encephalitis,
                                          pleurodynia, diabetes melitis,
                                          eye infections.
Echovirus..............................  Meningitis, encephalitis, rash,
                                          fever, gastroenteritis.
Norwalk virus and other caliciviruses..  Gastroenteritis.
Hepatitis A virus......................  Hepatitis.
Hepatitis E virus......................  Hepatitis.
Small round structured viruses           Gastroenteritis.
 (probably caliciviruses).
Rotavirus..............................  Gastroenteritis.
Enteric Adenovirus.....................  Respiratory disease, eye
                                          infections, gastroenteritis.
Astrovirus.............................  Gastroenteritis.
------------------------------------------------------------------------
(Data from the 1994 Encyclopedia of Microbiology, Underlineindicates
  disease causality rather than association)(Lederberg, 1992).

Bacterial Pathogens

    Bacterial pathogens may be primary pathogens (those that can cause 
illness in most individuals) or secondary or opportunistic pathogens 
(those that primarily cause illness only in sensitive sub-populations). 
Unlike most primary pathogens, some opportunistic bacterial pathogens 
can colonize and grow in the biofilm in water system distribution 
lines. Some waterborne bacterial agents cause disease by rapid growth 
and dissemination (e.g., Salmonella) while others primarily cause 
disease via toxin production (e.g., Shigella, E. coli O157, 
Campylobacter jejuni). Campylobacter, E. coli and Salmonella have a 
host range that includes both animals and humans; Shigella is 
associated with humans and some other primates (Geldreich, 1996). As 
noted previously, some waterborne bacterial pathogens can survive a 
long time outside their hosts.
    Most of the waterborne bacterial pathogens cause gastrointestinal 
illness, but some can cause severe illness too. For example, Legionella 
causes Legionnaires Disease, a form of pneumonia that has a fatality 
rate of about 15%. It can also cause Pontiac Fever, which is much less 
severe than Legionnaires Disease, but causes illness in almost everyone 
exposed. A few strains of E. coli can cause severe disease, including 
kidney failure. One strain, E. coli O157:H7 has caused several 
waterborne disease outbreaks since 1990. It is a prime cause of bloody 
diarrhea in infants, and can cause hemorrhagic colitis (severe 
abdominal cramping and bloody diarrhea). In a small percentage of 
cases, hemorrhagic colitis can lead to a life-threatening complication 
known as hemolytic uremic syndrome (HUS), which involves destruction of 
red blood cells and acute kidney failure. From 3% to 5% of HUS cases 
are fatal (CDC, 1999), and most commonly found in young children and 
the elderly. Some of the opportunistic pathogens can also cause a 
variety of illnesses including meningitis, septicemia, and pneumonia 
(Rusin et al., 1997).

    Table II-8.--Some Illnesses Caused by Major Waterborne Bacterial
                                Pathogens
------------------------------------------------------------------------
           Bacterial pathogen                       Illnesses
------------------------------------------------------------------------
Campylobacter jejuni...................  Gastroenteritis, meningitis,
                                          associated with reactive
                                          arthritis and Guillain-Barre
                                          paralysis.
Shigella species.......................  Gastroenteritis, dysentery,
                                          hemolytic uremic syndrome,
                                          convulsions in young children,
                                          associated with Reiters
                                          Disease (reactive
                                          arthropathy).
Salmonella species.....................  Gastroenteritis, septicemia,
                                          anorexia, arthritis,
                                          cholecystitis, meningitis,
                                          pericarditis, pneumonia,
                                          typhoid fever.

[[Page 30213]]

 
Vibrio cholerae........................  Cholera (dehydration and kidney
                                          failure).
Escherichia coli (several species).....  Gastroenteritis, hemolytic
                                          uremic syndrome (kidney
                                          failure).
Yersinia entercolitica.................  Gastroenteritis, acute
                                          mesenteric lymphadenitis,
                                          joint pain.
Legionella species.....................  Legionnaires Disease, Pontiac
                                          Fever
------------------------------------------------------------------------
(Data from the 1994 Encyclopedia of Microbiology, Underline indicates
  disease causality rather than association)(Lederberg, 1992).

E. Risk Estimate

1. Baseline Risk Characterization
    This section provides an estimate of the number of people that may 
be at risk of microbial illness associated with consumption of fecally 
contaminated drinking water in populations served by ground water 
systems. EPA has prepared estimates of the numbers of people at risk of 
viral illness (and possibly death) from three conditions in which fecal 
contamination may be introduced to ground water systems: fecal 
contamination in the source water of systems without disinfection; 
fecal contamination in the source water of systems with inadequate 
(less than 4-log as discussed later) or failed disinfection; and fecal 
contamination of the distribution system.
    The first condition in which EPA characterizes the baseline risk is 
for source contaminated ground water systems which do not have 
disinfection treatment. EPA characterizes the risk to consumers in 
these systems in five steps: (1) Calculating the population served by 
undisinfected systems using ground water sources; (2) determining the 
occurrence of the pathogens of concern in these systems; (3) assessing 
the exposure to the pathogens of concern; (4) determining the 
pathogenicity (likelihood of infection) based on dose-response 
information for each of the pathogens characterized; and (5) 
calculating the number of illnesses among the population served 
resulting from consumption of water containing the pathogens.
    EPA then estimates additional illnesses resulting from systems with 
inadequate or failed disinfection treatment and fecally contaminated 
source water, and systems in which fecal contamination is introduced 
into the distribution system. These additional illnesses are estimated 
based on the causes of contamination which lead to waterborne disease 
outbreaks reported to the CDC in ground water systems from 1991 to 
1996. To estimate these additional illnesses, EPA calculated the ratio 
of the outbreak illnesses in systems with inadequate or failed 
disinfection treatment to outbreak illnesses in systems without any 
disinfection, and the ratio of outbreak illnesses in systems with 
distribution system contamination to outbreak illnesses in systems 
without any disinfection.
2. Summary of Basic Assumptions
    This risk assessment uses a number of assumptions to arrive at an 
estimate of the number of people at risk of illness or death due to 
consumption of water from systems with fecal contamination. Some of 
these assumptions are necessary because data in these areas simply does 
not exist.
    The feasibility of performing a risk analysis on each and every 
microbial contaminant is diminished when considering the wide range of 
different microbial contaminants that exist, and that detection methods 
for all of these contaminants do not exist. Therefore, the risk 
assessment assumes that the only people exposed to viral contamination 
are the people served by those wells which test positive for the two 
viruses used in the risk assessment model, and the exposed population 
will be exposed to the virus concentration throughout the entire year. 
The assumption that the population is exposed only to viruses which are 
accurately described by the model viruses may lead to an 
underestimation of exposure.
    The model viruses which were chosen to act as surrogates for all 
viruses fall into two categories; those viruses which have low-to-
moderate infectivity but relatively severe health effects, and those 
viruses which have high infectivity but relatively mild health effects. 
Exposure to viruses that do not fall into these categories may result 
in an underestimate or overestimate of risk. Risks are not directly 
quantified for bacterial contaminants because EPA does not have 
sufficient data to directly model bacterial risk. However, EPA has 
adjusted its risk estimate for viral illness to approximate for the 
risk of bacterial illness.
    The simplifying assumptions used in this risk assessment, as well 
as assessing the exposure in only the positive wells, yields an 
estimated average risk that EPA assumes is a best estimate of the 
actual risk given available data.
3. Population Served by Untreated Ground Water Systems
    EPA estimates there are 44,000 community ground water systems (CWS) 
serving 88 million people; 19,000 non-transient, non-community ground 
water systems (NTNCWS) serving five million people; and 93,000 
transient non-community ground water systems (TNCWS) serving 15 million 
people (SDWIS, 1997a). Of these systems, EPA estimates that 68% percent 
of CWSs are disinfected (CWSS, 1997) (US EPA, 1997c). Larger CWSs are 
more likely to practice disinfection than are smaller CWSs (e.g., 81% 
of CWSs serving more than 100,000 people are disinfected while 45% of 
systems serving less than 100 people disinfect. Estimates of treatment 
for noncommunity water systems are not as detailed. However, based upon 
information from State drinking water programs, EPA estimates 28% of 
NTNCWS and 18% of TNCWS disinfect (US EPA, 1996a).
    Based upon the number of people served by ground water systems, and 
the percentage of systems which disinfect, EPA estimates that 18 
million people are served untreated ground water from CWSs, four 
million people are served untreated water from NTNCWSs, and 13 million 
people are served untreated water from TNCWSs. There is a potential for 
double or triple counting of the same people within these estimates 
since a number of people may be served ground water from more than one 
of the system type categories. For example, a person may consume water 
from a CWS at home, and a NTNCWS at work or a TNCS while on vacation. 
EPA has addressed the potential for double counting in the analysis by 
assuming that individuals do not consume water from each system type 
every day (see section V).
4. Pathogens Modeled
    EPA is concerned about ground water systems which are fecally 
contaminated since drinking water in these systems may contain 
pathogenic viruses and/or bacteria. A wide number of viral and 
bacterial pathogens have been associated with waterborne disease in 
ground water systems. However, there are inadequate data for EPA to

[[Page 30214]]

characterize the risk attributable to each pathogen because detection 
methods are not available for all pathogens. Additionally, detection 
methods which are available may be insensitive and incapable of 
detecting the presence of viruses at very low concentrations. However, 
even at low concentrations, viruses in drinking water can result in 
infection. To the extent that detection methods do not exist for a 
particular pathogen, there may be a resultant underestimation of the 
risk of illness and death.
    In this analysis, EPA estimates the number of illnesses annually 
associated with two types of pathogenic viruses found in fecally 
contaminated ground water. These two types of viruses are designated as 
Type A and Type B viruses for this analysis. Type A viruses represent 
those viruses which are highly infective, yet have relatively mild 
symptoms (e.g., gastroenteritis). For this analysis, rotavirus is used 
as a surrogate for all Type A viruses because rotavirus has been 
detected in drinking water sources, dose-response data have been 
prepared for rotavirus and rotavirus has been implicated as the 
etiologic agent in incidents of waterborne disease. Type B viruses 
represent those viruses which have low-to-moderate infectivity, yet 
have potentially more severe symptoms (e.g., myocarditis), and are 
represented by echovirus. Echovirus also has available dose-response 
data (Regli et al, 1991) and has been implicated in a waterborne 
disease outbreak (Haefliger et al., 1998).
    The risk assessment used model viruses as surrogates of the actual 
viruses present. As a result, the risk assessment provides an 
estimation of risks. The additional risks from other viruses may be 
higher or lower depending on their occurrence or pathogenicity. For 
example, if the risk assessment estimated the risks from exposure to 
Norwalk virus (a Type A virus), using rotavirus as a surrogate, the 
morbidity rate may be higher for adults than the rate assumed in the 
model. An outbreak in an Arizona resort in 1989 was believed to be 
caused by a Norwalk-like virus. This agent may have been responsible 
for an outbreak which caused illness in 110 out of 240 guests of all 
ages (Lawson et al, 1991), a 46% morbidity rate. This is much higher 
than the morbidity rate of 10% for Type A virus among people older than 
two. National occurrence data do not exist for many of the other 
pathogens that may occur in drinking water; therefore, EPA has limited 
its estimation of risk to only those viral pathogens for which 
occurrence data and dose response data are available.
    Occurrence studies show a significant occurrence of bacterial 
indicators in ground water wells; for example, almost 9% percent of the 
wells sampled in the AWWARF study tested positive for the presence of 
enterococci (Abbaszadegan et al., 1999). However, EPA cannot directly 
estimate national illnesses from bacterial pathogens such as 
Salmonella, due to a lack of occurrence data for those pathogens. EPA 
believes that the majority of waterborne illnesses due to unknown 
etiological agents are caused by viruses because viruses move more 
readily in the ground, remain viable longer and are more infectious 
than bacteria. Also, more methodologies exist for the identification of 
bacterial pathogens than for viral pathogens and therefore bacterial 
pathogens are more likely to be identifiable. The CDC data shows that 
for every 100 viral or unknown etiological agent illnesses there were 
20 bacterial illnesses. Therefore, EPA estimates that the number of 
viral illnesses can be increased by 20% to account for bacterial 
illnesses in ground water systems.
5. Microbial Occurrence and Concentrations
    EPA reviewed the ground water viral occurrence data (see discussion 
of occurrence studies in section II. C.) to develop estimates of: the 
portion of ground water sources which are contaminated with viruses, 
the period of time in which the wells are contaminated, and the 
concentration of viruses within the contaminated wells. EPA believes 
that improperly constructed wells may have significantly higher virus 
occurrence and concentrations than properly constructed wells (wells 
which do not comply with State well construction codes). Improperly 
constructed wells are likely to have more pathways for the introduction 
of viruses and less natural filtration by the overlying hydrogeologic 
material. Therefore, the exposure and risks from consumption of water 
from improperly constructed wells will most likely be higher. As a 
result, the exposure and risks should be assessed separately for 
properly and improperly constructed wells in order to develop a range 
reflecting national conditions.
    EPA determined that the study conducted by AWWARF represents 
conditions in properly constructed wells and the EPA/AWWARF (Lieberman 
et al., 1994, 1999) study represents conditions in improperly 
constructed wells. EPA selected the AWWARF study as representative of 
properly constructed wells (e.g., wells with casing and grout to 
confining layers, sanitary seals, etc.) because it excluded wells of 
improper construction and the wells sampled were representative of 
hydrogeologic conditions for water supply wells in the United States. 
However, the wells selected may not have been representative of the 
probability of fecal contamination in ground water wells nationally. As 
noted in section II.C.1., one-third of the wells in this study were 
originally selected for the purpose of evaluating the effectiveness of 
the PCR method based on criteria that may over represent high risk 
wells. The remaining two-thirds were selected to balance the sample 
with wells that were representative of hydrogeologic conditions for 
drinking water wells nationally. EPA requests comment and data which 
would help assess the representativeness of the wells in the AWWARF 
study sample. However, EPA believes that the AWWARF study data 
represents the best currently available data on occurrence of viral 
pathogens in properly constructed wells and has thus used it as the 
basis of baseline incidence estimates.
    EPA selected the EPA/AWWARF study to be representative of wells of 
improper construction because it sampled wells which were determined to 
be vulnerable to contamination. The EPA/AWWARF study considered wells 
as vulnerable based on one or more of the following considerations: 
hydrogeology, well construction, State nominations, microbial sampling 
results, close proximity to known sources of fecal contamination, and 
water quality history. For the purposes of the risk assessment, all 
wells determined to be vulnerable were used as surrogates for 
improperly constructed wells. The results from this study may over 
estimate the risks from improperly-constructed wells generally, since 
it included only wells that were deliberately selected through a 
several step process to be highly vulnerable to contamination (see 
section II.C.2.). EPA estimated that 83% of systems have properly 
constructed wells based upon data from ASDWA's Survey of Best 
Management Practices for Community Ground Water Systems (ASDWA, 1998).
    The AWWARF study data include viral cell culture assay results 
which detect the presence of viable enterovirus (including echovirus 
and other Type B viruses) in the samples. Twenty-one of the 442 wells 
sampled (4.8%) tested positive for the Type B viral cell culture. EPA 
determined that this data can be used to estimate the percentage of 
properly constructed wells which are contaminated at a given point in 
time with Type B viruses. The AWWARF

[[Page 30215]]

study data also include rotavirus PCR results which indicate that 62 of 
the 425 (14.6%) wells sampled contained rotavirus genetic material. EPA 
determined that the PCR results may be an overestimation of the portion 
of wells with viable Type A viruses since PCR methods do not 
distinguish between viable and non-viable viruses. To calculate the 
portion of PCR positive wells which contain viable viruses EPA compared 
the enterovirus (Type B) cell culture results to the enterovirus (Type 
B) PCR analysis and found that for every enterovirus cell culture 
positive well, there were 3.3 PCR enterovirus positive wells. EPA 
estimated that the 1/3.3 rotavirus PCR wells contained viable virus, 
and therefore 4.4% (14.6%/3.3) of all properly constructed wells were 
contaminated with Type B viruses at any one time. Viral and bacterial 
indicator data indicate there are a greater percentage of wells in the 
study which were fecally contaminated than contained the viral 
pathogens at the time of sampling. For example, almost 16% of all wells 
tested positive for viral cell culture, male specific coliphage or 
enterococci.
    The EPA/AWWARF study sampled wells vulnerable to contamination 
monthly for a one year period and found that 6.0% of the samples tested 
positive for enterovirus (Type B) cell culture. Since cell culture 
methods are not available for rotavirus (the representative of Type A 
viruses), the EPA/AWWARF study tested samples using PCR methods for the 
presence of rotavirus to estimate the occurrence of Type A viruses in 
improperly constructed wells. However, the PCR data is still under 
review by researchers and unavailable for consideration in this 
analysis. EPA therefore based the estimate of occurrence of viable Type 
A viruses in improperly constructed wells on the ratio of viable Type A 
virus in the AWWARF study (4.4%) to Type B viruses in the AWWARF study 
(4.7%). Applying this ratio (4.4%/4.7%) to the percentage of improperly 
constructed wells containing Type B viruses (6.0%), EPA estimates the 
percentage of improperly constructed wells with Type A virus 
contamination is 5.5%.
    EPA estimated Type A and Type B virus concentrations are 0.36 
viruses/100L for properly constructed wells based on the mean 
enterovirus concentration in the AWWARF study. EPA also estimated Type 
A and Type B virus concentrations to be 29 viruses/100L for improperly 
constructed wells based on the mean enterovirus concentration in EPA/
AWWARF study. Although these studies determined the concentrations of 
enteroviruses (Type B viruses) only, for the purposes of this analysis 
EPA assumed the concentrations of Type A viruses and Type B viruses 
were equivalent.
6. Exposure to Potentially Contaminated Ground Water
    EPA developed estimates of the population potentially exposed to 
viral pathogens based upon the estimates of population served by 
undisinfected systems and the portions of those systems which are 
estimated to be virally contaminated. In CWS, 18 million people are 
served undisinfected ground water. Assuming 17% of wells serving these 
people are improperly constructed (and 83% are properly constructed) 
from the results of the ASDWA BMP Survey (ASDWA, 1997), and Type A 
viruses occur in 4.4% of properly constructed wells and 5.5% of 
improperly constructed wells, the population potentially exposed to 
Type A viruses in CWS is 842,000. Similar calculations can be conducted 
to obtain the population exposed to Type A viruses in NTNCWS, as well 
as Type B viruses in all ground water systems. EPA's estimates of the 
population potentially exposed to the viruses are presented in Table 
II-9. Many of the people exposed to the Type A viruses are also exposed 
to the Type B viruses, therefore these number cannot be added.

   Table II-9.--Population Potentially Exposed to Virally Contaminated
          Drinking Water in Undisinfected Ground Water Systems
------------------------------------------------------------------------
                                            Population      Population
                                            potentially     potentially
               System type                  exposed to      exposed to
                                           type A virus    type B virus
------------------------------------------------------------------------
CWS.....................................         842,000         918,000
NTNCWS..................................         175,000         191,000
TNCWS...................................         567,000         619,000
------------------------------------------------------------------------

    To estimate the risk of illness from consumption of undisinfected 
ground water, EPA estimated people consume an average 1.2 liters of 
water per day based upon the 1994-1996 USDA Continuing Survey of Food 
Intakes by Individuals (US EPA, 2000a). EPA accounted for the 
variability in consumption by modeling consumption as a custom 
distribution fit to age groups in the survey data. EPA also assumed 
that people consume water from CWSs 350 days per year; from NTNCWSs 250 
days per year; and from TNCWSs 15 days per year. EPA notes that these 
assumptions may allow for some double counting of exposure, but EPA is 
not aware of data to allow a more refined breakdown of consumption. EPA 
requests comment on these assumptions.
7. Pathogenicity
    After estimating the population potentially exposed to untreated 
(i.e., not disinfected) contaminated ground water and the amount of 
water consumed, the next step is to assess the pathogenicity of the 
viruses. Once viruses are consumed, the likelihood of infection and 
illness varies depending on the virus.
    For this analysis, the likelihood of infection from ingestion of 
one or more Type A or Type B viruses are estimated based on dose 
response equations developed for rotavirus (Ward et al., 1986) and 
echovirus (Schiff et al., 1984), respectively. These equations estimate 
the annual probability of infection following consumption of a 
specified virus and are based on studies of healthy volunteers. The 
volunteers for these studies are typically between the ages of 20 and 
50, and therefore, may underestimate the probability of infection in 
sensitive subpopulations (e.g., children and elderly) and the 
immunocompromised (e.g., nursing home residents and AIDS patients). 
Rotavirus dose-response information was used to represent Type A 
viruses, while echovirus dose-response information was used to 
represent Type B viruses.
    Once a person becomes infected, the likelihood of illness 
(morbidity) varies, depending on the pathogen and the sensitivity of 
the consumer. For Type A viruses, EPA assumed the percent of people 
becoming ill once infected is 88% for children under the age of two 
(Kapikian and Chanock, 1996). EPA assumed a morbidity rate of 10% for 
all other populations based upon a study of a rotavirus outbreak 
(Foster et al., 1980) and incidents of rotavirus in families with 
infants ill with rotavirus (Wenman et al., 1979).
    EPA assumed the percent of people infected with Type B viruses who 
become ill also varies with age: 50% for children five years of age and 
less, 57% for individuals between 5 and 16 years of age, and 33% for 
people older than 16. EPA estimated these age-specific morbidity values 
based on data from a community-wide echovirus type 30 epidemic (Hall et 
al., 1970) and from the New York Viral Watch (Kogon et al., 1969).
    Secondary illnesses result from individuals being exposed to 
individuals who contracted the illness from drinking water. For this 
analysis, EPA estimates the additional number of

[[Page 30216]]

people who become ill as a result of secondary spread. For Type A 
viruses, EPA assumed that an additional 0.55 people will become ill 
from every child that becomes ill through consumption of drinking 
water. This assumption is based on a study of children under five years 
old, ill with rotavirus, who spread the illness to others in their 
households (Kapikian and Chanock, 1996). For Type B viruses EPA assumed 
that 0.35 additional people will become ill through secondary spread. 
This assumption was based on a review of various epidemiological 
studies for echovirus (Morens et al., 1991). There is some uncertainty 
as to the exact rate of secondary spread for Type B viruses, so EPA has 
assumed that the secondary spread rates range from 0.11 to 0.55.
    The probability that an ill person will die as a result of an 
illness is referred to as mortality. EPA expects Type A viruses to 
result in far fewer deaths than Type B viruses. EPA assumed a mortality 
rate for all age groups of 0.00073 percent. This assumption was based 
on an estimate of 20 rotavirus deaths per year out of 2,730,000 cases 
of rotavirus diarrhea in children 0-4 years old (Tucker et al., 1998). 
EPA assumed the mortality rate for Type B viruses be 0.92 percent for 
infants one month or less. This assumption was based upon studies of 
hospitalized infants (Kaplan and Klein, 1983). For the rest of the 
population, EPA assumed that 0.04 percent of people ill from Type B 
viruses will die. These estimates may underestimate the number of 
infant deaths due to Type B viral illnesses, since Jenista et al. 
(1984) and Modlin (1986) reported a three percent case fatality rate 
for infants (one month or less) which is three times the value used in 
the model.
8. Potential Illnesses
    EPA estimates, based upon the assumptions described earlier, that 
98,000 viral illnesses each year are caused by consuming drinking water 
in undisinfected public ground water systems. EPA further estimates 
that nine of these people die each year.
    EPA believes there are additional waterborne illnesses and deaths 
among consumers of drinking water from public ground water systems 
beyond those estimated due to contaminated source waters in 
undisinfected systems. Between 1991 and 1996 there were 1,260 
waterborne outbreak illnesses reported to CDC which were attributed to 
microbial contamination of the source and inadequate or interrupted 
disinfection, and 944 waterborne illnesses reported to CDC which were 
attributed to distribution system contamination in ground water 
systems. In that same period there were 2,924 reported outbreak 
illnesses in source contaminated undisinfected system. This results in 
0.43 (1,260/2,924) additional illnesses in source contaminated, ground 
water systems with failed disinfection for every illness from 
undisinfected, fecally contaminated ground water. Based on similar 
analysis, there are also 0.32 (944/2,924) additional illnesses due to 
distribution system contamination for every one illness due to source 
contamination in undisinfected ground water systems. (This ratio does 
not apply to transient noncommunity water systems, because they do not 
have distribution systems.) EPA assumed the ratios of the causes of 
reported outbreak illnesses is equal to the ratio of the causes of all 
waterborne illnesses. Therefore, EPA estimates, based upon these 
ratios, that an average of 42,000 additional illnesses and four 
additional deaths occur each year as a result of source contamination 
and inadequate or interrupted disinfection. EPA also estimates that an 
average of 28,000 additional illnesses and three additional deaths are 
caused each year by distribution system contamination. Table II-10 
presents the estimates of viral illness and death under current 
conditions.

                     Table II-10.--Estimates of Baseline Viral Illness and Death Due to Contamination of Public Ground Water Systems
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           No. of type A                   No. of type B                       total
                 Cause of contamination                        virus       No. of type A       virus       No. of type B     illnesses     Total deaths
                                                             illnesses     virus deaths      illnesses     virus deaths     types A & B     types A & B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source contamination/undisinfected system...............          78,000               1          20,000               8          98,000               9
Source contamination/disinfected system.................          34,000  ..............           8,000               4          42,000               4
Distribution system contamination.......................          22,000  ..............           6,000               3          28,000               3
                                                         -----------------------------------------------------------------------------------------------
    All Causes..........................................         134,000               1          34,000              14         168,000              16
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Because of a lack of occurrence data for bacterial pathogens in 
ground water, risks from bacterial contamination of ground water 
sources and distribution systems are not quantified in this assessment. 
Although it is believed that viruses are more readily transported 
through the subsurface than bacteria (Sinton et al., 1997), ground 
water system disease outbreaks caused by bacterial pathogens such as 
Shigella, Salmonella spp., and Campylobacter spp. and E. coli O157:H7 
have been reported. For the period 1971-1996, 56 outbreaks, resulting 
in more than 10,000 illnesses and 11 deaths, were attributed to 
bacterial pathogen contamination of public ground water systems. More 
than 20% of these bacterial outbreaks occurred since 1991, and several 
outbreaks were attributed to gross fecal contamination of distribution 
lines.
    As previously stated, there may be an additional 20% of illnesses 
caused by bacterial pathogens (in the absence of viral pathogens) in 
fecally contaminated ground water. Therefore, the numbers of illnesses 
and deaths presented in Table II-10 may underestimate the true numbers 
of annual illnesses and deaths by 20% (an estimated 34,000 additional 
illnesses and three additional deaths).
9. Summary of Key Observations
    In conclusion, EPA believes that at any one point in time (most 
approximately 90 percent) ground water systems provide uncontaminated 
water. However, the risk characterization described herein indicates 
that a subset of ground water systems represent a potential risk to 
public health, which clearly supports the need to proceed with 
regulation of these systems. According to the assessment, EPA estimates 
that approximately 168,000 people are at risk to viral illness and 16 
people are at risk of death, annually. It is noted that this analysis 
focuses primarily on the potential of gastrointestinal illness caused 
by exposure to viruses, therefore; the potential for additional 
illnesses from ground water contaminated only by pathogenic bacteria 
also exists and may account for an additional 34,000 illnesses and 
three deaths annually.

[[Page 30217]]

Therefore, the estimate of illnesses represents a potential 
underestimate of the actual illnesses attributed to consumption of 
water from ground water systems. Based on this analysis EPA believes 
that risk of microbial illness exists for a substantial number of 
people served by ground water systems. Consequently, EPA believes that 
the proposed regulatory provisions discussed later provide a meaningful 
opportunity for public health risk reduction.
10. Request for Comments
    EPA seeks comment on the data, criteria and methodology used in the 
risk assessment, and where any different approaches may be appropriate. 
EPA also seeks comment on the assumptions used in this assessment, as 
well as the conclusions reached, and any additional data that 
commenters may be able to provide on occurrence, exposure, infectivity, 
morbidity, or mortality associated with microbial pathogens in ground 
water.

F. Conclusion

    In EPA's judgment, the data and information presented in previous 
sections relating to outbreaks, occurrence, adverse microbial health 
effects, exposure, and risk characterization demonstrate that there are 
contaminants of concerns that exist in ground water at levels and at 
frequencies of public health concern. Moreover, as discussed in detail 
later, the Agency believes there are targeted risk-based regulatory 
strategies that provide a meaningful opportunity to reduce public 
health risk for a substantial number of people served by ground water 
sources.
    EPA recognizes that there are particular challenges associated with 
developing an effective regulatory approach for ground water systems. 
These include first, the large number of ground water systems; second, 
the fact that only a subset of these systems appear to have microbial 
contamination (although a larger number are likely to be vulnerable); 
and third, that most ground water systems range from being small to 
very small in terms of population served. These factors combine to 
underscore the fact that a one-size-fits-all approach cannot work. This 
point was made repeatedly by participants in public stakeholder 
meetings across the country, and EPA agrees. The task therefore is to 
develop a protective public health approach which ensures a baseline of 
protection for all consumers of ground water and sets in place an 
increasingly targeted strategy to identify high risk or high priority 
systems that require greater scrutiny or further action.

III. Discussion of Proposed GWR Requirements

    The information outlined earlier indicates that the primary causes 
of waterborne related illnesses are associated with source water 
contamination and untreated ground water, source water contamination 
and unreliable treatment, water system deficiencies, and a subset of 
waterborne disease outbreaks of unknown causes. The requirements and 
options proposed today address each of these areas through a multiple-
barrier approach which relies upon five major components: periodic 
sanitary surveys of ground water systems requiring the evaluation of 
eight elements and the identification of significant deficiencies; 
hydrogeologic assessments to identify wells sensitive to fecal 
contamination; source water monitoring for systems drawing from 
sensitive wells without treatment or with other indications of risk; a 
requirement for correction of significant deficiencies and fecal 
contamination through the following actions: eliminate the source of 
contamination, correct the significant deficiency, provide an 
alternative source water, or provide a treatment which achieves at 
least 99.99 percent (4-log) inactivation or removal of viruses, and 
compliance monitoring to insure disinfection treatment is reliably 
operated where it is used.

A. Sanitary Surveys

1. Overview and Purpose
    A key element of the multiple-barrier approach is periodic 
inspection of ground water systems through sanitary surveys. According 
to the Total Coliform Rule (TCR), a sanitary survey is an onsite review 
of the water source, facilities, equipment, operation and maintenance 
of a public water system for the purpose of evaluating the adequacy of 
such source, facilities, equipment, operation and maintenance for 
producing and distributing safe drinking water (40 CFR 141.2). The 
Agency believes that periodic sanitary surveys, along with appropriate 
corrective actions, are indispensable for assuring the long-term 
quality and safety of drinking water. When properly conducted, sanitary 
surveys can provide important information on a water system's design 
and operations and can identify minor and significant deficiencies for 
correction before they become major problems. By taking steps to 
correct deficiencies exposed by a sanitary survey, the system provides 
an additional barrier to microbial contamination of drinking water.
    The Agency proposes the following sanitary survey requirements: (1) 
States, or authorized agents, conduct sanitary surveys for all ground 
water systems at least once every three years for CWSs and at least 
once every five years for NCWSs; (2) sanitary surveys address all eight 
elements set out in the EPA/State Joint Guidance on sanitary surveys 
(outlined later in this section); (3) States provide systems with 
written notification which describes and identifies all significant 
deficiencies no later than 30 days of the on-site survey; and (4) 
systems consult with the State and take corrective action for any 
significant deficiencies no later than 90 days of receiving written 
notification of such deficiencies, or submit a schedule and plan to the 
State for correcting these deficiencies within the same 90 day period; 
and (5) States must confirm that the deficiencies have been addressed 
within 30 days after the scheduled correction of the deficiencies.
    A ground water system that has been identified as having 
significant deficiencies must do one or more of the following: 
eliminate the source of contamination, correct the significant 
deficiency, provide an alternate source water, or provide a treatment 
which reliably achieves at least 99.99 percent (4-log) inactivation or 
removal of viruses before or at the first customer. Ground water 
systems which provide 4-log inactivation or removal of viruses will be 
required to conduct compliance monitoring to demonstrate treatment 
effectiveness. The ground water system must consult with the State to 
determine which of the approaches, or combination of approaches, are 
appropriate for meeting the treatment technique requirement. Ground 
water systems unable to address the significant deficiencies in 90 
days, must develop a specific plan and schedule for meeting this 
treatment technique requirement, submit them to the State, and receive 
State approval before the end of the same 90-day period. For the 
purposes of this paragraph, a ``significant deficiency'' includes, : 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.
    Sanitary surveys provide a comprehensive and accurate record of the 
components of water systems, assess the operating conditions and 
adequacy of the water system, and determine if

[[Page 30218]]

past recommendations have been implemented effectively. The purpose of 
the survey is to evaluate and document the capabilities of the water 
system's sources, treatment, storage, distribution network, operation 
and maintenance, and overall management in order to ensure the 
provision of safe drinking water. In addition, sanitary surveys provide 
an opportunity for State drinking water officials or approved third 
party inspectors to visit the water system and educate operators about 
proper monitoring and sampling procedures, provide technical 
assistance, and inform them of any changes in regulations.
    Sanitary surveys have historically been conducted by State drinking 
water programs as a preventative tool to identify water system 
deficiencies that could pose a threat to public health. In 1976, EPA 
regulations established, as a condition of primacy, that States develop 
a systematic program for conducting sanitary surveys, with priority 
given to public water systems not in compliance with drinking water 
regulations (40 CFR 142.10 (b)(2)). This primacy requirement did not 
define the scope of sanitary surveys or specify minimum criteria.
    In 1989, the TCR included a provision that requires systems that 
serve 4,100 people or less and collecting fewer than five routine total 
coliform samples per month to conduct a periodic sanitary survey every 
five years, with an exception made for NCWS that use protected and 
disinfected ground water to conduct the survey every ten years. The 
TCR, however, does not establish what must be addressed in a sanitary 
survey or how such a survey should be conducted. The responsibility is 
on the system rather than the State for completing the sanitary survey 
(40 CFR 141.21(d)(2)). The TCR requires systems to use either a State 
official or an agent approved by the State to conduct the sanitary 
survey.
    The IESWTR (63 FR 69478, December 16, 1998), established 
requirements for primacy States to conduct sanitary surveys for all 
systems using surface water or ground water under the direct influence 
of surface water. The rule also requires States to have the appropriate 
authority for ensuring that systems address significant deficiencies. 
The State must perform a survey at least once every three years for 
CWSs and every five years for NCWSs. These surveys must encompass the 
eight major areas defined by the EPA/State Joint Guidance (discussed in 
section 3).
    This GWR proposal and the IESWTR differ in the requirements for a 
system to correct any significant deficiency. In the IESWTR, States are 
specifically required to have the appropriate rules or other authority 
to require systems to respond in writing to significant deficiencies 
outlined in a sanitary survey report within at least 45 days. A system, 
under this 45-day time frame, is required to notify the State in 
writing how and on what schedule it will address significant 
deficiencies noted in the survey. This GWR proposal differs from the 
IESWTR by proposing to require ground water systems to correct 
significant deficiencies and to do so within 90 days or seek a State 
approved schedule for plans requiring longer than 90 days.
2. General Accounting Office Sanitary Survey Investigation
    In 1993, the US General Accounting Office (US GAO) investigated 
State sanitary survey practices. The US GAO found that many sanitary 
surveys were deficient, and that follow-up on major problems was often 
lacking. This investigation, which is described next, was published as 
a report, Key Quality Assurance Program is Flawed and Underfunded (US 
GAO 1993).
    US GAO was directed by Congress to review State sanitary survey 
programs due to congressional concern that many States were cutting 
back on these programs, and thus undermining public health. Congress 
asked US GAO to determine in its report whether sanitary surveys are 
comprehensive enough to determine if a water system is providing safe 
drinking water and what the results indicate about water systems 
nationwide.
    As part of this effort, GAO sent a detailed questionnaire to 49 
States to attain a nationwide perspective on whether the States were 
conducting sanitary surveys, the frequency and comprehensiveness of the 
surveys, and what the survey results indicate about the operation and 
condition of water systems. To obtain more detailed information, the 
GAO also focused on 200 specific sanitary surveys conducted on CWSs in 
four States (Illinois, Montana, New Hampshire and Tennessee). This 
information was summarized in the GAO's report (US GAO 1993). The GAO 
report presented a number of key concerns, as discussed next.
    Frequency Varies Among States and is Declining Overall. At least 36 
States had a policy to conduct surveys of CWSs at intervals of three 
years or less; however, only 21 of these States were conducting surveys 
at this frequency. The remaining 15 States reported they were unable to 
implement this policy because their inspectors had other competing 
responsibilities that often took precedence over non-mandated 
requirements (e.g., sanitary surveys). Overall, the frequencies of the 
surveys vary from quarterly to 10 years. According to the report, 
States have reduced the frequency of surveys since 1988, a downward 
trend that is expected to continue.
    Comprehensiveness of Sanitary Surveys is Inconsistent. The report 
indicates that a comprehensive sanitary survey, as recommended in 
Appendix K of EPA's SWTR Guidance Manual (US EPA, 1990b), is frequently 
not conducted. Forty-five out of 48 States omitted one or more key 
elements defined in the 1990 guidance manual. The GAO noted wide 
variation among States in the comprehensiveness of their sanitary 
surveys. Some States, for example, omit inspections of water 
distribution systems and/or other key components or operations of water 
systems, others do not provide complete documentation of sanitary 
survey results. Based on a review of the 200 sanitary surveys, survey 
results which identify deficiencies were found to be inconsistently 
interpreted from one surveyor to another. In some cases, systems' 
deficiencies that could have been detected during a comprehensive 
survey may not be found until after water quality is affected and the 
root cause(s) investigated. By that time, however, consumers may 
already have ingested contaminated water (US GAO, 1993).
    Limited Efforts to Ensure that Deficiencies are Corrected. The GAO 
found that follow-up procedures for deficiencies were weak. The 
detailed review of the four States' sanitary surveys indicated that 
deficiencies frequently go uncorrected. Of the 200 surveys examined, 
about 80% disclosed deficiencies and 60% cited deficiencies that had 
already been identified in previous surveys. Of particular concern was 
the GAO finding that smaller systems (serving 3,300 or less) are in 
greatest need of improvements. Small systems compose a significant 
majority of all ground water systems. Ninety-nine percent 
(approximately 154,000) of ground water systems serve fewer than 10,000 
people and ninety-seven percent (approximately 151,000) serve 3,300 or 
fewer people.
    Results Poorly Documented. The GAO also found variation in how 
States document and interpret survey results. Proper documentation 
would facilitate follow-up on the problems detected.
    GAO recommended EPA work with States to establish minimum criteria 
on how surveys should be conducted and documented and to develop 
procedures

[[Page 30219]]

to ensure deficiencies are corrected. This proposal addresses these 
recommendations.
3. ASDWA/EPA Guidance on Sanitary Surveys
    Recognizing the essential role of sanitary surveys and the need to 
define the broad areas that all sanitary surveys should cover, EPA and 
ASDWA prepared a joint guidance on sanitary surveys entitled EPA/State 
Joint Guidance on Sanitary Surveys (1995). The guidance identified the 
following eight broad components that should be covered in a sanitary 
survey: source, treatment, distribution system, finished water storage, 
pumps and pump facilities and controls, monitoring/reporting/data 
verification, water system management and operations, and operator 
compliance with State requirements. The EPA/State Joint Guidance does 
not provide detailed instructions on evaluating criteria under the 
eight elements; however, EPA has recently issued detailed supplementary 
information as technical assistance (April 1999, Guidance Manual for 
Conducting Sanitary Surveys of Public Water Systems)(US EPA, 1999e).

--Source. The water supply source is the first opportunity for 
controlling contaminants. The reliability, quality, and quantity of the 
source should be evaluated during the sanitary survey using available 
information including results of source water assessments or other 
relevant information. A survey should assess the potential for 
contamination from activities within the watershed as well as from the 
physical components and condition of the source facility.
--Treatment. The treatment phase should consider evaluation of the 
handling, storage, use and application of treatment chemicals if the 
system includes application of any chemicals. A review of the treatment 
process should include assessment of the operation, maintenance, record 
keeping and management practices of the treatment system.
--Distribution System. Given the potential for contamination to spread 
throughout the distribution system, a thorough inspection of the 
distribution network is important. Review of leakage that could result 
in entrance of contaminants, monitoring of disinfection residual, 
installation and repair procedures of mains and services, as well as an 
assessment of the conditions of all piping and associated fixtures are 
necessary to maintain distribution system integrity.
--Finished Water Storage. A survey of the storage facilities is 
critical to ensuring the availability of safe water, and the adequacy 
of construction and maintenance of the facilities.
--Pumps/Pump Facilities and Controls. Pumps and pump facilities are 
essential components of all water systems. A survey should verify that 
the pump and its facilities are of appropriate design and properly 
operated and maintained.
--Monitoring/Reporting/Data Verification. Monitoring and reporting are 
needed to determine compliance with drinking water provisions, as well 
as to verify the effectiveness of source protection, preventative 
maintenance, treatment, and other compliance-related issues regarding 
water quality or quantity.
--Water System Management/Operations. The operation and maintenance of 
any water system is dependent on effective oversight and management. A 
review of the management process should ensure continued and reliable 
operation is being met through adequate staffing, operating supplies, 
and equipment repair and replacement. Effective management also 
includes ensuring the system's long-term financial viability.
--Operator compliance with State requirements. A system operator plays 
a critical role in the reliable delivery of safe drinking water. 
Operator compliance with State requirements includes state-specific 
operation and maintenance requirements, training and certification 
requirements, and overall competency with on-site observations of 
system performance.
    4. Other Studies
    As previously described (see section I.D.2.), ASDWA examined 28 
different BMPs to determine the effectiveness of each BMP in 
controlling microbial contamination. Within this study, 91.4% of 
systems surveyed had implemented a sanitary survey within the previous 
five years. The ASDWA survey found no significant association with 
systems that conducted sanitary surveys and no total coliform 
detections. The insignificance of the association between sanitary 
surveys and the detection of bacteria may be due to the fact that State 
sanitary surveys are designed to identify problems (ASDWA, 1998). 
However, correction of sanitary survey deficiencies was correlated with 
lower levels of total coliform, fecal coliform, and E. coli.
    EPA conducted a survey published in Ground Water Disinfection and 
Protective Practices in the United States (US EPA 1996a), which 
confirmed the GAO finding that considerable variability among States 
exists with regard to the scope and comprehensiveness of sanitary 
surveys.
    The Environmental Law Reporter (ELR), a private database of State 
and Federal statutes and regulations, provides some information on 
current State regulations for ground water systems. According to the 
ELR, only the State of Washington does not require sanitary surveys 
under the TCR requirement at 40 CFR 141.21(d). However, most State 
regulations found in the ELR are general in nature and do not 
specifically address the eight EPA/State Joint Guidance sanitary survey 
components. State regulations vary considerably in terms of types of 
systems surveyed, the content of the survey, and who is designated to 
conduct the surveys (e.g., a sanitarian). The database indicates that 
the majority of States (46 out of 50) do not specifically require 
systems to correct deficiencies. Significantly, a number of States do 
not appear to have legal authority to require correction of 
deficiencies. The ELR findings contained in the Baseline Profile 
Document for the Ground Water Rule (US EPA, 1999f) indicate that many 
sanitary survey provisions do not appear in State regulations. The GAO 
report confirmed that many States incorporated sanitary survey 
requirements into policy, thereby undercutting their legal 
enforceability.
5. Proposed Requirements
    EPA proposes to require periodic State sanitary surveys for all 
ground water systems specifically addressing all of the applicable 
sanitary survey elements noted earlier, regardless of population size 
served.
    With regard to the frequency of sanitary surveys, EPA proposes to 
require the State or a state-authorized third party to conduct sanitary 
surveys for all ground water systems at least once every three years 
for CWSs and at least once every five years for NCWSs. This approach 
would be consistent with the requirements of the IESWTR. CWSs would be 
allowed to follow a five-year frequency if the system either treats to 
4-log inactivation or removal of viruses or has an outstanding 
performance record in each of the applicable eight areas documented in 
previous inspections and has no history of TCR MCL or monitoring 
violations since the last sanitary survey. A State must, as part of its 
primacy application, include how it will decide whether a system has 
outstanding performance and is thus eligible for sanitary surveys at a 
reduced frequency.

[[Page 30220]]

    The Agency believes that periodic sanitary surveys, along with 
appropriate corrective measures, are indispensable for ensuring the 
long-term safety of drinking water. By taking steps to correct 
deficiencies exposed by a sanitary survey, the system provides an 
additional barrier to pathogens entering the drinking water.
    The definition of a sanitary survey used in the GWR differs from 
the definition of a sanitary survey in 40 CFR 141.2 by a parenthetical 
clause. For the purpose of Subpart S, a sanitary survey is ``an onsite 
review of the water source (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.'' This reflects a recommendation by the 1997 M/DBP 
Federal Advisory Committee Act that sanitary inspectors should use 
source water assessments and other information where available as part 
of the overall evaluation of systems. This change in definition 
reflects the value of Source Water Assessment and Protection Programs 
(SWAPPs) required by Congress in the 1996 SDWA amendments and the 
importance of utilizing information generated as a result of that 
activity.
    EPA is also proposing to require that State inspectors, as part of 
each sanitary survey, evaluate all applicable components defined in the 
EPA/State Joint Guidance on Sanitary Surveys and identify any 
significant deficiencies. Some stakeholders have suggested the 
comprehensiveness of sanitary surveys be tailored based upon system 
size and type. EPA requests comment on whether this would be an 
appropriate approach and if so, what factors or criteria should be 
considered in tailoring the scope or complexity of the sanitary survey.
    Individual components of a sanitary survey may be separately 
completed as part of a staged or phased State review process as part of 
ongoing State inspection programs within the established frequency 
interval. In its primacy package, a State which plans to complete the 
sanitary survey in such a staged or phased review process must indicate 
which approach it will take and provide the rationale for the specified 
time frames for sanitary surveys conducted on a staged or phased 
approach basis.
    EPA proposes to regard the requirements for sanitary surveys under 
the GWR as meeting the requirements for sanitary surveys under the TCR 
(40 CFR 141.21). The reason for this is that the frequency and criteria 
of a sanitary survey under the GWR is more stringent than that for the 
TCR. For example, the TCR does not define a sanitary survey as 
precisely as the GWR, which requires an evaluation of eight elements. 
In addition, the frequency of the sanitary survey under the TCR for 
CWSs is every five years, compared to three years (at least initially) 
under the GWR. Also, the TCR requires a survey every ten years for 
disinfected NCWSs using protected ground waters, as compared to every 
five years under the GWR. The scope of the systems that must conduct a 
sanitary survey also differs; under the TCR only systems that collect 
fewer than five routine samples per month and serve less than 4,100 
persons are required to undergo a sanitary survey, compared to all 
ground water systems under the GWR. Given that the proposed sanitary 
survey requirements under the GWR are more stringent than those under 
the TCR, EPA notes that a survey under the TCR cannot replace one 
conducted under the GWR, unless that survey meets the criteria 
specified in the GWR.
    As part of today's rule, a ``significant deficiency'' as identified 
by a sanitary survey includes: 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. This is a working 
definition developed by the EPA GWR workgroup.
    The Agency proposes to require the State to provide the system with 
written notification which identifies and describes any significant 
deficiencies found in a sanitary survey no later than 30 days after 
completing the on-site survey. States would not be required, in this 
rule, to provide the system with a complete sanitary survey report 
within the 30 days of completing the on-site survey. Rather, this rule 
requires that, at a minimum, the State provide the system a written 
list which clearly identifies and describes all significant 
deficiencies as identified during the on-site survey.
    EPA proposes to require a system to: (1) Correct any significant 
deficiencies identified in a sanitary survey as soon as possible, but 
no later than 90 days of receiving State written notification of such 
deficiencies, or (2) to submit a specific schedule and receive State 
approval on the schedule for correcting the deficiencies within the 
same 90-day period. The system must consult the State within this 90-
day period to determine the corrective action approach appropriate for 
that system, consistent with the State's general approach outlined in 
their primacy package. In performing a corrective action, the system 
must eliminate the source of contamination, correct the significant 
deficiency, provide an alternate source water, or provide a treatment 
which reliably achieves at least 99.99 percent (4-log) inactivation or 
removal of viruses before or at the first customer. Ground water 
systems which provide 4-log inactivation or removal of viruses will be 
required to conduct compliance monitoring to demonstrate treatment 
effectiveness. There are cases in which one or more of the corrective 
actions listed previously may be inappropriate for the nature of the 
problem, and in these cases only appropriate corrective actions must be 
taken. For example, a system with a significant deficiency in the 
distribution system should not install treatment at the source water as 
the corrective action; that system should correct the problem in the 
distribution system. There may also be fecal sources that a State does 
not identify as a significant deficiency, however the State may choose 
to use their authority to require source water monitoring to monitor 
the influence of that fecal source. Ground water systems which provide 
4-log inactivation or removal of viruses will be required to conduct 
compliance monitoring to demonstrate treatment effectiveness. States 
must confirm that the deficiency has been corrected, either through 
written confirmation from systems or a site visit by the State, within 
30 days after the 90-day or scheduled correction of the deficiency. 
Systems providing 4-log inactivation or removal of viruses need not 
undergo a hydrogeologic sensitivity assessment or monitor their source 
water for fecal indicators.
    As noted earlier, States would be required to have the appropriate 
rules or other authority to: (1) Ensure that public ground water 
systems correct any significant deficiencies identified in the written 
notification provided by the State (including providing an alternative 
source or 4-log inactivation or removal of viruses); and (2) ensure 
that a public ground water system confirm in writing any significant 
deficiency corrections made as a result of sanitary survey findings.
    The requirements in today's rule do not preclude a State from 
enforcing corrective action on any significant deficiencies whether or 
not they are identified through a sanitary survey.
    EPA is also proposing to require States, as part of their primacy 
application, to indicate how they will

[[Page 30221]]

define what constitutes a significant deficiency found in a sanitary 
survey for purposes of this rule. EPA believes that this requirement 
would provide the State sufficient latitude to work within their 
existing programs in addressing significant deficiencies yet provide 
facilities and the public with clear notice as to what kinds of system 
conditions constitute a significant deficiency. EPA recognizes the 
importance of enabling States the flexibility to identify and define 
sanitary survey deficiencies in broad categories under this requirement 
(e.g., unsafe source, improper well construction, etc.).
    Also, in its primacy application, States must specify if and how 
they will integrate SWAPP susceptibility determinations into the 
sanitary survey or the definition of significant deficiencies.
    Based upon input from a number of State and EPA Regional office 
experts, significant deficiencies of ground water systems may include 
but are not limited, to the following types of deficiencies:

--Unsafe source (e.g., septic systems, sewer lines, feed lots nearby);
--Wells of improper construction;
--Presence of fecal indicators in raw water samples;
--Lack of proper cross connection control for treatment chemicals;
--Lack of redundant mechanical components where chlorination is 
required for disinfection;
--Improper venting of storage tank;
--Lack of proper screening of overflow pipe and drain;
--Inadequate roofing (e.g., holes in the storage tank, improper hatch 
construction);
--Inadequate internal cleaning and maintenance of storage tank;
--Unprotected cross connection (e.g., hose bibs without vacuum 
breakers);
--Unacceptable system leakage that could result in entrance of 
contaminants;
--Inadequate monitoring of disinfectant residual and TCR MCL or 
monitoring violations.
6. Reporting and Record Keeping Requirements
    The GWR does not change the requirements on the system and the 
State to maintain reports and records of sanitary survey information as 
specified in 40 CFR 141.33(c) and 142.14(d)(1).
7. Request for Comments
    EPA requests comment on all the information presented earlier and 
the potential impacts on public health and regulatory provisions of the 
GWR. In addition, EPA specifically requests comments on alternative 
approaches.

Alternative Approaches

a. Content of a Sanitary Survey
i. Grandfathering and Scope of Sanitary Survey
    EPA requests comment on ``grandfathering'' of surveys conducted 
under the TCR if those surveys addressed all eight EPA/State Joint 
Guidance on Sanitary Surveys components. Under what circumstances 
should grandfathering be allowed? Are there circumstances under which 
grandfathering should be allowed even if the survey did not address all 
eight components?
    EPA is seeking comment on the level of detail EPA should use in 
establishing the sanitary survey requirement which addresses the eight 
sanitary survey components.
ii. Definition of Significant Deficiency
    EPA is also seeking comment on the proposed definition of 
``significant deficiencies.'' In this regard, EPA is requesting comment 
on whether or not the Agency should promulgate a minimum list of 
specific significant deficiencies for all States to use in their 
programs.
iii. Well Construction and Age
    EPA considered specifying, in addition to sanitary survey elements, 
well construction deficiencies and well age as surrogate measures of 
well performance as part of the hydrogeologic sensitivity assessment 
(HSA) or as an independent component from the sanitary survey or HSA. 
EPA considered identifying older wells as those more likely to be 
contaminated because of degradation to the construction materials over 
time. EPA concluded that wells may have been constructed adequately to 
protect public health, but records to document such construction may no 
longer be available. Given these circumstances, EPA recognizes that 
down-hole test methods to evaluate well construction, as required for 
some hazardous waste disposal methods, is neither desirable nor 
feasible for PWS wells. In addition, EPA found that there were few data 
to support the concept that older wells were more likely to be 
contaminated. In fact, data from two studies encompassing more than 200 
wells in Missouri suggest that newer wells were more likely to be 
contaminated than older wells (Davis and Witt, 1998, 1999 and Femmer, 
1999). Thus, EPA decided not to include well construction and age as 
measures of the potential fecal hazard to PWS wells.
    Almost all States have well construction standards, and trade 
associations, such as the American Water Works Association and the 
National Ground Water Association, have also provided recommendations 
for well construction. EPA recognizes the importance of designing, 
constructing and maintaining wells so as to maximize well life and 
yield and to minimize potential harmful contamination. Therefore, the 
Agency requests comment on whether well construction and age should be 
considered as a required element within a sanitary survey or 
specifically identified by States as a significant deficiency. EPA also 
requests comment on criteria for evaluating well construction and age.
b. Frequency
    EPA believes that a sanitary survey cycle of at least once every 
three years for CWSs (with certain exceptions discussed previously) and 
at least once every five years for NCWSs most properly balances public 
health protection and State burden issues and is consistent with the 
frequency required for surface water systems. However, the Agency seeks 
comment on whether other alternative time cycles might be appropriate 
together with any applicable rationale that supports that alternative 
frequency cycle. Specifically, EPA requests comment on requiring States 
to conduct sanitary surveys for all ground water systems every five 
years. EPA also requests comment on allowing States to conduct sanitary 
surveys less often than once every 5 years if the system provides 4-log 
inactivation or removal. The Agency requests comment on the resource 
implications for States and small systems to perform these surveys with 
a frequency of 3-5 years.
    In addition, the Agency seeks comment on requiring the State to 
conduct a sanitary survey for new systems prior to the system serving 
water to the public. This requirement would serve as an added public 
health measure to ensure new systems are in compliance with the GWR 
sanitary survey provisions.
c. Follow-Up Requirements
    EPA requests comment on requiring States to schedule an on-site 
inspection as follow-up to verify correction of significant 
deficiencies, rather than allowing States to accept written 
certification from systems to verify the correction. EPA requests 
comment on alternative approaches for a State to verify that a 
significant deficiency has

[[Page 30222]]

been corrected. EPA notes that follow-up in this context only applies 
to significant deficiencies.
d. Public Involvement
    EPA requests comment on including public involvement and/or 
meetings for certain systems to discuss the results of sanitary 
surveys. Congress wrote requirements for extensive public information 
and involvement in programs and decisions affecting drinking water 
safety throughout the 1996 amendments to SDWA. For example, in addition 
to the new requirement for CWSs to produce and distribute annually a 
Consumer Confidence Report, the public notice requirements for PWSs 
regarding violations of a national drinking water standard were made 
more effective, and States were required to ``make readily available to 
the public'' an annual report to the Administrator on the statewide 
record of PWS violations, see (SDWA 1414(c)(1)-(3)). Each State's 
triennial report to the Governor on the effectiveness of and progress 
under the capacity development strategy must also be available to the 
public. (See SDWA section 1420(c)(3)). EPA must make the information 
from the occurrence database ``available to the public in readily 
accessible form.'' (See SDWA section 1445(g)(5)). The public must be 
provided with notice and an opportunity to comment on the annual 
priority list of projects eligible for State Revolving Fund (SRF) 
assistance that States will publish as a part of their SRF intended use 
plans (See SDWA section 1452(b)(3)(B)). States ``shall make the results 
of the source water assessments * * * available to the public.'' (See 
SDWA section 1453(a)(7)). And, under several specific provisions of the 
SDWA as well as the Administrative Procedure Act, EPA generally must 
publish and make regulations, and a number of guidance and information 
documents, available for public notice and comment.
    These requirements, and others like them, are integral to both the 
philosophy and operation of the amended SDWA. They reflect Congress' 
view that public confidence in drinking water safety and informed 
support for any needed improvements must rest on full disclosure of all 
significant information about water system conditions and quality, from 
source to tap.
    The 1996 SDWA Amendments, and EPA's implementation of them, 
consistently provide for such disclosure and involvement by means that 
are informative, timely, understandable, and practicable for each size 
group of PWSs subject to them. EPA believes that the principles of 
public information and involvement must apply with equal validity to 
the GWR, and is considering including in the final rule provisions to 
apply these principles, for disclosure and involvement. EPA believes 
that the following approach meets both tests and principles, but 
solicits comment on alternative means of doing so.
    EPA requests comment on what approaches might be practicable, not 
burdensome and workable to involve the public in working with their 
system to address the results of their system's sanitary survey. 
Specifically, EPA requests comment on requiring ground water CWSs to 
notify their consumers, as part of the next billing cycle, of the 
completion of any sanitary survey, and any significant deficiency(s) 
and corrective action(s) identified. The system would also have to make 
information concerning the sanitary survey available to the public upon 
request. Alternatively, the system might be required to notify 
customers of the availability of the survey only, and provide copies on 
request, or include information about the survey in the annual Consumer 
Confidence Report (CCR). EPA requests comment on whether this approach 
should be extended to transient and nontransient NCWSs as well. EPA 
also requests comment on what approaches might be practicable, not 
burdensome and workable to involve the public in working with their 
system to address the results of their system's sanitary survey.

B. Hydrogeologic Sensitivity Assessment

1. Overview and Purpose
    Occurrence data collected at the source from public ground water 
systems suggest that a small percentage of all ground water systems are 
fecally contaminated. Because of the large number of ground water 
systems (156,000), the GWR carefully targets the high priority systems 
and has minimal regulatory burden for the remaining low priority 
systems. The GWR screens all systems for priority and only requires 
corrective action for fecally contaminated systems and systems with 
significant deficiencies. Thus, the challenge of the hydrogeologic 
sensitivity assessment is to identify ground water wells sensitive to 
fecal contamination. The assessment supplements the sanitary survey by 
evaluating the risk factors associated with the hydrogeologic setting 
of the system. EPA believes requiring hydrogeologic sensitivity 
analysis for all non-disinfecting ground water systems will reduce risk 
of waterborne disease by identifying systems with incomplete natural 
attenuation of fecal contamination. EPA bases the following 
requirements on: CDC outbreak case studies, USGS studies of ground 
water flow, State vulnerability maps, and US National Research Council 
reports on predicting ground water vulnerability.
    For the purposes of this rulemaking, EPA intends the term ``well'' 
to include any method or device that conveys ground water to the ground 
water system. The term ``well'' include springs, springboxes, vertical 
and horizontal wells and infiltration galleries so long as they meet 
the general applicability of the GWR (see section 141.400). The GWR 
does not apply to PWSs that are designated ground water under the 
direct influence of surface water; such systems are subject to the SWTR 
and IESWTR. EPA requests comment on this definition of ``well.''
    The hydrogeologic sensitivity assessment is a simple, low burden, 
cost-effective approach that will allow States to screen for high 
priority systems. Systems that are situated in certain hydrogeologic 
settings are more likely to become contaminated. EPA believes that a 
well obtaining water from a karst, fractured bedrock or gravel 
hydrogeologic setting is sensitive to fecal contamination unless the 
well is protected by a hydrogeologic barrier. A State may add 
additional sensitive hydrogeologic settings (e.g., volcanic aquifers) 
if it believes that it is necessary to do so to protect public health. 
A hydrogeologic barrier is defined as the physical, biological and 
chemical factors, singularly or in combination, that prevent the 
movement of viable pathogens from a contaminant source to a public 
supply well. In this proposal, a confining layer is one example of a 
hydrogeologic barrier. The strategy is for a State to consider 
hydrogeologic sensitivity first. If ground water systems not treating 
to 4-log inactivation of viruses are located in sensitive hydrogeologic 
settings, then the strategy allows the State to consider the presence 
of any existing hydrogeologic barriers that act to protect public 
health. If a hydrogeologic barrier is present, then the State can 
nullify the determination that a system is located in a sensitive 
hydrogeologic setting. If no suitable hydrogeologic barrier exists, 
then the GWR requires the system to conduct monthly fecal indicator 
source water monitoring. Finally, for those systems where monitoring 
results are positive for the presence of fecal indicators, under the 
proposed GWR, States may require systems to eliminate

[[Page 30223]]

the source of contamination, correct the significant deficiency, 
provide an alternate source water, or provide a treatment which 
reliably achieves at least 99.99 percent (4-log) inactivation or 
removal of viruses before or at the first customer. GWSs which provide 
4-log inactivation or removal of viruses will be required to conduct 
compliance monitoring to demonstrate treatment effectiveness.
    The States have experience implementing a wide variety of methods 
suitable for identifying hydrogeologically sensitive systems. Also, the 
States may collect hydrogeologic information through their SWAPP (see 
section I.B.) that is useful for the hydrogeologic sensitivity 
assessments under the GWR. EPA believes that it would be beneficial if 
the States coordinate their SWAPP analysis with the GWR. By using the 
information generated in the SWAPP for the GWR hydrogeologic 
sensitivity assessment, States can effectively reduce the burden 
associated with this requirement.
    EPA-approved vulnerability assessments conducted for the purpose of 
granting waivers under the Phase II and Phase V Rules may also serve as 
sources of hydrogeologic information useful to the State in assessing 
the hydrogeologic sensitivity of its GWSs under the GWR. Under the 
Phase II (56 FR 30268, July 1, 1991d)(US EPA,1991) and Phase V (57 FR 
31821, July 17, 1992)(US EPA,1992b) Rules, monitoring waivers may be 
granted to individual systems for specific regulated chemicals (e.g., 
PCBs and cyanide). Monitoring frequencies may be reduced or eliminated 
by the State if the system obtains a waiver based on previous sampling 
results and/or an assessment of the system's vulnerability to each 
Phase II and V contaminant. This evaluation must include the sampling 
results of neighboring systems, the environmental persistence and 
transport of the contaminant(s) under review, how well the source is 
protected by geology and well design, Wellhead Protection Assessments, 
and proximity of potential contamination sites and activities.

2. Hydrogeologic Sensitivity

    Sensitive hydrogeologic settings occur in aquifer types that are 
characterized by large interconnected openings (void space) and, 
therefore, may transmit ground water at rapid velocities with virtually 
no removal of pathogens. Sensitive aquifers may be present at or near 
the ground surface or they may be covered by overlying aquifers or 
soils. An aquifer is sensitive, independent of its depth or the nature 
of the overlying material, because average water velocities within that 
aquifer are rapid. This allows microbial contaminants to be transported 
long distances from their source at or near the surface and especially 
in the absence of a hydrogeologic barrier. In the following paragraphs, 
each sensitive aquifer type is briefly characterized. It is often 
difficult to determine the actual contaminant removal capabilities of 
an aquifer and the and ground water velocities within an aquifer. 
Consequently, the aquifer rock type can be a surrogate measure in the 
hydrogeologic sensitivity assessment. All soil and rocks have void 
space, but aquifers have the largest interconnected void space. The 
voids are filled with water that is tapped by a well. Without these 
interconnections, the water could not flow to a well. In those aquifers 
with the largest interconnected void space, ground water velocities can 
be comparable to the velocity of a river, and the rate of travel can be 
measured in kilometers per day (US EPA, 1997b). Compared to velocities 
in fine-grained granular aquifers (aquifers that are not considered 
sensitive under the GWR), ground water velocities in fractured media 
are large (Freeze and Cherry, 1979). Sensitive aquifers allow fecal 
contaminants to travel rapidly to a well, with little loss in number 
due to inactivation or removal.
    In the GWR, three aquifer types are identified as sensitive: (1) 
Karst aquifers, (2) fractured bedrock aquifers, and (3) gravel 
aquifers. Each aquifer type is characterized by the differing nature 
and origin of the interconnected void space. These distinctions are 
important to hydrogeologists identifying these aquifer types. To meet 
the requirements of the hydrogeologic sensitivity assessment of the 
GWR, it is sufficient for States to identify the aquifer type supplying 
a system. Karst, fractured bedrock and gravel aquifer types are at high 
risk to fecal contamination by virtue of their capability to rapidly 
transmit fecal contamination long distances over short time periods.
    Several means can be used to evaluate wells to determine if they 
are located in one of the three sensitive hydrogeologic settings 
proposed under the GWR. For example, hydrogeologic data are available 
from published and unpublished materials such as maps, reports, and 
well logs. The United States Geologic Service (USGS), U.S. Department 
of Agriculture's Natural Resource Conservation Service, USGS Earth 
Resources Observation System Data Center, the EPA Source Water 
Assessment and Protection Program and Wellhead Protection Program, 
State geological surveys, and universities have substantial amounts of 
regional and site-specific information. The USGS has published a 
national karst map (USGS, 1984) on which States can locate karst 
settings. Karst and other aquifers may also be identified on finer 
scale maps published by States or counties. For example, the State of 
Kentucky contains substantial karst terrain, documented in complete 
geologic maps at the scale of one inch: 2000 feet (7.5 minute 
quadrangles).
    States can base assessments on available information about the age 
and character of the regional geology, regional maps and rock outcrop 
locations. For example, in a karst setting, the State may have some 
additional information such as: (1) Observations of typical karst 
features such as sinkholes and disappearing streams; (2) well driller 
logs which noted the presence of limestone or crystalline calcite (a 
mineral that grows into openings in rock) or a drop in the drill string 
as it penetrated a karst opening; or (3) geologic reports (or 
unpublished geological observations) which identify the presence of 
limestone in rock outcrops in the vicinity of the well.
(a) Karst Aquifers
    Karst aquifers are aquifers formed in soluble materials (limestone, 
dolomite, marble and bedded gypsum) that have openings at least as 
large as a few millimeters in radius (EPA 1997b). Over geologic time 
periods, infiltrating precipitation (especially acid rain) moving 
through the aquifer has enlarged, by dissolution, the small openings 
that existed when the rock was formed. In mature karst terrain, 
characterized by relatively pure limestone located in regions with high 
precipitation, caves or caverns are formed in the subsurface, often 
large enough for human passage. Ground water has the potential to flow 
rapidly through karst because the void spaces are large and have a high 
degree of interconnection. In addition to the openings created by 
solution removal, karst aquifers, like all consolidated geologic 
formations, also contain fractures that transmit ground water. The size 
of these fractures may be small, but the fractures may also be more 
numerous than solution-enhanced openings. The fractures may or may not 
have a high degree of interconnection, and the degree of 
interconnection is a primary factor that controls the velocity of the 
ground water.

[[Page 30224]]

    Quinlan (1989) suggests that about 20 percent of the U.S. is 
underlain by limestone or dolomite which may be karst aquifers. East of 
the Mississippi River, almost forty percent of the U.S. is underlain by 
limestone, dolomite or marble that may be karst aquifers (Quinlan, 
1989). Karst areas are often identified by the formation of sinkholes 
at the ground surface. A sinkhole forms when the roof of a cave 
collapses and the material that was overlying the cave is dissolved or 
otherwise carried away by streams flowing through the cave. Sinkholes 
may also form or become enlarged as the direct result of vertical 
ground water flow dissolving the rock material to form a vertical 
passageway. Sinkholes represent direct pathways for fecal contamination 
to enter the aquifer from the surface. The surface topography may also 
be characterized by dry stream valleys in regions of high rainfall, by 
streams that flow on the ground surface but suddenly sink below ground 
to flow within a cave and by large springs where underground streams 
return to the surface. The degree of karst development in Missouri has 
been defined by Davis and Witt (1998) as primary and secondary karst: 
primary containing more than ten sinkholes per 100 square miles and 
secondary karst containing between one and ten sinkholes per 100 square 
miles. Other features suitable for identifying karst aquifers are 
described in EPA (1997b).
    The most direct method for ground water velocity determinations 
consists of introducing a tracer substance at one point in the ground 
water flow path and observing its arrival at other points in the path, 
usually at monitoring wells (Freeze and Cherry, 1979). Using tracer 
studies, ground water velocities in karst aquifers have been measured 
as high as 0.5 kilometers (km) per hour (US EPA, 1997b). In Florida, 
ground water velocities surrounding a well have been measured at 
several hundred meters (m) per hour (US EPA, 1997b). At Mammoth Cave, 
Kentucky, ground water velocities have been measured at more than 300 m 
per hour (US EPA, 1997b). In a confined karst aquifer in Germany, 
ground water traveled 200 m in less than 4 days (Orth et al., 1997). In 
the Edwards Aquifer, Texas, Slade et al., (1986) reported that dye 
traveled 200 feet in ten minutes. The water level in one well (582 feet 
deep with a water table 240 feet deep) began rising within one hour 
after a rainfall (Slade et al., 1986). These data suggest that ground 
water flows extremely rapidly through karst aquifers. Because ground 
water flows rapidly through karst aquifers, these aquifers are 
considered to be hydrogeologically sensitive aquifers under the GWR.
(b) Fractured Bedrock
    Bouchier (1998) characterizes a fractured bedrock aquifer as an 
aquifer which has fractures that provide the dominant flow-path. 
Although all rock types have fractures, the rock types most susceptible 
to fracturing are igneous and metamorphic rock types (US EPA, 1991c).
    Freeze and Cherry (1979) report void space as high as 10 percent of 
total volume in igneous and metamorphic rock. These rock types readily 
become fractured in the shallow subsurface as a result of shifts in the 
Earth's crust. Most fractures are smaller than one millimeter (mm) in 
width but each fracture's capability to transmit ground water varies 
significantly with the width of the fracture. A one mm fracture will 
transmit 1,000 times more water than a 0.1 mm fracture, provided that 
other factors are constant (e.g., hydraulic gradient) (Freeze and 
Cherry, 1979). Data presented in Freeze and Cherry (1979) suggest that 
the first 200 feet beneath the ground surface produces the highest 
water yields to wells. These data suggest that the fractures are both 
more numerous and more interconnected in the first 200 feet interval. 
The rate of ground water travel in fractured rock can be estimated 
through the results of tracer tests. Malard et al., (1994) report that 
dye traveled 43 m in a fractured aquifer in two hours. Becker et. al., 
(1998) report that water traveled 36 m in about 30 minutes. Therefore, 
ground water may travel as quickly as several hundreds of meters per 
day in fractured bedrock, comparable to travel times in karst aquifers.
    Aquifers that are comprised of igneous or metamorphic rock are 
often fractured bedrock aquifers, and their size is typically larger 
than a few tens or hundreds of square miles in area. EPA (1991c) has 
compiled a map showing the distribution of fractured bedrock aquifers 
in the U.S. Because ground water flows rapidly through fractured 
bedrock aquifers, these aquifers are considered to be hydrogeologically 
sensitive aquifers under the GWR.
(c) Gravel Hydrogeology
    Gravel aquifers are deposits of unconsolidated gravel, cobbles and 
boulders (material larger in size than pebbles). Due to the large grain 
sizes of gravel aquifers, ground water travels rapidly within these 
aquifers with little to no removal or filtration of contaminants from 
the ground water. Such gravel aquifers are typically produced by 
catastrophic floods, physical weathering by glaciers, flash-floods at 
the periphery of mountainous terrain or at fault-basin boundaries. For 
example, glacial flooding has produced the Spokane-Rathdrum Prairie 
aquifer which extends from Spokane, Washington to Coeur d'Alene, Idaho. 
Another gravel aquifer is associated with glacial flooding along the 
Umatilla River in Milton-Freewater, Oregon. The boulder zone in the 
Jacobs Sandstone and Baraboo Quartzite near Baraboo, Wisconsin may 
represent another example. Typically, these aquifers are small.
    Gravel aquifers are generally not alluvial aquifers. Alluvial 
aquifers, associated with typical river processes, normally have high 
proportions of sand mixed with the gravel. Sand or finer materials 
provide a higher probability of microorganism removal by the aquifer 
particles (Freeze and Cherry, 1979), and, therefore, greater public 
health protection. Because ground water flows rapidly through gravel 
aquifers, these aquifers are considered to be hydrogeologically 
sensitive aquifers under the GWR.
3. Hydrogeologic Barrier
    The second part of the hydrogeologic sensitivity assessment is 
determining the presence of a hydrogeologic barrier. Under the GWR, the 
States perform an initial screen for hydrogeologic sensitivity by 
determining whether a PWS utilizes a fractured bedrock, karst or gravel 
aquifer. States would then examine systems located in these sensitive 
aquifers and determine whether a hydrogeologic barrier is present. A 
hydrogeologic barrier consists of physical, chemical, and biological 
factors that, singularly or in combination, prevent the movement of 
viable pathogens from a contaminant source to a public water supply 
well. If the State determines that a hydrogeologic barrier is present, 
the hydrogeologic setting is no longer considered sensitive to fecal 
contamination. If no such barrier is present or if insufficient 
information is available to make such a determination, the system would 
be identified as a sensitive system.
    It is difficult to describe a single, detailed methodology for 
identifying a hydrogeologic barrier that can be used on a national 
basis. Geological and geochemical conditions, climate, and land uses 
are highly variable throughout the United States. In its primacy 
application, each State seeking consideration of a proposed 
hydrogeologic barrier under the rule may identify an approach for

[[Page 30225]]

determining the presence of a hydrogeologic barrier that addresses its 
own unique set of these variables (e.g., geological and geochemical 
conditions, climate, and land uses). In determining the presence of a 
hydrogeologic barrier, the State should evaluate specific 
characteristics of the hydrogeologic setting, discussed in more detail 
in the following paragraphs.
    Examples of characteristics to be considered in determining the 
presence of a hydrogeologic barrier include, but are not limited to: 
(1) Subsurface vertical and horizontal ground water travel times or 
distances sufficiently large so that pathogens become inactivated as 
they travel from a source to a public water supply well, or (2) 
unsaturated geological materials sufficiently thick so that 
infiltrating precipitation mixed with fecal contaminants is effectively 
filtered during downward flow to the water table.
    A confining layer is one type of hydrogeologic barrier EPA has 
identified which can result in sufficient protection in many settings. 
A confining layer may protect sensitive aquifers from fecal 
contamination. It is defined as a layer of material that is not very 
permeable to ground water flow which overlies an aquifer and acts to 
prevent water movement into the aquifer (US EPA, 1991b). Confined 
aquifers are bounded by confining layers and, therefore, generally 
occur at depth, separated from the water table aquifer at the surface. 
Confining layers are typically identified by the high water pressures 
in the underlying aquifer. Where present, a confining layer will 
separate an aquifer of high pressure from an overlying aquifer of lower 
pressure. The high water pressure in a confined aquifer can force water 
to flow naturally (without pumping) to heights greater than the ground 
surface, as in an artesian well. The confining layer is comprised of 
fine-grained materials such as clay particles, either as an 
unconsolidated layer or as a consolidated rock (e.g., shale). The small 
size of clay particles restricts the movement of water across or 
through the clay layer. Freeze and Cherry (1979) determined that water 
would take almost 10,000 years to pass through a 10 meters-thick 
unfractured layer of silt and clay deposited at the bottom of a glacial 
lake, such as the layers present in the northern part of the United 
States and the southern part of Canada. Therefore, the presence of a 
confining layer can provide public health protection.
    However, confining layers may be breached and, therefore, 
unprotective. Breaches may be natural (e.g., partly removed by erosion, 
sinkholes, faults, and fractures) or caused by humans (e.g., wells, 
mines, and boreholes). For example, an unplugged, abandoned well that 
breaches the confining layer is capable of providing a pathway through 
the confining layer, allowing water and contaminant infiltration into 
ground water. A thicker, unpunctured confining layer is considered most 
protective of the underlying aquifer. The State should consider such 
confined aquifer characteristics in determining the adequacy of a 
confining layer as a hydrogeologic barrier.
    EPA proposes to use the presence of a confining layer that is 
protective of the aquifer to act as a hydrogeologic barrier and nullify 
a sensitivity determination. Where the confining layer integrity is 
compromised by breaches or if the aquifer appears at the surface near 
the water supply well, the State shall determine if the layer is 
performing adequately to protect the well, and, therefore, public 
health. EPA estimates approximately 15 percent of undisinfected ground 
water system sources will be determined to be hydrogeologically 
sensitive (see RIA section 6.2.1.1).
4. Alternative Approaches to Hydrogeologic Sensitivity Assessment
    EPA recognizes that the States have substantial experience 
characterizing hydrogeology. Most States require some hydrogeologic 
information for reasons such as to delineate wellhead protection areas, 
manage ground water extraction or assess ground water contamination. 
EPA recognizes that there is no single approach for identifying systems 
at risk from source water contamination. In the GWR, a selected subset 
of hydrogeologic settings (karst, fractured bedrock and gravel 
aquifers) is hydrogeologically sensitive. These hydrogeologic settings 
are identified through regional and local maps that show the general 
distribution of these settings. Other approaches considered by EPA to 
identify sensitive systems, but not selected, require additional data 
that may not be available to all States. In the following paragraphs, 
alternative methods to identify sensitive systems are discussed, 
including the data requirements for implementing each approach.
(a) Horizontal Ground Water Travel Time
    Horizontal ground water travel time is the time that a water volume 
requires to travel through an aquifer from a fecal contamination source 
to a well. Viruses are longer lived than bacteria. Therefore, the 
ground water travel time should allow sufficient virus die-off to take 
place such that the concentration of viruses in the well water would be 
at or below a 1 in 10,000 annual risk level (Regli et. al., 1991). 
However, travel time determinations are site specific, and some methods 
are expensive and/or difficult to perform. Therefore, EPA is not 
prescribing a particular travel time as a hydrogeologic sensitivity 
assessment criterion under the GWR. Travel time information may be 
useful for evaluating hydrogeologic barrier performance, and States may 
make use of this information where available.
    Ground water travel time measurement methods include conservative 
tracer tests (e.g., dyes, stable isotopes), and travel time 
calculations. Conservative tracer tests may be used in all aquifer 
types including karst and fractured bedrock, as well as porous media 
aquifers. Tracer tests are expensive and difficult to perform. Ground 
water travel time calculations are only suitable for porous media 
aquifers. Because travel time methods are site-specific and their 
associated levels of uncertainty vary, EPA is not prescribing one 
travel time number or method to be used nationally.
    In evaluating whether to require a specific ground water travel 
time, EPA recognized that there are three problems with requiring this 
method for all States. First, all ground water travel time calculations 
require measurement of the aquifer porosity (void space). Aquifer 
porosity data are rare and usually must be estimated based on the 
aquifer character (e.g., sand, or sand and gravel). Second, ground 
water travel time calculations require knowledge of the distance 
traveled and water velocity; however, calculating travel time is 
complicated because ground water does not travel in a straight line. 
The ground water's flow path can be nearly straight, as in the case of 
cavernous karst or it can be very convoluted as found in fractured 
media. Third, the ground water travel time value represents the average 
travel time of a large water volume moving toward a well. Some water 
arrives more quickly than the average. Because viruses and bacteria are 
small in size their charge effects become important. As a result, some 
fecal contaminants may take the fastest path from source to well and 
arrive faster than the average water volume. Fecal contaminants 
introduced into an aquifer may or may not be channeled into flow paths 
that move faster than the average water volume. Thus, a calculation of 
the average ground water travel time is not as protective as the 
calculation of the first arrival time of the

[[Page 30226]]

ground water volume. Because of the additional uncertainty in 
calculating first arrival times, average travel times must be augmented 
with a safety factor. Travel time data, where available, may assist 
States in evaluating hydrogeologic barriers for localities where all 
sources of fecal contamination have been identified.
(b) Setback Distance
    A setback distance is the distance between a well and a potential 
contamination source. Many States already use setback distances around 
a well as exclusion zones in which septic tanks are prohibited.
    EPA compiled data on State sanitary setback distances for PWS 
wells. EPA found that there is little uniformity among the States. 
State setback distances from septic tanks or drain fields for new PWS 
wells range from 50 to 500 feet. Moreover, some States have differing 
setback distances depending on the well type (e.g., CWS versus NTNCWS 
and TNCWS ), the well pumping rate (e.g., greater or less than 50 
gallons per minute) or the microbial contaminant source type (e.g., 50 
feet from a septic tank and 10 feet from a sewer line).
    EPA considered using a strategy that included the setback distance 
as an element in determining the potential fecal hazard to systems. In 
this strategy, wells located near contamination sources are at risk. 
EPA concluded that it would be difficult to implement this strategy on 
a national scale for two reasons. First, the differing State setback 
distance requirements suggests that there is substantial disagreement 
among the States about an appropriate setback distance. Second, any 
setback distance selected for use in the GWR must be sufficiently large 
so as to protect a well from fecal contamination. The complexity of the 
processes that govern virus and bacterial transport in ground water and 
the variability of ground water velocity in sensitive hydrogeologic 
settings make it difficult, if not impossible, for EPA to specify 
setback distances that will be protective of public health for all 
hydrogeologic settings. Thus, EPA concluded that there was insufficient 
scientific data to mandate national setback distances in the GWR.
(c) Well and Water Table Depth
    Well depth is the vertical distance between the ground surface and 
the well intake interval or the bottom of the well. Water table depth 
is the vertical distance between the ground surface and the water 
table. Infiltrating ground water can require substantial time to reach 
a deep well or a deep water table because precipitation infiltrating 
downward to the water table and vertical ground water flow within an 
aquifer are typically slow, and thus the long infiltration path to a 
deep well or water table provides opportunities for inactivation or 
removal of pathogens and is protective against source water 
contamination.
    EPA considered identifying well depth and water table depth as 
alternative hydrogeologic sensitivity methods. Two key pieces of 
information would then be needed for each well: (1) Aquifer 
measurements that describe its capability to vertically transmit ground 
water and (2) measurements from the soil and other material overlying 
the water table that describe its capability to transmit infiltrating 
precipitation mixed with fecal contamination. EPA believes that few 
data are available to describe vertical ground water flow or 
infiltration on a national level. Thus, EPA concluded that there was 
insufficient data available to determine a well depth at which there 
exists a fecal contamination risk for all systems on a national scale.

5. Proposed Requirements

(a) Assessment Criteria
    Today's proposal provides that States shall identify high priority 
systems through a hydrogeologic sensitivity assessment. In this 
assessment, wells located in karst, fractured bedrock or gravel 
hydrogeologic settings are determined to be sensitive. The information 
provided in previous paragraphs shows that the wells located in these 
hydrogeologic settings are potentially at risk of fecal contamination 
because ground water velocities are high and fecal contamination can 
travel long distances over a short time. A hydrogeologic barrier can 
protect a sensitive aquifer, and if present, can nullify the 
sensitivity determination. In its primacy application, a State shall 
identify its approach to determine the presence of a hydrogeologic 
barrier. For example, a State may choose to consider a specific depth, 
hydraulic conductivity, and the presence of improperly abandoned wells. 
For systems with one or more wells that potentially produce ground 
water from multiple aquifers, the State shall identify its approach to 
making separate hydrogeologic sensitivity determinations and, if 
appropriate, hydrogeologic barriers identifications, for each well. For 
example, a State may choose to consider a specific depth and hydraulic 
conductivity, improperly abandoned wells. The system shall provide to 
the State or EPA, at its request, any pertinent existing information 
that would allow the State to perform a hydrogeologic sensitivity 
analysis. The hydrogeologic sensitivity assessment does not necessarily 
require an on-site visit by the State, provided the State has adequate 
information (geologic surveys, etc.) to make the assessment without a 
site visit.
    Discussions of proposed monitoring requirements for 
hydrogeologically sensitive systems are found in section III.D., and 
corrective action requirements are found in section III.E.
(b) Frequency of Assessment
    The States, or their authorized agent, shall conduct one 
hydrogeologic sensitivity assessments for each GWS that does not 
provide treatment to 4-log inactivation or removal of viruses. States 
shall conduct the hydrogeologic sensitivity assessment for all existing 
CWSs no later than three years after publication of the final rule in 
the Federal Register and for all existing NCWSs no later than five 
years after publication of the final rule in the Federal Register. 
States shall complete the hydrogeologic sensitivity assessment prior to 
a new ground water system providing drinking water for public 
consumption. EPA requests comment on these time frames. Some 
stakeholders have indicated that an assessment for hydrogeologically 
sensitive areas (karst, gravel, fractured rock) of a State can be 
quickly performed at the State level. If such data can be quickly 
gathered and an assessment easily performed, EPA questions putting off 
the routine monitoring requirements and public health protection that 
it would bring for three or five years. EPA requests comment on 
requiring the State to perform the hydrogeologic sensitivity assessment 
within one year of the effective date of the final GWR.
(c) Reporting and Record Keeping Requirements
    The State shall keep records of the supporting information and 
explanation of the technical basis for determinations of hydrogeologic 
sensitivity and of the presence of hydrogeologic barriers. The State 
shall keep a list of ground water systems which have had a sensitivity 
assessment completed during the previous year, a list of those systems 
which are sensitive, a list of those systems that are sensitive, but 
for which the State has determined a hydrogeologic barrier exists at 
the site sufficient for protecting public health, and a record of an 
annual evaluation of the State's program for conducting hydrogeologic 
sensitivity assessments.

[[Page 30227]]

6. Request for Comments

    EPA requests comments on all the information presented earlier and 
the potential impacts on public health and the regulatory provisions of 
the GWR.

a. Routine Monitoring Without State Assessment

    EPA requests comment on requiring systems to perform routine 
monitoring if the State fails to conduct a hydrogeologic sensitivity 
assessment. Under this provision, if the State fails to conduct a 
hydrogeologic sensitivity assessment within the time frame specified by 
the GWR, the systems would conduct fecal indicator monitoring once per 
month for every month they serve water to the public (see section 
Sec. 141.403(d), microbial analytical methods). The time frame for 
completing sensitivity assessments for all existing CWSs is no later 
than three years after the date of publication of the final rule in the 
Federal Register, and the time frame for all existing NCWSs is no later 
than five years after the date of publication of the final rule in the 
Federal Register. The systems could discontinue monitoring only after 
the State conducts a hydrogeologic sensitivity assessment and 
determines that the systems are not sensitive, or if the systems 
initiate and continue treatment to achieve 4-log inactivation or 
removal of viruses.
b. Vulnerability Assessment
    EPA requests comment on a detailed, on-site vulnerability 
investigation as an alternative to the Hydrogeologic Sensitivity 
Assessment. The alternative hydrogeologic investigation will assess the 
performance of all existing hydrogeologic barriers such as unsaturated 
zone thickness and composition (including the soil), the saturated zone 
thickness and composition above the well, intake interval, the 
frequency, duration and intensity of precipitation for all aquifer 
types, and will also require a detailed investigation of the well 
construction conditions by a certified well technician and a review of 
the well construction-related documentation from the sanitary survey 
and SWAPP assessment. The results of the detailed investigation must 
demonstrate that the existing hydrogeologic barriers, aquifer type and 
the well construction function to prevent the movement of viable 
pathogens from a contaminant source to a public water supply well. The 
demonstration may include ground water age dating, natural or 
artificial tracer test data, or ground water modeling results. See EPA 
1998b for more information on vulnerability assessments.
c. Sandy Aquifers
    EPA is proposing to require States to identify systems in karst, 
gravel and fractured rock aquifer settings as sensitive and these 
systems must perform routine source water monitoring. On March 13, 
2000, the Drinking Water Committee of the Science Advisory Board 
(DWCSAB) reviewed this issue and made several recommendations to EPA 
concerning a draft of this proposal. EPA requests comment on two DWCSAB 
recommendations concerning the hydrogeologic sensitivity assessment. 
The committee recommended that all ground water sources be required to 
monitor for bacterial indicators and coliphage for at least one year--
regardless of sensitivity determination. As an alternative approach, 
the committee recommended sand aquifers be included as sensitive 
settings. This recommendations was based on column studies of virus 
transport in soils that showed that viruses move rapidly through sandy 
soils and field studies of virus transport from septic tanks showing 
rapid movement into ground water from sandy coastal plains.

C. Cross Connection Control

    EPA is concerned about introduction of fecal contamination through 
distribution systems; however, EPA has not proposed cross connection 
control requirements in the GWR. EPA will work with the Microbial/DBP 
FACA to consider whether cross connection control should be required in 
future microbial regulations, particularly during the development of 
the Long Term 2 ESWTR, in the context of a broad range of issues 
related to distribution systems. EPA will also request input from the 
FACA on whether to require systems to maintain disinfection residual 
throughout the distribution system. EPA seeks comments or additional 
supporting data related to cross connection control or other 
distribution system issues. In particular to cross connections, the 
Agency requests public comment on: (1) Whether EPA should require 
States and/or systems to have a cross connection control program, (2) 
what specific criteria, if any, should be included in such a 
requirement, (3) how often a program should be evaluated, (4) and 
whether EPA should limit any requirement to only those connections 
identified as a cross connection by the public water system or the 
State. The Agency also requests comment on what other regulatory 
measures EPA should consider to prevent contamination of drinking water 
in the distribution system.

D. Source Water Monitoring

1. Overview and Purpose
    As previously stated, EPA recognizes that there are particular 
challenges associated with developing an effective regulatory approach 
for ground water systems. These include the large number of ground 
water systems that would be regulated, the fact that only a subset of 
these systems appear to have fecal contamination (although a larger 
number are likely to be sensitive), and that most ground water systems 
range from small to very small in terms of the population served. These 
factors combine to underscore the limitations of an across-the-board 
disinfection approach to regulation.
    As part of the multiple-barrier approach, EPA proposes source water 
monitoring requirements that fulfill the need for a targeted risk-based 
regulatory strategy by identifying those systems with source water 
contamination and systems with high sensitivity to possible fecal 
contamination--specifically undisinfected systems located in 
hydrogeologically sensitive aquifers. EPA believes that the proposed 
requirements provide a meaningful opportunity to reduce public health 
risk for a substantial number of people served by ground water sources. 
This section provides detailed information on current monitoring 
requirements, monitoring data, indicators of fecal contamination, co-
occurrence issues, and describes the proposed requirements.
    EPA proposes the following source water monitoring requirements for 
systems that do not treat 4-log removal and/or inactivation of viruses: 
(1) A system must collect a source water sample within 24 hours of 
receiving notification of a total coliform-positive sample taken in 
compliance with the TCR, and test for the presence of E. coli, 
enterococci or coliphage; and (2) any system identified by the State as 
hydrogeologically sensitive through a sensitivity assessment (see 
Sec. 141.403) must conduct routine monthly monitoring, during the 
months the system supplies water to the public, and analyze for E. 
coli, enterococci or coliphage. In either case, if any sample is fecal 
indicator-positive, the system would have to notify the State 
immediately and then the system must take corrective action.
    Currently, all systems must comply with the TCR (see section 
I.B.1.) and the MCL for nitrates and nitrites. In

[[Page 30228]]

addition, CWSs and NTNCWSs must monitor at the entrance of the 
distribution system for 15 additional inorganic chemicals associated 
with an MCL (e.g., antimony, arsenic) and sometimes other inorganic 
chemicals not associated with an MCL (calcium, orthophosphate, silica, 
sodium, sulphate; 40 CFR 141.23(b) and (c)). Systems will also have to 
comply with the Stage 1 DBPR, if they use a chemical disinfectant. CWSs 
must additionally monitor for certain organic chemicals and certain 
radionuclides. Ground water systems under the direct influence of 
surface water must satisfy the requirements of the SWTR and IESWTR.
    Microbial monitoring plays an important role in detecting fecal 
contamination in source waters, as well as in assessing best management 
practices, including in-place disinfection adequacy and distribution 
system integrity. It is the most direct way to determine the presence 
of fecal contamination. However, because of limitations on sample 
volume, monitoring frequency, and the species of microorganisms that 
can reasonably be monitored, non-detection of a fecal indicator does 
not necessarily mean fecal contamination is absent (see Tables III-2 
and 3).
2. Indicators of Fecal Contamination
    Two approaches for determining whether a well is contaminated are 
to monitor for the presence of either specific pathogens or more 
general indicators of fecal contamination. Monitoring for individual 
pathogens, however, is impractical because the large number and variety 
of pathogens require extensive sampling and numerous analytical 
methods. This is a process which is extremely time-consuming, 
expensive, and also technically demanding. Moreover, methods are not 
available for some pathogens and pathogen concentrations in water are 
usually sufficiently small so as to require analysis of large-volume 
samples, which significantly increases analytical costs. For these 
reasons, EPA is focusing on indicators of fecal contamination as a 
screening tool rather than on individual pathogens themselves. The 
Agency is considering several promising fecal indicators: E. coli, 
enterococci, somatic coliphage, and male-specific coliphage. Because 
these indicators are closely associated with fecal contamination, EPA 
believes that even a single positive sample should require urgent State 
notification and other follow-up activities.
    EPA considered three bacterial microorganisms as indicators of 
fecal contamination: E. coli, enterococci, and C. perfringens. E. coli 
and enterococci are both closely associated with fresh fecal 
contamination and are found in high concentrations in sewage and 
septage. Analytical methods are commercially available, simple, 
reliable, and inexpensive. E. coli is monitored under the TCR, and E. 
coli and enterococci are recommended by EPA as indicators for fecally 
contaminated recreational waters. A drawback is that these two groups 
may die out more quickly or be less mobile in the subsurface 
environment than some waterborne pathogens.
    As with E. coli and enterococci, C. perfringens is common in sewage 
(about 10 \6\ organisms per liter) and is associated with fecal 
contamination. Methods of detection are commercially available, simple, 
reliable, and relatively inexpensive. C. perfringens forms protective 
spores (endospores), and these spores survive much longer in some 
environments than most pathogens. Thus, these spores may be present in 
old fecal contamination where fecal pathogens are no longer viable. EPA 
rejected C. perfringens as an indicator of fecal contamination for GWSs 
based on co-occurrence data showing that the organism is seldom present 
in ground water when other fecal indicators are present (Lieberman et. 
al., 1999).
    Enteric viruses, much smaller in size than bacteria such as E. 
coli, may be more mobile than bacteria because they can slip through 
small soil pores more rapidly. Thus, viral pathogens may sometimes be 
present in ground water in the absence of bacterial indicators of fecal 
contamination. However, other factors such as sorption to soil and 
aquifer particles are also important in affecting the relative 
transport of viruses and bacteria in ground water.
    The coliphage are viruses that infect the bacterium E. coli. 
Because they do not often infect other bacteria, they (like E. coli) 
are closely associated with recent fecal contamination. Because they 
are viruses, their stability and transport within soil and under 
aquifer environmental conditions may be similar to the fate and 
transport of pathogenic viruses. There are two categories of 
coliphage--somatic coliphage and male-specific coliphage. The somatic 
coliphage are a heterogenous group that enters the cell wall of E. 
coli. The male-specific (also called the F-specific) phage are those 
that only enter through tiny hair-like appendages (pili) to the cell 
wall.
    There are issues about using coliphage as an indicator of fecal 
contamination in small communities. Individuals do not consistently 
shed coliphage. For example, Osawa et al. (1981) found that only 2.3% 
of infected individuals shed male-specific phage. Thus, the occurrence 
of these viruses in small septic tanks, which is an important source of 
fecal contamination in ground water wells, is uncertain. The issue of 
frequency and abundance is important because a primary source of fecal 
contamination in wells is thought to be nearby leaking septic tanks.
    To answer this question, EPA funded a study to determine (Deborde, 
1998, 1999) the frequency and density of coliphage occurrence in 
household septic tanks. Deborde (1998) collected and analyzed a sample 
from each of 100 sites in the Northwest and from each of 12 sites in 
the Midwest (3), Southwest (3), Northeast (3), and Southeast (3). All 
112 samples were analyzed for male-specific coliphage, while 33 were 
also analyzed for somatic coliphage. Table III-1 shows that male-
specific coliphage are present in about one-third of the septic tank 
samples, while somatic coliphage are present in two thirds of the 
samples tested. However, when found, the male-specific coliphage are 
present at a slightly higher level. The number of possible people per 
household (and therefore the number of virus sources) varied from one 
to seven, with an average of 2.8. In the next phase of the study, 
Deborde (1999), selected ten of the 112 sites (five coliphage-positive, 
five coliphage-negative) and collected three quarterly samples from 
each. The data indicate that significant changes in density occur over 
time. For the male-specific phage, the number of positive sites was 
40%, 60% and 40% for quarter 2, 3, and 4, respectively. For the somatic 
phage, the number of positive sites was 70%, 80% and 50% during these 
same three quarters. As in the first phase, somatic phage were detected 
more frequently and the male-specific phage were (when detected) more 
abundant.
    The data indicate that household septic tanks often (50-80%) 
contain measurable levels of somatic coliphage, suggesting that the 
somatic coliphage may be an appropriate indicator of fecal 
contamination in nearby source waters. However, the male-specific 
coliphage were present in the septic tanks in slightly less than half 
the sites at any one time. Based on these data, male-specific phage may 
not be suitable for detecting fecal contamination in source waters if 
the most likely contamination source is a household septic tank.

[[Page 30229]]



  Table III-1.--Frequency and Density of Coliphage In Household Septic
               Tanks, Preliminary Results (Deborde, 1998)
------------------------------------------------------------------------
           Coliphage                 Presence           Density \1\
------------------------------------------------------------------------
Male-specific.................  36% (44/112).....  9.7  x  10 \5\ PFU
                                                    \1\/L
Somatic.......................  67% (22/33)......  1.3  x  10 \5\ PFU
                                                    \1\ /L
------------------------------------------------------------------------
\1\ Plaque-Forming Units (PFU).

    Analytical methods for coliphage are available and are far less 
expensive than methods for pathogenic virus detection. However, the 
coliphage detection methods are still somewhat more expensive than 
those for the common indicator bacteria. EPA is in the process of 
funding the development of more sensitive, less expensive analytical 
methods for the somatic and male-specific coliphage.
    EPA also considered methods using polymerase chain reaction (PCR) 
for identifying specific viruses. PCR amplifies the nucleic acid of the 
targeted virus, which then can be detected and identified by various 
procedures. An advantage of this method over those for coliphage is 
that it can identify the presence of specific viruses pathogenic to 
humans. Methods using PCR may be specific, sensitive, and much more 
rapid than other methods for pathogenic virus. However, current PCR 
technology cannot yet determine whether a virus is viable or infectious 
and is significantly more expensive than the culture methods for the 
above fecal indicators (currently about $250-300 per sample). EPA 
expects substantial reductions in this cost as the method is further 
developed. Nevertheless, in spite of the current limitations of PCR, a 
positive result in a ground water sample would strongly imply that a 
pathway exists for virus contamination of ground water.
    EPA did not consider total coliform bacteria or heterotrophic 
bacteria as fecal indicators because both groups grow naturally in soil 
and water, and thus are not specific indicators of fecal contamination.
    According to a survey of ground water data by the AWWARF study (see 
Table II-6), C. perfringens was only detected in one of 57 samples 
(1.8%). Thus, EPA eliminated this organism from consideration. See 
Tables III-2 and 3 for occurrence data on candidate indicators.

                         Table III-2.--Presence/Absence of Indicators at Enterovirus-Positive Sites (Generally, One Sample/Site)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Number of                                    Enterococci or
                                                             positive          Total        E. coli or         fecal       Somatic phage    F-specific
                          Study                             enterovirus      coliforms         fecal       streptococci       (100 L)     phage  (100 L)
                                                               sites         (100 mL)        coliforms       (100 mL)
--------------------------------------------------------------------------------------------------------------------------------------------------------
AWWARF Study............................................              22               4              NA           \1\ 2           \2\ 0       \2\ 2 (3)
Missouri Alluvial Study.................................              11               5               3               5               1               0
Missouri Ozark Plateau..................................              10               0               0               0               0              2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Only 11 enterovirus-positive sites tested.
\2\ 15 liter samples.


      Table III-3.--Data From EPA/AWWARF Study. Number of Times Indicator Was Positive in 12 Monthly Samples at Enterovirus-Contaminated Sites \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                         Somatic           F-specific
    Enterovirus-positive site ( \1/12\ pos)      Total  coliform-  E. coli  positive     Enterococci-        coliphage-         coliphage
                                                                positive                              positive         positive \2\       positive \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
029......................................................                 12                 12                 12                 12                 11
031......................................................                 12                  6                  5                  9                  3
047......................................................                 12                 10                 12                 12                  4
061......................................................                 11                 11                 10                 11                  8
091......................................................                 10                  3                  5                 12                  0
097......................................................                  5                  0                  1                  4                  0
099......................................................                  2                  0                  1                  0                  1
                                                          ----------------------------------------------------------------------------------------------
    Total................................................                 64                 42                 46                 60                27
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sample volume: bacteria 300 mL; coliphage most between 10-100L; enterovirus: average of 6,037 L.
\2\ Host for somatic coliphage: E. coli C; host for F-specific coliphage: WG49.

    The data strongly shows that a single negative sample is usually 
not sufficient to demonstrate the absence of fecal contamination, and 
that repeated sampling is necessary. Based on the data, EPA does not 
believe that one fecal indicator is clearly superior to the others.
    The coliphage sample volume in the studies in Table III-3 ranged 
from 10L to 100L (compared to 100-300 mL for the bacterial indicators). 
EPA believes that it would be unreasonable to expect systems to collect 
and transport these high water volumes. However, as stated earlier, 
several sensitive coliphage methods have been developed that can be 
used with a more reasonable volume (100-1000 mL).
    Thus, for the reasons indicated earlier, EPA is proposing E. coli, 
coliphage and enterococci as appropriate monitoring tools for source 
water. Because these three fecal indicators are closely associated with 
fecal contamination, the Agency believes that a single source water 
positive E. coli, coliphage or enterococci sample is sufficient to 
consider the source water as fecally contaminated. Repeated sampling is 
proposed for routine monitoring (described in the next section) since 
it may take more than one sample to identify intermittent 
contamination. Additional support for this approach is provided by 
Christian and Pipes (Christian and Pipes, 1983), who found that 
coliforms follow a lognormal distribution pattern in small distribution 
systems (i.e., coliforms are not uniformly distributed). EPA has no 
reason to suspect that this non-uniform pattern should be different in 
source waters. Only one additional sample is proposed after triggered 
monitoring (described in the next section) since the

[[Page 30230]]

sample is taken immediately after an indication of contamination.
    The Agency recognizes that errors in sample collection and testing 
may contaminate a sample, and therefore would allow the State to 
invalidate such samples, on a case-by-case basis, in the same manner 
required under the TCR (141.21(c)(1)(i) and (iii) for invalidating 
total coliform samples. However, EPA believes that errors in sample 
collection rarely lead to contamination. This is based on a study by 
Pipes and Christian (Pipes and Christian, 1982), where water samplers 
and other individuals tried to contaminate 111 sample bottles 
containing 100-mL of sterile dechlorinated tap water by placing a 
finger into the mouth of each bottle and shaking the bottle vigorously 
for about 5 seconds. Only 5.4% of the samples were found to contain 
total coliforms.
    Thus, the Agency believes that States should invalidate positive 
samples sparingly. Under the GWR, the State would be allowed to 
invalidate a positive source water sample if (1) the laboratory 
establishes that improper sample analysis caused the positive result or 
(2) the State has substantial grounds to believe that a positive result 
is due to a circumstance or condition which does not reflect source 
water quality, documents this in writing, and signs the document. In 
this case, another source water sample must be taken within 24 hours of 
receiving notice from the State.

3. Proposed Requirements

a. Routine Source Water Monitoring
    EPA stated in the previous section on hydrogeology that a State 
would be required to determine the hydrogeological sensitivity of each 
system not treating to 4-log inactivation or removal of viruses. If the 
State determines that the well(s) serving such a system draws water 
from a sensitive aquifer, that system would be required to collect a 
source water sample each month that it provides water to the public and 
test the sample for the fecal indicator specified. If any sample 
contains a fecal indicator, the system would be required to notify the 
State immediately and address the contamination within 90 days unless 
the State has approved a longer schedule (see Sec. 141.404).
    Under the GWR, if a system detects no fecal indicator-positive 
samples after 12 monthly samples, the State would be allowed to reduce 
routine source water monitoring to quarterly. The State would be 
allowed, after the first year of monthly samples, to waive source water 
monitoring altogether for a system if the State determines that fecal 
contamination of the well(s) is highly unlikely, based on sampling 
history, land use pattern, disposal practices in the recharge area, and 
proximity of septic tanks and other fecal contamination sources. PWSs 
that do not operate year-round would need to conduct monthly sampling 
for more than one year to collect the twelve monthly samples. EPA 
requests comment on allowing such systems to monitor monthly for only 
one seasonal period when the system is in operation.
b. Source Water Sample After a Total Coliform-Positive Under the TCR
    EPA proposes that when a non-disinfecting ground water system is 
notified that a sample is total coliform-positive under the TCR, that 
system would have to collect, within 24 hours of being notified, at 
least one source water sample. This requirement would be in addition to 
all monitoring and testing requirements under the TCR. The source water 
sample would be tested for either E. coli, coliphage or enterococci, as 
determined by the State. A system that chooses to first test for total 
coliforms in the source water, and then test any total coliform-
positive culture for E. coli would meet the requirement.
    If any sample is E. coli-positive, coliphage-positive or 
enterococci-positive, the system would be required to meet 
Sec. 141.404. EPA believes that a total coliform-positive sample in the 
distribution system, followed by a fecal indicator-positive sample in 
the source water, indicates a serious contamination problem.
    The Agency would allow the State to waive source water monitoring 
for any system, on a case-by-case basis, if the State determines that 
the total coliform-positive is associated solely with a distribution 
system problem. In this case, a State official would be required to 
document the decision, including the rationale for this decision, in 
writing, and sign the document.
c. Confirmation of Positive Source Water Sample
    The Agency recognizes that false-positive results may occasionally 
occur with most microbial methods (i.e., a non-target microbe is 
identified by the method as a target microbe). For example, the false-
positive rate for E. coli is 7.2% for the E*Colite Test, 2.5% for the 
ColiBlue24 Test, and 4.3% for the membrane filter test using MI Agar.
    Therefore, EPA would allow the State to invalidate a positive 
source water sample where a laboratory establishes that improper sample 
analyses caused the positive result or if the State has substantial 
grounds to believe that a positive result was due to a circumstance or 
condition that did not reflect source water quality and documents this 
in writing. For example, a State may invalidate a positive source water 
sample if a subsequent validation step for the same sample fails to 
confirm the presence of the fecal indicator being used. These 
provisions are consistent with the invalidation criteria under the TCR 
(40 CFR 141.21(c)).
    EPA believes that, in the interest of public health, a positive 
sample by any of the methods listed in Table III-4 should be regarded 
as a fecal indicator-positive source water sample. This assumption is 
supported by the Pipes and Christian study (Pipes and Christian, 1982) 
study mentioned previously, which shows that sample collector handling 
error is rarely a cause of fecal contamination. Nevertheless, the 
Agency recognizes that contamination during sampling and analysis may 
occur, albeit rarely, and is proposing to allow the State to invalidate 
a fecal indicator-positive in a routine monitoring sample under certain 
circumstances in the manner described in this section. EPA is also 
proposing to allow confirmation of a fecal indicator-positive routine 
source water sample. Specifically, the rule would permit the State to 
allow a system to waive compliance with the treatment technique in 
Sec. 141.404, after a single fecal indicator-positive source water 
sample on a case-by-case basis, if--
    (1) The system collects five repeat source water samples within 24 
hours after being notified of a source water-positive result;
    (2) The system has the samples analyzed for the same fecal 
indicator as the original sample;
    (3) All the repeat samples are fecal indicator-negative; and
    (4) All required source water samples (routine and triggered) 
during the past five years were fecal indicator-negative.
    Under this approach, a system would not necessarily have to comply 
with the specified treatment requirements on the basis of a single, 
isolated fecal indicator-positive sample if all additional monitoring 
showed that no problem exists. The Agency believes that this limited 
level of confirmation would not undermine public health protection. 
Conversely, the Agency believes that two fecal indicator-positive 
source water samples at a site provides strong evidence that the source 
water has been fecally contaminated.
    The Agency is also proposing that a total coliform-positive sample 
in the

[[Page 30231]]

distribution system accompanied by a fecal indicator-positive source 
water sample be sufficient grounds for requiring compliance with the 
treatment requirements. The Agency argues that it would be unreasonable 
to expect a sample collector to accidently contaminate two samples 
taken at least one day apart, and also contends that the likelihood of 
a false-positive result occurring in both of two samples is much lower 
than in a single sample. Thus, the Agency believes that, in this 
circumstance, there is a significant probability that the source water 
is indeed fecally contaminated. Moreover, the Agency notes that, under 
the TCR, two consecutive total coliform-positive samples, one of which 
is E. coli-positive, is sufficient grounds for an acute violation of 
the MCL for total coliforms. For these reasons, EPA believes that it is 
reasonable to require a system with a total coliform-positive sample in 
the distribution system followed by a fecal indicator-positive source 
water sample to comply with the treatment requirements. However, EPA 
also recognizes that, by itself, a positive total coliform result is 
not always an indication of fecal contamination (even if the sample 
result is not a false positive). EPA requests comment on waiving 
compliance of the treatment techniques after a single positive 
triggered monitoring source water sample based upon five negative 
repeat samples as described previously in this section.

4. Analytical Methods

    EPA proposes to approve the following methods (listed in 141.403), 
with the sample volume of 100 mL, for source water monitoring of E. 
coli, enterococci and coliphage. A system would have to use one of 
these methods. Most of the proposed analytical methods for E. coli for 
source water monitoring are consensus methods described in Standard 
Methods for the Examination of Water and Wastewater (19th and 20th 
ed.). 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. Information 
about these methods is available in the Federal Register (63 FR 41134-
41143, July 31, 1998; 64 FR 2538-2544, January 14, 1999) and in the 
EPAWater Docket. Of the three enterococci methods, two are consensus 
methods in Standard Methods; while the third (Enterolert) was described 
in a peer-reviewed journal article (Budnick et al., 1996). The 
description for each of the proposed E. coli and enterococci methods 
state explicitly that the method is appropriate for fresh waters or 
drinking waters.
    EPA is proposing the approval of two newly developed coliphage 
methods for detecting fecal contamination.
    The Agency has conducted performance studies on the two proposed 
methods, using ten laboratories: a new two-step enrichment method and a 
single-agar layer method used for decades, but recently optimized for 
ground water samples. For the two-step enrichment method, using 100-mL 
spiked water samples (reagent water and ground water) and two E. coli 
hosts (CN-13 and Famp), laboratories detected one plaque-
forming unit (PFU) 60-90% of the time. For the optimized single-agar 
layer method, using the same water type and volume (but higher 
coliphage spike) and same two E. coli hosts, recoveries ranged from 61% 
to 178%, based upon a coliphage spike level determined by a standard 
double-agar layer test.
    Based upon the results of performance testing, EPA believes that 
these two coliphage tests are satisfactory for monitoring ground water 
in compliance with this rule. The two test protocols and study results 
are available for review in EPA's Water Docket.
    EPA is proposing requiring that systems collect and test at least a 
100-mL sample volume. The Agency recognizes that a 1-L sample volume 
will provide ten times more sensitivity than a 100-mL sample. However, 
the Agency also understands that the greater sample volume would also 
weigh ten times more, and thus cost more to ship to a laboratory. Data 
exists that indicate more frequent smaller-volume samples are better in 
detecting fecal contamination than a smaller number of high volume 
samples (Haas,1993). AWWARF is funding a study on this issue, and data 
should be available shortly. The Agency requests comment on the most 
appropriate sample volume.
    For any of the methods described previously, the maximum allowable 
time between ground water sample collection and the initiation of 
analysis in the certified laboratory, is 30 hours. This would be 
consistent with the TCR. The Agency would prefer a shorter time, but 
believes that a sizable percentage of small systems have difficulty 
getting their samples to a certified laboratory within 30 hours. In 
addition, unlike the SWTR where the density is measured, EPA is 
proposing in the GWR to require analysis for microorganism detection 
alone. The Agency believes that the detection of an organism is less 
sensitive to change than measurement of density, and thus a 30-hour 
transit time would be reasonable.
5. Request for Comments
    EPA requests comments on proposed indicators of fecal contamination 
and analytical methods. In addition, EPA requests comments on the 
following alternative approaches.
(a) Source Water Samples after an MCL Violation of the TCR
    EPA requests comment on requiring a system that violates the MCL 
for total coliforms, or detects a single fecal coliform/E. coli-
positive sample under the TCR, to collect five source water samples, 
rather than a single source water sample as proposed. The Agency 
believes this alternative approach would be reasonable, given that both 
events are sufficiently important to require the system to notify the 
State (and, for a MCL violation, the public) as opposed to a single 
total coliform-positive sample which does not require notification. 
Under this approach, systems would be required to collect five source 
water samples within 24 hours for every MCL violation or positive E. 
coli or fecal coliform sample in the distribution system and test them 
for one of the EPA-specified fecal indicators. If any source water 
sample were positive, the system would have to treat or otherwise 
protect the drinking water. This monitoring requirement would be in 
addition to requirements under the TCR.
(b) Sampling of Representative Wells
    EPA recognizes that most CWSs have more than one well, raising the 
question about whether the system would need to monitor all wells or 
just one representative well. One approach would be to require a system 
to sample all wells because this approach provides more reliable public 
health protection. However, the Agency notes that wells belonging to a 
system may vary in their sensitivity to fecal contamination.
    If a system is drawing water from more than one well in a 
hydrogeologically sensitive aquifer, EPA believes that all such wells 
should be sampled routinely, unless the State can identify a single 
representative well or, the well (or subset of wells) sensitive to 
fecal contamination. If a system is required to collect a source water 
sample as a result of a total coliform-positive sample in the 
distribution system (triggered monitoring), EPA believes that all wells 
should be sampled, unless the State can identify a single 
representative well or the well (or

[[Page 30232]]

subset of wells) most vulnerable to fecal contamination. Alternatively, 
if the total coliform-positive sample was found in a part of the 
distribution system supplied by a single well, then it might be 
acceptable to sample that specific well alone. The Agency seeks comment 
on these alternatives and other approaches.
    EPA recognizes that systems may have storage tanks or other water 
holding tanks between the wellhead and the distribution system. 
Therefore the Agency also requests comment on whether further 
definition is needed for exactly where source water samples should be 
taken; e.g., at the well, the tank, or at any point before the water 
enters the distribution system. The Agency seeks comment on where 
source water samples should be collected.
(c) Distribution System Monitoring for Fecal Indicators
    One alternative approach for distribution system monitoring is to 
augment total coliform/E. coli testing in the distribution system with 
one or more additional fecal indicators. For example, under this 
approach, a system would be required to monitor coliphage or 
enterococci at the same frequency as it monitors for total coliforms. 
This approach recognizes that fecal indicators differ in their 
effectiveness in detecting fecal contamination, and that this 
effectiveness may vary with environmental conditions. Thus, more than 
one fecal indicator should stand a greater likelihood of detecting 
fecal contamination than a single indicator (i.e., E. coli under the 
TCR). This approach would be more expensive for systems, but may be 
counterbalanced by the greater likelihood of detecting fecal 
contamination. EPA seeks comment on this monitoring approach.
(d) Persistent Monitoring Non-Compliers
    EPA requests comment on defining a persistent non-complier of 
monitoring requirements and, specifically what any additional 
monitoring, public notification or treatment requirements should 
pertain to them.
(e) Monitoring of Disinfecting Systems
    Some States currently require disinfected systems to monitor their 
source water to ensure that the system would be protected against the 
potential risk of fecal contamination in the event of a disinfectant 
failure. The Agency requests comment on requiring a disinfected system 
to test its source water periodically.
    The Agency also requests comment on requiring all ground water 
systems (including those that disinfect to 4-log removal/ inactivation 
of viruses) to collect a source water sample after a total coliform-
positive in the distribution system (triggered monitoring). Systems may 
want or need to change their disinfection practices or take other 
source water protection actions based on discovering that their source 
water is contaminated.
(f) Multiple Fecal Indicators
    EPA is proposing to require ground water systems to monitor 
coliphage, E. coli, or enterococci, as determined by the State, in the 
source water. On March 13, 2000, the Drinking Water Committee of the 
Science Advisory Board (DWCSAB) made a few recommendations to EPA 
concerning a draft of this proposal.
    The DWCSAB recommended unanimously, and the Agency is requesting 
comment on, requiring monitoring for both bacterial and viral 
indicators for both routine and triggered monitoring. Specifically, EPA 
is requesting comment on whether systems that must monitor their source 
water be required to monitor for both a bacterium (E.coli or 
enterococci) and virus (male specific and somatic coliphage). As 
discussed earlier, occurrence data show that fecal indicators differ in 
their scope and this may vary with environmental conditions. The DWCSAB 
noted that the scientific literature documents significant differences 
between transport and survival of bacteria and viruses. Coliphage and 
human viruses are smaller than bacterial indicators and thus under 
certain conditions may travel faster through the ground than bacteria; 
alternately, bacterial indicators are often at much higher 
concentrations in fecal matter than coliphage, and thus may be a more 
sensitive indicator than coliphage relatively near the contamination 
source. The use of both bacteria and coliphage indicators could provide 
better ability to detect fecal contamination and greater protection of 
human health. However it would also entail a higher probability of 
false positive results, and higher sampling costs to the systems.
    The DWCSAB believed that the proposed indicators (E.coli, 
enterococci, and coliphage) are appropriate. The DWCSAB noted that both 
E. coli and enterococci are effective bacterial indicators. E. coli 
methods may be more familiar to many laboratories which may be 
advantageous. The enterococci may be somewhat hardier in terms of 
environmental persistence and perhaps more fecal specific. The media 
for enterococci is more selective and less subject to background growth 
with regards to the viral indicators. The DWCSAB recommended both 
somatic and male-specific coliphage be required when viral monitoring 
of the source water is conducted because they will detect a larger 
population of coliphage. The DWCSAB stated that laboratory methods are 
available to detect both coliphages and that they believe that a method 
can be made available to detect both coliphages on a single host (using 
a single host such as E. coli C3000) so that it would not be necessary 
to collect and test two samples for coliphage.
(g) Monitoring Frequency and Number of Samples To Identify Fecal 
Contamination
    As stated previously, the proposed rule would require systems with 
sensitive wells to conduct monthly routine monitoring. The Agency 
believes that monitoring more frequently than monthly would increase 
the probability for detecting fecal indicator organisms sooner in a 
fecally contaminated well. However, the Agency also recognizes that 
more intensive monitoring could be overly burdensome to many small 
systems. Less than monthly monitoring would likely delay fecal 
contamination detection, and thus continue a possible health risk for a 
longer time. EPA concludes that monthly monitoring is the most 
appropriate balance between monitoring costs and prompt fecal 
contamination detection.
    The total number of samples needed to determine whether a ground 
water is fecally contaminated depends on the fecal indicator used, the 
sample volume, and the level and duration of fecal contamination in the 
source water. Because the EPA/AWWARF study described in section II.C.2. 
monitored contaminated wells repeatedly, the results of this study were 
used to assess the likelihood (95%, 99%, 99.9% confidence) of detecting 
fecal contamination with different indicators, number of samples and 
level of fecal contamination actually in the ground water. The Agency 
then determined the minimum number of samples necessary to detect 
contamination, allowing for a small percentage of samples where fecal 
contamination is not detected. The EPA/AWWARF study operated in two 
phases. In Phase I, the EPA/AWWARF researchers identified a set of 93 
wells thought to be vulnerable to fecal contamination. In Phase II, the 
researchers conducted further analysis, including monthly monitoring 
for virus and bacteria, on a subset of 23 of the Phase I wells which 
demonstrated total coliform and/or fecal bacteria contamination and on 
an additional 7

[[Page 30233]]

wells chosen for their unique physical or chemical characteristics.
    From the wells tested in Phase II of the EPA/AWWARF study, seven 
sites tested positive for enterovirus in at least one sample of the 
twelve collected during the year. These seven waters are considered to 
be representative of ground water that are highly fecally contaminated 
at least part of the year. In such waters, a good indicator should be 
present in almost every sample, therefore, the number of non-detects 
should be very low. Combining the monthly results for these seven 
waters, there are 84 results for each indicator. Table III-5 shows the 
proportion of positives among the 84 results for each of four 
indicators.

 Table III-5.--Indicator Performance in Seven Highly-Contaminated Waters
------------------------------------------------------------------------
                                                               Samples
                                                               positive
                         Indicator                            (percent)
                                                                (N=84)
------------------------------------------------------------------------
E. coli....................................................           50
Enterococci................................................         54.8
Somatic Coliphage..........................................         71.4
F-Specific Coliphage.......................................        32.1
------------------------------------------------------------------------
N = number of samples.

    If P is the probability of a positive sampling result (a detect) 
for a single indicator sample assay, then the probability of at least 
one positive result for N repeated independent samples is 1-(1-
P)N. The probability of ``N'' non-detects is (1-
P)N.. Table III-6 shows the probabilities of ``N'' non-
detects for the same indicators as a function of the number of 
independent sample assays (N).

   Table III-6.--Probability of Non-Detects in Ground Water That is Highly Fecally Contaminated at Least Part of the Year (Where `N' Is the Number of
                                                                   Independent Assays)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Number of samples (N)
                                                      --------------------------------------------------------------------------------------------------
                    Indicator \1\                        N = 1      N = 2      N = 4      N = 6      N = 12     N = 24     N*  5      N*1  1    N*  0.1
                                                       (percent)  (percent)  (percent)  (percent)  (percent)  (percent)   percent    percent    percent
--------------------------------------------------------------------------------------------------------------------------------------------------------
E.coli...............................................         50         25        6.3        1.6        0.1        0.1          5          7         10
Enterococci..........................................       45.2       20.5        4.2        0.9        0.1        0.1          4          6          9
Somatic Coliphage....................................       28.6        8.2        0.7        0.1        0.1        0.1          3          4          6
F-Specific Coliphage.................................       67.9         46       21.2        9.8        1.0        0.1          8         12        18
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sample volume was 300 ml for E. coli and enterococci, 10-100L for coliphage
N* = Smallest number of samples for which the error rate is less than or equal to the specified percentage (5%, 1%, 0.1%).

    Table III-6 shows that six to18 source water samples are needed, 
depending on the fecal indicator (and sample volume used), to determine 
with a 99.9% probability that a fecal indicator positive will be 
detected in ground water that is highly contaminated at least part of 
the year.
    A similar analysis was conducted using the results for the 10 
waters that tested positive for E. coli at least once (N=12), but 
negative for enterovirus. These waters were defined as moderately 
contaminated during at least part of the year. Because these waters 
probably do not contain enteroviruses at easily detectable levels, the 
incidence of waterborne disease is probably less. Table III-7 shows the 
probabilities of ``N'' non-detects for different numbers of independent 
sample assays (N).

 Table III-7.--Probability of Non-Detects in Ground Water That is Moderately Fecally Contaminated at Least Part of the Year (Where `N' is the Number of
                                                                   Independent Assays)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Number of samples (N)
                                                      --------------------------------------------------------------------------------------------------
                      Indicator                          N = 1      N = 2      N = 4      N = 6      N = 12     N = 24     N*  5      N*  1     N*  0.1
                                                       (percent)  (percent)  (percent)  (percent)  (percent)  (percent)   percent    percent    percent
--------------------------------------------------------------------------------------------------------------------------------------------------------
E.coli...............................................       71.7       51.4       26.4       13.5        1.8        0.1          9         14         21
Enterococci..........................................       67.5       45.6       20.8       9.55        0.9        0.1          8         12         18
Somatic..............................................       72.5       52.6       27.6       14.5        2.1        0.1         10         15         22
F-Specific...........................................       96.7       93.4       87.3       81.6       66.6       44.3         89        136       204
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sample volume was 300 ml for E. coli and enterococci, 10-100L for coliphage
N* = Smallest number of samples for which the error rate is less than or equal to 5.0%, 1% and 0.1%.

    Table III-7, shows that 8 to 89 samples are needed, depending on 
the indicator selected, to determine with a 95% probability that a 
fecal indicator positive will be detected in a well that is moderately 
contaminated at least part of the year.
    Based on the data described previously and statistics, EPA 
concludes that, given a margin of safety for the analysis, 12 samples 
would be sufficient for determining the presence of fecal contamination 
in sensitive wells. For systems operating year round, 12 monthly 
samples will provide data throughout the year, increasing the 
likelihood of detecting the seasonal presence of fecal contamination.
    EPA requests comment on the monitoring approach discussed 
previously and the analysis and the assumptions used.
(h) Triggered Monitoring in Systems Without a Distribution System
    EPA believes that circumstances exist that might not require the 
collection of a source water sample after a total coliform-positive 
sample in the distribution system. For example, if an

[[Page 30234]]

undisinfected system does not have a distribution system, any sample 
taken for compliance with the TCR is essentially a source water sample. 
Therefore, the Agency is requesting comment on whether to allow States 
to waive ``triggered'' source water sampling for systems without 
distribution systems if the system is also taking TCR samples at least 
quarterly. If the total coliform-positive sample from the distribution 
system is fecal coliform-or E. coli-positive, the system would be 
required to meet the treatment technique. There might also be 
provisions for repeat sampling in this case.
(i) Routine Monitoring in Systems Without a Distribution System.
    EPA requests comment on whether to allow States to substitute TCR 
monitoring for routine monitoring in hydrogeologically sensitive 
systems if the system does not have a distribution system and takes at 
least one total coliform sample per month under the TCR for every month 
it provides water to the public. Such a system would be monitoring 
source water under the TCR. The State would be allowed to reduce or 
waive monthly monitoring after twelve negative monthly samples. The 
rule would require a system that has a total coliform-positive sample 
that is also E. coli (or fecal coliform)-positive to meet the treatment 
requirements in Sec. 141.404.
(j) Source Water Monitoring for All Systems
    EPA is proposing to require source water monitoring requirements 
for systems that do not treat to 4-log inactivation or removal of 
viruses and have either a total coliform-positive sample taken in 
compliance with the TCR, or any system identified by the State as 
hydrogeologically sensitive. On March 13, 2000 the Drinking Water 
Committee of the Science Advisory Board (DWCSAB) reviewed this issue 
and made several recommendations to EPA concerning a draft of this 
proposal. The DWCSAB raised concerns that under this approach many 
untreated ground water systems will not be monitored at the source, 
particularly in light of available occurrence data indicating 
contamination between 4 and 31 percent of ground water systems, a 
number of which many not be located in hydrogeologically sensitive 
areas. DWCSAB unanimously recommended that all ground water systems 
monitor for both bacterial and viral indicators. EPA requests comment 
on whether routine source water samples should be required for all 
ground water systems that do not notify the State that they achieved 4-
log inactivation or removal of virus. EPA also requests comment upon 
the appropriate frequency (monthly or quarterly) for routine monitoring 
if it were required for all systems. EPA also requests comment upon 
whether this monitoring should be performed in conjunction with 
sanitary surveys so as to provide data for the sanitary survey and to 
reduce the capacity burden on laboratories by taking advantage of the 
phased timing of sanitary surveys (every 3 years for CWSs and every 5 
years for NCWs).

E. Treatment Techniques for Systems With Fecally Contaminated Source 
Water or Uncorrected Significant Deficiencies

1. Overview and Purpose
    EPA proposes that a public ground water system with uncorrected 
significant deficiencies or fecally contaminated source water must 
apply a treatment technique or develop application for a longer State-
approved treatment technique within 90 days of notification of the 
problem. Under the SDWA, the State may extend the 90 day deadline up to 
two additional years if the State determines that additional time is 
necessary for capital improvements (SDWA, 1412(b)(10)). As part of this 
requirement and in consultation with the State, systems must eliminate 
the source of contamination, correct the significant deficiency, 
provide an alternate source water, or provide a treatment which 
reliably achieves at least 99.99 percent (4-log) inactivation or 
removal of viruses before or at the first customer. Ground water 
systems which provide 4-log inactivation or removal of viruses will be 
required to conduct compliance monitoring to demonstrate treatment 
effectiveness.
    EPA is proposing 99.99% (4-log) virus inactivation or removal as 
the minimum level of treatment since it is the level required of 
surface water systems under the SWTR and because, the World Health 
Organization (WHO) states that disinfection processes must achieve at 
least 4-log reduction of enteric viruses (WHO, 1996). Which treatment 
technique approach is chosen will depend on existing State programs, 
policies or regulations. States must describe in their primacy 
application the treatment technique they will require and under what 
circumstances. If the treatment technique is not provided within 90 
days, or if it is not implemented by the system in accordance with 
schedule requirements, the system is in violation of the treatment 
technique requirements of the GWR.
    States and systems can select a number of treatment technologies to 
achieve 4-log virus inactivation or removal. The treatment technologies 
which have demonstrated the ability to achieve 4-log virus inactivation 
are chlorine, chlorine followed by ammonia (chloramines), chlorine 
dioxide, ozone, ultraviolet radiation (UV) and anodic oxidation. 
Reverse osmosis (RO) and nanofiltration (NF) have demonstrated the 
ability to achieve 4-log removal of viruses.
    The Agency is also proposing requirements for systems that treat to 
monitor the disinfection and State notification requirements any time a 
system fails to disinfect to 4-log inactivation or removal of viruses. 
As part of this proposal, systems serving 3,300 or more people per day 
must monitor the disinfection continuously. Systems serving fewer than 
3,300 people per day must monitor the disinfection by taking daily grab 
samples. When a system continuously monitors chemical disinfection, the 
system must notify the State any time the residual disinfectant 
concentration falls below the State-determined residual disinfectant 
concentration and is not restored within four hours. When a system 
monitors chemical disinfection by taking daily grab samples the system 
must maintain the State-determined residual disinfectant concentration 
in all samples taken. If any sample does not contain the required 
concentration, the system must take follow-up samples every four hours 
until the required residual disinfectant concentration is restored. The 
system must notify the State any time the system does not restore the 
disinfectant concentration to the required level within 4 hours.
a. Background
    A key element of the multiple-barrier approach is disinfection 
where fecal contamination or significant deficiencies are not or cannot 
be corrected. EPA recognizes that the GWR must provide system-specific 
flexibility due to the diverse configuration and variability of the 
numerous public ground water systems in operation and allow for State-
specific flexibility. Therefore, the proposed treatment technique 
requirements are designed to support the multiple-barrier approach, yet 
provide flexibility to meet system-specific concerns.
    EPA recognizes that States use varying approaches and that a 
State's preferred approach comes from extensive experience in dealing 
with uncorrected significant deficiencies and

[[Page 30235]]

contaminated source water. States may require systems to take differing 
approaches to providing treatment techniques, depending upon many 
factors, including the system's configuration, or State policies or 
regulations. Therefore, the proposed GWR attempts to build on the 
strengths of existing State programs, yet provide requirements which 
ensure safe drinking water for all consumers. Under the proposed GWR, 
States may require systems to eliminate the source of contamination, 
correct the significant deficiency, provide an alternate source water, 
or provide a treatment which reliably achieves at least 99.99 percent 
(4-log) inactivation or removal of viruses before or at the first 
customer. Ground water systems which provide 4-log inactivation or 
removal of viruses will be required to conduct compliance monitoring to 
demonstrate treatment effectiveness. For example, a State may have a 
policy or regulation requiring a system to consider an alternative 
source of safe drinking water before considering the use of 
disinfection. Alternatively, the State may require the system to 
disinfect to 4-log virus inactivation without first considering the use 
of corrective BMPs or alternative sources of safe drinking water. The 
approach the State will use to require a treatment technique for 
uncorrected significant deficiencies or fecally contaminated source 
water must be described in the State's primary enforcement application 
(primacy). EPA expects a State to build upon existing ground water 
programs to meet today's proposed regulations. In any case, systems 
which do not provide the appropriate State-determined treatment 
technique within the 90 day deadline, and do not have a State-approved 
plan in place for complying with the treatment technique requirement 
within 90 days, are in violation of the treatment technique 
requirements of the GWR.
b. Corrective Action Background Information
    This section presents background information used by EPA to develop 
the proposed treatment technique requirements for ground water systems 
with uncorrected sanitary survey significant deficiencies or fecally 
contaminated source water. Specifically discussed is information 
related to current State treatment technique requirements, and the 
protectiveness of treatment techniques, as well as a discussion of 
disinfection as it relates to uncorrected significant deficiencies and 
fecally contaminated source water.
i. Alternative Sources of Safe Drinking Water
    Limited data exists on the effectiveness of systems using an 
alternative source as a treatment technique against uncorrected 
significant deficiencies or fecally contaminated source water. However, 
since many States require a wide range of BMPs to be followed prior to 
placing an alternative source into service, it is believed that this 
treatment technique would be effective. In addition, some States 
require the local hydrogeology or sources of contamination to be 
considered for all new sources of drinking water, and would, therefore, 
provide some assurance that an alternative source as a treatment 
technique is effective. Several States require systems with source 
water contamination to provide an alternative source, if possible.
ii. Background Information on Eliminating the Source of Contamination
    As with the effectiveness of providing alternative source water as 
a treatment technique for uncorrected significant deficiencies or 
fecally contaminated source water, limited data exists on the 
effectiveness of eliminating the source of contamination as a treatment 
technique. The report on the Analysis of Best Management Practices for 
Community Ground Water Systems Survey Data Collected by the Association 
of State Drinking Water Administrators (ASDWA, 1998) provides 
information on the effectiveness of BMPs in reducing total coliform 
positives, however, it does not address those BMPs used in response to 
a source water fecal contamination event. The report does show that 
when correcting significant deficiencies, a significant pairwise 
association exists in reducing both total and fecal coliform positive 
samples. A wide range of State requirements exist for the use of BMPs, 
with some States requiring the use of one or more BMPs in response to 
contamination events.
iii. Disinfection
    Under today's proposal, disinfection is defined as the inactivation 
or removal of fecal microbial contamination. As noted earlier, 
corrective actions to met the GWR treatment technique includes 
disinfection. Chemical disinfection of viruses involves providing a 
dosage of a disinfectant for a period of time for the purposes of 
inactivating the viruses. For most treatment strategies, the level of 
inactivation achieved varies depending on the target microorganism, 
residual disinfectant concentration, ground water temperature and pH, 
water quality and the contact time. The CT value is the residual 
disinfectant concentration multiplied by the contact time. 
Specifically, the contact time is the time in minutes it takes the 
water to move between the point of disinfectant application and a point 
before or at the first customer during peak hourly flow. The 
concentration is the residual disinfectant concentration in mg/L before 
or at the first customer, but at or after the point the contact time is 
measured. A system compares the CT value achieved to the published CT 
value for a given level of treatment (e.g., 4-log inactivation of 
viruses) to determine the level of treatment attained. As long as the 
CT value achieved by the system meets or exceeds the CT value needed to 
inactivate viruses to 4-log, the system meets the treatment technique 
requirement.
    Four-log virus inactivation can also be achieved by UV 
disinfection, which differs from some other treatment technologies, in 
that providing a residual concentration is not possible. When using UV 
disinfection, a light dosage is applied to the water to target the 
attainment of IT values (measured in mWs/cm \2\). IT is the light 
irradiance (measured in mW/cm \2\) to which the target organisms are 
exposed, multiplied by the time for which the irradiance is applied 
(measured in seconds). A system compares the IT value achieved to the 
published IT value for a given level of treatment (e.g., 4-log 
inactivation of viruses) to determine the level of treatment attained. 
Systems required to disinfect with UV disinfection under the GWR must 
provide 4-log inactivation of viruses at a minimum. As long as the 
system attains IT values necessary for 4-log virus inactivation, the 
system meets the treatment technique requirement.
    Removal, in the context of treatment of microbially contaminated 
ground water, is the physical straining of the microbial contamination, 
and is usually accomplished through filtration. For the purposes of 
disinfection of microbially contaminated ground water, removal is 
accomplished by membrane processes. Membrane processes physically 
remove viruses from the water based on the size of the virus and the 
size of the membrane's pores. When the absolute size of the membrane's 
pores (the molecular weight cut-off, or MWCO) are substantially smaller 
than the diameter of the virus, removal of the virus can be achieved. 
Therefore, membrane filtration technologies with MWCO substantially 
less than the diameter of

[[Page 30236]]

viruses can be effective treatment technologies for 4-log virus 
removal.
iv. State Requirements
    EPA used the Baseline Profile Document for the Ground Water Rule 
(USEPA, 1999f) to assess current State treatment technique 
requirements. The EPA survey Ground Water Disinfection and Protective 
Practices in the United States (US EPA, 1996a) was used where the 
Baseline Profile Document for the Ground Water Rule (USEPA, 1999f) 
lacked certain information. These data are important in illustrating 
the wide range of State requirements that exists in ground water 
systems. The GWR attempts to build on existing State practices and 
provide State flexibility to address system-specific concerns.
    Based on an analysis of information in the Baseline Profile 
Document for the Ground Water Rule (USEPA, 1999f), there is great 
variability nationwide in State statutes, regulations, and policies for 
when and how systems must apply treatment techniques. The variability 
ranges from 11 States requiring across-the-board disinfection, several 
other States requiring systems to attempt to eliminate the real or 
potential source of fecal contamination before considering 
disinfection, to some States requiring systems with fecally 
contaminated source water to provide an alternative source of safe 
drinking water. Almost all of the States have statutes, regulations, or 
policies for treatment techniques that define under what circumstances 
treatment techniques are necessary. Twenty-eight of the 39 States which 
do not require across-the-board disinfection require application of 
treatment techniques based on the microbial quality of the water and 12 
of the 39 require application of treatment techniques based on the 
sanitary quality of the system.
    How a system applies treatment techniques also varies considerably 
from State to State. For example, 36 of the 50 States specify 
requirements on the use of disinfectant residuals in the distribution 
system, while five States require 4-log inactivation of viruses at the 
source.
v. Disinfection Technologies
    In ground water systems, 4-log inactivation of viruses can be 
accomplished by disinfection with free chlorine, chloramines, chlorine 
dioxide, ozone, on-site oxidant generation (anodic oxidation) or 
ultraviolet radiation (UV). Reverse osmosis (RO) and nanofiltration 
(NF) can achieve 4-log removal of viruses. Chlorine, chloramines, 
chlorine dioxide, ozone, UV, RO and NF are all listed as small system 
compliance technologies for the SWTR. EPA also suggests that small 
systems consider on-site oxidant generation for SWTR compliance 
purposes (US EPA, 1998c).
    Chemical disinfection technologies are commonly used to provide 
disinfection prior to distribution, and must attain specific CT values 
(which vary depending on the technology) to achieve 4-log virus 
inactivation. Free chlorine disinfection is the most commonly practiced 
chemical disinfection technology, and requires a CT value of four to 
provide 4-log inactivation of viruses at a water temperature of 
15 deg.C, and a pH of 6-9 (USEPA, 1991a).
    The required CT values for 4-log virus inactivation when using 
chloramines or chlorine dioxide are higher than when using free 
chlorine (Table III-8). The CT values for 4-log inactivation of viruses 
at a pH of 6-9 and a temperature of 15 deg.C are 16.7 mg-min/L for 
chlorine dioxide and 994 mg-min/L for chloramines (US EPA, 1991a). The 
CT value for chloramines applies to systems which generate chloramines 
by the addition of free chlorine, followed by the addition of ammonia. 
This chloramine CT value for 15 deg.C was obtained by extrapolating CT 
values from a study performed by Sobsey, et al, (1988) at 5 deg.C. 
These CT values for chlorine and chloramines studied HAV, which, 
compared to other viruses which occur in fecally contaminated ground 
water, is relatively resistant to chlorine disinfection. The CT value 
for chlorine dioxide was obtained from a study of chlorine dioxide 
inactivation of HAV by chlorine dioxide at 5 deg.C (Sobsey, et al., 
1988). The CT value obtained in this study was adjusted to 15 deg.C, 
and had a safety factor of two applied. Considering that chlorine 
dioxide has a higher CT value than chlorine and due to site specific 
situations, chlorine dioxide may not be a feasible disinfection 
technology for all systems. Additional studies have been conducted 
using free chlorine on Coxsackie virus B5 and poliovirus 1 (Kelly and 
Sanderson, 1958), and information on these studies is provided in Table 
III-8. Although the CT values for HAV were included in the guidance 
manual to the SWTR intended for surface water systems, the CT values 
are applicable to ground water systems, since they are based on 
disinfectant residual (i.e., after demand) concentrations.
    Many systems apply free chlorine disinfection in a contact basin 
prior to distribution for virus inactivation, followed by ammonia 
addition prior to distribution (to form chloramines) to protect the 
water as it travels through the distribution system, since chloramines 
provide a longer lasting residual than free chlorine. Due to the high 
CT value for chloramines, some additional disinfection prior to 
distribution would probably be needed.
    A system that must disinfect may also need to increase the CT value 
attained if the CT value attained does not achieve the 4-log 
inactivation of viruses. Under some circumstances, this can be 
accomplished by providing a higher disinfectant dosage (and hence, a 
higher disinfectant residual), or a longer contact time (by providing 
additional storage). Data from the CWSS (1995) suggests that many CWSs 
(and some NCWSs) served by ground water may already have storage in 
place and may be able to achieve 4-log virus inactivation without 
additional storage. According to the CWSS, 59% of community ground 
water systems have distribution system storage tanks, including 34% of 
systems serving less than 100 people (CWSS, 1995). This number 
increases to 95% for systems serving 10,001-100,000 people. Twenty-
eight percent of ancillary community ground water systems were found to 
have storage. According to the CWSS, ancillary systems are those 
systems for which providing drinking water is not their primary 
business (e.g., restaurants).

                             Table III-8.  Disinfection Studies Using Chlorine, Chlorine Dioxide and Chloramines on Viruses
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Studies conducted                                        Effectiveness                   Additional notes
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Log
            Disinfectant                   Virus studied          Reference & date      removal       CT           Residual              Comments
--------------------------------------------------------------------------------------------------------------------------------------------------------
Chlorine............................  HAV....................  Sobsey et al., 1988...          4      \1\ 4  Y                    safety factor = 3
                                                               Sobsey et al., 1988...          4     \1\ 30  Y                    pH = 10 safety factor
                                                                                                                                   = 3
                                      Coxsackie B5...........  Kelly & Sanderson,              4  pH = 6, T = 28 deg.C
                                                                1958.                                 c1.07

[[Page 30237]]

 
                                      \1\ Poliovirus.........  Kelly & Sanderson,              4  pH of 6-9, unless otherwise noted.
\2\ Table adapted from Technologies and Costs for Ground Water Disinfection (USEPA, 1993).

    Ozone, unlike chlorine dioxide and chloramines, is a stronger 
disinfectant than chlorine and would require less contact time (and 
less storage) at a similar dosage (Table III-9) to inactivate viruses. 
The CT value for 4-log inactivation of HAV using ozone is 0.6 mg-min/L 
at a pH of 6-9 and a temperature of 15 deg.C (US EPA, 1991a). The CT 
data for ozone were obtained from a study by Roy et al., (1982). This 
study obtained data for 2-log inactivation of poliovirus 1 at 5 deg.C. 
The CT value for 4-log virus inactivation listed in Table III-8 is an 
extrapolation of the 2-log inactivation value assuming first-order 
kinetics, as well as an adjustment for inactivation at 15 deg.C. In 
addition, a safety factor of three was applied to the CT values. 
However, the CT value required for 4-log virus inactivation may depend 
on the virus. Poliovirus 1 (Kaneko, 1989) and enteric viruses (Finch et 
al., 1992) have demonstrated other CT requirements in studies; however, 
it is uncertain whether or not all other experimental conditions were 
the same (e.g., temperature) .
    Numerous studies on viral inactivation using UV have been 
conducted, with Table III-9 presenting some of the findings. According 
to these studies, 4-log UV disinfection of HAV requires an IT of 
between 16 mWs/cm \2\ (Battigelli et. al., 1993) and 39.4 mWs/cm\2\ 
(Wilson et al., 1992). IT is the UV light irradiance multiplied by the 
contact time. Other studies have shown variable IT values, depending on 
the virus studied (Table III-9). Harris et al. (1987) found that an IT 
of 120 mWs/cm \2\ (including a safety factor of 3) was required for 4-
log inactivation of poliovirus. Unlike many of the other alternative 
treatment technologies, the efficacy of UV disinfection is not 
dependent on the temperature and pH.

                                   Table III-9.--Disinfection Studies Using Ozone, Membrane Filters and UV on Viruses
--------------------------------------------------------------------------------------------------------------------------------------------------------
                             Studies conducted                                           Effectiveness                         Additional notes
--------------------------------------------------------------------------------------------------------------------------------------------------------
          Disinfectant               Virus studied      Reference E & date      Log removal              CT              Residual          Comments
--------------------------------------------------------------------------------------------------------------------------------------------------------
\4\ Ozone.......................  Poliovirus.........  Roy et al.,1982....  4..................  \1\ 0.6...........  N                safety factor = 3.
                                  Poliovirus.........  Herbold et al.,1989  4-6................  .008..............  N                T = 10 deg.C.
                                                       Kaneko, 1989.......  4..................  5.................  N
                                  enterics...........  Finch et al.,1992..  4..................  3.................  N
                                  HAV................  Hall & Sobsey, 1993  3.9-6.0............  0.167.............  N                Also MS2.
                                                       Herbold et al.,1989  4-6................  0.22..............  N                T = 10 deg.C.
                                                       Vaughn et al,1990..  4..................  0.40..............  N                T = 4 deg.C.
                                  MS2................  Finch et al.,1992..  2.7-7..............  7.2...............  N                T = 22 deg.C.
                                                       Finch et al.,1992..  4..................  .013..............  N                T = 22 deg.C.
RO..............................  0.5 nm.............  Jacangelo et         \2\ 100% removal...  50-70% recovery...  N                MWCO0.5 nm.
                                                        al.,1995.
                                  MS2................  Adham et al.,1998..  1.4-7.4............  N/A...............  N
NF..............................  0.5-13   US EPA, 1993.......  \2\ 100% removal...  60-80% recovery...  N                MWCO 200-400
                                   nm.                                                                                                 Daltons.
UV\3\  \4\......................  MS2................  Snicer et al.,1996.  4..................  87.4-93...........  N                Ground water.
                                                       Roessler & Severin,  4..................  63....  N                ..................
                                                        1996.
                                  HAV................  Wiedenmann et        4..................  20      N                ..................
                                                        al.,1993.
                                                       Battigelli et        4..................  16................  N                ..................
                                                        al.,1993.
                                                       Wilson et al.,1992.  4..................  39.4..............  N                Also Rota SA11,
                                                                                                                                       Poliovirus 1.
\3\ \4\ UV continued............  Rotavirus..........  Roessler & Severin,  4..................  25....  N                ..................
                                                        1996.
                                  Poliovirus.........  Harris et al.,1987.  4..................  120...............  N                Safety factor = 3.
                                                       Chang et al.,1985..  3-4................  30....  N                ..................
                                  Rotavirus SA11.....  Battigelli et        4..................  42................  N                Approximately 4-
                                                        al.,1993.                                                                      log.
                                                       Chang et al.,1985..  3-4................  30....  N                ..................
                                  Coxsackie B5.......  Battigelli et        4..................  29................  N                Approximately 4-
                                                        al.,1993.                                                                      log.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CT values are values for 15  deg.C and a pH of 6-9, unless otherwise noted.
\2\ Removal based on pore size.
\3\ Inactivation measured by IT, rather than CT. IT is the UV irradiance multiplied by the contact time.
\4\ Table adapted from Technologies and Costs for Ground Water Disinfection (USEPA, 1993)


[[Page 30238]]

    When systems use anodic oxidation the primary disinfectant 
generated is free chlorine. Therefore, the CT value for anodic 
oxidation is the same as free chlorine (Table III-8). However, when 
using anodic oxidation other disinfectants are also generated, and data 
suggests that the combined effects of these disinfectants are stronger 
than that of free chlorine alone; however, this effect has not been 
substantiated.
    Removal as a ground water treatment technique provides public 
health protection through physical filtering of water using membrane 
processes. The effectiveness of a particular membrane technology 
depends on the size of the target organism and the size of the 
membrane's pores (Table III-9). Membrane filters achieve removals when 
the MWCO of the filter is significantly smaller than the diameter of 
the target organism. Viruses range in diameter from approximately 20-
900 nm and may be effectively removed using reverse osmosis (RO) and 
nanofiltration (NF), having MWCOs of approximately 5 nm and 30 nm, 
respectively. Those technologies which provide removal of microbial 
contamination cannot provide a disinfectant residual, and must be 
applied prior to the distribution of the water.
vi. Free Chlorine in the Distribution System
    Chlorine disinfection is the most commonly practiced disinfection 
technology for microbial contamination of ground water. Many ground 
water systems which practice chlorine disinfection do so by providing a 
free chlorine residual at the entry point to the distribution system. 
In general, the level of inactivation achieved using disinfectants such 
as chlorine increases the longer the disinfectant is in contact with 
the water (i.e., contact time). This is true only when there is an 
available supply of chlorine. When the chlorine dissipates there is no 
further increase in the inactivation level. Therefore, when systems use 
a chlorine residual at the entry point to the distribution system, 
microbes (including viruses) are inactivated at varying levels through 
the length of the distribution system, and the risk of illness from 
pathogens originating in the source water decreases with increased 
travel time through a well-maintained distribution system if there is 
sufficient residual. For example, if customers at the first service 
connection in the water main receive water disinfected to 4-log virus 
inactivation, those customers farther along the distribution main would 
receive water disinfected to levels greater than 4-logs as long as 
disinfectant remains, and no additional contamination has entered the 
distribution system.
    EPA conducted analyses to evaluate the potential effectiveness of a 
free chlorine distribution system residual to provide 4-log 
inactivation of viruses originating in the source water. It was assumed 
that the customer at the first service connection received water 
disinfected to 4-log virus inactivation. Preliminary analysis indicates 
that a number of ground water systems can achieve at least 4-log virus 
inactivation throughout the distribution system. Some systems can 
provide this log inactivation by maintaining a 0.2 mg/l free chlorine 
residual at the entry point to the distribution system (as required by 
the SWTR) and a contact time of 20 minutes prior to the first customer. 
Data suggests that as many as 77% of small community ground water 
systems (i.e., serving less than 10,000 customers) may achieve 4-log 
virus inactivation prior to the first customer during maximum flow 
conditions (AWWA, unpublished data 1998). When a ground water system 
uses a free chlorine distribution system residual to disinfect 
contaminated source water, the level of virus inactivation is likely 
well in excess of 4-log, especially when taking into account the time 
the water awaits usage in the customers' piping beyond the service 
connection. This extra holding time in the distribution system 
increases the CT value achieved and therefore increases the log 
inactivation level achieved. A system may also need to apply a free 
chlorine residual at the entry point to the distribution system that is 
higher than 0.2 mg/L to maintain a detectable residual throughout the 
distribution system, which may lead to higher levels of virus 
inactivation. In these instances, increased levels of protection would 
be provided for customers served by all service connections along the 
distribution main. Assuming 4-log virus inactivation at the first 
customer, it could also be assumed that customers at service 
connections at later points in the distribution system would receive 
water disinfected to higher levels of inactivation, in many cases much 
higher.
    For some systems application of a 0.2 mg/L free chlorine residual 
at the entry point to the distribution system and a detectable free 
chlorine residual throughout the distribution system will not achieve 
4-log virus inactivation. In some cases this will be because the system 
does not achieve adequate contact time, and these systems may have to 
increase the contact time by installing extra distribution system 
storage, increasing the free chlorine residual concentration, adding 
supplemental disinfection (such as disinfection in a contact basin) or 
reconfiguring the system. However, based on 1998 AWWA data, EPA 
believes that most ground water CWSs will have sufficient contact time.
    EPA considered requiring systems to apply a disinfectant residual 
at the entry point to the distribution system and maintain a detectable 
disinfectant residual throughout the distribution system. However, EPA 
decided against including it in the proposed GWR since a disinfectant 
residual is more accepted as a distribution system tool than for 
controlling source water contamination. EPA will address the issue of 
maintaining a residual in future rulemaking efforts (e.g. long term 2 
ESWTR) as part of a broad discussion on distribution system issues for 
all PWSs.
2. Proposed Requirements
    EPA proposes the following requirements for ground water systems 
with an uncorrected significant deficiency or fecally contaminated 
source water. The requirements for treatment techniques, disinfection 
monitoring, and notification to ensure public health protection are 
addressed.
    EPA proposes treatment technique requirements as one barrier in the 
multiple barrier approach. Treatment techniques contribute to public 
health protection by eliminating public exposure to the source of 
pathogens, through eliminating the source of contamination, requiring 
the system to provide an alternative source as the State deems 
appropriate, correcting significant deficiencies that can act as a 
potential pathway for contamination, or disinfection to remove, or 
inactivate the microbial contaminants. Information related to the 
effectiveness of these treatment techniques can be found in the ASDWA 
BMP study Results and Analysis of ASDWA Survey of BMPs in Community 
Ground Water Systems (ASDWA, 1998), as well as the SWTR.
a. Treatment Technique Requirements for Systems With Uncorrected 
Significant Deficiencies or Source Water Contamination
    EPA proposes requiring ground water systems with an uncorrected 
significant deficiency or source water contamination to apply an 
appropriate treatment technique, as determined by the State, within 90 
days of detection of the significant deficiency or source water 
contamination. If they cannot apply an appropriate treatment technique 
within that time frame, they must at a minimum have a State-

[[Page 30239]]

approved plan and specific schedule for doing so. Treatment techniques 
include: eliminate the source of contamination, correct the significant 
deficiency, provide an alternate source water, or provide a treatment 
which reliably achieves at least 99.99 percent (4-log) inactivation or 
removal of viruses before or at the first customer. Some treatment 
techniques are inappropriate solutions for the nature of the problem. 
For example, a system with contamination entering the distribution 
system must not address the problem by providing treatment at the 
source.
    Ground water systems which provide 4-log inactivation or removal of 
viruses will be required to conduct compliance monitoring to 
demonstrate treatment effectiveness. If a system is unable to address 
the significant deficiency within 90 days, the system must develop a 
specific plan and schedule for providing a treatment technique, submit 
the plan and schedule to the State and receive State approval on the 
plan and schedule within the same 90 days. EPA expects the system to 
consult with the State on interim measures to ensure safe water is 
provided during the 90 day correction time frame. During this 90 day 
period the State and system must identify and apply a permanent 
treatment technique appropriate for that system, consistent with the 
State's general approach outlined in their primacy package. If the 
treatment technique is not complete within 90 days (or the deadline 
specified in the State-approved plan), the system is in violation of 
the treatment technique requirements of the GWR.
b. Disinfection Options
    EPA proposes requiring systems that disinfect due to uncorrected 
significant deficiencies or fecally contaminated source water to 
provide disinfection adequate to achieve at least 4-log inactivation or 
removal of viruses as determined by the State. When a system provides 
disinfection for uncorrected significant deficiencies or fecally 
contaminated source water, EPA recommends that the State use EPA-
published CT tables to determine what treatment technologies and what 
disinfection parameters are appropriate for the system. If a system is 
currently providing 4-log disinfection and therefore does not monitor 
the source water for fecal indicators, per Sec. 140.403, then that 
system must meet the definition and requirements of disinfection as 
described in this section.
c. Monitoring the Effectiveness and Reliability of Treatment
    EPA proposes requiring systems with uncorrected significant 
deficiencies or fecally contaminated source water under this proposal 
to monitor the effectiveness and reliability of disinfection as 
follows. This monitoring must be conducted following the last point of 
treatment, but prior to each point of entry to the distribution system.
    Systems serving 3,300 or more people that chemically disinfect must 
monitor (using continuous monitoring equipment fitted with an alarm) 
and maintain the required residual disinfectant concentration 
continuously to ensure that 4-log virus inactivation is provided every 
day the system serves water to the public. EPA recommends that the 
State use EPA-developed CT tables to determine if the system meets the 
residual concentration and contact time requirements necessary to 
achieve 4-log virus inactivation. As a point of comparison, the surface 
water system size cutoff for systems to measure the residual 
disinfectant four or fewer times per day is 3,300 people served.
    Systems serving 3,300 or fewer people that chemically disinfect 
must monitor and maintain the residual disinfectant concentration every 
day the system serves water to the public. The system will monitor by 
taking daily grab samples and measuring for the State-determined 
concentration of disinfectant to ensure that 4-log virus inactivation 
is provided. EPA recommends that the State use EPA-developed CT tables 
to determine if the system meets the residual concentration and contact 
time requirements necessary to achieve 4-log virus inactivation. If the 
daily grab measurement falls below the State-determined value, the 
system must take follow-up samples every four hours until the required 
residual disinfectant concentration is restored.
    Systems using UV disinfection must monitor for and maintain the 
State-prescribed UV irradiance level continuously to ensure that 4-log 
virus inactivation is provided every day the system serves water to the 
public. EPA recommends that the State use EPA-developed IT tables to 
determine if the system meets the irradiance and contact time 
requirements necessary to achieve 4-log virus inactivation.
    Systems that use membrane filtration as a treatment technology are 
assumed to achieve at least 4-log removal of viruses when the membrane 
process is operated in accordance with State-specified compliance 
criteria, or as provided by EPA, and the integrity of the membrane is 
intact. Applicable membrane filtration technologies are RO, NF and any 
membrane filters developed in the future that have MWCOs that can 
achieve 4-log virus removal.
    When monitoring on a continuous basis, the system must notify the 
State any time the residual disinfectant concentration or irradiance 
falls below the State-prescribed level and is not restored within four 
hours. This notification must be made as soon as possible, but in no 
case later than the end of the next business day.
    When the system takes daily grab sample measurements, the system 
must notify the State any time the residual disinfectant concentration 
falls below the State-prescribed level and is not restored within four 
hours. This notification must be made as soon as possible, but in no 
case later than the end of the next business day.
    Any time a system using membrane filtration as a treatment 
technology fails to operate the process in accordance with State-
specified compliance criteria, or as provided by EPA, or a failure of 
the membrane integrity occurs, and the compliance operation or 
integrity is not restored within four hours, the system must notify the 
State. This notification must be made as soon as possible, but in no 
case later than the end of the next business day.
    These requirements are consistent with those for surface water 
systems. Four hours is the cutoff time by which a surface water system 
must restore the free chlorine residual level at entry to the 
distribution system to 0.2 mg/L, if the free chlorine residual at entry 
to the distribution system falls below 0.2 mg/L. In addition, a surface 
water system must notify the State anytime the residual disinfectant 
entering the distribution system falls below 0.2 mg/L and is not 
restored within 4 hours. This notification must be made by the end of 
the next business day.
    EPA proposes that systems which were required to provide treatment 
for uncorrected significant deficiencies or fecally contaminated source 
water may discontinue treatment if the State determines the need for 
treatment no longer exists and documents such a decision.
d. Eliminating the Source of Contamination
    For systems eliminating the source of contamination, EPA proposes 
that the system and State develop a strategy using appropriate BMPs 
considering the characteristics of the system and the nature of the 
significant deficiency or contamination.

[[Page 30240]]

e. Reporting Outbreaks
    As required in 141.32(a)(iii)(D) for undisinfected surface water 
systems; EPA proposes that if any ground water system has reason to 
believe that a disease outbreak is potentially attributable to their 
drinking water, it must report the outbreak to the State as soon as 
possible, but in no case later than the end of the next business day.
f. Treatment Technique Violations
    The GWR proposes the following three treatment technique 
violations, requiring the ground water system to give public 
notification:
    (a) A ground water system with a significant deficiency identified 
by a State, which does not correct the deficiency, provide an 
alternative source, or provide 4-log inactivation or removal of viruses 
within 90 days, or does not obtain, within the same 90 days, State 
approval of a plan and schedule for meeting the treatment technique 
requirement, is in violation of the treatment technique.
    (b) A ground water system that detects fecal contamination in the 
source water and does not eliminate the source of contamination, 
correct the significant deficiency, provide an alternate source water, 
or provide a treatment which reliably achieves at least 99.99 percent 
(4-log) inactivation or removal of viruses before or at the first 
customer within 90 days, or does not obtain within the same 90 days, 
State approval of a plan for meeting this treatment technique 
requirement, is in violation of the treatment technique unless the 
detected sample is invalidated by the State or the treatment technique 
is waived by the State. Ground water systems which provide 4-log 
inactivation or removal of viruses will be required to conduct 
compliance monitoring to demonstrate treatment effectiveness.
    (c) A ground water system which fails to address either a 
significant deficiency as provided in (a) or fecal contamination as 
provided in (b) according to the State-approved plan, or by the State-
approved deadline, is in violation of the treatment technique. In 
addition, a ground water system which fails to maintain 4-log 
inactivation or removal of viruses, once required, is in violation of 
the treatment technique, if the failure is not corrected within four 
hours.
    EPA requests comment on which (if any) of these proposed treatment 
technique violations should or should not be treatment technique 
violations. EPA also requests comment as to whether a ground water 
system which has a source water sample that is positive for E. coli, 
coliphage or enterococci should be in violation of the treatment 
technique.
3. Public Notification
    Sections 1414(c)(1) and (c)(2) of the 1996 SDWA, as amended, 
require that public water systems notify persons served when violations 
of drinking water standards occur. EPA has recently (64 FR 25963, May 
13, 1999) proposed to revise the public notification regulations to 
incorporate new statutory provisions enacted under the 1996 SDWA 
amendments. EPA recently promulgated the final Public Notification Rule 
(PNR), under part 141. Subsequent EPA drinking water regulations that 
affect public notification requirements will amend the PNR as a part of 
each individual rulemaking. The GWR is proposing Tier 1 (discussed 
next) public notification requirements for the treatment technique 
violations (see Sec. 141.405). EPA requests comment on the GWR public 
notification requirements.
    The purpose of public notification is to alert customers to 
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 public water system 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 proposed 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 regulations requiring a Tier 1 notice include: Violation 
of the TCR, where fecal contamination is present; nitrate violations; 
chlorine dioxide violations; and other waterborne emergencies. The 
State is explicitly authorized to add other violations and situations 
to the Tier 1 list when necessary to protect public health from short-
term exposure.
    Tier 2 is for other violations and situations with potential to 
have serious adverse effects on human health. Notice is required within 
30 days, with extension up to three months at the discretion of the 
State or primacy agency. Violations requiring a Tier 2 notice include 
all other MCL and treatment technique violations 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 the monitoring violations.
    Today's regulatory action proposes to make the presence of a fecal 
indicator in a source water sample, failure to monitor source water and 
treatment technique violations as Tier 1 public notification 
requirements. Any GWSs with a violation or situation requiring Tier 1 
public notification must notify the public within 24 hours of the 
violation. GWS's that must make an annual CCR report, as discussed in 
III.A.7.d., must include any Tier 1 violations or situations in their 
next CCR report and include the health effects language described later 
in Appendix B of subpart Q. The following violations or situations 
require Tier 1 notice:
    (a) A ground water system which has a source water sample that is 
positive for E. coli, coliphage, or enterococci under Sec. 141.403, 
unless it is invalidated under Sec. 141.403(i);
    (b) Failure to conduct required monitoring, including triggered 
monitoring when a system has a positive total coliform sample in the 
distribution system and routine monitoring when the system is 
identified by the State as hydrogeologically sensitive;
    (c) A ground water system with a significant deficiency identified 
by a State which does not correct the deficiency, provide an 
alternative source, or provide 4-log inactivation or removal of viruses 
within 90 days, or does not obtain, within the same 90 days, State 
approval of a plan and schedule for meeting the treatment technique 
requirement in Sec. 141.404;
    (d) A ground water system that detects fecal contamination in the 
source water and does not eliminate the source of contamination, 
provide an alternative water source, or provide 4-log inactivation or 
removal of viruses within 90 days, or does not obtain within the same 
90 days, State approval of a plan for meeting this treatment technique 
requirement (unless the detected sample is invalidated under 
Sec. 141.403(i) or the treatment technique is waived under 
Sec. 141.403(j)); and
    (e) A ground water system which fails to address either a 
significant deficiency as provided in (c) or fecal contamination as 
provided in (d) according to the

[[Page 30241]]

State-approved plan, or by the State-approved deadline. (In addition, a 
ground water system which fails to maintain 4-log inactivation or 
removal of viruses, once required, is in violation of the treatment 
technique if the failure is not corrected within 4 hours.)
    EPA believes that these violations pose an immediate and serious 
public health threat. Fecal contamination is an acute contaminant and 
therefore illnesses and even deaths can occur through small volumes or 
short exposure to fecally contaminated drinking water. Illnesses can be 
avoided by alerting the public immediately. The proposed tiering 
requirements under the GWR are designed to be consistent with those for 
the Total Coliform Rule. Failure to test for fecal coliform or E. coli 
when any repeat sample tests positive for coliform is considered a Tier 
1 violation requiring a Tier 1 notice under current Public Notification 
Regulations. EPA believes that failure to collect source water samples 
as proposed under the GWR poses an equivalent public health threat to 
the failure to test for fecal coliform or E. coli under the TCR. EPA 
believes that an undisinfected ground water system with either a TC 
positive in the distribution system or with a source found to be 
hydrogeologically sensitive has an increased likelihood of microbial 
contamination that if not monitored, presents a public health threat 
which requires immediate notice. EPA acknowledges that in some 
circumstances, the hydrogeologic sensitivity assessment may not be as 
indicative of the presence of microbial contamination in the ground 
water system as is the presence of total coliform in the distribution 
system. Given this potential situation, the Agency requests comment 
upon whether the failure to perform routine source water monitoring 
should be considered a lower Tier violation to avoid alarming the 
public unnecessarily. EPA also requests comment on the other proposed 
public notification requirements presented in this section.
4. Request for Comments
    EPA requests comments on all the information presented earlier and 
the potential impacts on public health and regulatory provisions of the 
GWR. In addition, EPA specifically requests comments on the following 
alternative approaches. In particular, EPA requests comment on the 
following public health issues associated with disinfection. 
Stakeholders have raised concern about the potential risk from 
improperly managed or applied chemical disinfectants. Some stakeholders 
suggest that requiring small system operators who may lack training or 
expertise to apply chemical disinfection could lead to collateral 
health and safety risks. EPA requests comment on this issue. The Agency 
also requests input on alternative approaches for addressing 
demonstrated microbial contamination and the associated acute microbial 
health risks.
Alternative Approaches
a. Distribution System Residuals
    EPA requests comment on requiring a 0.2 mg/L free chlorine residual 
at the entry points to the distribution system and a detectable free 
chlorine residual throughout the distribution system for all or some 
systems (e.g., all systems serving 3,300 or more people). EPA also 
seeks comment on whether or not systems should be able to use a 0.2 mg/
L free chlorine residual at the entry to, and detectable throughout, 
the distribution system to meet the disinfection requirements proposed 
as part of the GWR.
b. Other Log-Inactivation Levels
    EPA seeks comment on the adequacy of 4-log virus inactivation or 
removal to protect public health from fecally contaminated ground water 
sources. Additionally, EPA requests comment on requiring additional 
levels of disinfection under certain circumstances. For example, 
increasing the log virus inactivation may be appropriate for 
contaminated systems with known sources of fecal contamination in close 
proximity to a well.
c. Supplemental Disinfection Strategies
    EPA requests comment on whether, for certain systems with source 
water contamination, it may not be possible to achieve 4-log virus 
inactivation at the first customer either because of the distribution 
system size or configuration (e.g., the first customer is relatively 
close to the point of disinfectant application). EPA requests comment 
on possible supplemental disinfection strategies.
d. Mandatory Disinfection for Systems in Sensitive Hydrogeology
    EPA seeks comment on requiring disinfection for ground water 
systems which obtain their water from a sensitive aquifer regardless of 
microbial monitoring results (see section III.B.). This would provide 
proactive public health protection by disinfecting a sensitive source 
water before contamination becomes apparent.
e. Point-of-Entry Devices
    EPA seeks comment on EPA approving the use of point-of-entry 
devices to disinfect contaminated source water. This would allow 
systems to provide protection to individual households, and may be 
cost-effective for some very small systems. However, the system would 
be responsible for maintaining the devices and this could result in 
significant expenditure of resources.
f. Across-the-Board Disinfection
    EPA seeks comment on requiring all systems to disinfect, or 
requiring disinfection based on system type (e.g., CWS), or size of the 
system (e.g., greater than 3,300). The SWTR requires all systems 
obtaining their water from a surface water source to disinfect. EPA 
notes that 1996 SDWA, as amended requires that EPA should develop 
regulations requiring disinfection for ground water systems ``as 
necessary''.
g. Health and Fiscal Impacts on Small Systems (i.e., Competing 
Priorities)
    EPA requests comment on whether or not potential health effects and 
fiscal impacts specific for small systems should be included in the 
GWR. Specifically, EPA seeks comment on what other regulatory 
priorities will compete with the GWR and what implementation issues 
this will present (e.g., disinfection under the GWR versus compliance 
with the DBPR, difficulty in obtaining resources for simultaneous 
compliance with arsenic, radon, ground water and DBP regulations).
h. Differing Disinfection Strategies for Significant Deficiencies and 
Source Water Contamination
    EPA seeks comment on whether a different disinfection strategy 
should be required depending on whether the system has an uncorrected 
significant deficiencies or fecally contaminated source water. Under 
this alternative, EPA could require systems with uncorrected 
significant deficiencies to provide only a disinfectant residual of 0.2 
mg/L free chlorine at entry to the distribution system, while those 
systems with fecally contaminated source water would be required to 
provide disinfection to ensure that the system achieves 4-log virus 
inactivation or removal prior to entry to the distribution system.
i. Shutting Down Systems With Uncorrected Significant Deficiencies
    EPA seeks comment on whether and based on what criteria systems 
with uncorrected significant deficiencies should not be allowed to 
disinfect as a

[[Page 30242]]

treatment technique, but instead would not be allowed to serve water to 
the public. Under certain circumstances this approach is used by some 
States. For example, disinfection is not an effective strategy for 
treating the significant deficiency of poor distribution system 
integrity.
j. Correction Time Frame
    EPA requests comment on the criteria States must use to determine 
the adequacy of schedules which go beyond 90 days (e.g., corrections 
which require significant capital investments or external technical 
expertise).
    EPA also requests comment on an alternative approach for addressing 
correction of significant deficiencies. The alternate approach consists 
of: (1) A requirement that the State notify the system in writing 
within 30 days of conducting the sanitary survey listing the 
significant deficiency, (2) a requirement for the system to correct the 
significant deficiencies as soon as possible, but no later than 180 
days of receipt of the letter from the State or in compliance with a 
schedule of any length agreed upon by the State, and (3) the 
requirement that the system notify the State in writing that the 
significant deficiencies have been corrected within 10 days after the 
date of completion. Under this alternative, a system that does not 
correct significant deficiencies within 180 days or within the time 
frames of a schedule agreed upon by the State is in violation of a 
treatment technique and must provide public notice. The Agency seeks 
comment on whether this particular alternative correction scheme would 
be appropriate for the purposes of this rule.
    The Agency is also seeking comment on a second alternative approach 
for establishing deadlines to complete corrective actions of 
significant deficiencies. Under this approach, States, as part of their 
primacy requirement to identify and define the significant 
deficiencies, may develop and submit to EPA for approval, deadlines for 
the completion of corrective actions for specific types or categories 
of significant deficiencies. When a specific corrective action is not 
implemented within the State deadline, a State must take appropriate 
action to ensure that the system meets the corrective action 
requirement. Any corrective action that extends beyond 180 days to 
complete, must be enforceable by the State through a compliance 
agreement or an administrative order or judicial order. As part of 
primacy, the State must also provide a plan for how the State will meet 
the time frames established in their procedures for identifying, 
reporting, correcting, and certifying significant deficiencies within 
the 180 days. The Agency seeks comment on whether this alternative 
correction scheme might also be appropriate.
k. Required Disinfectant Residual Concentration
    EPA requests comment on requiring systems that disinfect to 
maintain a specified default disinfectant residual level. This 
requirement would apply when the State fails to provide the system with 
a State-determined disinfectant concentration to meet the 4-log 
inactivation/removal requirement within the 90-day correction time 
frame. Under this approach, systems that must treat would be required 
to maintain a 0.2 mg/L free chlorine residual at entry to the 
distribution system and a detectable free chlorine residual throughout 
the distribution system. EPA also requests comment on other 
concentrations of residual free chlorine to be maintained both at entry 
to the distribution system and throughout the distribution system 
(e.g., 0.5 mg/L free chlorine at entry to the distribution system and 
0.2 mg/L free chlorine throughout the distribution system).
l. Record Keeping for 4-log Inactivation Requirements
    EPA requests comment upon whether systems which disinfect to comply 
with the GWR must maintain records of the State notification of the 
proper residual concentrations (when using chemical disinfection), 
irradiance level (when using UV), or State-specified compliance 
criteria (when using membrane filtrations) needed to achieve 4-log 
inactivation or removal of virus. EPA also requests comment on systems 
keeping records of the level of disinfectant residuals maintained, as 
well as how long the system should keep the records (e.g., three 
years). These records may be valuable in the operation of the system 
because they will serve as permanent records for subsequent operators 
and/or owners of the ground water system.
m. Differing Monitoring Requirements for Consecutive Systems
    EPA requests comment on any GWR requirements that should not apply 
to consecutive systems. Consecutive systems are those PWSs that receive 
some or all of their water from other PWSs. Such systems would 
certainly need to undergo the proposed sanitary survey to assure that 
they are delivering safe water to their customers. EPA also requests 
comment on whether the hydrogeologic sensitivity assessment and any 
corresponding source water monitoring should be the responsibility of 
the water seller or the consecutive system. EPA requests comments on 
whether or not a consecutive system should be required to monitor 
treatment compliance in their distribution system if the seller has met 
4-log inactivation or removal of viruses. In addition, EPA requests 
comment on the selling system being required to conduct triggered 
source water monitoring when the consecutive system has a total-
coliform positive in the distribution system.
n. State Primacy Requirements
    EPA requests comment on the scope and appropriateness of the GWR 
State primacy requirements. The primacy requirements include the 
following:
     Sanitary surveys: State will describe how it will 
implement the sanitary survey, including rationales and time frames for 
phasing in sanitary surveys, how it will decide that a CWS has 
outstanding performance, and how the State will utilize data from its 
SWAPP;
     Hydrogeologic Sensitivity Assessment: State will identify 
its approach to determining the adequacy of a hydrogeologic barrier, if 
present;
     Source Water Monitoring: State will describe its approach 
and rationale for determining which of the fecal indicators (E. Coli, 
coliphage or enterococci) ground water systems must use for routine 
and/or triggered monitoring;
     Treatment Techniques: State will describe treatment 
techniques, including how it will provide systems with the disinfectant 
concentration (or irradiance) and contact time required to achieve 4-
log virus inactivation; the approach the State must use to determine 
which specific treatment option (correcting the deficiency, eliminating 
the source of contamination, providing an alternative source, or 
providing 4-log inactivation or removal of viruses) is appropriate for 
addressing significant deficiencies or fecally contaminated source 
water and under what circumstances; and how the State will consult with 
ground water systems regarding the treatment technique requirements.
o. State Reporting Requirements
    The proposed rule contains many reporting requirements for States 
to submit to EPA. EPA requests comment on the scope and appropriateness 
of these reporting requirements. The GWR reporting requirements include 
the following:
     Sanitary Survey: State will report an annual list of 
ground water systems that have had a sanitary survey

[[Page 30243]]

completed during the previous year and an annual evaluation of the 
State's program for conducting sanitary surveys.
     Hydrogeologic Sensitivity Assessment: State will report 
lists of ground water systems that have had a sensitivity assessment 
completed during the previous year, those ground water systems which 
are sensitive, ground water systems which are sensitive, but for which 
the State has determined that a hydrogeologic barrier exists, and an 
annual evaluation of the State's program for conducting hydrogeologic 
sensitivity assessments.
     Source Water Monitoring: State will report an annual list 
of ground water systems that have had to test the source water, a list 
of determinations of invalid samples, and a list of waivers of source 
water monitoring provided by the State.
     Treatment Techniques: State will report lists of ground 
water systems that have had to meet treatment technique requirements 
for significant deficiencies or contaminated source water, 
determinations to discontinue 4-log inactivation or removal of viruses, 
ground water systems that violated the treatment technique 
requirements, and an annual list of ground water systems that have 
notified the State that they are currently providing 4-log inactivation 
or removal of viruses.

IV. Implementation

    This section describes the regulations and other procedures and 
policies States have to adopt, and the requirements that public ground 
water systems would have to meet to implement today's proposal were it 
to be finalized as proposed. Also discussed are the compliance 
deadlines for these requirements. States must continue to meet all 
other conditions of primacy in Part 142 and ground water systems must 
continue to meet all other applicable requirements of Part 141.
    Section 1413 of the SDWA establishes requirements that a State or 
eligible Indian Tribe must meet to maintain primary enforcement 
responsibility (primacy) for its public water systems. These include 
(1) adopting drinking water regulations that are no less stringent than 
Federal NPDWRs in effect under sections 1412(a) and 1412(b) of the Act, 
(2) adopting and implementing adequate procedures for enforcement, (3) 
keeping records and making reports available on activities that EPA 
requires by regulation, (4) issuing variances and exemptions (if 
allowed by the State) under conditions no less stringent than allowed 
by sections 1415 and 1416, and (5) adopting and being capable of 
implementing an adequate plan for the provision of safe drinking water 
under emergency situations.
    40 CFR part 142 sets out the specific program implementation 
requirements for States to obtain primacy for the Public Water Supply 
Supervision (PWSS) Program, as authorized under section 1413 of the 
Act. In addition to adopting the basic primacy requirements, States may 
be required to adopt special primacy provisions pertaining to a 
specific regulation. These regulation-specific provisions may be 
necessary where implementation of the NPDWR involves activities beyond 
those in the generic rule. States are required by 40 CFR 142.12 to 
include these regulation-specific provisions in an application for 
approval of their program revisions. These State primacy requirements 
apply to today's proposed rule, along with the special primacy 
requirements discussed next. The proposed regulatory language under 
section 142 applies to the States. The proposed regulatory language in 
section 141 applies to the public water systems.
    The 1996 SDWA amendments (see section 1412(b)(10)) provide 3 years 
after promulgation for compliance with new regulatory requirements. 
Accordingly, the GWR requirements that apply to the PWS directly, 
specifically requirements found under section 141 of this proposal 
(monitoring and corrective action), are effective three years after the 
promulgation date. The State may, in the case of an individual system, 
provide additional time of up to two years if necessary, for capital 
improvements in accordance with the statute.
    Section 1413(a)(1) allows States two years after promulgation of 
the final GWR to adopt drinking water regulations that are no less 
stringent than the final GWR. EPA proposes to require States to submit 
their primacy application concerning the GWR (see section 142 of the 
proposed regulatory language) within two years of the promulgation of 
the final GWR and EPA will review and approve (if appropriate) the 
application within 90 days of submittal (1413(b)(2). This schedule will 
provide all States with approved primacy for the GWR by the three years 
after [DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL REGISTER].
    If the GWR is finalized as proposed today, the States will have 
three years from the effective date (six years from the GWR 
promulgation date) to complete all community water system sanitary 
surveys and five years from the effective date (eight years from the 
GWR promulgation date) to complete all non-community water system 
sanitary surveys. The monitoring and corrective action requirements 
would be effective on the effective date of the final rule (three years 
after the GWR promulgation date).

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

    This section summarizes the Health Risk Reduction and Cost Analysis 
in support of the GWR as required by section 1412(b)(3)(C) of the 1996 
SDWA. In addition, under Executive Order 12866, Regulatory Planning and 
Review, EPA must estimate the costs and benefits of the GWR in a 
Regulatory Impact Analysis (RIA) and submit the analysis to the Office 
of Management and Budget (OMB) in conjunction with publishing the 
proposed rule. EPA has prepared an RIA to comply with the requirements 
of this Order and the SDWA Health Risk Reduction and Cost Analysis 
(USEPA, 1999a). The RIA has been published on the Agency's web site, 
and can be found at http://www.epa.gov/safewater. The RIA can also be 
found in the docket for this rulemaking (US EPA, 1999a).
    The goal of the following section is to provide an analysis of the 
costs, benefits, and other impacts to support decision making during 
the development of the GWR.

A. Overview

    The analysis conducted for this rule quantifies cost and benefits 
for four scenarios; the proposed regulatory option (multi-barrier 
option), the sanitary survey option, the sanitary survey and triggered 
monitoring option, and the across-the-board disinfection option. All 
options include the sanitary survey provision. The sanitary survey 
option would require the primacy agent to perform surveys every three 
to five years, depending on the type of system. If any significant 
deficiency is identified, a system is required to correct it. The 
sanitary survey and triggered monitoring option adds a source water 
fecal indicator monitoring requirement triggered by a total coliform 
positive sample in the distribution system. The multi-barrier option 
adds a hydrogeologic sensitivity assessment to these elements which, if 
a system is found to be sensitive, results in a routine source water 
fecal indicator monitoring requirement. The multi-barrier option and 
the sanitary survey and triggered monitoring options are both a 
targeted regulatory approach designed to identify wells that are 
fecally contaminated or are at a high risk for contamination. The 
across-the-board disinfection option would require all systems to 
install treatment instead

[[Page 30244]]

of trying to identify only the high risk systems; therefore, it has no 
requirement for sensitivity assessment or microbial monitoring.
    Costs for each option varied and were driven by the number of 
systems that would need to fix a significant deficiency or take 
corrective action, such as installing treatment or rehabilitating a 
well, in response to fecal contamination. The majority of costs for all 
options, with the exception of the across-the-board option, are the 
result of systems having to fix an actual or potential fecal 
contamination problem. The mean annual costs of the various options 
range from $73 million to $777 million using a three percent discount 
rate and $76 million to $866 million using a seven percent discount 
rate. (Note some costs have not been quantified and are not included in 
these totals, see section V.B.)
    These total annual quantified costs can be compared to the annual 
monetized benefits of the GWR. The annual mean benefits of the various 
rule options range from $33 million to $283 million. This result is 
based on the quantification of the number of acute viral illnesses and 
deaths avoided attributable to this rule. This rule will also decrease 
bacterial illness and death associated with fecal contamination of 
ground water. EPA did not directly calculate the actual numbers of 
illness associated with bacterially contaminated ground water because 
the Agency lacked the necessary bacterial pathogen occurrence data 
(e.g., number of wells contaminated with Salmonella) to include it in 
the risk model. However, in order to monetize the benefit from reduced 
bacterial illnesses and deaths from fecally contaminated ground water, 
the Agency used the ratio of viral and unknown etiology outbreak 
illnesses to bacterial outbreak illnesses reported to CDC for 
waterborne outbreaks in ground water systems.
    Several non-health benefits from this rule were also considered by 
EPA but were not monetized. The non-health benefits of this rule 
include avoided outbreak response costs (such as the costs of providing 
public health warnings and boiling drinking water), and possibly the 
avoided costs of averting behavior and reduced uncertainty about 
drinking water quality. There are also non-monetized disbenefits, such 
as increased exposure to DBPs.
    Additional analysis was conducted by EPA to look at the incremental 
impacts of the various rule options, impacts on households, benefits 
from reduction in co-occurring contaminants, and increases in risk from 
other contaminants. Finally, the Agency evaluated the uncertainty 
regarding the risk, benefits, and cost estimates.

B. Quantifiable and Non-Quantifiable Costs

    In estimating the cost of each rule option, the Agency considered 
impacts on public water systems and on States. The GWR will result in 
increased costs to some PWSs for monitoring, corrective action of 
significant deficiencies, and installing treatment, but these vary 
depending on the option. With all rule options, a greater portion of 
the regulatory burden will be placed on those systems that do not 
currently disinfect to a 4-log inactivation of virus. States will incur 
costs for an incremental increase in sanitary survey requirements, for 
conducting hydrogeologic sensitivity assessments, and for follow-up 
inspections. Both systems and States would incur implementation costs. 
Some costs of today's rule options were not quantified (such as land 
acquisition, public notification costs and corrections to all potential 
significant deficiencies (See section V. B.4.)).
1. Total Annual Costs
    In order 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 allowed the Agency to 
capture the variability in PWS configuration, current treatment in 
place and source water quality.
    Table V-1 shows the estimated mean and range of annual costs for 
each rule option. At both a three and seven percent discount rate for 
the first three options, the costs increase as more components are 
added for identifying fecally contaminated wells and wells vulnerable 
to fecal contamination. The fourth option of across-the-board 
disinfection is the most costly because it would require all systems to 
install treatment regardless of actual fecal contamination or the 
potential to become fecally contaminated. Costs for the States to 
implement these rule options are also included in the four cost 
estimates. Discount rates of three and seven percent were used to 
calculate the annualized value for the national compliance cost 
estimate. The seven percent rate represents the standard discount rate 
required by OMB for benefit-cost analyses of government programs and 
regulations.

           Table V-1.--Annual Costs of Rule Options ($Million)
------------------------------------------------------------------------
                                            3% Discount     7% Discount
                 Option                   rate  $million  rate  $million
                                           mean  [range]   mean  [range]
------------------------------------------------------------------------
Sanitary Survey.........................             $73             $76
                                               [$71-$74]        [$74-78]
Sanitary Survey and Triggered Monitoring            $158            $169
                                             [$153-$162]      [$163-174]
Multi-barrier (Proposed) Option.........            $183            $199
                                              [$177-188]      [$192-206]
Across-the-Board Disinfection...........            $777            $866
                                             [$744-$810]     [$823-$909]
------------------------------------------------------------------------

2. System Costs
    In order to calculate the cost impact of each rule option on public 
water systems, EPA had to estimate the current baseline of systems and 
their current treatment practices, and then estimate how many systems 
would be affected by the various option requirements based on national 
occurrence information. The industry baseline discussion is located in 
section I.C. of this preamble. Estimates of the cost compliance 
requirements for each rule option are captured in a decision

[[Page 30245]]

tree analysis. The decision tree is comprised of various percentage 
estimates of the number of systems that will fall into each regulatory 
component category. Rule components include corrective action costs or 
costs to address significant deficiencies, monitoring costs, start-up 
costs, and reporting costs. Each of the rule options contains various 
combinations of these rule components with the sanitary survey option 
containing the fewest requirements.
    Overall, these rule options provide a great amount of flexibility, 
with the exception of across-the-board disinfection, and this has 
complicated the cost analysis. Data were not always available to 
estimate the number of systems that would fall under the various rule 
components. EPA used data, where available but also consulted with 
experts and stakeholders to get the best possible estimates of the cost 
of this rule. More information on the GWR decision tree and how each 
element was estimated can be found in the Appendix to the GWR RIA (US 
EPA, 1999a).
    As previously mentioned, the main cost component of the first three 
rule options results from systems having to take corrective action in 
response to fecal contamination or to fix significant deficiencies that 
could result in well contamination. In order to analyze the different 
rule options, the Agency had to distinguish between correction of 
significant deficiencies and the corrective actions that result from a 
confirmed source water positive sample for E. coli, enterococci or 
coliphage. In addition, it would be extremely challenging to cost out 
all conceivable corrective actions or significant deficiencies that a 
system could potentially encounter. As a result, the Agency focused on 
a representative estimate of potential types of corrective actions and 
significant deficiencies as shown in Table V-2 and Table V-3, 
respectively.
    The choice of treatment technique (in consultation with the State) 
is also influenced by the size of the system. This is captured in the 
decision tree analysis by assigning probabilities (by system size) that 
a certain corrective action will be chosen. These probabilities are 
based on the relative cost of each action, data on existing 
disinfection practices, and best professional judgment. Additional 
significant deficiencies related to improper treatment were included in 
the cost analysis for systems that currently disinfect. These 
deficiencies are also captured in the decision tree and are listed in 
Table V-3.

    Table V-2.--Treatment Techniques To Address Positive Source Water
                                 Samples
------------------------------------------------------------------------
                         Corrective action: \1\
-------------------------------------------------------------------------
Rehabilitating an existing well
Drilling a new well
Purchasing water (consolidation)
Eliminating known sources of contamination
Installing disinfection (8 choices of technologies)
------------------------------------------------------------------------
\1\ Choice varies with systems size and corrective action feasibility.

    Each treatment technique can be addressed by various low or high 
cost alternatives. For example, a lower cost fix for many systems would 
be to rehabilitate a well while a higher cost fix would be to drill a 
new well. It is possible that not all States, in coordination with 
systems, would choose the relatively lower cost alternative of well 
rehabilitation. It would depend on the well itself and also the problem 
that was being addressed. In addition, if the model predicted that a 
system would install treatment, the choice of treatment is contingent 
on system size. To capture these alternative possibilities, the Agency 
considered different combinations of low and high cost alternatives. 
For instance, when the low cost corrective action alternative was run, 
the model estimated a greater percentage of systems choosing the lower 
cost well rehabilitation option versus the higher cost option of 
drilling a new well. To account for the uncertainty in the types of 
significant deficiencies identified and in the treatment technique 
taken, the cost model was run for each of the following combinations of 
low and high costs alternatives.
     Low significant deficiency cost/low treatment technique 
cost
     Low significant deficiency cost/high treatment technique 
cost
     High significant deficiency cost/low treatment technique 
cost
     High significant deficiency cost/high treatment technique 
cost
    These combinations of low and high cost are reflected in the range 
of cost estimates shown in Table V-1 for the multi-barrier option 
(proposed option), the sanitary survey and triggered monitoring option, 
and the across-the-board option. For the sanitary survey option, only 
the high and low costs associated with significant deficiencies were 
included in the analysis. As stated earlier, treatment technique costs 
are the result of source water monitoring which is not included with 
the sanitary survey option.

                  Table V-3.--Significant Deficiencies
------------------------------------------------------------------------
                        Significant deficiencies
-------------------------------------------------------------------------
Unsealed well or inadequate well seal
Improper well construction
Inadequate roofing on a finished water storage tank
Evidence of vandalism at finished water storage tank
Unprotected cross connection in the distribution system
Booster pump station which lacks duplicate pumps
Additional significant deficiencies for disinfecting systems:
  Inadequate disinfection contact time
  Inadequate application of treatment chemicals
------------------------------------------------------------------------

    In addition to the treatment technique costs, EPA estimated the 
cost to systems for monitoring. All options would have some monitoring 
costs. However, the monitoring costs vary depending on the rule option 
as indicated in Table V-4. Regardless of the option, the triggered and 
routine monitoring applies only to systems that do not disinfect to a 
4-log inactivation of virus.
    Both the triggered and routine monitoring costs are calculated 
based on the cost of the test and the operator's time to take and 
transport the sample. EPA assumed that if this source water sample is 
positive, all systems would take five repeat samples to confirm the 
positive (although this is an optional rule component). For routine 
monitoring, the Agency assumed that all systems would monitor their 
source water monthly for the first year and quarterly thereafter at the 
States' determination. However, in some cases the State may allow the 
system to discontinue monitoring after 12 monthly samples or it could 
also require the system to continue with monthly monitoring. The cost 
of disinfectant compliance monitoring varies with system size and would 
be required for any system that currently disinfects or installs 
treatment as a result of the GWR. For large systems, EPA assumed that 
an automated monitoring system would be installed; for smaller systems, 
EPA assumed that a daily grab sample would be taken. A more detailed 
explanation of each of these monitoring schemes is located in section 
III. D. and section III E.2.c.

[[Page 30246]]



           Table V-4.--Monitoring Requirements by Rule Option
------------------------------------------------------------------------
                                                            Disinfectant
              Option                 Triggered    Routine    compliance
                                    monitoring  monitoring   monitoring
------------------------------------------------------------------------
Sanitary Survey...................                            
Sanitary Survey and Triggered                          
 Monitoring Option................
Multi-barrier (Proposed) Option...              
Across-the Board Disinfection                                 
 Option...........................
------------------------------------------------------------------------

    Finally, the Agency accounted for a system's start-up costs to 
comply with the GWR . These costs include time to read and understand 
the rule, mobilization and planning, and training. EPA assumed start-up 
costs would remain constant across the rule options. The Agency also 
estimated system costs for reporting and recordkeeping of any positive 
source water samples.
3. State Costs
    Similar to the system cost, State costs also vary by rule option. 
Depending on the option, States would face increased costs from the 
incremental difference in the sanitary survey requirements and 
frequency, from conducting a one-time hydrogeologic sensitivity 
assessments, and tracking monitoring information for those options with 
a monitoring requirement. States would also have start-up and annual 
costs for data management and training. If a system needs longer than 
90 days to complete a treatment technique or repair a significant 
deficiency, the State would have to approve the time schedule and plan.
    By including start-up costs, annual fixed costs, and incremental 
sanitary survey costs in the decision tree analysis for all rule 
options, EPA accounted for these State costs. The analysis also assumed 
costs for State review and approval of plans for treatment techniques. 
The cost for the one-time sensitivity assessments is included for the 
proposed rule option analysis.
4. Non-Quantifiable Costs
    Although EPA has estimated the cost of all the rule's components on 
drinking water systems and States, there are some costs that the Agency 
did not quantify. These non-quantifiable costs result from 
uncertainties surrounding rule assumptions and from modeling 
assumptions. For example, EPA did not estimate a cost for systems to 
acquire land if they needed to build a treatment facility or drill a 
new well. This was not considered because many systems will be able to 
construct new wells or treatment facilities on land already owned by 
the utility. In addition, if the cost of land was prohibitive, a system 
may chose another lower cost alternative such as connecting to another 
source. A cost for systems choosing this alternative is quantified in 
the analysis. The cost estimates do not include costs for public 
notification which are proposed. These estimates have not been included 
because EPA has no data on which to base an estimate of the number of 
treatment techniques violations or the number of times systems will 
fail to perform source water monitoring.
    In addition, the Agency did not develop costs for all conceivable 
significant deficiencies or corrective actions that a system may 
encounter. Instead, a representative sample was chosen as shown in 
Tables V-2 and V-3.

C. Quantifiable and Non-Quantifiable Health and Non-Health Related 
Benefits

    The primary benefits of today's proposed rule come from reductions 
in the risks of microbial illness from drinking water. In particular, 
the GWR focuses on reducing illness and death associated with viral 
infection. Exposure to waterborne bacterial pathogens are also reduced 
by this rule and the benefits are monetized, but not by the same method 
used to calculate reductions in viral illness and death because of data 
limitations. It is likely that these monetized illness calculations 
which are based on a cost of illness (COI) rather than a willingness to 
pay (WTP) approach, underestimate the true benefit because they do not 
include pain and suffering associated with viral and bacterial illness.
    Additional health benefits such as reduced chronic illness were 
investigated, but were not quantified or monetized in this analysis. 
Other non-health benefits will likely result from this rule but were 
also not quantified or monetized. These non-health related benefits are 
discussed in sections V.A. and V.C. 2.
1. Quantifiable Health Benefits
    The benefits analysis focused on estimating reductions in viral and 
bacterial illness and death that would result from each of the rule 
options. The first part of the analysis estimates the baseline (pre-
GWR) level of illness as a result of microbial contamination of ground 
water. A discussion about how the Agency estimated this baseline risk 
is located in section II. E. of today's proposal. An important 
component of these risk estimates is the effect that these pathogens 
have on children (especially infants) because they are more likely to 
have severe illness and die from viral infection than the general 
population. A detailed discussion of risks to children is located in 
section VI. G.
    The second part of the analysis focused on the reduction in risk 
that results from the various rule components. These components include 
identifying high risk wells, fixing significant deficiencies, increased 
monitoring for some systems, and possibly installing treatment in the 
event that a problem can not be fixed or a new source found. To 
calculate these changes, the risk-assessment model was re-run using new 
assumptions based on reductions in viral exposure which results from 
different levels of fecal contamination identified by each rule option.
    To model the reduction in source contamination that would result 
from implementation of the four regulatory options, EPA assumed 
reductions in the number of ground water systems/points of entry that 
are potentially contaminated with viral pathogens under baseline 
conditions. The reduction varies with expectations regarding the 
effectiveness of each option in identifying and correcting significant 
defects at the source. Reductions in treatment failure rate and in 
distribution system contamination are also addressed for each option. 
The estimated reductions in contamination which are expected for each 
rule option are summarized in Table V-4a. These estimates are based 
upon information from consultations by the Agency with stakeholders and 
the Agency's best professional judgement regarding the effectiveness of 
sanitary surveys and upon co-occurrence rates of fecal indicators with 
pathogenic viruses. See section 5.3 of the GWR RIA for a detailed 
discussion of the basis for the estimated reductions.

[[Page 30247]]



                                             Table V-4a. Estimated Contamination Reductions for GWR Options
                                                                      [In Percent]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     Estimated reduction in viral source contamination of      Estimated reduction in rate     Estimated reduction in
                                              undisinfected ground water sources               of disinfection failure for       distribution system
        Regulatory option        ------------------------------------------------------------        GWSs with viral         contamination with virus of
                                      Properly  constructed        Improperly  constructed     contamination of the source              GWSs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Option 1. Sanitary Survey Only..  0                             40-60                         0-26 (CWS)                    0-25
                                                                                              0-43 (NCWS)\1\                (NA for TNC) \2\
Option 2. Sanitary Survey and     30-54                         58-82                         77-100                        0-25
 Triggered Monitoring.                                                                                                      (NA for TNC) \2\
Option 3. Multi-Barrier           38-77                         63-91                         77-100                        0-25
 (Proposed).                                                                                                                (NA for TNC) \2\
Option 4. Across-the-Board        100                           100                           77-100                        0-25
 Disinfection.                                                                                                              (NA for TNC) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Non-community water systems (NCWS), both transient and nontransient, have an estimated reduced risk of contamination of 0-43%; community water
  systems (CWS) reduced risk is 0-26%.
\2\ Reduction of risk in transient non-community (TNC) systems was not considered.

    After the reductions in viral illnesses and death were estimated, 
the Agency estimated the monetized benefit from the reduction in 
bacterial illnesses and death associated with each rule option. EPA 
could not directly calculate the actual numbers of illnesses and death 
associated with bacterially contaminated ground water because the 
Agency lacked the necessary pathogen occurrence information to include 
it in the risk model. In order to estimate the benefit from reducing 
bacterial illnesses and deaths from fecally contaminated ground water, 
the Agency relied on CDC's outbreak data ratio of viral outbreaks and 
outbreaks of unknown etiology believed to be viral to bacterial 
outbreaks in ground water. These data indicate that for every five 
viral outbreaks, there is one bacterial outbreak. It was further 
assumed that the cost of these bacterial illnesses would be comparable 
to viral illness estimates.
    To assign a monetary value to the illness, EPA estimated costs-of-
illness ranging from $158 to $19,711 depending upon the age of the 
individual and severity of illness (see Exhibits 5-9 and 5-10 in the 
RIA). These are considered lower-bound estimates of actual benefits 
because it does not include the pain and discomfort associated with the 
illness. This issue is discussed in greater detail in the GWR RIA 
(USEPA, 1999a). Mortalities were valued using a value of statistical 
life estimate (VSL) of $6.3 million consistent with EPA policy. The VSL 
estimate is based on a best-fit distribution of 26 VSL studies and this 
distribution has a mean of $4.8 million per life in 1990 dollars. For 
this analysis, EPA updated this number to 1999 dollars which results in 
a mean VSL value of $6.3 million. Table V-5 shows the annual monetized 
benefits by rule option.

                     Table V-5.--Quantified and Monetized Benefits by Rule Option ($Million)
----------------------------------------------------------------------------------------------------------------
                                                           Morbidity           Mortality        Total  $million
                       Options                         $million  [range]   $million  [range]        [range]
----------------------------------------------------------------------------------------------------------------
Sanitary Survey.....................................                 $22                 $11                 $33
                                                             [$7 to $38]         [$2 to $20]         [$9 to $58]
Sanitary Survey and Triggered Monitoring............                $120                 $58                $178
                                                          [$100 to $140]        [$47 to $68]      [$147 to $209]
Multi-Barrier Proposed ( Option)....................                $139                 $66                $205
                                                          [$115 to $163]        [$54 to $79]      [$169 to $242]
Across-the-Board Disinfection.......................                $192                 $91                $283
                                                          [$174 to $210]       [$81 to $101]      [$255 to $311]
----------------------------------------------------------------------------------------------------------------

2. Non-Quantifiable Health and Non-Health Related Benefits
    Although viral and some bacterial illness have been linked to 
chronic diseases, insufficient data was available to forecast the 
number of avoided chronic cases that would result from each rule 
option. A review of medical and epidemiological data identified several 
chronic diseases linked to viral infections. The strongest evidence 
links Group B coxsackievirus infections with Type 1-insulin-dependent 
diabetes and also to heart disease. Bacterial illness can also result 
in longer-term complications including arthritis, recurrent colitis, 
and hemolytic uremic syndrome. Most of these chronic illnesses and 
longer term complications are extremely costly to treat.
    Using cost-of-illness (COI) estimates instead of willingness-to-pay 
(WTP) estimates to monetize the benefit from illness reduction 
generally results in underestimating the actual benefits of these 
reductions. In general, the COI approach is considered a lower bound 
estimate of WTP because COI does not include pain and suffering. EPA 
requests comment on the use of an appropriate WTP study to calculate 
the reduction in illness benefits of this rule.

D. Incremental Costs and Benefits

    Today's proposed rule options represent the incremental costs and 
benefits of this rule. Both costs and benefits increase as more fecal 
contamination detection measures are added to the sanitary surveys for 
the first three options. The proposed option has the highest cost of 
these three incremental options, but it also produces incrementally 
more benefits.

[[Page 30248]]

    The fourth option, across-the-board disinfection, is the most 
costly because it would require all systems to install treatment or to 
upgrade to 4-log removal/inactivation. It would not provide the 
flexibility of the other three options and would not target 
specifically high risk systems. Similar to the first three options, 
this option also includes the sanitary survey provision. This is 
included to address problems in the distribution systems and with 
disinfection failure.
    Table V-6 and Table V-6a show the monetized costs, benefits and net 
benefits for all four options using both a three percent and seven 
percent discount rate, respectively. It is important to remember that 
non-quantified costs and benefits are not included in these net benefit 
numbers.

                              Table V-6.--Net Benefits--3% Discount Rate ($Million)
----------------------------------------------------------------------------------------------------------------
                                                                    Mean annual     Mean annual    Net benefits
                             Options                                costs (3%)     benefits \1\    of the  means
                                                                     $million        $million        $million
----------------------------------------------------------------------------------------------------------------
Sanitary Survey.................................................             $73             $33           ($40)
Sanitary Survey and Triggered Monitoring........................             158             178              20
Multi-Barrier (Proposed)........................................             183             205              22
Across-the-board Disinfection...................................             777             283          (494)
----------------------------------------------------------------------------------------------------------------
\1\ Does not include non-quantified benefits which would increase the net benefits of these rule options.


                             Table V-6a.--Net Benefits--7% Discount Rate ($Million)
----------------------------------------------------------------------------------------------------------------
                                                                    Mean annual     Mean annual
                             Options                                costs  (7%)    benefits \1\    Net benefits
                                                                     $million        $million        $million
----------------------------------------------------------------------------------------------------------------
Sanitary Survey.................................................             $76             $33           ($43)
Sanitary Survey and Triggered Monitoring........................             169             178               9
Multi-Barrier (Proposed)........................................             199             205               6
Across-the-board Disinfection...................................             866             283          (583)
----------------------------------------------------------------------------------------------------------------
\1\ Does not include non-quantified benefits which would increase the net benefits of these rule options.

E. Impacts on Households

    Overall, the average annual cost per household for the first three 
rule options are small across most system size categories as shown in 
Table V-7. However, costs are greater for the smallest size category 
across all options. This occurs because there are fewer households per 
system to share the cost of any corrective action or monitoring 
incurred by the systems. For example, under the Multi-Barrier option 
household costs would increase by approximately $5 per month for those 
served by the smallest size systems (100 people) while those served by 
the largest size systems (>100,000 people) would face only a $0.02 
increase in monthly household costs. As previously mentioned, the 
majority of the cost from the first three rule options is the result of 
systems having to correct significant deficiencies in their systems or 
to take corrective action in response to fecal contamination. On 
average, household costs resulting from the first three rule options 
increase from $2.45 to $3.86 annually. The most expensive option, 
across-the-board disinfection, also has the highest average household 
costs at $19.37 annually.

Table V-7.--Average Annual Household Cost for GWR Options for CWS Taking Corrective Action or Fixing Significant
                                                     Defects
----------------------------------------------------------------------------------------------------------------
                                                                     Sanitary
                                                                    survey and     Multi-barrier    Across-the-
                 Size categories                     Sanitary        triggered        option           board
                                                   survey option    monitoring      (proposed)     disinfection
                                                                      option                          option
----------------------------------------------------------------------------------------------------------------
100.............................................          $29.86          $67.19          $62.48         $191.87
101-500.........................................           11.23           15.02           18.95           81.38
501-1,000.......................................            5.72            6.29            6.25           38.79
1,001-3,300.....................................            2.99            2.91            3.39           23.45
3,301-10,000....................................            1.39            1.46            2.74           16.78
10,001-50,000...................................            0.62            0.59            0.62            4.87
50,001-100,000..................................            0.30            0.70            1.01           10.37
100,001-1,000,000...............................            0.32            0.20            0.27            1.66
Average.........................................            2.45            3.34            3.86           19.37
----------------------------------------------------------------------------------------------------------------


[[Page 30249]]

F. Cost Savings From Simultaneous Reduction of Co-Occurring 
Contaminants

    If a system chooses to install treatment, it may choose a 
technology that would also address other drinking water contaminants. 
For example, when using packed tower aeration to treat radon, it is the 
accepted engineering practice, and in some States an existing 
requirement, to also install disinfection treatment for removal of 
microbial contaminants introduced in the aeration treatment process. 
Depending on the dosage and contact time, the routine disinfection 
would also address possible or actual fecal contamination in the source 
water. If systems had an iron or manganese problem, the addition of an 
oxidant and filtration can 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 is currently in the process of 
proposing rules to address radon and arsenic. Because of the 
difficulties in establishing which systems would have all three 
problems of fecal contamination, radon, and arsenic or any combination 
of the three, no estimate was made of the potential cost savings from 
addressing more than one contaminant simultaneously. EPA also 
recognizes that while there may be savings from treating several 
contaminants simultaneously relative to treating each of them 
separately, there may also be significant economic impacts to some 
systems (especially small systems), if they have to address several 
contaminants in a relatively short time frame. Because of the lack of 
good data on co-occurrence of contaminants, EPA has not considered 
these simultaneous impacts in the analysis of household and per system 
costs.

G. Risk Increases From Other Contaminants

    The RIA for today's rule contains a detailed discussion of the 
increased risk from other contaminants that may result from GWR 
requirements. Most of the risk stems from currently untreated systems 
installing disinfection. When disinfection is first introduced into a 
previously undisinfected system, the disinfectant can react with pipe 
scale causing increased risk from some contaminants and water quality 
problems. Contaminants that may be released include lead, copper, and 
arsenic. It could also lead to a temporary discoloration of the water 
as the scale is loosened from the pipe. These risks can be reduced by 
gradually phasing in disinfection to the system, by routine flushing of 
distribution system mains and by maintaining a proper corrosion control 
program.
    Using a chlorine-based disinfectant or ozone 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 
and is currently being further considered by the Stage II M-DBP FACA. 
Systems could avoid this problem by choosing an alternative 
disinfection technology such as ultraviolet disinfection or membrane 
filtration, though this may increase treatment costs. The GWR cost 
estimate includes such additional treatment costs for a portion of 
systems taking corrective action.

H. Other Factors: Uncertainty in Risk, Benefits, and Cost Estimates

    Today's proposal models the current baseline risk from fecal 
contamination in ground water as well as the reduction in risk and the 
cost for four rule options. There is uncertainty in the baseline number 
of systems, the risk calculation, the cost estimates, and the 
interaction of other rules currently being developed. These 
uncertainties are discussed further in the following section.
    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. Therefore, EPA does not have a reliable estimate of how many of 
these mixed systems exist. To the extent that systems classified in 
SDWS as surface water or ground water under the influence of surface 
water may also have ground water wells not under the influence of 
surface water and thus be subject to this rule, the costs and benefits 
estimated here would be understated. In addition, the SDWIS data on 
non-community water systems does not have a consistent reporting 
convention for population served. Some States may report the population 
served over the course of a year, while others may report the 
population served on an average day. Also, SDWIS does not require 
States to provide information on current disinfection practices and, in 
some cases, it may overestimate the daily population served. For 
example, a park may report the population served yearly instead of 
daily. EPA is looking at new approaches to address these issues, and 
both are discussed in the Requests for Comment section V.I.
    The risk calculations concerning the baseline number of illnesses 
and the reduction of illnesses that results from the various rule 
options contains uncertainty. For example, a nationally representative 
study of baseline microbial occurrence in ground water does not exist. 
EPA chose the AWWARF study (described in section II.C.1) to represent 
properly constructed wells because, of the thirteen available studies, 
it is the most representative of national geology. EPA also relied on 
data from the EPA/AWWARF study to represent improperly constructed 
wells because this study targeted wells vulnerable to contamination and 
tested wells monthly for a year. However, EPA recognizes the variable 
nature of these studies, as discussed in detail in section II.C. 
Additionally, EPA had to rely on CDC outbreak data to characterize the 
causes of endemic ground water disease. As discussed in section II. B., 
the U.S. National Research Council suggests that CDC numbers only 
represent a small percentage of actual waterborne disease outbreaks. 
The Agency also 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 ground 
water systems or if other rules, such as the TMDL, CAFO, and Class V 
UIC Well Rules result in decreased fecal contamination.
    EPA did not have dose-response data for all viruses and bacteria 
associated with previous ground water disease outbreaks. For viral 
illness, the Agency used echo and rota viruses 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 low-to-medium infectivity viruses that cause severe illness and 
high infectivity viruses that cause more mild illness. Further, there 
is considerable uncertainty in the dose-response functions used, even 
for these two viruses. Dose-response 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. 
There is likely to be variability in both of these parameters across 
populations and based on case specific circumstances, and only limited 
data are available. Another uncertainty

[[Page 30250]]

concerns the number of baseline bacterial illness caused by ground 
water contamination. The bacterial risk could not be modeled because of 
lack of occurrence and dose-response data. Estimates of bacterial 
illness were made based on a ratio of bacterial to viral outbreak as 
documented by CDC and applied to the viral risk estimate discussed 
previously. There is also considerable uncertainty in quantifying the 
effectiveness of various regulatory options in reducing risk. There is 
little data currently on which to base quantitative estimates of the 
effectiveness of sanitary surveys or routine monitoring in reducing 
microbial risk, though there is some qualitative research suggesting 
that these can be effective strategies. To model risk reduction 
quantitatively, EPA relied primarily on best professional judgment. The 
quantitative estimates of risk reduction used in the analysis are 
summarized in Table V-4a.
    There is also uncertainty in the valuation of risk reduction 
benefits. For this analysis EPA used a 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. In general, however, COI 
estimates understate benefits because they do not account for the value 
people place on reduced pain and suffering.
    Some costs of today's proposed rule are also uncertain because of 
the diverse nature of possible significant deficiencies systems would 
need to address. Also, the rule's flexibility leads to some uncertainty 
in estimates of who will be affected by each rule component and how 
States and systems will respond to significant deficiencies. These 
uncertainties could either under or overestimate the costs of the rule.
    EPA is in the process of proposing regulations for radon and 
arsenic in drinking water, which can impact some ground water systems. 
EPA also intends to finalize the Stage II Disinfection Byproducts Rule 
by the statutory deadline of May 2002. It is extremely difficult to 
estimate the combined effects of these future regulations on ground 
water systems because of various combinations of contaminants that some 
systems may need to address. However, it is possible for a system to 
choose treatment technologies that would deal with multiple problems. 
Therefore, the total cost impact of these drinking water rules is 
uncertain; however, it may be less than the estimated total cost of all 
individual rules combined. Conversely, the impacts on households and 
individual systems of multiple rules is cumulative, and in some cases 
maybe greater than the impacts estimated in the RIA of each rule 
separately.

I. Benefit Cost Determination

    The Agency has determined that the benefits of the proposed GWR 
justify the costs. The mean quantified benefits exceed the mean 
quantified costs by $22 million using a three percent discount rate and 
$6 million using a seven percent discount rate. EPA made this 
determination based on provisions of the multi-barrier option that 
include improved sanitary surveys, hydrogeologic sensitivity 
assessments triggered and routine monitoring provisions corrective 
actions, and compliance monitoring. Overall, these elements will reduce 
the risk of microbial contamination reaching the consumer. The 
quantified cost of these provisions were compared to the monetized 
benefits that result from the reduction in viral and bacterial illness 
and death. In addition, other non-monetized benefits further justify 
the costs of this rule.

J. Request for Comment

    The Agency requests comment on all aspects of the GWR RIA. 
Specifically, EPA seeks input into the following two issues.
1. NTNC and TNC Flow Estimates
    In the GWR RIA, EPA estimates the cost of the GWR on NTNC and TNC 
water systems by using flow models. However, these flow models were 
developed to estimate flows only for CWS and they may not accurately 
represent the much smaller flows generally found in NTNC and TNC 
systems. The effect of the overestimate in flow would be to inflate the 
cost of the rule for these systems. The Agency requests comment on an 
alternative flow analysis for NTNC and TNC water systems described 
next.
    Instead of using the population served data to determine the 
average flow for use in the rule's cost calculations, this alternative 
approach would re-categorize NTNC and TNC water systems based on 
service type (e.g., restaurants or parks). Service type would be 
obtained from SDWIS data. However, service type data is not always 
available because it is a voluntary SDWIS data field. Where 
unavailable, the service type would be assigned based on statistical 
analysis. Estimates of service type design flows would be obtained from 
engineering design manuals and best professional judgment if no design 
manual specifications exist.
    In addition, each service type category would also have 
corresponding rates for average population served and average water 
consumption. These would be used to determine contaminant exposure 
which is used in the benefit determination. Note that the current 
approach of assuming that the entire population served drinks an 
average of 1.2 liters per day for 250 days (from NTNCWSs) and 15 days 
(from TNCWs) may lead to an overestimation of benefits. For example, 
schools and churches would be two separate service type categories. 
They each would have their own corresponding average design flow, 
average population served (rather than the population as reported in 
SDWIS), and average water consumption rates. These elements could be 
used to estimate a rule's benefits and costs for the average church and 
the average school.
2. Mixed Systems
    Current regulations require that all systems that use any amount of 
surface water as a source be categorized as surface water systems. This 
classification applies even if the majority of water in a system is 
from a ground water source. Therefore, SDWIS does not provide the 
Agency with information to identify how many mixed systems exist. This 
information would help the Agency to better understand regulatory 
impacts. Further, to the extent that mixed systems are classified as 
surface water, the costs and benefits of this proposed rule are 
underestimated.
    EPA is investigating ways to identify how many mixed systems exist 
and how many mix their ground and surface water sources at the same 
entry point or at separate entry points within the same distribution 
systems. For example, a system may have several plants/entry points 
that feed the same distribution system. One of these entry points may 
mix and treat surface water with ground water prior to its entry into 
the distribution system. Another entry point might use ground water 
exclusively for its source while a different entry point would 
exclusively use surface water. However, all three entry points would 
supply the same system classified in SDWIS as surface water.
    One method EPA could use to address this issue would be to analyze 
CWSS data then extrapolate this information to SDWIS to obtain a 
national estimate of mixed systems. CWSS data, from approximately 1,900 
systems, details sources of supply at the level of the entry point to 
the distribution system and further subdivides flow by source type. The 
Agency is considering this

[[Page 30251]]

national estimate of mixed systems to regroup surface water systems for 
certain impact analyses when regulations only impact one type of 
source. For example, surface water systems that get more than 50 
percent of their flow from ground water would be counted as a ground 
water system in the regulatory impact analysis for this rule. The 
Agency requests comment on this methodology and its applicability for 
use in regulatory impact analysis.

VI. Other Requirements

A. Regulatory Flexibility Act (RFA), as Amended by the Small Business 
Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601 et 
seq.

1. Background
    The 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.
2. Use of Alternative Definition
    The RFA provides default definitions for each type of small entity. 
It 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. secs. 601(3)--(5)). In 
addition, agencies must consult with SBA's Chief Counsel for Advocacy 
to establish an alternative small business definition.
    EPA is proposing the GWR which contains provisions which apply to 
small PWSs serving fewer than 10,000 persons. This is the cut-off level 
specified by Congress in the 1996 Amendments to the Safe Drinking Water 
Act for small system flexibility provisions. Because this definition 
does not correspond to the definitions of ``small'' for small 
businesses, governments, and non-profit organizations, EPA requested 
comment on an alternative definition of ``small entity'' in the 
preamble to the proposed Consumer Confidence Report (CCR) regulation 
(63 FR 7620, February 13, 1998). Comments showed that stakeholders 
support the proposed alternative definition. EPA also consulted with 
the SBA Office of Advocacy on the definition as it relates to small 
business analysis. In the preamble to the final CCR regulation (63 FR 
4511, August 19, 1998). EPA stated its intent to establish this 
alternative definition for regulatory flexibility assessments under the 
RFA for all drinking water regulations and has thus used it in this 
proposed rulemaking. The SBA Office of Advocacy agrees with the use of 
this definition in this rulemaking.

3. Initial Regulatory Flexibility Analysis

    In accordance with section 603 of the RFA, EPA prepared an initial 
regulatory flexibility analysis (IRFA) that examined the impact of the 
proposed rule on small entities along with regulatory alternatives that 
could reduce that impact. The IRFA addresses the following issues:
     The reasons the Agency is considering this action;
     The objectives of, and legal basis for the proposed rule;
     The number and types of small entities to which the rule 
will apply;
     Projected reporting, recordkeeping, and other compliance 
requirements of the proposed rule, including the classes of small 
entities which will be subject to the requirements and the type of 
professional skills necessary for preparation of the reports and 
records;
     The other relevant Federal rules which may duplicate, 
overlap, or conflict with the proposed rule; and,
     Any significant alternatives to the components under 
consideration which accomplish the stated objectives of applicable 
statutes and which may minimize any significant economic impact of the 
proposed rule on small entities.
a. The Reasons the Agency Is Considering This Action
    EPA believes that there is a substantial likelihood that fecal 
contamination of ground water supplies is occurring at frequencies and 
levels which 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 which 
consume them.
    Fecal contamination is introduced to ground water from a number of 
sources including, septic systems, leaking sewer pipes, landfills, 
sewage lagoons, cesspools, and storm water runoff. Microorganisms can 
be transported with the ground water as it moves through an aquifer. In 
addition, the transport of microorganisms to wells or other ground 
water system sources can also be affected by poor well construction 
(e.g., improper well seals) which can result in large, open conduits 
for fecal contamination to pass unimpeded into the water supply.
    Waterborne pathogens contained in fecally contaminated water can 
result in a variety of illnesses which range in the severity of their 
outcomes from mild diarrhea to kidney failure or heart disease. The 
populations which are particularly sensitive to waterborne and other 
pathogens include, infants, young children, pregnant and lactating 
women, the elderly and the chronically ill. These individuals may be 
more likely to become ill as a result of exposure to the pathogens, and 
are likely to have a more severe illness. A complete discussion of the 
public health concerns addressed by the GWR can be found in section II 
of the preamble.
b. The Objectives of, and the Legal Basis for, the Proposed Rule
    EPA is proposing the GWR pursuant to section 1412(b)(8) of the 
SDWA, as amended in 1996, 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 1996 amendments establish a statutory deadline of May 2002. 
EPA, however, intends to finalize the GWR in the year 2000 to coincide 
with implementation of other drinking water regulations and programs, 
such as the Disinfection Byproducts Rule, the Arsenic Rule, the Radon 
Rule and the Source Water Assessment and Protection Program (SWAPP). 
EPA believes systems and States will better plan for changes in 
operation and capital improvements if they presented them with future 
regulatory requirements at one time.
c. Number of Small Entities Affected
    According to the December 1997 data from EPA's Safe Drinking Water 
Information System (SDWIS), there are 156,846 community water systems 
and non-community water supplies providing potable ground water to the 
public, of which 155,254 (99 percent) are classified by EPA as small 
entities. EPA estimates that these small ground water systems serve a 
population of more than 48 million. Roughly one-quarter of these 
systems are estimated to be community water systems serving fixed 
populations on a year-round basis.
    Under the proposed option, all community and non-community water 
systems are affected by at least one requirement; the sanitary survey 
provision. The other GWR components are estimated to affect different 
numbers

[[Page 30252]]

of small systems. For example, over 4,300 small systems are expected to 
have to fix significant deficiencies each year.
d. Small Entity Impacts
Reporting and Recordkeeping for the Proposed GWR
    Under the proposed Multi-Barrier option, there are a number of 
recordkeeping and reporting requirements for all ground water system 
(including small systems). To minimize the burden with these 
provisions, the EPA is proposing a targeted risk-based regulatory 
strategy whereby the monitoring requirements are based on system 
characteristics and not directly related to system size. In this 
manner, the multi-barrier option takes a system-specific approach to 
regulation, although a sanitary survey is required of all community and 
non-transient non-community water systems. However, the implementation 
schedule for this requirement is staggered (e.g., every three to five 
years for CWSs and every five years for NCWSs), which should provide 
some relief for small systems because there are proportionately more 
NCWSs.
    To address concerns over the potential cost of additional 
monitoring for small systems, the proposed GWR 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). In this proposal, only systems that do not 
reliably treat to 4-log inactivation or removal of viruses are required 
to test for the presence of E. coli, coliphage, or enterococci in the 
source water within 24 hours of a total coliform positive sample in the 
distribution system.
    Only systems determined to be hydrogeologically sensitive and do 
not already treat to 4-log inactivation or removal of viruses are 
required to conduct the additional routine monitoring. If no fecal 
indicators are found after 12 months of monitoring, the State may 
reduce the monitoring frequency for that system. Similarly, if a non-
sensitive system does not have a distribution system, any sample taken 
for TCR compliance is effectively a source water sample, so an 
additional triggered source water sample would not be required. In both 
cases, however, if the system has a positive sample for E. coli, 
coliphage, or fecal coliform, the system is required to conduct the 
necessary follow-up actions.
Small Entity Compliance Costs for the Proposed GWR
    Estimates of the cost of complying with each component of the 
multi-barrier approach are presented next. The estimated impacts for 
this proposed option are based on the national mean compliance cost 
across the four compliance scenarios. System-level impacts are 
investigated using various corrective action and significant defects 
scenarios. The high correction action/low significant defect scenario 
is considered a typical cost estimate. For more information on these 
scenarios and cost assumptions, consult the Regulatory Impact Analysis 
for the Proposed Ground Water Rule (USEPA, 1999a) which is available 
for review in the water docket.
    In determining the costs and benefits of this proposed rule, EPA 
considered the full range of both potential costs and benefits for the 
rule. The flexibility of the risk-based targeted approach of the rule 
aims to reduce the cost of compliance with the rule. Small systems will 
benefit from the flexibility provided in this design. For example, a 
small system with fecal contamination will, in consultation with the 
State, be able to select the least costly corrective action. Also, 
small systems serving less than 3,300 people which disinfect will only 
be required to monitor their treatment effectiveness one time per day 
as opposed to the continuous monitoring required for larger systems 
which disinfect. Estimates of annual CWS compliance costs for the 
multi-barrier approach are presented in Table VI-1.

              Table VI-1.--Annual Compliance Costs for the Proposed GWR by CWS System Size and Type
----------------------------------------------------------------------------------------------------------------
                                                           System size/population served
         CWS system type         -------------------------------------------------------------------------------
                                        100           101-500        501-1,000      1,001-3,300      3,301-10K
----------------------------------------------------------------------------------------------------------------
Publicly-Owned..................            $825            $934         $1,238$          $1,950          $4,480
Privately-Owned.................             799             933           1,449           1,730           5,358
All Systems.....................             805             933           1,328           1,893           4,652
----------------------------------------------------------------------------------------------------------------

e. Coordination With Other Federal Rules
    To avoid duplication of effort, the proposed GWR encourages States 
to use their source water assessments when the assessment provides data 
relevant to the sensitivity assessment of a system. Although not a 
regulatory program, source water assessments are currently being 
performed by States. The schedule for the sensitivity assessment 
(within six years for CWS and eight years for NCWS) should allow States 
to complete the assessment and the first round of sanitary surveys 
concurrently if they choose to do so.
    EPA has structured this GWR proposal as a targeted, risk-based 
approach to reducing fecal contamination. The only regulatory 
requirement that applies to all ground water systems is the sanitary 
survey. The Agency has also considered other drinking water 
contaminants that may be of concern when a system install disinfection. 
Specifically, adding disinfection may result in an increase in other 
contaminants of concern, depending on the characteristics of the source 
water and the distribution system. These contaminants include 
disinfection byproducts, lead, copper, and arsenic. EPA believes that 
these issues, when they occur will be very localized and may be 
addressed through selection of the appropriate corrective action. EPA 
has provided States and systems with the flexibility to select among a 
variety of corrective actions. These include options such as UV 
disinfection, or purchasing water from another source, which would 
avoid these types of problems.
f. Minimization of Economic Burden
Description of Regulatory Options
    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. These options are described in more detail in 
section III of this preamble.
    On an annual basis, the cost of the proposed alternative ranges 
from $182.7 million to $198.6 million, using a three and seven percent 
discount rate. System costs make up 89 percent of the total

[[Page 30253]]

rule costs. In developing this proposal, however, EPA considered the 
recommendations to minimize the cost impact to small systems. The 
proposed multi-barrier, risk-based approach was designed to achieve 
maximum public health protection while avoiding excessive compliance 
costs associated with Across-the-Board Disinfection regulatory 
compliance requirements.
    To mitigate the associated compliance cost increases across water 
systems, the proposed GWR also provides States with considerable 
flexibility when implementing the rule. This flexibility will allow 
States to work within their existing program. Similarly, the rule 
allows States to consider the characteristics of individual systems 
when determining an appropriate corrective action. For example, States 
have the flexibility to allow systems to obtain a new source, or use 
any disinfection treatment technology, provided it achieves 4-log 
inactivation or removal of pathogens.
4. Small Entity Outreach and Small Business Advocacy Review Panel
    As required by section 609(b) of the RFA, as amended by SBREFA, EPA 
also conducted outreach to small entities and convened a Small Business 
Advocacy Review Panel to obtain advice and recommendations of 
representatives of the small entities that potentially would be subject 
to the rule's requirements. The SBAR Panel members for the GWR were the 
Small Business Advocacy Chair of the Environmental Protection Agency, 
the Director of the Standards and Risk Management Division in the 
Office of Ground Water and Drinking Water (OGWDW) within EPA's Office 
of Water, the Administrator for the Office of Information and 
Regulatory Affairs of the Office of Management and Budget (OMB), and 
the Chief Counsel for Advocacy of the Small Business Administration 
(SBA). The Panel convened on April 10, 1998, and met seven times before 
the end of the 60-day Panel period on June 8, 1998. The SBAR Panel's 
report Final Report of the SBREFA Small Business Advocacy Review Panel 
on EPA's Planned Proposed Rule for National Primary Drinking Water 
Regulations: Ground Water, the small entity representatives (SERs) 
comments on components of the GWR, and the background information 
provided to the SBAR Panel and the SERs are available for review in the 
Office of Water docket. This information and the Panel's 
recommendations are summarized in section VI.A.4.a.
    Prior to convening the SBAR Panel, EPA consulted with a group of 22 
SERs likely to be impacted by a GWR. The SERs included small system 
operators, local government officials (including elected officials), 
small business owners (e.g., a bed and breakfast with its own water 
supply), and small nonprofit organizations (e.g., a church with its own 
water supply for the congregation). The SERs were provided with 
background information on the GWR, on the need for the rule and the 
potential requirements. The SERs were asked to provide input on the 
potential impacts of the rule from their perspective. All 22 SERs 
commented on the information provided. These comments were provided to 
the SBAR Panel when the Panel convened. After a teleconference between 
the SERs and the Panel, the SERs were invited to provide additional 
comments on the information provided. Three SERs provided additional 
comments on the rule components after the teleconference. In general, 
the SERs consulted on the GWR were concerned about the impact of the 
rule on small water systems (because of their small staff and limited 
budgets), the additional monitoring that might be required, and the 
data and resources necessary to conduct a hydrogeologic sensitivity 
assessment or sanitary survey. There was also considerable discussion 
about how nationally representative the source data was. SER suggested 
providing flexibility to the States implementing these provisions and 
opposed mandatory disinfection across-the-board. SERs expressed support 
for existing monitoring requirements as a means of determining 
compliance, and some supported increased requirements for total 
coliform monitoring.
    Consistent with the RFA/SBREFA requirements, the Panel evaluated 
the assembled materials and small-entity comments related to the 
elements of the IRFA. A copy of the Panel report is in the Office of 
Water docket for this proposed rule.
a. Number of Small Entities to Which the Rule Will Apply
    When the IRFA was prepared, EPA estimated that there were over 
157,000 small ground water systems that could be affected by the GWR, 
serving a population of more than 48 million. Roughly one-third of 
these systems are community water systems (CWS). The remainder are non-
community water systems (NCWS) (i.e. non-transient non-community such 
as schools and transient non-community such as restaurants). A more 
detailed and current discussion of the impact of the proposed rule on 
small entities can be found in section V of this preamble.
    The SBAR Panel recommended that, given the number of systems that 
could be affected by the rule, EPA should consider focusing compliance 
requirements on those systems most at risk of fecal contamination. The 
GWR addresses this issue and is designed to target the systems at 
highest risk. Risk characterization is based on system characteristics, 
i.e., significant deficiencies in operation or maintenance and 
hydrogeologic sensitivity to contamination. A system is not required to 
perform an action such as source water microbial monitoring until the 
State has cause to believe the system is at risk.
    The Panel also recommended that the rule requirements be based on 
system size. Because the GWR is a targeted risk-based rule, the 
regulatory strategy is based on system-specific risk indicators that 
are not directly related to system size. However, the monitoring 
required for treatment effectiveness (compliance monitoring) varies 
based on system size. Ninety-seven percent of all ground water systems 
serve less than 3,300 people. Under the proposed GWR, disinfecting 
ground water systems serving less than 3,300 people must monitor 
treatment by taking daily grab samples. Disinfecting ground water 
systems serving 3,300 or more people must monitor treatment 
continuously.
    The SBAR Panel advocated that States be provided with flexibility 
when implementing the rule. The GWR also addresses this issue. As 
discussed earlier in sections III.A.1. and 2. of this proposal, States 
have considerable flexibility in addressing potential problems in small 
systems. In particular, States have the flexibility to define and 
identify significant system deficiencies and to describe their 
approaches to identifying the presence of hydrogeologic barriers to 
contamination. States also have the flexibility to require correction 
of fecal contamination or use any disinfection treatment technology, 
provided it achieves 4-log (99.99%) inactivation or removal of viruses. 
Similarly, the rule allows States to consider the characteristics of 
individual systems when determining an appropriate corrective action.
b. Record Keeping and Reporting and Other Compliance Requirements
    Because small systems frequently have minimal staff and resources, 
including data on the underlying hydrogeology of the system, the SBAR 
Panel recommended that EPA focus the record keeping, reporting, and 
compliance requirements on those systems at greatest risk of fecal

[[Page 30254]]

contamination. The Panel also recommended that EPA consider tailoring 
the requirements based on system size (e.g., the smaller systems would 
not have to monitor as frequently or perform sanitary surveys on the 
same schedule.)
    The GWR proposed today is a targeted risk-based regulatory 
strategy. The regulatory strategy is based on system characteristics 
(i.e., hydrogeologic sensitivity; TCR positive in the distribution 
system) and is not directly related to system size. However, the 
monitoring required for treatment effectiveness (compliance monitoring) 
varies based on system size. Ninety-seven percent of all ground water 
systems serve less than 3,300 people. Under the proposed GWR, 
disinfecting ground water systems serving less than 3,300 people must 
monitor treatment by taking daily grab samples. Disinfecting ground 
water systems serving 3,300 or more people must monitor treatment 
continuously. In addition, the only across-the-board requirement is for 
sanitary surveys, but the implementation schedule is staggered (e.g., 
every 3 years for CWS and every 5 years for NCWS) which should provide 
some relief for small systems because there are proportionately more 
that are NCWS. EPA is also requesting comment on several options that 
would reduce the required frequency of sanitary surveys. Because many 
small systems may not have easy access to the records that would 
ideally be available for a hydrogeologic sensitivity assessment or a 
sanitary survey, EPA, after consulting with stakeholders and the SBAR 
Panel, has determined that it will not use the lack of adequate well 
records, the lack of a cross connection program, or intermittent 
pressure fluctuations as automatic triggers to indicate risk of 
potential contamination. These factors may be considered along with 
others that more definitively demonstrate risk. This strategy will 
enable States to focus their resources on the systems which need the 
most surveillance or follow-up action and will avoid penalizing systems 
with limited resources.
    With respect to the potential cost of additional monitoring for 
small systems, particularly if the rule required viral monitoring, the 
SBAR Panel offered several recommendations. First, the Panel suggested 
that, to the extent possible, the GWR should build on the existing 
monitoring framework in the TCR. Given the low cost of the Total 
Coliform test, the Panel noted that an increase in the frequency and 
the locations for TCR monitoring or additional samples in the source 
water if the system has a Total Coliform positive sample would be 
preferable to other fecal indicator tests, given the current cost of a 
viral test. However, the Panel also recommended that the EPA continue 
to develop a lower cost, more accurate test to identify viral and 
bacterial contamination in drinking water.
    Today's proposal does build on the existing TCR monitoring 
framework by using the results of the TCR monitoring to determine if 
source water monitoring is required. In the proposal, a system is 
required to test for the presence of E. coli, coliphage, or enterococci 
in the source water within 24 hours of a total coliform positive sample 
in the distribution system. Only systems determined to be 
hydrogeologically sensitive that do not already treat their water to 4-
log inactivation or removal are required to conduct the additional 
routine monitoring. These systems must test their source water monthly. 
If no fecal indicators are found after 12 consecutive months of 
monitoring, the State may reduce the monitoring frequency for that 
system. Similarly, if a non-sensitive system does not have a 
distribution system, any sample taken for TCR compliance is effectively 
a source water sample so an additional triggered source water sample 
would not be required. In both cases, however, if the system has an E. 
coli, coliphage, or fecal coliform positive sample, the system is 
required to conduct the necessary follow-up actions.
    The GWR also has incorporated low-cost fecal contamination 
indicator tests. EPA-approved methods for detecting bacterial 
indicators of fecal contamination, including E. coli and enterococci, 
are already widely used and are low cost (approximately $25 per 
sample). In addition, EPA is currently developing viral monitoring 
methods which will cost approximately the same as existing bacterial 
methods.
    The SBAR Panel recommended that States be provided with flexibility 
when implementing the rule. For example, while States must have the 
authority to require the correction of significant deficiencies, States 
should also have the flexibility to determine which deficiencies are 
``significant'' from a public health perspective. When a State 
determines that corrective action is necessary, it should have the 
flexibility to determine what actions a system should take, including 
but not limited to disinfection. Similarly, States should also have the 
flexibility to require disinfection across-the-board for all or a 
subset of the public water supply systems in their State. States should 
also be given the flexibility to choose from the full range of 
disinfection technologies that will meet the public health goals of the 
rule.
    As discussed earlier in sections III.A.1. and 2. of this proposal, 
States have considerable flexibility in addressing potential problems 
in small systems particularly with respect to sanitary survey, where 
States define and identify significant deficiencies, and in conducting 
hydrogeologic sensitivity assessments. The GWR allows States 
flexibility to work within their existing programs and define and 
identify significant deficiencies. States also have the flexibility to 
require correction of fecal contamination or use any disinfection 
treatment technology, provided it achieves 4-log (99.99%) inactivation 
or removal of viruses. Similarly, the rule allows States to consider 
the characteristics of individual systems when determining an 
appropriate corrective action.
    The Panel was also concerned about the potential cost of 
disinfection and recommended that EPA include a full range of variables 
when determining both the potential cost burden and benefits of the 
rule.
    In determining the costs and benefits of today's proposed rule, EPA 
considered the full range of both potential costs and benefits for the 
rule. The flexibility in the rule is designed to reduce the cost of 
compliance with the rule, particularly for small systems. While 
determining the costs of the various technologies, EPA has estimated 
the percentage of systems in consultation with the States that will 
choose between the different technologies, in part based on system 
size. When determining the benefits of today's proposal, EPA considered 
a range of benefits from reduction in illness and mortality to outbreak 
cost avoided and possibly reduced uncertainty and averting behaviors. 
However, only reductions in acute viral and bacterial illness and 
decreases in mortality from virus are monetized. More detailed cost and 
benefit information is included in the GWR RIA (US EPA, 1999a) for 
today's proposal. Because systems are highly variable, the SBAR Panel 
recommended that States be given the flexibility to determine 
appropriate maintenance or cross connection control measures for each 
system and to the extent practicable maintenance measures should be 
performance-based.
    EPA recognizes that systems' characteristics are highly variable. 
States have considerable flexibility when working with systems to 
address significant deficiencies, conduct hydrogeological sensitivity 
assessments,

[[Page 30255]]

and take corrective action. Cross connection control will be considered 
under a future rulemaking (i.e., the Long Term 2 Enhanced Surface Water 
Treatment Rule).
c. Other Federal Rules
    To avoid duplication of effort, the SBAR Panel recommended using 
the State Source Water Assessment and Protection Program (SWAPP) plans 
and susceptibility assessments as a component of the hydrogeologic 
sensitivity assessment process. To further streamline the process, 
especially for small systems, the Panel also recommended combining the 
hydrogeologic sensitivity assessment with the sanitary surveys.
    In today's GWR proposal, States are encouraged to use their SWAPP 
assessments when the assessment provides data relevant to the 
hydrogeologic sensitivity assessment of a system. The schedule for 
sensitivity assessments (six years after the GWR is promulgated in the 
Federal Register for CWS and eight years after the GWR is promulgated 
in the Federal Register for NCWS) should allow States to complete the 
assessment and the first round of sanitary surveys concurrently if they 
choose to do so.
d. Significant Alternatives
    Because the SBREFA consultation was conducted early in the 
regulatory development process before there was a draft proposal, few 
comments were received on specific regulatory alternatives. In general, 
the SERs supported the approach described in the outreach materials 
while at the same time commenting on particular aspects of the approach 
that might be burdensome or otherwise problematic. Their concerns echo 
the comments received on other parts of the IRFA.
    The SBAR Panel reiterated their suggestion that compliance 
requirements be tailored to the system size. In particular, if the 
minimum monitoring frequency and the frequency for sanitary surveys for 
the smallest systems (e.g., those serving less than 500 people) could 
be reduced, it would reduce both the resources necessary to comply with 
the rule and record keeping required by the system.
    EPA has structured today's proposal as a targeted risk-based 
approach to reducing fecal contamination. The only requirement that 
affects all GWSs is the sanitary survey. The required frequency for 
sanitary surveys for community systems is once every three years which 
may be changed by the State to once every five years if the system 
either treats to 4-log inactivation or removal of virus or has an 
outstanding performance record documented in previous inspections and 
has no history of total coliform MCL or monitoring violations since the 
last sanitary survey under current ownership. The required frequency 
for sanitary surveys is once every five years for noncommunity systems. 
The majority of the small systems are noncommunity systems so the 
majority of systems will only have a sanitary survey once every five 
years. At this frequency, EPA believes that the requirements will not 
be burdensome for even the smallest systems, however EPA is also 
requesting comment on less frequent sanitary survey requirements.
    Similarly, the only additional monitoring requirements in today's 
proposal are for undisinfected systems that are either located in 
sensitive hydrogeologic settings or have a total coliform positive 
sample in the distribution system. The monitoring required for a total 
coliform positive sample under the TCR would be a one-time event while 
the monitoring for sensitive systems would be on a routine monthly 
basis for at least 12 samples.
    Finally, the SBAR Panel noted that disinfection of public water 
supplies may result in an increase in other contaminants of concern, 
depending on the characteristics of the source water and the 
distribution system. Of particular concern were disinfection 
byproducts, lead, copper, and arsenic.
    EPA has discussed these issues previously in section V.G. of the 
GWR preamble. EPA believes that these issues, when they occur, will 
typically be localized and transitory. These risk/risk tradeoffs are 
considered qualitatively in the RIA and EPA will provide guidance on 
how to address these issues when the rule is finalized.
e. Other Comments
    The panel members could not reach consensus regarding the use of 
occurrence data to support the rule. Some panel members expressed the 
concern that the occurrence estimates discussed by EPA with the SERs 
overestimated the actual occurrence of fecal contamination and the 
studies used did not provide a true picture of national occurrence. EPA 
recognizes and understands the concerns about the available data 
expressed by these panel members. However, the Agency believes, after 
consulting with experts in the field, that the available data may 
underestimate the extent of ground water contamination because of 
limitations with sampling methods and frequency. EPA believes that a 
central issue for all participants and stakeholders in this rulemaking 
is how to interpret the available data. EPA agrees that the GWR must be 
based on the best available data, good science and sound analysis. The 
studies described in the materials presented to the SERs and SBAR Panel 
during the SBREFA process were conducted at different times and for 
different reasons; each requires careful analysis to ensure its proper 
use and to avoid misuse. A more detailed discussion of the occurrence 
studies and request for comment on their interpretation is provided in 
section II.C. of today's proposal.
    EPA invites comments on all aspects of the proposal and its impacts 
on small entities.

B. Paperwork Reduction Act

    The information collection requirements in this proposed rule have 
been submitted for approval to the Office of Management and Budget 
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An 
Information Collection Request (ICR) document has been prepared by EPA 
(ICR No. 1934.01) and a copy may be obtained from Sandy Farmer by mail 
at Collection Strategies Division; U.S. Environmental Protection Agency 
(2822); 1200 Pennsylvania Ave., NW, Washington, DC 20460, by email at 
[email protected], or by calling (202) 260-2740. A copy may 
also be downloaded from the Internet at http://www.epa.gov/icr. For 
technical information about the collection contact Jini Mohanty by 
calling (202) 260-6415.
    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 in 
Part 141, for systems, and Part 142, for States are mandatory. The 
information collected is not confidential.
    EPA estimates that the annual burden on PWSs and States for 
reporting and record keeping will be 326,215 hours. This is based on an 
estimate that 56 States and territories will each need to provide 3 
responses each year with an average of 524 hours per response, and that 
52,331 systems will each provide 2.3 responses each year with an 
average of less than 2 hours per response. The labor burden is 
estimated for the following activities: Reading and understanding the 
rule, planning, training, and meeting primacy requirements. The 
recordkeeping and reporting burden also includes capital costs of 
$1,376,302 for capital

[[Page 30256]]

improvements by PWSs (installation of disinfection monitoring 
equipment).
    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 are listed in 40 CFR Part 9 and 48 CFR Chapter 15.
    Comments are requested on the Agency's need for this information, 
the accuracy of the provided burden estimates, and any suggested 
methods for minimizing respondent burden, including the use of 
automated collection techniques. Send comments on the ICR to the 
Director, Collection Strategies Division; U.S. Environmental Protection 
Agency (2822); 1200 Pennsylvania Ave, N.W.; Washington, DC 20460; and 
to the Office of Information and Regulatory Affairs, Office of 
Management and Budget, 725 17th St., N.W., Washington, DC 20503, marked 
``Attention: Desk Officer for EPA.'' Include the ICR number in any 
correspondence. Since OMB is required to make a decision concerning the 
ICR between 30 and 60 days after May 10, 2000, a comment to OMB is best 
assured of having its full effect if OMB receives it by June 9, 2000. 
The final rule will respond to any OMB or public comments on the 
information collection requirements contained in this proposal.

C. Unfunded Mandates Reform Act

1. Summary of UMRA Requirements
    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 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 UMRA section 202, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in State, local and tribal government expenditures, in the 
aggregate, or private sector expenditures, 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 notification to 
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.
2. Written Statement for Rules With Federal Mandates of $100 Million or 
More
    EPA has determined that this rule contains a Federal mandate that 
may result in expenditures of $100 million or more for the private 
sector in any one year.
    Table VI-2 presents a breakdown of the estimated $182.7 to$198.6 
million annual cost for today's proposed rule (the proposed Multi-
Barrier Option). Public ground water systems owned by State, local and 
tribal governments will incur $51.2 to $56.5 million of these costs and 
States will incur an additional $20.1 to $22.1 million for a total 
public sector cost of $71.3 to $78.7 million dollars per year. Public 
ground water systems which are owned by private entities will incur a 
total cost of $111.5 to $ 119.9 million per year, $5.5 to $7 million of 
which is incurred by entities that operate a public water system as a 
means of supporting their primary business (e.g., a mobile home park 
operator).

      Table VI-2.--Public and Private Costs for of the Proposed GWR
------------------------------------------------------------------------
                                                                 Percent
                                        Annual mean cost range*     of
             System type                     (millions $)         total
                                                                   cost
------------------------------------------------------------------------
Public PWS Cost......................  $51.2 to $56.5..........       28
State Cost...........................  20.1 to 22.1............       11
                                      ----------------------------------
Total Public Cost....................  71.3 to 78.7............       40
                                      ==================================
Private PWS Cost.....................  106.0 to 113.0..........       57
Ancillary PWS Cost...................  5.5 to 7.0..............        4
                                      ----------------------------------
    Total Private Cost...............  111.5 to 119.9..........       60
                                      ==================================
    Total Cost.......................  182.7 to 198.6..........     100
------------------------------------------------------------------------
Note: Cost range based upon a 3% and 7% discount rate.

    Thus, today's rule is subject to the requirements of sections 202 
and 205 of the UMRA, and EPA has prepared a written statement which is 
summarized next. A more detailed description of this analysis is 
presented in EPA's Regulatory Impact Analysis of the GWR (US EPA, 
1999a) which is included in the Office of Water docket for this rule.
a. Authorizing Legislation
    Today's proposed rule is promulgated pursuant to section 1412(b)(8) 
of the SDWA, as amended in 1996, 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.''
    Section 1412 (b)(8) also establishes a statutory deadline for 
promulgation of the GWR of no later than the date on which the 
Administrator promulgates a Stage II rulemaking for disinfectants and 
disinfection byproducts. EPA intends to finalize the GWR in the year 
2000 to allow systems to consider the combined impact of this rule, the 
radon rule, the arsenic rule and the Stage 1 DBP rule on their design 
and treatment modification as well as their capital investment 
decisions. EPA believes States and systems will better plan for changes 
in operation and capital improvements, if they are presented with 
future requirements at one time.
b. Cost Benefit Analysis
    Section V of this preamble discusses the cost and benefits 
associated with the GWR . Also, EPA's Regulatory Impact Analysis of the 
GWR (US EPA, 1999a) contains a detailed cost benefit analysis. The 
analysis quantifies cost and benefits for four scenarios: the proposed 
regulatory option, the sanitary survey

[[Page 30257]]

option, the sanitary survey and triggered monitoring option, and the 
across-the-board disinfection option. Table VI-3 summarizes the range 
of annual costs and benefits for each rule option.

                        Table VI-3.--Annual Benefits and Costs of Rule Options ($Million)
----------------------------------------------------------------------------------------------------------------
                                                        Annual benefits   Annual costs  (3%)   Annual costs \2\
                       Option                         \1\  mean  [range]     mean  [range]        (7%)  mean
                                                            $million           $million        [range]  $million
----------------------------------------------------------------------------------------------------------------
Sanitary Survey.....................................                 $33                 $73                 $76
                                                             [$9 to $58]        [$71 to $74]        [$74 to $78]
Sanitary Survey and Triggered Monitoring............                $178                $158                $169
                                                          [$147 to $209]       [$152 to $19]      [$163 to $174]
Multi-barrier (Proposed ) Option....................                $205                $183                $199
                                                          [$169 to $242]      [$177 to $188]      [$192 to $206]
Across-the-Board Disinfection.......................                $283                $777                $866
                                                          [$255 to $311]      [$744 to $810]     [$823 to $909]
----------------------------------------------------------------------------------------------------------------
\1\ does not include benefits from reduction in chronic illness, reduced pain and suffering, or non-health
  benefits.
\2\ does not include non-quantified costs such as land acquisition or increases in other contaminants (e.g.,
  DBPs).

    Costs varied with each option and were driven by the number of 
systems that would need to fix a significant deficiency, take 
corrective action in response to fecal contamination, or install 
treatment. The annual mean cost of the four rule options ranges from 
$73 million to $866 million using a three percent and seven percent 
discount rate. For the first three options, the costs increase as more 
components are added for identifying fecally contaminated wells and 
wells sensitive to fecal contamination. However, the cost of these 
components (e.g., hydrogeologic sensitivity assessment, routine and 
triggered monitoring) are minor compared to the costs of correcting 
fecal contamination. The fourth option of across-the-board disinfection 
is the most costly because it would require all systems to have 
treatment regardless of actual or potential fecal contamination. Costs 
for the States to implement this rule are also included in the four 
cost estimates. Some costs, such as land acquisition where necessary to 
install treatment, were not included because of the difficulty of 
estimating them.
    These total annual monetized costs can be compared to the annual 
monetized benefits of the GWR. The annual monetized mean benefits of 
today's rule range from $33 million to $283 million as shown in Table 
VI-2. This result is based on the quantification of the number of acute 
viral illnesses and deaths avoided attributable to each option as well 
as the reduction in acute bacterial illness attributable to each 
option. For illness, EPA used a cost-of-illness number to estimate the 
benefits from the reduction in viral illness that result from this 
rule. This is considered a lower-bound estimate of actual benefits 
because it does not include the pain and discomfort associated with the 
illness. Mortalities were valued using a value of statistical life 
estimate consistent with EPA policy.
    This rule will also decrease bacterial illness associated with 
fecal contamination of ground water. EPA did not directly calculate the 
actual numbers of illness associated with bacterially contaminated 
ground water because the Agency lacked the necessary pathogen 
occurrence data to include it in the risk model. However, in order to 
get an estimate of the number of bacterial illness from fecally 
contaminated ground water, the Agency used the ratio of viral and 
unknown etiology outbreak illness to bacterial outbreak illnesses 
reported to CDC's for waterborne outbreaks in ground water. It was 
further assumed that the cost of these bacterial illnesses would be 
comparable to viral illness estimates. This rule also considered but 
did not monetize the health benefit from the reduction in chronic 
illness associated with some viral and bacterial infections (see 
section II.D.).
    Various Federal programs exist to provide financial assistance to 
State, local, and tribal governments in complying with this rule. The 
Federal government provides funding to States that have primary 
enforcement responsibility for their drinking water programs through 
the Public Water Systems Supervision Grants Program. Additional funding 
is available from other programs administered either by EPA or other 
Federal agencies. These include EPA's Drinking Water State Revolving 
Fund (DWSRF), U.S. Department of Agriculture's Rural Utilities' Loan 
and Grant Program, and Housing and Urban Development's Community 
Development Block Grant Program.
    For example, SDWA authorizes the Administrator of the EPA to award 
capitalization grants to States, which in turn can provide low cost 
loans and other types of assistance to eligible public water systems. 
The DWSRF assists public water systems with financing the costs of 
infrastructure needed to achieve or maintain compliance with SDWA 
requirements. Each State has considerable flexibility in determining 
the design of its DWSRF Program and to direct funding toward its most 
pressing compliance and public health protection needs. States may 
also, on a matching basis, use up to 10 percent of their DWSRF 
allotments for each fiscal year to assist in running the State drinking 
water program. In addition, States have the flexibility to transfer a 
portion of funds to the Drinking Water State Revolving Fund from the 
Clean Water State Revolving Fund.
    Furthermore, a State can use the financial resources of the DWSRF 
to assist small systems, the majority of which are ground water 
systems. In fact, a minimum of 15% of a State's DWSRF grant must be 
used to provide infrastructure loans to small systems. Two percent of 
the State's grant may be used to provide technical assistance to small 
systems. For small systems that are disadvantaged, up to 30% of a 
State's DWSRF may be used for increased loan subsidies. Under the 
DWSRF, Tribes have a separate set-aside which they can use.
    In addition to the DWSRF, money is available from the Department of 
Agriculture's Rural Utility Service (RUS) and Housing and Urban 
Development's Community

[[Page 30258]]

Development Block Grant (CDBG) program. RUS provides loans, guaranteed 
loans, and grants to improve, repair, or construct water supply and 
distribution systems in rural areas and towns up to 10,000 people. In 
Fiscal Year 1997, the RUS had over $1.3 billion in available funds. 
Also, three sources of funding exist under the CDBG program to finance 
building and improvements of public facilities such as water systems. 
The three sources of funding include: (1) direct grants to communities 
with populations over 200,000; (2) direct grants to States, which they 
in turn award to smaller communities, rural areas, and colonias in 
Arizona, California, New Mexico, and Texas; and (3) direct grants to 
US. Territories and Trusts. The CDBG budget for Fiscal Year 1997 
totaled over $4 billion dollars.
c. Estimates of Future Compliance Costs and Disproportionate Budgetary 
Effects
    To meet the UMRA requirement in section 202, EPA analyzed future 
compliance costs and possible disproportionate budgetary effects. The 
Agency believes that the cost estimates, indicated earlier and 
discussed in more detail in section V of this rule, accurately 
characterize future compliance costs of the proposed rule.
    In analyzing disproportionate impacts, the Agency considered three 
measures: reviewing the impacts on small systems versus large systems; 
reviewing the costs to public versus private water systems; and 
reviewing the household costs for each proposed rule option. It is also 
possible that some States or EPA Regions may face greater challenges 
from the GWR because they have comparatively more ground water systems. 
However, States that have a larger percentage of systems also receive a 
greater share of the Public Water Systems Supervision Grants Program 
and the DWSRF. A detailed analysis of these impacts is presented in the 
Regulatory Impact Analysis of the GWR (US EPA, 1999a).
    The first measure of disproportionate impact considers the cost 
incurred by small and large systems. As a group, small systems will 
experience a greater impact than large systems under the GWR. The 
higher cost to the small ground water systems is mostly attributable to 
the large number of these types of systems (i.e., 99% of ground water 
systems serve 10,000). Other reasons for the disparity include: (1) 
Large systems are more likely to already disinfect their ground water 
(disinfection exempts a system from triggered and routine monitoring), 
(2) large systems typically have greater technical and operational 
expertise, and (3) they are more likely to engage in source water 
protection programs. The potential economic impact among the small 
systems will be the greatest for systems serving less than 100 persons, 
as shown in Table VI-4.

     Table VI-4.--Average Annual Household Costs for GWR Options for CWS Taking Corrective Action or Fixing
                                               Significant Defects
----------------------------------------------------------------------------------------------------------------
                                                          Sanitary survey                       Across-the-board
           Size categories             Sanitary survey     and triggered      Multi-barrier       disinfection
                                            option       monitoring option  option (proposed)        option
----------------------------------------------------------------------------------------------------------------
100.................................              29.86              67.19              62.48             191.87
101-500.............................              11.23              15.02              18.95              81.38
501-1,000...........................               5.72               6.29               6.25              38.79
1,001-3,300.........................               2.99               2.91               3.39              23.45
3,301-10,000........................               1.39               1.46               2.74              16.78
10,001-50,000.......................               0.62               0.59               0.62               4.87
50,001-100,000......................               0.30               0.70               1.01              10.37
100,001-1,000,000...................               0.32               0.20               0.27               1.66
Average.............................               2.45               3.34               3.86              19.37
----------------------------------------------------------------------------------------------------------------

    The second measure of impact is the relative total cost to 
privately owned water systems compared to that incurred by publicly 
owned water systems. The majority of the small systems are privately-
owned (61% of the total). As a result, privately-owned systems as a 
group will have a slightly larger share of the total costs of the rule. 
However, EPA has no basis for expecting cost per-system to differ 
systematically with ownership.
    The third measure, household costs, can also be used to gauge the 
impact of a regulation and to determine whether there are 
disproportionately high impacts in particular segments of the 
population. Table VI-4 shows household costs by system size for each 
rule component. On average, annual household costs increases 
attributable to the first three rule options range from $2.45 to $3.86 
(Table VI-4). For these three options, 90 percent of households will 
face less than a $5 increase in annual household costs. The most 
expensive option, Across-the-Board Disinfection, results in the highest 
average annual household costs of $19.37. However, household costs 
increase across all options for those households served by the smallest 
sized systems. This occurs because they serve fewer households, and as 
a result, there are fewer households to share the system's compliance 
costs.
d. Macro-economic Effects
    Under UMRA section 202, EPA is required to estimate the potential 
macro-economic effects of the regulation. These types of effects 
include those on productivity, economic growth, full employment, 
creation of productive jobs, and international competitiveness. Macro-
economic effects tend to be measurable in nationwide econometric models 
only if the economic impact of the regulation reaches 0.25 percent to 
0.5 percent of Gross Domestic Product (GDP). In 1998, real GDP was 
$7,552 billion, so a rule would have to cost at least $18 billion to 
have a measurable effect. A regulation with a smaller aggregate effect 
is unlikely to have any measurable impact unless it is highly focused 
on a particular geographic region or economic sector. The macro-
economic effects on the national economy from the GWR should not have a 
measurable effect because the total annual costs for the proposed 
option range from $183 million to $199 million per year using a three 
and seven percent discount rate. Even the most expensive option, 
Across-the-Board Disinfection falls below the measurable threshold. The 
costs are not expected to be highly focused on a particular geographic 
region or sector.

[[Page 30259]]

e. Summary of EPA's Consultation With State, Local, and Tribal 
Governments and Their Concerns
    Consistent with the intergovernmental consultation provisions of 
section 204 of UMRA, EPA has initiated consultations with the 
governmental entities affected by this rule. EPA held four public 
meetings for all stakeholders and three Association of State Drinking 
Water Administrators early involvement meetings. 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. A more detailed description of the SBREFA process can be 
found in section VI.A. of this preamble. 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. Twelve State drinking water representatives 
also participated in the Agency's GWR workgroup.
    In addition to these consultations, EPA circulated a draft of this 
proposed rule and requested comment from the public through an informal 
process. Specifically, on February 3, 1999, EPA posted on the EPA's 
Internet web page and mailed out over 300 copies of the draft to people 
who had attended the 1997 and 1998 public stakeholder meetings as well 
as people on the EPA workgroup. EPA received 80 letters or electronic 
responses to this draft: 34 from State government (representing 30 
different States), 26 from local governments, ten from trade 
associations, six from Federal government agencies, and four from other 
people/organizations. No comments were received from tribal 
governments. EPA reviewed the comments carefully and considered their 
merit. Today's proposal reflects many of the commenters' points and 
suggestions. For example, numerous commenters felt that proposing a 
requirement to monitor source water using coliphage at this time was 
premature based on currently available data. EPA has recently completed 
round robin testing of coliphage methods and is requesting comment on 
the use of these methods.
    To inform and involve tribal governments in the rulemaking process, 
EPA presented the GWR at the 16th Annual Consumer Conference of the 
National Indian Health Board, at the annual conference of the National 
Tribal Environmental Council, and at an EPA Office of Ground Water and 
Drinking Water (OGWDW)/Inter Tribal Council of Arizona, Inc. tribal 
consultation meeting. Over 900 attendees representing Tribes from 
across the country attended the National Indian Health Board's Consumer 
Conference and over 100 Tribes were represented at the annual 
conference of the National Tribal Environmental Council. At both 
conferences, an EPA representative conducted two workshops on EPA's 
drinking water program and upcoming regulations, including the GWR.
    Comments received from tribal governments regarding the GWR focused 
on concerns and some opposition to mandatory disinfection for ground 
water systems. They also suggested that any waiver process be 
adequately characterized by guidance and simple to implement. EPA 
agrees with concerns of Tribes and has designed the proposed GWR so 
that disinfection is not mandatory. Systems will have the opportunity 
to correct significant deficiencies, eliminate the source of 
contamination, obtain a new source of water, or install disinfection to 
achieve 4-log inactivation or removal of virus. However, some systems 
in coordination with the primacy agent or State, might choose 
disinfection over these other options because it may be the least 
costly alternative.
    At the OGWDW/Inter Tribal Council of Arizona meeting, 
representatives from 15 Tribes participated. In addition, over 500 
Tribes and tribal organizations were sent the presentation materials 
and meeting summary. Because many Tribes have ground water systems, 
participants expressed concerns over some elements of the rule. 
Specifically, they had concerns about how the primacy agent would 
determine significant deficiencies identified in a sanitary survey and 
how the sensitivity assessment would be conducted. Because no Tribes 
currently have primacy, EPA is the primacy agent and will identify 
significant deficiencies as part of sanitary surveys and conduct the 
hydrogeologic sensitivity assessment as outlined in section III. A. and 
III.B. of this preamble.
    The Agency believes the proposed option in the GWR will provide 
public health benefits to individuals by reducing their exposure to 
fecal contamination through targeted expenditures to address 
significant deficiencies or fecal contamination. As discussed earlier 
in paragraph IV.C.1.c, over 90 percent of households will incur 
additional costs of less than $3.00 per month based on EPA's proposed 
regulatory approach. EPA will consider other options for the final rule 
as outlined in this proposal and discussed next.
f. Regulatory Alternatives Considered
    As required under section 205 of the UMRA, EPA considered several 
regulatory alternatives and numerous methods to identify ground water 
systems most at risk to microbial contamination. A detailed discussion 
of these alternatives can be found in section V of the preamble and 
also in the RIA for the GWR(US EPA, 1999a). Today's proposal also seeks 
comment on many regulatory options that EPA will consider for the final 
rule.
g. Selection of the Least Costly, Most Cost-Effective or Least 
Burdensome Alternative That Achieves the Objectives of the Rule
    As discussed earlier, EPA has considered various regulatory options 
that would reduce microbial contamination in ground water systems. EPA 
believes that the proposed option as described in today's rule, is the 
most cost effective option that achieves the rule's objective to reduce 
the risk of illness and death from microbial contamination in PWS 
relying on ground water. This option is a targeted approach where costs 
are driven by the number of systems having to fix fecal contamination 
problems and correct significant deficiencies that could lead to fecal 
contamination. EPA requests comment on how possible modifications to 
the proposed option, as outlined in section III of the preamble, may 
affect not only the cost but also the objectives of this rule.
3. Impacts on Small Governments
    In developing this rule, EPA consulted with small governments to 
address impacts of regulatory requirements in the rule that might 
significantly or uniquely affect small governments. In preparation for 
the proposed GWR, EPA conducted an analysis on small government impacts 
and included small government officials or their designated 
representatives in the rulemaking process. As discussed previously, a 
variety of stakeholders, including small governments, had the 
opportunity for timely and meaningful participation in the regulatory

[[Page 30260]]

development process through the SBREFA process, public stakeholder 
meetings, and tribal meetings. Representatives of small governments 
took part in the SBREFA process for this rulemaking and they also 
attended public stakeholder meetings. Through such participation and 
exchange, EPA notified some potentially affected small governments of 
requirements under consideration and provided officials of affected 
small governments with an opportunity to have meaningful and timely 
input into the development of regulatory proposals. A more detailed 
discussion of the SBREFA process and stakeholder meetings can be found 
in section VI.A. and section VI.C.2.e, respectively.
    In addition, EPA will educate, inform, and advise small systems 
including those operated by small government about GWR requirements. 
One of the most important components of this process will be the Small 
Entity Compliance Guide which is required by the SBREFA of 1996. This 
plain-English guide will explain what actions a small entity must take 
to comply with the rule. Also, the Agency is developing fact sheets 
that concisely describe various aspects and requirements of the GWR.
D. National Technology Transfer and Advancement Act
    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Pub L. No. 104-113, Sec. 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 the Office of Management and Budget (OMB), 
explanations when the Agency decides not to use available and 
applicable voluntary consensus standards.
    EPA also notes that the Agency plans to implement in the future a 
performance-based measurement system (PBMS) that would allow the option 
of using either performance criteria or reference methods in its 
drinking water regulatory programs. The Agency is determining the 
specific steps necessary to implement PBMS in its programs. Final 
decisions have not yet been made concerning the implementation of PBMS 
in water programs. However, EPA is evaluating what relevant performance 
characteristics should be specified for monitoring methods used in the 
water programs under a PBMS approach to ensure adequate data quality. 
EPA would then specify performance requirements in its regulations to 
ensure that any method used for determination of a regulated analyte is 
at least equivalent to the performance achieved by other currently 
approved methods.
    Once EPA has made its final determinations regarding implementation 
of PBMS in programs under the Safe Drinking Water Act, EPA would 
incorporate specific provisions of PBMS into its regulations, which may 
include specification of the performance characteristics for 
measurement of regulated contaminants in the drinking water program 
regulations.
1. Microbial Monitoring Methods
    The proposed rulemaking involves technical standards. Ground water 
systems that are identified by the State as having hydrogeologically 
sensitive wells as described in Secs. 142.16(k)(3) and 141.403(a), and 
ground water systems that have a TCR positive sample as described in 
Sec. 141.403(b) of today's proposed rule must sample and test their 
source water. GWSs must test for at least one of the following fecal 
indicators: E. coli, enterococci and coliphage using one of the methods 
in Sec. 141.403(d) and discussed in greater detail in III.D.4. Table 
VI-5 lists the microbial methods which must be used for source water 
monitoring.
    EPA proposes to use several approved methods. For testing E. coli 
and enterococci, the methods in Sec. 141.403(d) are either consensus 
methods or new methods that EPA has recently approved for drinking 
water monitoring with the exception of Enterolert (a method for 
enterococci) for which EPA is proposing approval through this 
rulemaking. EPA is also proposing testing source waters for the 
presence for coliphage. EPA proposes to use EPA Method 1601: Two-Step 
Enrichment Presence-Absence Procedure and EPA Method 1602: Single Agar 
layer Procedure.
    While the Agency identified Standards Methods, Method 9211D 
Coliphage Detection (20th edition of Standard Methods for the 
Examination of Water and Wastewater) as being potentially applicable, 
EPA does not propose to use it in this rulemaking. The use of this 
voluntary consensus standard would not meet the Agency's needs because 
the method does not detect male specific coliphage, the sample volume 
is inappropriately small (20 ml versus the GWR's proposed 100 ml sample 
requirement), and according to the method, the sensitivity may not be 
high enough to detect one coliphage in a 100 ml sample. EPA welcomes 
comments on this aspect of the proposed rulemaking and, specifically, 
invites the public to identify potentially-applicable voluntary 
consensus standards and to explain why such standards should be used in 
this regulation.

                     Table VI-5.--Microbial Methods
------------------------------------------------------------------------
             Analytical methods for source water monitoring
-------------------------------------------------------------------------
               Indicator                            Method\1\
------------------------------------------------------------------------
E. coli................................  Colilert Test (Method 9223B)
                                          \2\ \3\
                                         Colisure Test (Method 9223B)
                                          \2\ \3\
                                         Membrane Filter Method with MI
                                          Agar \4\ \5\
                                         m-ColiBlue24 Test \4\ \6\
                                         E*Colite Test \4\ \7\
                                         May also use the EC-MUG (Method
                                          9212F) \2\ and NA-MUG (Method
                                          9222G) \2\ E. coli
                                          confirmation step Sec.
                                          141.21(f)(6) after the EPA
                                          approved Total Coliform
                                          methods in Sec.  141.21(f)(3)
enterococci............................  Multiple-Tube Tech. (Method
                                          9230B) \1\
                                         Membrane Filter Tech. (Method
                                          9230C) \1\ \8\
                                         Enterolert \3\
Coliphage..............................  EPA Method 1601: Two-Step
                                          Enrichment Presence-Absence
                                          Procedure \9\
                                         EPA Method 1602: Single Agar
                                          layer Procedure \9\
------------------------------------------------------------------------
\1\ The time from sample collection to initiation of analysis may not
  exceed 30 hours. Systems are encouraged but not required to hold
  samples below 10  deg.C during transit.
\2\ Methods are approved and described in Standard Methods for the
  Examination of Water and Wastewater (20th edition).
\3\ Medium available through IDEXX Laboratories, Inc., One IDEXX Drive,
  Westbrook, Maine 04092.
\4\ EPA approved drinking water methods.
\5\ Brenner, K.P., C.C. Rankin, Y.R. Roybal, G.N. Stelma, P.V. Scarpino,
  and A.P. Dufour. 1993. New medium for the simultaneous detection of
  total coliforms and Escherichia coli in water. Appl. Environ.
  Microbiol. 59:3534-3544.
\6\ Hach Company, 100 Dayton Ave., Ames, IA 50010.
\7\ Charm Sciences, Inc., 36 Franklin St., Malden, MA 02148-4120.
\8\ Proposed for EPA approval, EPA Method 1600: MF Test Method for
  enterococci in Water (EPA-821-R-97-004 (May 1997)) is an approved
  variation of Standard Method 9230C.
\9\ Proposed for EPA approval are EPA Methods 1601 and 1602, which are
  available from the EPA's Water Resources Center, Mail code: RC-4100,
  1200 Pennsylvania Ave. NW, Washington, DC 20460.


[[Page 30261]]

E. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866, (58 FR 51,735,October 4,1993) the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to OMB review and the requirements of the 
Executive Order. The Order defines ``significant regulatory action'' as 
one that is likely to result in a rule that may: (1) Have an annual 
effect on the economy of $100 million or more or adversely affect in a 
material way the economy, a sector of the economy, productivity, 
competition, jobs, the environment, public health or safety, or State, 
local, or tribal governments or communities; (2) create a serious 
inconsistency or otherwise interfere with an action taken or planned by 
another agency; (3) materially alter the budgetary impact of 
entitlement, grants, user fees, or loan programs or the rights and 
obligations of recipients thereof; or (4) raise novel legal or policy 
issues arising out of legal mandates, the President's priorities, or 
the principles set forth in the Executive Order.
    Pursuant to the terms of Executive Order 12866, EPA has determined 
that this rule is a ``significant regulatory action''. As such, this 
action was submitted to OMB for review. Changes made in response to OMB 
suggestions or recommendations are documented in the public record.

F. Executive Order 12898: Environmental Justice

    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 
Agency has considered environmental justice issues concerning the 
potential impacts of this action and has consulted with minority and 
low-income stakeholders.
    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. There are two aspects of 
today's proposed rule that relate specifically to this policy: the 
overall nature of the rule, and the convening of a stakeholder meeting 
specifically to address environmental justice issues. The GWR applies 
to all public water systems: community water systems, nontransient 
noncommunity water systems, and transient noncommunity water systems 
that use ground water as their source water. Consequently, the health 
protection benefits provided by this proposal are equal across all 
income and minority groups served by these systems. Existing 
regulations such as the SWTR and IESWTR provide similar health benefit 
protection to communities that use surface water or ground water under 
the direct influence of surface water.
    As part of EPA's responsibilities to comply with Executive Order 
12898, 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. Topics discussed included treatment 
techniques, costs and benefits, data quality, health effects, and the 
regulatory process. Participants included national, State, tribal, 
municipal, and individual stakeholders. EPA conducted the meetings by 
video conference call with participants in eleven cities. This meeting 
was a continuation of stakeholder meetings that started in 1995 to 
obtain input on the Agency's drinking water programs. The major 
objectives for the March 12, 1998 meeting were: solicit ideas from 
environmental justice (EJ) stakeholders on known issues concerning 
current drinking water regulatory efforts; identify key issues of 
concern to EJ stakeholders; and receive suggestions from EJ 
stakeholders concerning ways to increase representation of EJ 
communities in EPA's Office of Water regulatory efforts. In addition, 
EPA developed a plain-English guide specifically for this meeting to 
assist stakeholders in understanding the multiple and sometimes complex 
drinking water issues.

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 ``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.
    This proposed rule is subject to this Executive Order because it is 
an economically significant regulatory action as defined by Executive 
Order 12866, and EPA believes that the environmental health or safety 
risk addressed by this action may have a disproportionate effect on 
children. Accordingly, EPA has evaluated the environmental health or 
safety effects of viruses on children. The results of this evaluation 
are contained in section II.E. of the preamble and in the RIA for 
today's rule (US EPA, 1999a). A copy of RIA and its supporting 
documents have been placed in the Office of Water docket for this 
proposal.
1. Risk of Viral Illness to Children and Pregnant Women
    The risk of illness and death due to viral contamination of 
drinking water depends on several factors, including the age and the 
immune status of the exposed individual. Two groups that are at 
increased risk of illness and mortality due to waterborne pathogens are 
children and pregnant women (Gerba et al., 1996). For example, 
rotavirus infections can occur in people of all ages, however they 
primarily affect young children (US EPA, 1999b). Infants and young 
children have higher rates of infection and disease from enteroviruses 
than other age groups (US EPA, 1999b). Several viruses 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 paralytic polio, heart 
disease, encephalitis, hemorrhagic conjunctivitis, hand-foot-and-mouth 
disease and diabetes mellitis (CDC, 1997; Modlin, 1997; Melnick, 1996; 
Cherry, 1995; Berlin and Rorabaugh, 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 (US 
EPA, 1999c). Coxsackievirus and echovirus may be transmitted from the 
mother to the child in utero (Gerba et al., 1996).
    To comply with Executive Order 13045, EPA calculated the baseline 
risk (e.g., risk without this rule) and with-rule reduction of risk 
from waterborne illness and mortality for children. To address the 
disproportionate risk of waterborne illness and mortality to children 
under this rulemaking, EPA applied age-specific parameters regarding 
morbidity to the risk assessment. The risk assessment first

[[Page 30262]]

extracted the proportion of the population that falls into several age 
categories that may be more or less susceptible to waterborne viral 
illness than the general population. The extraction was done separately 
for two model viruses. Bacterial illnesses are not addressed in this 
analysis, however, EPA estimates that bacterial illnesses account for 
an additional 20% of viral illnesses.
    When assessing the risk of illness due to viruses of low-to-medium 
infectivity (using echovirus as a surrogate), the age categories used 
were less than one month of age, one month to five years of age, five 
to sixteen years of age and greater than sixteen years of age. It was 
assumed that 50% of children less than five years old would become ill 
once infected with low-to-medium infectivity viruses; while 57% of 
children five years to sixteen years of age and 33% of people over 
sixteen would become ill once infected. This estimate was based on a 
community-wide echovirus type 30 epidemic (Hall, 1970). See Appendix A 
of the RIA.
    When assessing the risk of illness due to viruses of high 
infectivity (using rotavirus as a surrogate) the age categories used 
were less than two years of age, two to five years of age, five to 
sixteen years old and greater than sixteen years old. It was assumed 
that 88% of children less than two years old would become ill once 
infected with high infectivity viruses; while 40% was assumed for 
everyone else. The morbidity rates for high infectivity viruses were 
based on data from Kapikian and Chanock (1996) for children less than 
two. For other age categories, EPA has conservatively estimated a 
morbidity of 10 based upon studies of rotavirus illness in households 
with newborn children (Wenman et al., 1979) and of an outbreak in an 
isolated community (Foster et. al., 1980). See Appendix A of the RIA.
    In addition to illness, EPA also considered child mortality 
attributable to waterborne microbial illness. For low-to-medium 
infectivity viruses, 0.92% of children less than one month of age who 
become ill were assumed to die based on information from Jenista et 
al., (1984) and Modlin (1986), while .041% of people greater than one 
month old who become ill were assumed to die. For viruses of high 
infectivity, 0.00073% of infected children less than four years old 
were assumed to die (Tucker et al., 1998). The low-to-medium 
infectivity viruses result in a higher mortality rate than the high 
infectivity viruses because the low-to-medium infectivity viruses cause 
more serious health effects.
    The proposed GWR specifically targets systems with existing or 
potential fecal contamination, including viral contamination. To 
estimate the benefits to children from today's proposed rule, the 
Agency calculated the number of illnesses and deaths avoided by the 
rule for the children less than 5 years old and for children between 
the ages of 5 and 16. Table VI-6 presents a summary of these estimates. 
Overall, the proposed rule would result in 26,566 less illnesses caused 
by viruses per year occurring in children 16 years of age and less. The 
proposed rule is also expected to result in 2 less deaths per year due 
to viral illness among children aged 16 or less.

   Table VI-6.--Reductions of Viral Illness and Death in Children Resulting from Various Regulatory Approaches
----------------------------------------------------------------------------------------------------------------
                                   Illness reduction    Death reduction    Illness reduction    Death reduction
             Options                  (ages 0-5)          (ages 0-5)       (5-16 years old)    (5-16 years old)
----------------------------------------------------------------------------------------------------------------
Sanitary Survey Only............               2,292                   0               1,773                   0
Sanitary Survey and Triggered                 13,044                   1               9,974                   1
 Monitoring.....................
Multi-barrier (Proposed)........              15,058                   1              11,508                   1
Across-the-board Disinfection...              21,125                   1              16,059                   2
----------------------------------------------------------------------------------------------------------------

    The Agency believes the proposed multi-barrier approach will 
provide the most cost-effective method of reducing viral and bacterial 
illness in children that results from contaminated ground water. The 
proposed option will reduce 3,500 more cases of viral illness in 
children each year than the sanitary survey and triggered monitoring 
option. This additional reduction is obtained with only a slightly 
larger increase in total annual costs. Conversely, the additional 
reductions in illness gained with the across-the-board option comes at 
a much higher cost. It is estimated that the across-the-board option 
will cost approximately $12,000 more per case of illness avoided than 
the multi-barrier approach.
2. Full Analysis of the Microbial Risk Assessment
    A full analysis of the microbial risk assessment is provided in the 
Appendix to the RIA for the proposed GWR, and a summary is provided in 
this preamble (see section II.E.).
    The public is invited to submit or identify peer-reviewed studies 
and data, of which EPA may not be aware, that assessed results of early 
life exposure to viruses and bacteria.

H. Consultations with the Science Advisory Board, National Drinking 
Water Advisory Council, and the Secretary of Health and Human Services

    In accordance with section 1412 (d) and (e) of the SDWA, the Agency 
did consult with the Science Advisory Board and will request comment 
from the National Drinking Water Advisory Council (NDWAC) and the 
Secretary of Health and Human Services on the proposed rule.

I. Executive Order on 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''. Under 
section 6 of Executive Order 13132, EPA may not issue a regulation that 
has Federalism 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 State and local governments, or EPA consults with 
State and local officials early in the process of developing the 
proposed regulation. EPA also may not issue a regulation that has 
Federalism implications and that preempts State

[[Page 30263]]

law, unless the Agency consults with State and local officials early in 
the process of developing the proposed regulation.
    If EPA complies by consulting, Executive Order 13132 requires EPA 
to provide to the Office of Management and Budget (OMB), in a 
separately identified section of the preamble to the final rule, a 
Federalism summary impact statement (FSIS). The FSIS must include a 
description of the extent of EPA's prior consultation with State and 
local officials, a summary of the nature of their concerns and the 
Agency's position supporting the need to issue the regulation, and a 
statement of the extent to which the concerns of State and local 
officials have been met. Also, when EPA transmits a draft final rule 
with Federalism implications to OMB for review pursuant to Executive 
Order 12866, EPA must include a certification from the Agency's 
Federalism Official stating that EPA has met the requirements of 
Executive Order 13132 in a meaningful and timely manner.
    EPA has concluded that this proposed rule may have Federalism 
implications since it may impose substantial direct compliance costs on 
local governments, and the Federal government will not provide the 
funds necessary to pay those cost. Accordingly, EPA provides the 
following FSIS as required by section 6(b) of Executive Order 13132.
    As discussed in section I.A., EPA met with a variety of State and 
local representatives including several local elected officials, who 
provided meaningful and timely input in the development of the proposed 
rule. Summaries of the meetings have been included in the public record 
for this proposed rulemaking. EPA consulted extensively with State, 
local, and tribal governments. For example, four public stakeholder 
meetings were held in Washington, DC, Portland, Oregon, Madison 
Wisconsin and Dallas, Texas. EPA also held three early involvement 
meetings with the Association of State Drinking Water Administrators. 
Several key issues were raised by stakeholders regarding the GWR 
provisions, many of which were related to reducing burden and 
maintaining flexibility. The Office of Water was able to reduce burden 
and increase flexibility by creating a targeted risk based approach 
which builds upon existing State programs. It should be noted that this 
rule is important because it will reduce the incidence of fecally 
contaminated drinking water supplies by requiring corrective actions 
for fecally contaminated systems or systems with a significant risk of 
fecal contamination resulting in a reduced waterborne illness. Because 
consultation on this proposed rule occurred before the November 2, 
1999, effective date of Executive Order 13132, EPA will initiate 
discussions with State and local elected officials regarding the 
implications of this rule during the public comment period.

J. Executive Order 13084: Consultation and Coordination With Indian 
Tribal Governments

    Under Executive Order 13084, EPA may not issue a regulation that is 
not required by statute, that significantly or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments, or EPA consults with those 
governments. If EPA complies by consulting, Executive Order 13084 
requires EPA to provide to the OMB, in a separately identified section 
of the preamble to the rule, a description of the extent of EPA's prior 
consultation with representatives of affected tribal governments, a 
summary of the nature of their concerns, and a statement supporting the 
need to issue the regulation. In addition, Executive Order 13084 
requires EPA to develop an effective process permitting elected 
officials and other representatives of Indian tribal governments ``to 
provide meaningful and timely input in the development of regulatory 
policies on matters that significantly or uniquely affect their 
communities.''
    EPA has concluded that this rule will significantly affect 
communities of Indian tribal governments because 92 percent of PWSs in 
Indian Country are ground water systems. It will also impose 
substantial direct compliance costs on such communities, and the 
Federal government will not provide the funds necessary to pay the 
direct costs incurred by the tribal governments in complying with the 
rule. In developing this rule, EPA consulted with representatives of 
tribal governments pursuant to Executive Order 13084. EPA's 
consultation, the nature of the tribal governments' concerns, and EPA's 
position supporting the need for this rule are discussed in section 
VI.C. which addresses compliance with UMRA.
    As described in section VI.C.2.e. of the UMRA discussion, EPA held 
extensive public meetings that provided the opportunity for meaningful 
and timely input in the development of the proposed rule. Summaries of 
the meetings have been included in the Office of Water public docket 
for this rulemaking. In addition, the Agency presented the rule and 
asked for comment at three tribal conferences. Two consultations took 
place at national conferences; one for the National Indian Health Board 
and the other for the National Tribal Environmental Council. The third 
consultation was conducted in conjunction with the Inter-Tribal Council 
of Arizona, Inc. A more detailed discussion of these consultations can 
be found in the UMRA consultation section (section VI.C.2.c.).

K. Plain Language

    Executive Order 12866 and the President's memorandum of June 1, 
1998, require each agency to write its rules in plain language. EPA 
invites comments on how to make this proposed rule easier to 
understand. For example: Has EPA organized the material to suit 
commenters' needs? Are the requirements in the rule clearly stated? 
Does the rule contain technical language or jargon that is not clear? 
Would a different format (grouping and order of sections, use of 
headings, paragraphs) make the rule easier to understand? Would shorter 
sections make this rule easier to understand? Could EPA improve clarity 
by adding tables, lists, or diagrams? What else could EPA do to make 
the rule easier to understand?

VII. Public Comment Procedures

    EPA invites you to provide your views on this proposal, approaches 
we have not considered, the potential impacts of the various options 
(including possible unintended consequences), and any data or 
information that you would like the Agency to consider. Many of the 
sections within today's proposed rule contain ``Request for Comment'' 
portions which the Agency is also interested in receiving comment on.

A. Deadlines for Comment

    Send your comments on or before July 10, 2000. Comments received 
after this date may not be considered in decision making on the 
proposed rule.

B. Where To Send Comment

    Send an original and 3 copies of your comments and enclosures 
(including references) to W-98-23 Comment Clerk, Water Docket (MC4101), 
USEPA, 1200 Pennsylvania Ave., NW, Washington DC 20460. Hand deliveries 
should be delivered to the Comment Clerk, Water Docket (MC4101), USEPA 
401 M , Washington, D.C. 20460. Comments may also be submitted 
electronically to [email protected]. Electronic comments must 
be submitted as an

[[Page 30264]]

ASCII, WP5.1, WP6.1 or WP8 file avoiding the use of special characters 
and form of encryption. Electronic comments must be identified by the 
docket number W-98-23. Comments and data will also be accepted on disks 
in WP 5.1, 6.1, 8 or ASCII file format. Electronic comments on this 
notice may be filed online at many Federal Depository Libraries. Those 
who comment and want EPA to acknowledge receipt of their comments must 
enclose a self-addressed stamped envelope. No facsimiles (faxes) will 
be accepted. Comments may also be submitted electronically to [email protected].

C. Guidelines for Commenting

    To ensure that EPA can read, understand and therefore properly 
respond to comments, the Agency would prefer that commenters cite, 
where possible, the paragraph(s) or sections in the notice or 
supporting documents to which each comment refers. Commenters should 
use a separate paragraph for each issue discussed. Note that the Agency 
is not soliciting comment on, nor will it respond to, comments on 
previously published regulatory language that is included in this 
notice to ease the reader's understanding of proposed language. You may 
find the following suggestions helpful for preparing your comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide technical information and/or data to support your views.
    4. If you estimate potential burden or costs, explain how you 
arrived at the estimate.
    5. Indicate what you support, as well as what you disagree with.
    6. Provide specific examples to illustrate your concerns.
    7. Make sure to submit your comments by the deadline in this 
proposed rule.
    8. At the beginning of your comments (e.g., as part of the 
``Subject'' heading), be sure to properly identify the document you are 
commenting on. You can do this by providing the docket control number 
assigned to the proposed rule, along with the name, date, and Federal 
Register citation.

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U.S. Environmental Protection Agency (USEPA). 1991c. Delineation of 
Wellhead Protection Areas in Fractured Rocks. Transferability of 
Results. P. 71-84. Environmental Protection Agency, Washington DC.
U.S. Environmental Protection Agency (USEPA). 1991d. Phase II. 56 FR 
30268.

[[Page 30267]]

U.S. Environmental Protection Agency (USEPA). 1990a. Drinking Water; 
Announcement of Public Meeting to Discuss the Preliminary Concept 
Paper for the Ground Water Disinfection Requirements. Meeting 
Notice. 55 FR 21093, May 22, 1990.
U.S. Environmental Protection Agency (USEPA). 1990b. Surface Water 
Treatment Rule Guidance Manual. Environmental Protection Agency, 
Washington DC.
U.S. Environmental Protection Agency (USEPA). 1989a. Office of 
Water, Total Coliform Rule; Final Rule. 54 FR 27544, June 29, 1989.
U.S. Environmental Protection Agency (USEPA). 1989b. Drinking Water; 
National Primary Drinking Water Regulations: Disinfection; 
Turbidity, Giardia lamblia, Viruses, Legionella, and Heterotrophic 
Bacteria; Final Rule, 54 FR 27486, June 29, 1989.
U.S. Environmental Protection Agency (USEPA). 1989c. Office of 
Water, Cross-Connection Control Manual. (Washington, DC: U.S. 
Government Printing Office, Publication No. EPA 570/9-89-007, 1989).
U.S. EPA. 1985a. Drinking Water Criteria Document for Viruses. ECAO-
CIN-451, June, 1985.
U.S. EPA. 1985b. Drinking Water Criteria Document for Legionella. 
EPA-60/X-85-051, March 1985.
U.S. EPA. 1984. Drinking Water Criteria Document of Heterotrophic 
Bacteria., Draft 5, May 25, 1984.
U.S. General Accounting Office (USGAO). Drinking Water Key Quality 
Assurance Program is Flawed and Underfunded, GAO/RCED-93-97. April 
1993.
USGS 1984: Davies, W.E., J.H. Simpson, G.C. Ohlmacher, W.S. Kirk, 
and E.G. Newton. Engineering Aspects of Karst. In National Atlas of 
the United States of America. U.S. Geological Survey. Map #38077-AW-
NA-07M-00.
Vaughn, J.M. 1996. ``Sample Analyses.'' in Attachment, unpublished 
letter on the analysis of alluvial wells in Missouri by Jerry Lane, 
Missouri Department of Natural Resources, Rolla, MO, November 7, 
1996.
Vaughn, J.M., Y.S. Chein, J.F. Novotny and D. Strout. 1990. Effects 
of Ozone Treatment on the Infectivity of Hepatitis A Virus. Can. 
Journ. Of Microbiol. 36(8):557-560.
Velazquez, F. R., D. O. Matson, J. J. Calva, M. Lourdes Guerrero, 
Ardythe L. Morrow, Shelly Carter-Campbell, Roger I. Glass, Mary K. 
Estes, Larry K. Pickering, and Guillermo M. Ruiz-Palacios. 1996. 
Rotavirus infection in infants as protection against subsequent 
infections.@ N. Engl. J. Med. 335:1022-1028.
Ward, R.L. 1986. Human Rotavirus Studies in Volunteers: 
Determinations of infectious Dose and Serological Response to 
Infection. J. Inf. Dis. 154(5):871.
WHO. 1996. Microbiological Criteria. In: Guidelines for Drinking 
Water Quality: Health Criteria and Other Supporting Information. 
Vol. 2. World Health Organization. Geneva.
Wiedenmann, A., B. Fischer, C. Straub, H. Wang, B. Flehmig and D. 
Schoenen. 1993. Disinfection of Hepatitis A Virus and MS2 Coliphage 
in Water by Ultraviolet Irradiation: Comparison of UV-
Susceptibility. Water Sci. Tech. Vol. 27, No.3-4, pp. 335-338.
Wenman, W. M., D. Hinde, S. Felthan and M. Gurwith. 1979. Rotavirus 
in adults. Results of a prospective study. @ 1979. N. Engl. J. Med. 
301 (6): 303-306.
Wilson B.R., P.F. Roessler, E. VanDellen, M. Abbaszadegan, and C.P. 
Gerba. 1992. Coliphage MS2 as a UV Water Disinfection Efficacy Test 
Surrogate for Bacterial and Viral Pathogens. Proceedings of the 
Water Quality Technology Conference. American Water Works 
Association. Toronto Ontario, Canada. May.
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.'' Wat. Res.. Vol. 33, pp 53-64.
Yates, M.V. 1999. Viruses and Indicators in Ground water, Results of 
Repeated Monitoring. Unpublished report, February 23, 1999.xxx

List of Subjects in 40 CFR Parts 141 and 142

    Environmental protection, Indians-lands, Intergovernmental 
relations, Radiation protection, Reporting and recordkeeping 
requirements, Water.

    Dated: April 17, 2000.
Carol M. Browner,
Administrator.
    For the reasons set forth in the preamble, title 40 chapter I of 
the Code of Federal Regulations is proposed to be amended as follows:

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

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

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

    2. 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 Sec. 142.16(k)(2) 
of this chapter, at the frequencies specified, may be used to meet the 
sanitary surveys requirements of this section.
* * * * *
    3. Section 141.154 is amended by adding paragraph (f) to read as 
follows:


Sec. 141.154  Required additional health information.

* * * * *
    (f) Ground water systems that detect E. coli, enterococci or 
coliphage in the source water as required by Sec. 141.403 must include 
the health effects language prescribed by Appendix B of subpart Q of 
this part.
* * * * *
    4. Section 141.202 as added by the final rule published on May 4, 
2000 is amended by adding entry (9) in numerical order to the table in 
paragraph (a) 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
-------------------------------------------------------------------------
 
              *        *        *        *        *
  (9) Violation of the treatment technique for the Ground Water Rule (as
   specified in Sec.  141.405(a) through (c) or when E. coli,
   enterococci, or coliphage are present as specified in Sec.  141.403)
   or when the water system fails to test for E. coli, enterococci,
   coliphage (as specified in Sec.  141.403).
 
              *        *        *        *        *
------------------------------------------------------------------------

    5. Appendix A of subpart Q as added by the final rule published on 
May 4, 2000 is amended by adding entry 8. under I.A. ``Microbiological 
Contaminants'' and by adding entry G. under IV. ``Other Situations 
Requiring Public Notification'' to read as follows:

[[Page 30268]]



     Appendix A to Subpart Q of Part 141.--NPDWR Violations and Other Situations Requiring Public Notice \1\
                                     (Including D/DBP and IESWTR Violations)
----------------------------------------------------------------------------------------------------------------
                                                               MCL/MRDL/TT violations    Monitoring and testing
                                                                         \2\              procedure violations
                                                             ---------------------------------------------------
                         Contaminant                            Tier of                   Tier of
                                                                 public                    public
                                                                 notice      Citation      notice      Citation
                                                                required                  required
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
A. Microbiological Contaminants
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
8. GWR TT violations........................................            1      141.405          N/A          N/A
 
*                  *                  *                  *                  *                  *
                                                        *
                               IV. Other Situations Requiring Public Notification
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
----------------------------------------------------------------------------------------------------------------
G. Fecal indicators for GWR: E. coli, enterococci, coliphage            1      141.403            1     141.403
----------------------------------------------------------------------------------------------------------------
Appendix A Endnotes
\1\ Violations and other situations not listed in this table (e.g., reporting violations and 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.

* * * * *
    6. Appendix B to subpart Q as added by the final rule published on 
May 4, 2000 is amended by adding a new entry 1c in numerical order un 
A. ``Microbiological Contaminants'' and by redisinating entries C. 
through H. as D. through I. and adding a new C. in alphabetical order 
to read as follows:

                             Appendix B of 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
-------------------------------------------------------------------------------------------------------------------------------------------- --------------
 
                   *                  *                  *                  *                  *                  *                  *
--------------------------------------------------------------------------------------------------------------------------------------------------------
A. Microbiological Contaminants
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                   *                  *                  *                  *                  *                  *                  *
1c. Fecal indicators (GWR):
    i. E. coli.......................  Zero.....................  None....................  Fecal indicators are bacteria or viruses whose
    ii. enterococci..................  None.....................                             presence indicates that the water may be
    iii. coliphage...................  None.....................                             contaminated with human or animal wastes.
                                                                                             Microbes in these wastes can cause short-term
                                                                                             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
 
                   *                  *                  *                  *                  *                  *                  *
C. Ground Water Rule (GWR) TT          None.....................  TT......................  Inadequately treated or inadequately protected
 violations.                                                                                 water may contain disease-causing organisms.
                                                                                             These organisms include bacteria and viruses
                                                                                             which can cause symptoms such as diarrhea,
                                                                                             nausea, cramps, and associated headaches.
 
                  *                  *                  *                  *                  *                  *                  *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Appendix B Endnotes
1. MCLG--Maximum contaminant level goal.
2. MCL--Maximum contaminant level.


[[Page 30269]]

* * * * *
    7. Appendix C to subpart Q as added in the final rule published on 
May 4, 2000 amended by adding the following abbreviation in 
alphabetical order to read as follow:

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

* * * * *

GWR Ground Water Rule

* * * * *
    9. A new subpart S is proposed to be added to read as follows:
Subpart S--Ground Water Rule
Sec.
141.400   General requirements and applicability.
141.401   Sanitary survey information request.
141.402   Hydrogeologic sensitivity assessment information request.
141.403   Microbial monitoring of source water and analytical 
methods.
141.404   Treatment technique requirements.
141.405   Treatment technique violations.
141.406   Reporting and record keeping.

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. All public water systems that are served solely 
by ground water. The requirements in this subpart also apply to subpart 
H systems that distribute ground water that is not treated to 4-log 
inactivation or removal of viruses before entry into the distribution 
system. Systems supplied by ground water under the direct influence of 
surface water are regulated under subparts H and P of this part, not 
under this subpart. For the purposes of this subpart, ``ground water 
system'' is defined as any public water system meeting this 
applicability statement.
    (c) General requirements. These regulations in this subpart 
establish requirements related to sanitary surveys, hydrogeologic 
sensitivity assessments, and source water microbial monitoring 
performed at ground water systems as defined by paragraph (b) of this 
section. The regulations in this subpart also establish treatment 
technique requirements for these ground water systems which have 
fecally contaminated source waters, as demonstrated under Sec. 141.403, 
or significant deficiencies as identified in a sanitary survey 
conducted by a State under either Sec. 142.16(k)(2) of this chapter or 
by EPA under SDWA section 1445. Ground water systems with fecally 
contaminated source water or significant deficiencies must meet one or 
more of the following treatment technique requirements: eliminate the 
source of contamination, correct the significant deficiency, provide an 
alternate source water, or provide a treatment which reliably achieves 
at least 99.99 percent (4-log) inactivation or removal of viruses 
before or at the first customer. Ground water systems which provide 4-
log inactivation or removal of viruses will be required to conduct 
compliance monitoring to demonstrate treatment effectiveness.
    (d) Compliance dates. Ground water systems must comply with the 
requirements of this subpart beginning [DATE 3 YEARS AFTER PUBLICATION 
OF THE FINAL RULE IN THE FEDERAL REGISTER.


Sec. 141.401  Sanitary survey information request.

    Ground water systems must provide the State at its request, any 
pertinent existing information that would allow the State to perform a 
sanitary survey as described in Sec. 142.16(k)(2) of this chapter. For 
the purposes of this subpart, ``sanitary survey,'' as conducted by the 
State, includes but is not limited to an onsite review of the water 
source (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.


Sec. 141.402  Hydrogeologic sensitivity assessment information request.

    Ground water systems must provide the State at its request, any 
pertinent existing information that would allow the State to perform a 
hydrogeologic sensitivity assessment as described in Sec. 142.16(k)(3) 
of this chapter.


Sec. 141.403  Microbial monitoring of source water and analytical 
methods.

    (a) Routine monitoring. Any ground water system that draws water 
from a hydrogeologically sensitive drinking water source, as determined 
under Sec. 142.16(k)(3) of this chapter, and that does not provide 4-
log inactivation or removal of viruses, must collect a source water 
sample each month that it provides water to the public and test the 
sample for the fecal indicator specified by the State under paragraph 
(d) of this section. Ground water systems must begin monitoring the 
month after being notified of the hydrogeologic sensitivity assessment.
    (b) Triggered monitoring. Any ground water system that does not 
provide 4-log inactivation or removal of viruses, and is notified of a 
total coliform-positive sample under Sec. 141.21, must collect, within 
24 hours of notification, at least one source water sample and have the 
sample tested for the fecal indicator specified by the State under 
paragraph (d) of this section. This requirement is in addition to all 
monitoring and testing requirements under Sec. 141.21.
    (c) Systems with disinfection. Ground water systems currently 
providing 4-log inactivation or removal of viruses must notify the 
State of such and must conduct compliance monitoring in accordance with 
Sec. 141.404(c). This notification must be made by the effective date 
of the rule. All new systems must notify the State of the level of 
virus inactivation they are achieving prior to serving their first 
customer.
    (d) Analytical methods. Source water samples must be tested for one 
of the following fecal indicators: E. coli, coliphage, or enterococci, 
as specified by the State. For whichever fecal indicator is specified 
by the State, the ground water system must use one of the analytical 
methods listed in the following table:

             Analytical Methods for Source Water Monitoring
------------------------------------------------------------------------
               Indicator                            Method\1\
------------------------------------------------------------------------
E. coli................................  Colilert Test (Method
                                          9223B)\2,\ \3\
                                         Colisure Test (Method
                                          9223B)\2,\ \3\
                                         Membrane Filter Method with MI
                                          Agar\4,\ \5\
                                         m-ColiBlue24 Test \4,\ \6\
                                         E*Colite Test \4,\ \7\
                                         May also use the EC-MUG (Method
                                          9212F) \2\ and NA-MUG (Method
                                          9222G) \2\ E. coli
                                          confirmation step Sec.
                                          141.21(f)(6) after the EPA
                                          approved Total Coliform
                                          methods in Sec.  141.21(f)(3)
enterococci............................  Multiple-Tube Tech. (Method
                                          9230B) \1\
                                         Membrane Filter Tech. (Method
                                          9230C) \1,\ \8\
                                         Enterolert \3\
Coliphage..............................  EPA Method 1601: Two-Step
                                          Enrichment Presence-Absence
                                          Procedure\9\
                                         EPA Method 1602: Single Agar
                                          layer Procedure\9\
------------------------------------------------------------------------
\1\ The time from sample collection to initiation of analysis may not
  exceed 30 hours. Systems are encouraged but not required to hold
  samples below 10 deg.C during transit.
\2\ Methods are approved and described in Standard Methods for the
  Examination of Water and Wastewater (20th edition).

[[Page 30270]]

 
\3\ Medium available through IDEXX Laboratories, Inc., One IDEXX Drive,
  Westbrook, Maine 04092.
\4\ EPA approved drinking water methods.
\5\ Brenner, K.P., C.C. Rankin, Y.R. Roybal, G.N. Stelma, P.V. Scarpino,
  and A.P. Dufour. 1993. New medium for the simultaneous detection of
  total coliforms and Escherichia coli in water. Appl. Environ.
  Microbiol. 59:3534-3544.
\6\ Hach Company, 100 Dayton Ave., Ames, IA 50010.
\7\ Charm Sciences, Inc., 36 Franklin St., Malden, MA 02148-4120.
\8\ Proposed for EPA approval, EPA Method 1600: MF Test Method for
  enterococci in Water (EPA-821-R-97-004 (May 1997)) is an approved
  variation of Standard Method 9230C.
\9\ Proposed for EPA approval are EPA Methods 1601 and 1602, which are
  available from the EPA's Water Resources Center, Mail code: RC-4100,
  1200 Pennsylvania Ave. NW, Washington, DC 20460.

    (e) Notification of State. If any source water sample is positive 
for E. coli, coliphage, or enterococci, the ground water system shall 
notify the State as soon as possible after the system is notified of 
the test result, but in no case later than the end of the next business 
day, and take corrective action in accordance with Sec. 141.404(b).
    (f) Resampling after invalidation. Where the State invalidates a 
positive source water sample under paragraph (i) of this section, the 
ground water system must collect another source water sample and have 
it analyzed for the same fecal indicator within 24 hours of being 
notified of the invalidation.
    (g) Triggered monitoring waiver. The State may waive triggered 
source water monitoring as described in Sec. 141.403(b) due to a total 
coliform-positive sample, on a case-by-case basis, if the State 
determines that the total coliform positive sample is associated solely 
with a demonstrated distribution system problem. In such a case, a 
State official must document the decision, including the rationale for 
the decision, in writing, and sign the document.
    (h) Reduce frequency for routine monitoring. The State may reduce 
routine source water monitoring to quarterly if a hydrogeologically 
sensitive ground water system detects no fecal indicator-positive 
samples in the most recent twelve monthly samples, during the months 
the ground water system is in operation. Moreover, the State may, after 
those twelve monthly samples, waive source water monitoring altogether 
for a ground water system if the State determines, and documents the 
determination in writing, that fecal contamination of the well(s) has 
not been identified and is highly unlikely based on the sampling 
history, land use pattern, disposal practices in the recharge area, and 
proximity of septic tanks and other fecal contamination sources. If the 
State determines that circumstances have changed, the State has the 
discretion to reinstate routine monthly monitoring. In any case, a 
State official must document the determination in writing, including 
the rationale for the determination, addressing each factor noted in 
this paragraph and sign the document.
    (i) Invalidation of samples. A source water sample may be 
determined by the State to be invalid only if the laboratory 
establishes that improper sample analysis occurred or the State has 
substantial grounds to believe that a sample result is due to 
circumstances that do not reflect source water quality. In such a case, 
a State official must document the decision, including the rationale 
for the decision, in writing, and sign the document. The written 
documentation must state the specific cause of the invalid sample and 
what action the ground water system or laboratory has taken or will 
take to correct this problem. A positive sample may not be invalidated 
by the State solely on the grounds that repeat samples are negative.
    (j) Repeat sampling. A ground water system may apply to the State, 
and the State may consider, on a one-time basis, to waive compliance 
with the treatment technique requirements in Sec. 141.404(b), after a 
single fecal indicator-positive from a routine source water sample as 
required in Sec. 141.403(a), if all the following conditions are met:
    (1) The ground water system collects five repeat source water 
samples within 24 hours after being notified of a source water fecal 
indicator positive result;
    (2) The ground water system has the samples analyzed for the same 
fecal indicator as the original sample;
    (3) All the repeat samples are fecal indicator negative; and
    (4) All required source water samples (routine and triggered) 
during the past five years were fecal indicator-negative.


Sec. 141.404  Treatment technique requirements.

    (a) Ground water systems with significant deficiencies. As soon as 
possible, but no later than 90 days after receiving written 
notification from the State of a significant deficiency, a ground water 
system must do one or more of the following: eliminate the source of 
contamination, correct the significant deficiency, provide an alternate 
source water, or provide a treatment which reliably achieves at least 
99.99 percent (4-log) inactivation or removal of viruses before or at 
the first customer. Ground water systems which provide 4-log 
inactivation or removal of viruses will be required to conduct 
compliance monitoring to demonstrate treatment effectiveness. The 
ground water system must consult with the State to determine which of 
the approaches, or combination of approaches, are appropriate for 
meeting the treatment technique requirement. Ground water systems 
unable to address the significant deficiencies in 90 days, must develop 
a specific plan and schedule for meeting this treatment technique 
requirement, submit them to the State, and receive State approval 
before the end of the same 90-day period. For the purposes of this 
paragraph, a ``significant deficiency'' includes: 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 potential for causing the introduction of 
contamination into the water delivered to consumers.
    (b) Ground water systems with source water contamination. As soon 
as possible, but no later than 90 days after the ground water system is 
notified that a source water sample is positive for a fecal indicator, 
the ground water system must do one or more of the following: eliminate 
the source of contamination, correct the significant deficiency, 
provide an alternate source water, or provide a treatment which 
reliably achieves at least 99.99 percent (4-log) inactivation or 
removal of viruses before or at the first customer. Ground water 
systems which provide 4-log inactivation or removal of viruses will be 
required to conduct compliance monitoring to demonstrate treatment 
effectiveness. The ground water system must consult with the State to 
determine which of the approaches, or combination of approaches, are 
appropriate for meeting the treatment technique requirement. Ground 
water systems unable to address the contamination problem in 90 days 
must develop a specific plan and schedule for meeting this treatment 
technique requirement, submit them to the State, and receive State 
approval before the end of the same 90-day period specified previously. 
This requirement also applies to ground water systems for which States 
have waived source water monitoring under Sec. 141.403(h) and have a 
fecal coliform-or E. coli-positive while testing under Sec. 141.21.
    (c) Compliance monitoring. Ground water systems that provide 4-log 
inactivation or removal of viruses, or begin treatment pursuant to 
paragraph (a) or (b) of this section, must monitor the effectiveness 
and reliability of treatment as follows:

[[Page 30271]]

    (1) Chemical disinfection. (i) Ground water systems serving 3,300 
or more people must continuously monitor and maintain the State-
determined residual disinfectant concentration every day the ground 
water system serves water to the public.
    (ii) Ground water systems serving fewer than 3,300 people must 
monitor and maintain the State-determined residual disinfectant 
concentration every day the ground water system serves water to the 
public. The ground water system will monitor by taking a daily grab 
sample during the hour of peak flow or another time specified by the 
State. If any daily grab sample 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.
    (2) UV disinfection. Ground water systems using UV disinfection 
must continuously monitor for and maintain the State-prescribed UV 
irradiance level every day the ground water system serves water to the 
public.
    (3) Membrane filtration. Ground water systems that use membrane 
filtration as a treatment technology are assumed to be achieving at 
least 4-log removal of viruses when the membrane process is operated in 
accordance with State-specified compliance criteria developed under 
Sec. 142.16(k)(5)(ii) of this chapter, or as provided by EPA, and the 
integrity of the membrane is intact. Applicable membrane filtration 
technologies are reverse osmosis (RO), nanofiltration (NF), and any 
membrane filters developed in the future that have absolute MWCOs 
(molecular weight cut-offs) that can achieve 4-log virus removal.
    (d) Discontinuing treatment. Ground water systems may discontinue 
4-log inactivation or removal of viruses if the State determines based 
on an on-site investigation, and documents that determination in 
writing, that the need for 4-log inactivation or removal of viruses no 
longer exists. Ground water systems are subject to triggered monitoring 
in accordance with Sec. 141.403(b).


Sec. 141.405  Treatment technique violations.

    The following are treatment technique violations which require the 
ground water system to give public notification pursuant to Appendix A 
of subpart Q of this part, using the language specified in Appendix B 
of subpart Q of this part.
    (a) A ground water system with a significant deficiency identified 
by a State (as defined in Sec. 141.401) which does not correct the 
deficiency, provide an alternative source, or provide 4-log 
inactivation or removal of viruses within 90 days, or does not obtain, 
within the same 90 days, State approval of a plan and schedule for 
meeting the treatment technique requirement in Sec. 141.404, is in 
violation of the treatment technique.
    (b) A ground water system that detects fecal contamination in the 
source water and does not eliminate the source of contamination, 
correct the significant deficiency, provide an alternate source water, 
or provide a treatment which reliably achieves at least 99.99 percent 
(4-log) inactivation or removal of viruses before or at the first 
customer within 90 days, or does not obtain within the same 90 days, 
State approval of a plan for meeting this treatment technique 
requirement, is in violation of the treatment technique unless the 
detected sample is invalidated under Sec. 141.403(i) or the treatment 
technique is waived under Sec. 141.403(j). Ground water systems which 
provide 4-log inactivation or removal of viruses will be required to 
conduct compliance monitoring to demonstrate treatment effectiveness.
    (c) A ground water system which fails to address either a 
significant deficiency as provided in paragraph (a) of this section or 
fecal contamination as provided in paragraph (b) of this section 
according to the State-approved plan, or by the State-approved 
deadline, is in violation of the treatment technique. In addition, a 
ground water system which fails to maintain 4-log inactivation or 
removal of viruses, is in violation of the treatment technique, if the 
failure is not corrected within four hours.


Sec. 141.406  Reporting and record keeping.

    (a) Reporting. In addition to the requirements of Sec. 141.31, 
ground water systems regulated under this subpart must provide the 
following information to the State:
    (1) Ground water systems conducting continuous monitoring must 
notify the State any time the residual disinfectant concentration 
(irradiance in the case of UV) falls below the State-determined value 
and is not restored within 4 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) Ground water systems taking daily grab samples must notify the 
State any time the residual disinfectant concentration falls below the 
State-determined value and is not restored within 4 hours, as 
determined by follow-up samples. 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.
    (3) Ground water systems using membrane filtration must notify the 
State any time the membrane is not operated in accordance with standard 
operation and maintenance procedures for more than 4 hours, or any 
failure of the membrane integrity occurs and is not restored within 4 
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. 
These operation and maintenance procedures will be provided by EPA or 
developed by the State under Sec. 142.16(k)(5)(ii) of this chapter.
    (4) If any source water sample is positive for E. coli, coliphage, 
or enterococci, the ground water system shall notify the State as soon 
as possible, but in no case later than the end of the next business 
day, and take corrective action in accordance with Sec. 141.404(b).
    (5) If any ground water system has reason to believe that a disease 
outbreak is potentially attributable to their drinking water, it must 
report the outbreak to the State as soon as possible, but in no case 
later than the end of the next business day.
    (6) After implementation of any required treatment techniques, a 
ground water system must provide as soon as possible, but in no case 
later than the end of the next business day, written confirmation to 
the State that the corrective action required by Sec. 141.404(a) and 
(b) were met.
    (7) Notification that the ground water system is currently 
providing 4-log inactivation or removal of viruses.
    (b) Record keeping. In addition to the requirements of Sec. 141.33, 
ground water systems regulated under this subpart must maintain the 
following information in their records:
    (1) Documentation showing the fecal indicator the State is 
requiring the ground water system to use.
    (2) Documentation showing consultation with the State on approaches 
for addressing significant deficiencies including alternative plans and 
schedules and State approval of such plans and schedules.
    (3) Documentation showing consultation with the State on approaches 
for addressing source water fecal contamination including alternative 
plans and schedules and State approval of such plans and schedules.

[[Page 30272]]

PART 142--NATIONAL PRIMARY DRINKING WATER REGULATIONS 
IMPLEMENTATION

    1. 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.

    2. 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 
determinations, including all supporting information and an explanation 
of the technical basis for each decision, made under the following 
provisions of 40 CFR part 141, subpart S for the Ground Water Rule.
    (i) Section 142.16(k)(3)--State determinations of source water 
hydrogeologic sensitivity, and determinations of the presence of 
hydrogeologic barriers.
    (ii) Section 141.404(c) `` notification to individual ground water 
systems of the proper residual disinfection concentrations (when using 
chemical disinfection), irradiance level (when using UV), or EPA-
specified or State specified compliance criteria (when using membrane 
filtration) needed to achieve 4-log inactivation of viruses.
    (iii) Section 141.403(g)--waivers of triggered monitoring.
    (iv) Section 141.403(h)--reductions of monitoring.
    (v) Section 141.403(i)--invalidation of positive source water 
samples.
    (vi) Section 141.403(j)--waiver of compliance with treatment 
technique requirements.
    (vii) Section 141.404(a)--notifications of significant 
deficiencies, consultation with the ground water systems, including 
written confirmation of corrections of significant deficiencies by 
ground water systems and written records of State site visits and 
approved plans and schedules.
    (ix) Section 141.404(d)--determinations of when a ground water 
system can discontinue 4-log inactivation or removal of viruses.
* * * * *
    3. Section 142.15 is amended by adding paragraphs (c)(6) through 
(10) to read as follows:


Sec. 142.15  Reports by States.

* * * * *
    (c) * * *
    (6) Sanitary surveys. An annual list of ground water systems that 
have had a sanitary survey completed during the previous year and an 
annual evaluation of the State's program for conducting sanitary 
surveys under Sec. 142.16(k)(2).
    (7) Hydrogeologic sensitivity assessments. An annual list of ground 
water systems that have had a sensitivity assessment completed during 
the previous year, a list of those ground water systems which are 
sensitive, a list of ground water systems which are sensitive, but for 
which the State has determined that a hydrogeologic barrier exists at 
the site sufficient for protecting public health, and an annual 
evaluation of the State's program for conducting hydrogeologic 
sensitivity assessments under Sec. 142.16 (k)(3).
    (8) Source water microbial monitoring. An annual list of ground 
water systems that have had to test the source water as described under 
Sec. 141.403 of this chapter, a list of determinations of invalid 
samples, and a list of waivers of source water monitoring provided by 
the State.
    (9) Treatment technique compliance. An annual list of ground water 
systems that have had to meet treatment technique requirements for 
significant deficiencies or contaminated source water under 
Sec. 141.404 of this chapter, a list of determinations to discontinue 
4-log inactivation or removal of viruses, and a list of ground water 
systems that violated the treatment technique requirements.
    (10) Ground water systems providing 4-log inactivation or removal 
of viruses. An annual list of ground water systems that have notified 
the State that they are currently providing 4-log inactivation or 
removal of viruses.
* * * * *
    4. Section 142.16 is amended by adding and reserving paragraphs (i) 
and (j) and adding paragraph (k) to read as follows:


Sec. 142.16  Special primacy requirements.

* * * * *
    (i) [Reserved]
    (j) [Reserved]
    (k) 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 a description of how the State will accomplish the following 
program requirements:
    (1) Enforceable requirements. (i) States must have the appropriate 
rules or other authority to ensure that ground water systems take the 
steps necessary to address, in accordance with Sec. 141.404(a) of this 
chapter, any significant deficiencies identified in the written 
notification provided by the State as required under paragraph (k)(2) 
of this section.
    (ii) States must have appropriate rules or other authority to 
ensure that ground water systems respond in writing in regard to the 
resolution of significant deficiencies identified in the written 
notification provided by the State following identification of the 
significant deficiencies.
    (iii) States must have the appropriate rules or other authority to 
ensure that ground water systems take the steps necessary to address, 
in accordance with Sec. 141.404(b) of this chapter, any fecal 
contamination identified during routine or triggered monitoring in 
accordance with Sec. 141.403(a) and (b) of this chapter.
    (2) Sanitary survey. In its primacy application the State must 
describe how it, or an authorized agent, will implement a sanitary 
survey program that meets the requirements of this section.
    (i) For the purposes of this paragraph (k)(2), ``sanitary survey'' 
includes, but is not limited to, an onsite review of the water source 
(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.
    (ii) The State, or an authorized agent, must conduct sanitary 
surveys for all ground water systems. The sanitary survey must address 
the eight sanitary survey components listed in paragraphs (k)(2)(ii)(A) 
through (H) of this section no less frequently than every three years 
for community systems and no less frequently than every five years for 
noncommunity systems. The first sanitary survey for community water 
systems must be completed by [DATE 6 YEARS AFTER DATE OF PUBLICATION OF 
THE FINAL RULE IN THE FEDERAL REGISTER] and for noncommunity water 
systems, must be completed by [DATE 8 YEARS AFTER DATE OF PUBLICATION 
OF THE FINAL RULE IN THE FEDERAL REGISTER].
    (A) Source.
    (B) Treatment.
    (C) Distribution system.
    (D) Finished water storage.
    (E) Pumps, pump facilities, and controls.

[[Page 30273]]

    (F) Monitoring and reporting and data verification.
    (G) System management and operation.
    (H) Operator compliance with State requirements.
    (iii) After the initial sanitary survey for ground water systems in 
accordance with Sec. 142.16(k)(2)(ii), the State may reduce the 
frequency of sanitary surveys for community water systems to no less 
frequently than every five years, if the ground water system either 
treats to 4-log inactivation or removal of viruses or has an 
outstanding performance record documented in previous inspections and 
has no history of total coliform MCL or monitoring violations under 
Sec. 141.21 of this chapter as determined by the State, since the last 
sanitary survey under the current ownership. In its primacy 
application, the State must describe how it will decide whether a 
community water system has outstanding performance and is thus eligible 
for sanitary surveys at a reduced frequency.
    (iv) States may complete components of a sanitary survey as part of 
a staged or phased State review process within the established 
frequency specified in paragraph (k)(2)(ii) or (iii) of this section. 
In its primacy application, a State which plan to complete the sanitary 
survey in a staged or phased State review process must indicate which 
approach it will take and provide the rationale for the specified time 
frames for sanitary surveys conducted on a staged or phased approach 
basis.
    (v) Sanitary surveys that meet the requirements of this subpart, 
including the requisite eight components identified in paragraph 
(k)(2)(ii) of this section and conducted at the specified frequency, 
are considered to meet the requirements for sanitary surveys under the 
Total Coliform Rule (TCR) as described in Sec. 141.21 of this chapter. 
Note however, compliance only with the TCR sanitary survey requirements 
may not be adequate to meet the revised scope and frequency sanitary 
survey requirement of this subpart.
    (vi) States must provide ground water systems with written 
notification identifying and describing any significant deficiencies 
identified at the ground water system no later than 30 days after 
identifying the significant deficiencies. States will provide ground 
water systems with written notification by certified mail or on-site 
from the sanitary survey inspector. In its primacy application, the 
State must indicate how it will define what constitutes a significant 
deficiency for purposes of this subpart. For the purposes of this 
paragraph, a ``significant deficiency'' includes: 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 potential for causing the introduction of 
contamination into the water delivered to consumers.
    (vii) In its primacy application, the State must describe how it 
will consult with the ground water system regarding the treatment 
technique requirements specified in Sec. 141.404 and criteria for 
determining when a ground water system has met the 4-log inactivation 
or removal of viruses of this chapter.
    (viii) States must confirm that the deficiency has been addressed, 
either through written confirmation from ground water systems or a site 
visit by the State, within 30 days after the ground water system has 
met the treatment technique requirements under Sec. 141.404(a) of this 
chapter.
    (ix) In its primacy application, the State must specify if and how 
it will integrate Source Water Assessment and Protection Program 
(SWAPP) susceptibility determinations into the sanitary survey and the 
definition of significant deficiency.
    (3) Hydrogeologic sensitivity assessments. (i) For the purposes of 
this paragraph (k)(3), ``hydrogeologic sensitivity assessment'' means 
the methodology used by the State to identify whether ground water 
systems are obtaining water from karst, gravel, or fractured bedrock 
aquifers. A State may add additional hydrogeologic sensitive settings, 
e.g., volcanic aquifers. A well obtaining water from a karst, gravel or 
fractured bedrock aquifer is sensitive to fecal contamination unless 
the well is protected by a hydrogeologic barrier. A ``hydrogeologic 
barrier'' consists of physical, chemical and biological factors that, 
singularly or in combination, prevent the movement of viable pathogens 
from a contaminant source to a ground water system well.
    (ii) The State, or an authorized agent, must conduct a one-time 
hydrogeologic sensitivity assessment for all existing ground water 
systems not providing 4-log inactivation or removal of viruses by [DATE 
SIX YEARS AFTER DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL 
REGISTER] for community water systems and by [DATE EIGHT YEARS AFTER 
DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL REGISTER] for non-
community water systems. The State, or an authorized agent, must 
conduct a hydrogeologic sensitivity assessment for new systems prior to 
their serving water to the public.
    (iii) In its primacy application, a State must identify its 
approach to determine the adequacy of a hydrogeologic barrier, if 
present, as part of its effort to determine the sensitivity of a ground 
water system in a hydrogeologic sensitivity assessment.
    (4) Source water microbial monitoring. (i) In its primacy 
application, the State must identify its approach and rationale for 
determining which of the fecal indicators (E. coli, coliphage, or 
enterococci) ground water systems must use in accordance with 
Sec. 141.403(d) of this chapter.
    (ii) The State may waive triggered source water monitoring as 
described in Sec. 141.403(b) of this chapter due to a total coliform-
positive sample, on a case-by-case basis, if the State determines that 
the total coliform positive sample is associated solely with a 
demonstrated distribution system problem. In such a case, a State 
official must document the decision, including the rationale for the 
decision, in writing, and sign the document.
    (iii) The State may reduce routine source water monitoring to 
quarterly if a hydrogeologically sensitive ground water system detects 
no fecal indicator-positive samples in the most recent twelve 
consecutive monthly samples during the months the ground water system 
is in operation. Moreover, the State may, after those twelve 
consecutive monthly samples, waive source water monitoring altogether 
for a ground water system if the State determines, in writing, that 
fecal contamination of the well(s) has not been identified and is 
highly unlikely, based on the sampling history, land use pattern, 
disposal practices in the recharge area, and proximity of septic tanks 
and other fecal contamination sources. If the State determines that 
circumstances have changed, the State has the discretion to reinstate 
routine monthly monitoring. In any case, a State official must document 
the determination in writing, including the rationale for the 
determination, and sign the document.
    (iv) The State may determine a source water sample to be invalid 
only if the laboratory establishes that improper sample analysis 
occurred or the State has substantial grounds to believe that a sample 
result is due to circumstances that do not reflect source water 
quality. In such a case, a State official must document the decision, 
including the rationale for the decision, in writing, and sign the 
document. The written documentation must state the specific cause of 
the invalid sample and what action the ground water system or 
laboratory has taken or must take to

[[Page 30274]]

correct this problem. A positive sample may not be invalidated by the 
State solely on the grounds that repeat samples are negative, though 
this could be considered along with other evidence that the original 
sample result does not reflect source water quality.
    (v) A ground water system may apply to the State, and the State may 
consider, on a one-time basis, to waive compliance with the treatment 
technique requirements in Sec. 141.404(a) of this chapter, after a 
single fecal indicator-positive from a routine source water sample as 
required in Sec. 141.403(a) of this chapter, if all the following 
conditions are met:
    (A) The ground water system collects five repeat source water 
samples within 24 hours after being notified of a source water fecal 
positive result;
    (B) The ground water system has the samples analyzed for the same 
fecal indicator as the original sample;
    (C) All the repeat samples are fecal indicator negative; and
    (D) All previous source water samples (routine and triggered) 
during the past 5 years were fecal indicator-negative.
    (5) Treatment technique requirements. (i) In its primacy 
application, the State must describe how it must provide every ground 
water system treating to 4-log inactivation or removal the disinfectant 
concentration (or irradiance) and contact time to achieve 4-log virus 
inactivation or removal. EPA recommends that the State use applicable 
EPA-developed CT tables (IT (the product of irradiance, in mW/
cm2, multiplied by exposure time, in seconds) in the case of 
UV disinfection) to determine the concentration (or irradiance) and 
contact time that it will require ground water systems to achieve 4-log 
virus inactivation.
    (ii) If the State intends to approve membrane filtration for 
treatment it must, in its primacy application, describe the monitoring 
and compliance requirements, including membrane integrity testing, that 
it will require of ground water systems to demonstrate proper operation 
of membrane filtration technologies.
    (iii) In its primacy application, a State must describe the 
approach it must use to determine which specific treatment technique 
option (correcting the deficiency, eliminating the source of 
contamination, providing an alternative source, or providing 4-log 
inactivation or removal of viruses) is appropriate for addressing 
significant deficiencies or fecally contaminated source water and under 
what circumstances. In addition, the State must describe the approach 
it intends to use when consulting with ground water systems on 
determining the treatment technique options.
    (iv) States must confirm that the ground water system has addressed 
the source water fecal contamination identified under routine or 
triggered monitoring in accordance with Sec. 141.403(a) and (b) of this 
chapter, either through written confirmation from ground water systems 
or a site visit by the State, within 30 days after the ground water 
system has met the treatment technique requirements under 
Sec. 141.404(b) of this chapter.

[FR Doc. 00-10763 Filed 5-9-00; 8:45 am]
BILLING CODE 6560-50-P