Safe Drinking Water Act (SDWA): Selected Regulatory and Legislative Issues

Safe Drinking Water Act (SDWA):
Selected Regulatory and Legislative Issues
Updated November 26, 2008
Mary Tiemann
Specialist in Environmental Policy
Resources, Science, and Industry Division

Safe Drinking Water Act (SDWA):
Selected Regulatory and Legislative Issues
Much progress has been made in assuring the quality of public water supplies
since the Safe Drinking Water Act (SDWA) was first enacted in 1974. Public water
systems must meet extensive regulations, and public water system management has
become a much more complex and professional endeavor. The Environmental
Protection Agency (EPA) has regulated some 91 drinking water contaminants, and
more regulations are pending. In 2005, EPA reported that the number of systems
reporting no violations of drinking water standards reached a new high of 94% in

2003. Despite such progress, however, an array of issues and challenges remain.

In the 110th Congress, key issues have involved infrastructure funding needs,
related compliance issues, and concerns caused by detections of unregulated
contaminants in drinking water, such as perchlorate and pharmaceuticals and
personal care products (PPCPs). Another issue involves the adequacy of existing
regulations (such as trichloroethylene (TCE)) and EPA’s pace in reviewing and
potentially revising older standards. Congress last reauthorized SDWA in 1996.
Although funding authority for most SDWA programs expired in FY2003, Congress
continues to appropriate funds annually for these programs. No broad reauthorization
bills have been proposed, as EPA, states, and water systems continue efforts to
implement and comply with the requirements of the 1996 law and new regulations.
A long-standing and overarching SDWA issue concerns the cumulative cost and
complexity of drinking water standards and the ability of water systems, especially
small systems, to comply with standards. The issue of the affordability of drinking
water regulations, such as those for arsenic, radium, and disinfection by-products, has
merged with the larger debate over what is the appropriate federal role in assisting
communities with financing drinking water infrastructure.
Water infrastructure financing legislation has been offered in recent Congresses
to authorize increased funding for the DWSRF program and to provide grant
assistance for small communities. In the 110th Congress, bills were offered to
provide technical, financial, and other compliance assistance to small communities.
The Senate Environment and Public Works Committee reported several drinking
water bills, including a broad water infrastructure financing bill, S. 3617. None of
the legislation was enacted, and the debate continues over the federal role in the
funding of projects needed for SDWA compliance, and for water infrastructure
improvement in general.
Several bills have been introduced to address the underground injection of
carbon dioxide (CO2) for long-term sequestration as a means of reducing greenhouse
gas emissions. P.L. 110-140 (H.R. 6), the Energy Independence and Security Act of
2007, includes carbon sequestration research and development provisions, and
specifies that geologic sequestration (GS) activities will be subject to SDWA
provision related to protecting underground drinking water sources. In July 2008,
EPA proposed regulations under SDWA to provide a national permitting framework
for managing the underground injection of CO2 for commercial-scale GS projects.

In troduction ......................................................1
Last Major Reauthorization and Amendments.......................2
Regulated Public Water Systems..................................3
Safe Drinking Water Act Issues.......................................4
Regulating Drinking Water Contaminants...........................4
Contaminant Candidate List.................................4
Regulatory Determinations..................................5
Unregulated Contaminant Monitoring..........................5
Standard-Setting ...........................................6
Recent and Pending Rules...................................7
Perchlorate in Drinking Water....................................9
Pharmaceuticals in Drinking Water...............................11
Drinking Water Infrastructure Needs and Funding...................14
Small Systems Issues..........................................17
Exemptions .............................................17
Small System Variances and Affordability.....................18
Affordability Criteria Review...............................18
Small System Legislation...................................19
Underground Injection Control and Carbon Sequestration.............20
Carbon Sequestration and Storage............................21
Congressional Hearings and Reports, and Documents....................24
Additional Reading...............................................24
List of Tables
Table 1. Size Categories of Community Water Systems....................3
Table 2. Recent and Pending Regulatory Actions.........................8
Table 3. Drinking Water State Revolving Fund Program Funding,
FY1997-FY2009 .............................................15

Safe Drinking Water Act (SDWA):
Selected Regulatory and Legislative Issues
The Safe Drinking Water Act1 (SDWA) is the primary federal law for protecting
public water supplies from harmful contaminants. First enacted in 1974, and broadly
amended in 1986 and 1996, the SDWA is administered through programs that
regulate contaminants in public water supplies, provide funding for infrastructure
projects, protect underground sources of drinking water, and promote the capacity of
water systems to comply with SDWA regulations.
The Environmental Protection Agency (EPA) is the federal agency responsible
for administering SDWA; however, the 1974 law established a federal-state structure
in which EPA may delegate primary enforcement and implementation authority
(primacy) for the drinking water program to states and tribes. The state-administered
Public Water Supply Supervision (PWSS) program remains the basic program for
regulating public water systems, and EPA has delegated primacy for this program to
all states, except Wyoming and the District of Columbia (which SDWA defines as
a state); EPA has responsibility for implementing the PWSS program in these two
jurisdictions and throughout most of Indian lands.2
Since the law was first enacted, much progress has been made in assuring the
quality of public water supplies. EPA has regulated some 91 drinking water
contaminants, and more regulations are pending. In 2005, EPA reported that the
number of public water systems reporting no violations of the health-based standards
reached 94% in 2003.3 However, drinking water safety concerns and challenges
remain. EPA and state enforcement data indicate that water systems still incur tens
of thousands of violations of SDWA requirements each year. Although these
violations primarily involve monitoring and reporting requirements, they also include
thousands of violations of standards and treatment techniques. Moreover, monitoring
and reporting violations create uncertainty as to whether systems actually met the

1 Title XIV of the Public Health Service Act, as added by P.L. 93-523 and subsequently
amended (42 U.S.C. 300f-300j-26).
2 For purposes of the PWSS program, the term “state” includes 57 states, commonwealths,
and territories that have been approved to implement the drinking water program within
their jurisdiction. It also includes the Navajo Nation, which received EPA approval to
implement its drinking water program in 2000.
3 U.S. Environmental Protection Agency, Providing Safe Drinking Water in America: 2003
National Public Water Systems Compliance Report. Office of Enforcement and Compliance
Assurance. Report No. EPA 305-R-05-002. September 2005. 19 p. plus appendices.

applicable health-based standards. While noting increased compliance levels in the
2005 report, EPA estimated that only 65% of violations of health-based standards
and 23% of violations of monitoring and reporting requirements were reported to the
EPA database, thus increasing uncertainty as to the quality of water provided by
many systems. EPA and the states have resolved some data quality and reporting
problems, and efforts continue to address this issue. In 2008, EPA reported that
91.5% of the total population served by community water systems received drinking
water that met all health-based standards during FY2007, up from 89.4% in FY2006.4
Concern also exists over the potential health effects of drinking water contaminants
for which standards have not been set, such as perchlorate and methyl tertiary butyl
ether (MTBE). The act requires EPA to continually evaluate contaminants that may
be candidates for regulation; however, EPA’s perceived lack of action on
contaminants of concern has generated criticism in Congress and elsewhere.
Last Major Reauthorization and Amendments
Congress last broadly revised the act with the Safe Drinking Water Act
Amendments of 1996 (P.L. 104-182). These changes resulted from a multi-year effort
to amend a statute that was widely criticized as having too little flexibility, too many
unfunded mandates, and an arduous but unfocused regulatory schedule. Among the
key provisions, the 1996 amendments authorized a drinking water state revolving
loan fund (DWSRF) program to help public water systems finance projects needed
to comply with SDWA regulations. The amendments also established a process for
selecting contaminants for regulation based on health risk and occurrence, gave EPA
some added flexibility to consider costs and benefits in setting most new standards,
and established schedules for regulating certain contaminants (such as
Cryptosporidium, disinfection byproducts, arsenic, and radon).
The 1996 law added several provisions aimed at building the capacity of water
systems (especially small systems) to comply with SDWA regulations. It imposed
many new requirements on the states. For example, the amendments require state
programs for source water assessment, operator certification and training, and
compliance capacity development. The law also requires community water systems
to provide customers with annual “consumer confidence reports” that contain
information on regulated contaminants found in the local drinking water. Congress
authorized appropriations for most SDWA programs through FY2003, and although
most funding authorities have expired, broad reauthorization bills have not been
proposed, as EPA, states, and public water systems remain focused on meeting the
requirements of the 1996 amendments.
In 2002, drinking water security provisions were added to the SDWA through
the Public Health Security and Bioterrorism Preparedness and Response Act of 2002
(P.L. 107-188). Title IV of that act included requirements for community water
systems serving more than 3,300 people to conduct vulnerability assessments and

4 U.S. Environmental Protection Agency, FY2009 Annual Performance Plan and
Congressional Justification, Program Performance and Assessment, p. 795.

prepare emergency response plans. The law also required the EPA to conduct
research on preventing and responding to terrorist or other attacks.5
Regulated Public Water Systems
Federal drinking water regulations apply to some158,200 privately and publicly
owned water systems that provide piped water for human consumption to at least 15
service connections or that regularly serve at least 25 people. (The law does not
apply to private residential wells.) Of these systems, 52,837 are community water
systems (CWSs) that serve most people in the United States — a total residential
population of roughly 282 million year-round. All SDWA regulations apply to these
systems. Nearly 19,200 systems are non-transient, non-community water systems
(NTNCWSs), such as schools or factories, that have their own water supply and serve
the same people for more than six months but not year-round. Most drinking water
requirements apply to these systems. Another 86,210 systems are transient non-
community water systems (TNCWSs) (e.g., campgrounds and gas stations) that
provide their own water to transitory customers. TNCWSs generally are required to
comply only with regulations for contaminants that pose immediate health risks (such
as microbial contaminants), with the proviso that systems that use surface water
sources must also comply with filtration and disinfection regulations.
Of the nearly 53,000 community water systems, roughly 83% serve 3,300 or
fewer people. While large in number, these systems provide water to just 9% of the
population served by all community systems. In contrast, 8% of community water
systems serve more than 10,000 people, and they provide water to 81% of the
population served. Fully 85% (16,348) of non-transient, non-community water
systems and 97% (83,351) of transient noncommunity water systems serve 500 or
fewer people. These statistics give some insight into the scope of financial,
technological, and managerial challenges many public water systems face in meeting
a growing number of complex federal drinking water regulations. Table 1 provides
statistics for community water systems.
Table 1. Size Categories of Community Water Systems
System size Number ofcommunityPopulationservedPercentage ofcommunityPercentage ofpopulation
(population served)water systems(millions)water systemsserved
Very small (25-500)29,6664.9356%2%
Small (501-3,300)14,38920.8527%7%
Medium (3,301-10,000)4,74827.519%10%
Large (10,001-100,000)3,648102.757%36%
Very large (>100,000)386126.301%45%
To t a l 52,837 282.3 100% 100%
Source: Adapted from US Environmental Protection Agency, Factoids: Drinking Water and Ground
Water Statistics for 2005.

5 For more information, see CRS Report RL31294, Safeguarding the Nation’s Drinking
Water: EPA and Congressional Actions, by Mary Tiemann.

Safe Drinking Water Act Issues
Current drinking water quality issues include the gap between infrastructure
funding needs and spending; the capacity of public water systems, especially small
systems, to comply with a growing set of complex standards; and contamination of
water supplies by unregulated contaminants, such as perchlorate and methyl tertiary
butyl ether (MTBE). An emerging issue concerns proposals for large-scale storage
of carbon dioxide deep underground to mitigate greenhouse gas emissions and the
potential impacts this activity might have on groundwater quality. In July 2008, EPA
proposed regulations to manage geologic sequestration under the authority of the
Safe Drinking Water Act’s groundwater protection provisions.
In the 110th Congress, bills were offered to address drinking water issues, such
as small system infrastructure funding needs (S. 1933 and S. 199) and compliance
problems facing small communities (S. 1429 and H.R. 2141). Various bills also
proposed to address contamination of water supplies by specific contaminants,
including perchlorate (S. 24, S. 150, and H.R. 1747), lead (H.R. 2076), and arsenic
and other naturally occurring contaminants (H.R. 2141). The Senate Environment
and Public Works Committee held hearings on selected EPA activities, including
perchlorate regulation. The House Natural Resources Committee held a hearing on
the impacts of perchlorate contamination on groundwater supplies. The House
Energy and Commerce Committee held a hearing on the contamination of drinking
water at Camp Lejeune by trichloroethylene (TCE), related health and cleanup issues,
and EPA’s pace in updating its 1989 drinking water standard for TCE. Relatedly, S.
1911 and H.R. 5527 would have required EPA to promptly issue a new TCE
standard. The Senate Environment and Public Works Committee reported perchlorate
bills, S. 24 (S.Rept. 110-483) and S. 150 (S.Rept. 110-484), TCE legislation (S.

1911, S.Rept. 110-486), and legislation to authorize a small system grant program (S.

1933, S.Rept. 110-475). The committee also reported S. 3617 (S.Rept. 110-509), the
Water Infrastructure Financing Act, which would have authorized a grant program
and increased funding for drinking water and wastewater infrastructure. Other
reported bills included S. 2970 (S.Rept. 110-487) to help water utilities develop and
implement climate change adaptation policies, and S. 199 (S.Rept. 110-476), to
increase the authorization of appropriations for water and wastewater grants for
Alaska’s rural and Native villages. None of the bills was enacted.
In the 1996 SDWA amendments, Congress authorized appropriations for most
SDWA programs through FY2003; however, broad SDWA reauthorization efforts
were not on the agenda in the 110th Congress. As with other EPA-administered
statutes having expired funding authority, Congress has continued to appropriate
funds annually for SDWA programs.
Regulating Drinking Water Contaminants
Contaminant Candidate List. The SDWA Amendments of 1996 directed
EPA to publish, every five years, a list of unregulated contaminants that are known
or anticipated to occur in public water systems and that may require regulation. EPA
published contaminant candidate lists (CCLs) in 1998 (CCL 1) and in 2003 (CCL 2).
In February 2008, EPA published for public comment a draft CCL 3 that contains 93

chemicals or chemical groups and 11 microbiological contaminants (73 Fed. Reg.

9627). The list includes commercial and agricultural chemicals, biological toxins,

disinfection byproducts, and pathogens; 16 chemicals, including perchlorate, were
carried over from CCL 2. EPA screened some 7,500 chemicals and microbes and
selected 104 candidates for the draft CCL 3. However, as discussed below, the list
does not include any pharmaceuticals, and EPA is now reviewing the adequacy of its
screening process, which was recommended by the National Academy of Sciences.
Regulatory Determinations. Starting in 2001, and every five years
thereafter, the EPA is required to determine whether or not to regulate at least five
of the listed contaminants. The act requires the EPA to evaluate contaminants that
present the greatest health concern, and then to regulate those contaminants that
occur at concentration levels and frequencies of public health concern, where
regulation presents a meaningful opportunity for health risk reduction.
In July 2008, EPA published final regulatory determinations for 11
contaminants from the CCL 2. All of the determinations were decisions not to
regulate. In making these determinations, EPA noted that the data indicated that the
contaminants either did not appear to occur in public water systems, or had low levels
of occurrence at levels of health concern, and that regulating the contaminants did not
present a meaningful opportunity for health risk reduction. For those contaminants
with low occurrence frequencies, EPA is updating the health advisories to reflect new6
information or to include information on degradation byproducts.
The agency did not make determinations for two chemicals that have been
detected in numerous water supplies and have received considerable congressional
attention: perchlorate and MTBE. EPA noted that a regulatory determination will
soon be published for perchlorate, and that a decision was not made for MTBE
because the health risk assessment for MTBE is being revised.
Unregulated Contaminant Monitoring. The 1996 amendments directed
EPA to establish criteria for a program to monitor unregulated contaminants. This
monitoring program enables EPA to collect data for contaminants that are not
regulated but are suspected to be present in drinking water. Every five years, EPA
is required to identify as many as 30 contaminants to be monitored. This list is largely
based on the Contaminant Candidate List. All systems serving more than 10,000
people and a sample of smaller systems must monitor for the contaminants. The
resulting data are added to the National Contaminant Occurrence Database (NCOD).
EPA published the first unregulated contaminant monitoring rule (UCMR 1) in 1999
requiring monitoring for 26 chemicals. In January 2007, EPA issued the second rule
(UCMR 2), requiring systems to monitor for 25 chemicals over a 12-month period
between 2008 through 2010.7 EPA had included perchlorate on the draft UCMR 2
list, but deleted it from the final list. EPA stated that it has sufficient perchlorate
occurrence data, but some advocates of perchlorate regulation were critical of EPA’s
decision not to require further monitoring.

6 Information on the CCL2 and the rationale behind EPA’s regulatory determinations are
available at [].
7 January 4, 2007 (72 Fed. Reg. 367-398)

Standard-Setting. As amended in 1996, the act directs EPA to promulgate
a National Primary Drinking Water Regulation for a contaminant if the Administrator
determines that the following three criteria are met:
!the contaminant may have adverse health effects;
!it is known, or there is a substantial likelihood, that the contaminant
will occur in public water systems with a frequency and at levels of
public health concern; and
!its regulation presents a meaningful opportunity for health risk
reduction for persons served by public water systems.
Drinking water regulations generally include numerical standards that establish
the highest level of a contaminant that may be present in water supplied by public
water systems. Where it is not economically or technically feasible to measure a
contaminant at very low concentrations, EPA may establish a treatment technique in
lieu of a standard.
Developing a drinking water regulation is a complex process, and EPA must
address technical, scientific, and economic issues. The agency must (1) estimate the
extent of occurrence of a contaminant in sources of drinking water nationwide; (2)
evaluate the potential human exposure and risks of adverse health effects to the
general population and to sensitive subpopulations; (3) ensure that analytical methods
are available for water systems to use in monitoring for a contaminant; (4) evaluate
the availability and costs of treatment techniques that can be used to remove a
contaminant; and (5) assess the impacts of a regulation on public water systems, the
economy, and public health. Regulation development typically is a multi-year
process. EPA may expedite procedures and issue interim standards to respond to
urgent threats to public health.
After reviewing health effects studies, EPA sets a nonenforceable maximum
contaminant level goal (MCLG) at a level at which no known or anticipated adverse
health effects occur and that allows an adequate margin of safety. EPA also
considers the risk to sensitive subpopulations, such as infants and children. For
carcinogens and microbes, EPA generally sets the MCLG at zero. Because MCLGs
are based only on health effects and not on analytical detection limits or the
availability or cost of treatment technologies, they may be set at levels that are not
technically feasible for water systems to meet.
Once the MCLG is established, EPA then sets an enforceable standard, the
maximum contaminant level (MCL). The MCL generally must be set as close to the
MCLG as is “feasible” using the best technology or other means available, taking
costs into consideration (SDWA §1412(b)).8 The act does not discuss how EPA
should consider cost in determining feasibility; consequently, EPA has relied on
legislative history for guidance. Congress last addressed this issue in the Senate
report accompanying the 1996 amendments, which stated that “feasible” means the
level that can be reached by large, regional drinking water systems applying best

8 For a more detailed discussion, see CRS Report RL31243, Safe Drinking Water Act: A
Summary of the Act and Its Major Requirements, by Mary Tiemann.

available treatment technology. The Senate committee report explained that this
approach is used because 80% of the population receives its drinking water from
large community water systems, and thus, safe water can be provided to most of the
population at very affordable costs.9
However, because standards are based on cost considerations for large systems,
Congress expected that standards could be less affordable for smaller systems. In
1996, Congress expanded the act’s variance and exemption provisions to give small
systems some added compliance flexibility. (See the discussion below on Small
System Issues.) Congress further revised the act to require EPA, when proposing a
standard, to publish a determination as to whether or not the benefits of a proposed
standard justify the costs. If EPA determines that the benefits do not justify the costs,
EPA, in certain cases, may promulgate a standard that is less stringent than the
feasible level and that “maximizes health risk reduction benefits at a cost that is
justified by the benefits.”10 EPA used this authority to establish new standards for
arsenic and radium.
Recent and Pending Rules. EPA’s rulemaking activities include a January
2006 rule package that expanded existing requirements to control pathogens
(especially Cryptosporidium) and disinfectants (e.g., chlorine) and their byproducts
(e.g., chloroform). These rules, the Long Term 2 Enhanced Surface Water Treatment
Rule (LT2 Rule) and the Stage 2 Disinfectant and Disinfection Byproduct Rule
(Stage 2 DBP), complete a series of statutorily mandated rules that impose
increasingly strict controls on the presences of pathogens and disinfectants and their11
byproducts in water systems. EPA promulgated a related Ground Water Rule to
establish disinfection requirements for systems relying on ground water. In the past
several years, EPA also issued standards for several radionuclides, including uranium
and radium, and a revised standard for arsenic. These rules are expected to reduce
an array of health risks for consumers, but they have potentially significant costs for
the communities that must expand treatment facilities to comply with the standards.
In September 2007, EPA completed targeted revisions to the Lead and Copper
Rule (LCR). The revisions are intended to address weaknesses identified during a
nationwide review of the rule, following the discovery of high lead levels in12
Washington, DC, tap water in 2004. The changes involved regulatory requirements
for monitoring, treatment, customer notification, and lead service line replacement.
More comprehensive revisions to the LCR are under way. Among ongoing
rulemakings, EPA has been working to finalize a radon rule (proposed in 1999), and
has been evaluating numerous contaminants, including perchlorate and MTBE, for
possible regulation. Table 2 reviews the purposes and status of several recently
completed or proposed drinking water regulations and guidelines.

9 U. S. Senate. Safe Drinking Water Amendments Act of 1995, Report of the Committee on
Environment and Public Works on S. 1316. S.Rept. 104-169. p. 14. November 7, 1995.
10 SDWA §1412(b)(6); 42 U.S.C. 300g-1.
11 Information on these rules can be found at [].
12 The newly revised Lead and Copper Rule and more information on lead in drinking water
are available at [].

Table 2. Recent and Pending Regulatory Actions
Regulatory(Fed. Reg.
Ac t i on Notice) P urpose
Revisions to Lead10/10/2007EPA promulgated targeted changes to the LCR to improve implementation in
and Copper Rule(72 Fed.the areas of monitoring, treatment, customer awareness, and lead service line
(LCR)Reg. 57781)replacement, to better control exposures to lead in drinking water. The
Finalrevisions do not affect the lead MCLG or action level, or the rule’s basic
requirements. (A comprehensive revision of the rule is under way.)
Unregulated1/4/2007 SDWA requires EPA to publish every five years a list of unregulated
Contaminant(72 Fed.contaminants to be monitored. This second UCMR requires monitoring of 25
Monitoring RuleReg. 367)chemicals during 2008-2010. These data provide the main occurrence and
(UCMR 2)Finalexposure data for EPA to determine whether to regulate the contaminants.
(Perchlorate was included in the first UCMR and in the draft, but not final,
UCMR 2.)
Ground Water11/8/2006The 1996 amendments directed EPA to require disinfection for all public
Rule (GWR)(71 Fed.water systems, including all surface water systems and, as necessary, ground
Reg. 65574)water systems to provide greater protection against microbial pathogens.
Proposed Revision3/2/2006EPA proposed options for revising its criteria for determining whether a
of National(71 needed to comply with a standard is affordable for small systems
AffordabilityReg. 65573)and for revising its methodology for determining if an affordable variance
Methodology andtechnology protects public health. As provided for in the 1996 amendments,
Methodology tostates may grant variances to small systems for standards that EPA
Identify Variancedetermines are unaffordable. Under the current criteria, no small system
Technologiesvariances are available.
Long-Term 21/5/2006Supplements existing rules by increasing Cryptosporidium treatment
Enhanced Surface(71 Fed.requirements for higher risk systems. Contains provisions to reduce risks
Water TreatmentReg. 653)from uncovered finished water reservoirs and to ensure that systems maintain
Rule (LT2 Rule)Finalmicrobial protection when they act to decrease the formation of disinfection
byproducts (DBPs).
Stage 21/4/2006Builds on existing rules to strengthen requirements for higher risk systems to
Disinfectants and(71 Fed.reduce potential health risks from DBPs in drinking water, which form when
Disinfection By-Reg. 387)disinfectants are used to control microbial pathogens. Tightens monitoring
Products RuleFinal requirements for 2 groups of DBPs, trihalomethanes (TTHM) and haloacetic
(DBPR)acids (HAA5). (This rule was issued with the LT2 Rule to address concerns
about risk tradeoffs between pathogens and disinfection byproducts.)
Proposed Radon11/2/1999As provided for in P.L. 104-182, EPA proposed a multimedia approach to
Rule(64 Fed.reducing radon risks in indoor air (the biggest exposure source) whilea
Reg. 59245)protecting public health from radon in drinking water. EPA proposed an
alternative standard (AMCL) and requirements for multimedia mitigation
(MMM) programs to address radon in indoor air. A community water system
(CWS) may comply with the AMCL if the state develops an MMM program
or the CWS develops a state-approved MMM program. EPA also proposed a
stricter radon MCL to apply in states that do not implement MMM programs.
a. Most of the risk from exposure to radon in drinking water comes from breathing radon released
from water (e.g., during showering or cooking) and not from ingesting the water. EPA estimates that
1-2% of the radon in indoor air comes from drinking water. Most of the radon present in indoor air
seeps into homes and other buildings from underlying soil.

Perchlorate in Drinking Water
Perchlorate is the explosive component of solid rocket fuel, fireworks, road
flares, and other products. Used heavily by the Department of Defense (DOD) and
related industries, perchlorate also occurs naturally (including in areas of the
Southwest) and is present in some organic fertilizer. This compound has been
detected in sources of drinking water for more than 11 million people, usually at low
levels. It also has been found in milk, fruits, vegetables, and bread. Perchlorate is
known to disrupt the uptake of iodine in the thyroid, potentially affecting thyroid
function. A key concern is that, if sufficiently severe, impaired thyroid function in
pregnant or nursing women may impair brain development in fetuses and nursing
infants. Because of this concern, bills have been repeatedly introduced in recent
Congresses to require EPA to set a drinking water standard for perchlorate.13
Over the past decade, EPA has been evaluating perchlorate to determine
whether a federal drinking water standard is warranted. Regulatory issues have
involved the relative risk reduction benefits and costs of federal regulation, including
environmental cleanup and water treatment costs, both of which are driven by federal
and state standards. Another question has concerned the amount of perchlorate
exposure that is attributable to food compared to drinking water. Under SDWA, EPA
must regulate a contaminant if the Administrator determines that the contaminant
occurs at a frequency and level of public health concern, and that its regulation
presents a meaningful opportunity for reducing health risks. Uncertainty about the
health risks associated with exposure to perchlorate at low levels slowed EPA efforts
to determine whether to establish a standard and, relatedly, environmental cleanup
standards for use at Superfund and other contaminated sites.
In the absence of a federal standard, states have begun to adopt their own
measures. Massachusetts established a drinking water standard for perchlorate of 2
ppb in 2006, and California adopted a standard of 6 ppb. Several states have issued
health goals or advisory levels, ranging from 1 ppb in Maryland (advisory level) and
New Mexico (drinking water screening level) to 4 ppb in Texas (residential
groundwater cleanup level).
EPA identified perchlorate as a candidate for regulation in 1998, but concluded
that information was insufficient at that time to make a regulatory determination. The
agency listed perchlorate as a priority for further research on health effects and
treatment technologies and for collecting occurrence data. In 1999, EPA required
water systems to monitor for perchlorate under the Unregulated Contaminant
Monitoring Rule (UCMR) to determine the frequency and levels at which it is present
in public water supplies nationwide. In monitoring conducted under the UCMR,
perchlorate was detected in 153 public water systems in 25 states, out of 3,600 water
systems sampled nationwide. In August 2005, EPA proposed a second UCMR that
included perchlorate for additional monitoring between 2007 and 2011. Most
commentors did not support another round of perchlorate monitoring. Many felt that
further monitoring would impose costs but would not likely yield much beneficial

13 For further discussion, see CRS Report RS21961, Perchlorate Contamination of Drinking
Water: Regulatory Issues and Legislative Actions, by Mary Tiemann.

information. In the final rule, EPA announced that it had collected sufficient
occurrence data for perchlorate and that further monitoring was not needed (72
Federal Register 367, January 4, 2007).
The health effects assessments surrounding EPA’s efforts to regulate perchlorate
have been controversial. In 2002, EPA issued a draft risk assessment that concluded
that potential human health risks of perchlorate exposure include effects on the
developing nervous systems and thyroid tumors. The findings were based on rat
studies that observed tumors and adverse effects in fetal brain development. This
controversial draft assessment included a revised draft reference dose (RfD) intended
to protect the most sensitive groups against these effects. That dose roughly
translated to a drinking water standard of 1 part per billion (ppb). EPA’s 1999 draft
level had translated to a standard of roughly 32 ppb.
Because the reference dose provides the basis for determining the level at which
a drinking water standard is set, and because these standards are, in turn, the basis of
environmental cleanup standards, DOD and other perchlorate users and
manufacturers have followed EPA’s perchlorate risk assessment efforts closely. As
a result of interagency debate over the draft assessment, in 2003, EPA, the DOD,
NASA, the Office of Management and Budget, and other federal agencies asked the
National Research Council (NRC) to review the science for perchlorate and EPA’s
draft risk assessment.
The NRC released its study in January 2005.14 The NRC committee broadly
agreed with several of EPA’s findings, but suggested several changes to the draft risk
assessment. Among other findings, the committee concluded that rat studies are of
limited use for assessing human health risk associated with perchlorate exposure, and
the committee recommended that EPA base its assessment on human data. The NRC
calculated an RfD for perchlorate that incorporated an uncertainty factor intended to
protect the most sensitive populations. EPA adopted the NRC’s recommended RfD,
which translates to a drinking water equivalent level of 24.5 ppb. (If EPA were to
develop an MCL, it would adjust this number to take into account the amount of
perchlorate exposure that comes from other sources, especially food.)
Despite the NRC recommendations, substantial disagreement has persisted
regarding what level of exposure is safe, especially for fetuses and infants, and what
drinking water standard is appropriate. Several studies have indicated that thyroid
changes occur in humans at significantly higher concentrations of perchlorate than
the amounts typically observed in water supplies.15 However, a 2006 study by the
Centers for Disease Control and Prevention (CDC) of a representative sample of the
U.S. population found that environmental exposures to perchlorate have an effect on
thyroid hormone levels in women with iodine deficiency. The researchers reported

14 National Research Council, Health Implications of Perchlorate Ingestion, Board on
Environmental Studies and Toxicology, National Academies Press, January 2005, 177 p.
15 Michael A. Kelsh et al., “Primary Congenital Hypothyroidism, Newborn Thyroid
Function, and Environmental Perchlorate Exposure Among Residents of a Southern
California Community,” Journal of Occupational Environmental Medicine,45(10) p. 1116-

1127, October 2003.

that more than one-third of the 1,111 women in the study were iodine deficient, and
the median level of urinary perchlorate measured in the women was 2.9 ppb.16
On October 3, 2008, EPA announced a preliminary determination not to set a
standard for perchlorate, noting that less than 1% of water systems have perchlorate
levels above EPA’s health reference level (discussed below). EPA concluded that
perchlorate failed to meet two of SDWA’s regulatory criteria (i.e., that a contaminant
occurs frequently at levels of health concern, and that establishing a national drinking
water standard would provide a “meaningful opportunity for health risk reduction”).
In response, EPA’s Science Advisory Board’s (SAB’s) Drinking Water Committee
argued that, given perchlorate’s occurrence and well-documented toxicity, EPA must
have a compelling basis to support a determination not to regulate. The SAB
requested more time to review the new model used by EPA, and to comment on the
preliminary determination. If the final determination is not to regulate, EPA will
develop a nonenforceable health advisory to guide state and other officials on health
effects, monitoring and treatment technologies, and expected safe exposure levels.
In the 110th Congress, perchlorate again was on the agenda. S. 24 was
introduced following EPA’s decision not to require further monitoring for perchlorate
as an unregulated contaminant (as discussed above under “Regulatory
Determinations”). This bill would have required water systems to test for perchlorate
and disclose its presence in annual consumer confidence reports. Similarly, in the
absence of a decision by EPA to regulate perchlorate, S. 150 proposed to require EPA
to issue a perchlorate health advisory within 90 days of enactment, and to promptly
establish a drinking water standard. In September 2008, the Senate Environment and
Public Works Committee reported S. 24 (S.Rept. 110-483) and S. 150 (S.Rept. 110-
484). In the House, H.R. 1747 would have required EPA to issue a perchlorate
standard. In 2007, the Environment and Hazardous Materials Subcommittee of the
House Committee on Energy and Commerce held markup and forwarded H.R. 1747
to the full committee. No further action occurred on these bills.
Pharmaceuticals in Drinking Water
As monitoring technologies have become available and testing has increased,
traces of more pharmaceuticals and personal care products (PPCPs) have been
detected in surface waters and drinking water supplies. Pharmaceuticals include
prescription drugs, veterinary drugs, and over-the-counter medicines. Personal care
products cover a broad spectrum and include cosmetics, hair products, sun-screens,
fragrances, anti-bacterial soaps, and vitamins. These chemicals are released to the
environment in various ways, including elimination of human and animal waste,
disposal of unused medicines down the toilet, veterinary drug usage, hospital waste
disposal, and industrial discharges.

16 Benjamin C. Blount, James L. Pirkle, et al., “Urinary Perchlorate and Thyroid Hormone
Levels in Adolescent and Adult Men and Women Living in the United States,” Centers for
Disease Control and Prevention, Environmental Health Perspectives, 114(12), p. 1865-1871,
December 2006.

Although significant research is being conducted, much is unknown about the
occurrence and movement of PPCPs in the environment, their occurrence in drinking
water supplies, or about the potential health risks from exposure to PPCPs at
extremely low levels through drinking water. Nonetheless, the detection of
pharmaceuticals and related products in public water supplies generates concern,
because many of these products are specifically designed to have a biological effect
in humans, animals, and/or plants. Pharmaceuticals often contain chemical
compounds that can affect the endocrine system by altering, mimicking, or impeding
the function of hormones. Such endocrine disrupting chemicals (EDCs) have the
potential to affect growth, development, reproduction, and metabolism. Over the
past decade, scientists and regulators have become increasingly concerned about the
effects that exposures to low levels of PPCPs may be having on aquatic organisms,
and also potentially on human health.17
The U.S. Geological Survey (USGS) and EPA have identified a wide array of
research needs and gaps that, if addressed, would help delineate the scope of
environmental and human health issues that might result from the presence of PPCPs
in the environment. The USGS has conducted research on the occurrence of
hormones, pharmaceuticals, and other wastes in residential, industrial, and
agricultural wastewater, and has found that a broad range of these chemicals occur
commonly downstream from large urban areas and concentrated animal production
areas. 18
EPA has been conducting and supporting numerous PPCP research projects in
several areas, including the relative importance of different sources of PPCPs in the
environment (e.g., veterinary vs. human medicine), how PPCPs move through the
environment, human exposure pathways, ecological exposure pathways, monitoring
and detection tools, assessment of potential human health effects, and assessment of
potential ecological effects. Research is also being conducted to evaluate the ability
of drinking water treatment technologies to remove various PPCPs.
Ecological research has received particular attention because exposure risks for
aquatic life have been considered to be much greater than those for humans.19
Nonetheless, a key research issue concerns the possible health risks from exposure
to very low doses of the myriad chemicals found in PPCPs. Because PPCPs occur
in the environment at low concentrations, their effects may be subtle. Among other
research gaps, EPA has identified a need to develop tests that can detect more subtle
health effects.

17 For more information on EDCs and potential health risks, see CRS Report RL31267,
Environmental Exposure to Endocrine Disruptors: What Are the Human Health Risks?, by
Linda Schierow and Eugene H. Buck.
18 See for example, U.S. Geological Survey, Pharmaceuticals, Hormones, and Other
Organic Wastewater Contaminants in U.S. Streams, USGS FS-027-02, June 2002.
19 Aquatic organisms face higher risks of exposure than humans for several reasons. For
example, these organisms have continuous exposure, and generally are exposed to higher
concentrations of PPCPs in untreated water, compared to treated drinking water.

The agency is also conducting a study to determine the amount of PPCPs that
are discharged to wastewater treatment plants from various sources. As part of this
study, EPA is evaluating how hospitals and other institutions dispose of unused
medications.20 Other research projects address the development of analytical methods
to determine the source and fate of PPCPs in the environment.
As noted above, EPA proposed its third list of unregulated contaminants being
considered for regulation in February 2008. This Contaminant Candidate List 3 (CCL
3) contains 104 contaminants, none of which are pharmaceuticals. Following recent
reports of the detection of pharmaceuticals and commonly used over-the-counter
drugs in the drinking water supplies of 24 large community water systems, EPA has
asked its Science Advisory Board (SAB) and stakeholders to evaluate and comment
on the contaminant candidate screening and selection process to determine whether
the process requires revision.21
Because of ecological concerns, as well as human health concerns, regulating
contaminants in drinking water represents only part of the response to this multi-
faceted problem. Recognizing that people and animals will continue to take and use
pharmaceutical products, water suppliers and other stakeholders consider changes at
wastewater treatment plants to be a key part of the solution.
The Association of Metropolitan Water Agencies (AMWA), which represents
the largest publicly owned water systems, has made several recommendations to
address this emerging drinking water issue. Among these recommendations, the
AMWA strongly encouraged EPA to make research on treatment technologies a high
priority, and urged water utilities to inform consumers of efforts to monitor and
remove pharmaceuticals from water sources. AMWA also called for EPA and the
Food and Drug Administration (FDA) to determine whether the presence of trace
amounts of pharmaceuticals results in short-term or long-term effects on health and
the environment, recommended that the federal government take the lead in
developing a national program for disposing of unused prescriptions, and called for
animal feeding operations to reduce their contributions of antibiotics and steroids into
water supplies.22
H.R. 6820, introduced on August 1, 2008, proposed to require EPA to work
with other agencies to conduct a study on the presence of PPCPs in the nation’s
drinking water supplies. The bill would have required the Administrator to submit
reports to Congress on the types, levels, and sources of PPCPs found in drinking
water; the human health and ecological effects of PPCPs; monitoring and removal
technologies; disposal methods; and other information.

20 For further information on PPCPs and related EPA activities, see [].
21 Information of the CCL3 is available at, [].
22 Association of Metropolitan Water Agencies, AMWA Discusses Pharmaceuticals in Water
Supplies, March 11, 2008, [].

Drinking Water Infrastructure Needs and Funding
A persistent SDWA issue concerns the ability of water systems to construct or
upgrade infrastructure to comply with drinking water regulations and, more broadly,
to ensure the provision of a safe and reliable water supply. In the 1996 amendments,
Congress responded to growing complaints about the act’s unfunded mandates and
authorized a drinking water state revolving loan fund (DWSRF) program to help
water systems finance infrastructure projects needed to meet drinking water standards
and address the most serious health risks. The program authorizes EPA to award
annual capitalization grants to states. States then use their grants (plus a 20% state
match) to provide loans and other assistance to public water systems. Communities
repay loans into the fund, thus replenishing the fund and making resources available
for projects in other communities. Eligible projects include installation and
replacement of treatment facilities, distribution systems, and some storage facilities.
Projects to replace aging infrastructure are eligible if they are needed to maintain
compliance or to further public health protection goals.23
The SDWA authorized appropriations for the DWSRF program totaling $9.6
billion, including $1 billion for each of FY1995 through FY2003. Since FY1997,
Congress has appropriated more than $10.3 billion for this program, including $829.0
million (after applying the 1.56% across-the-board rescission) for FY2008. The
President requested $842.2 million for FY2009. Specific EPA appropriations were
not passed, and the consolidated appropriations act for FY2009 (P.L. 110-329)
generally extended funding for EPA programs at FY2008 levels through March 6,

2009. (Table 3 lists funding levels for the DWSRF program since its inception.)

Through June 2007, the EPA had awarded $8.13 billion in capitalization grants,
which, when combined with the state match, bond proceeds, loan principal
repayments, and other funds, amounted to $13.9 billion in DWSRF funds available
for loans and other assistance. Also, as of June 2007, 5,346 projects had received
assistance, and total assistance provided by the program reached $12.63 billion.
The DWSRF program is well-regarded, but many state and local officials and
interest groups have argued that greater investment in water infrastructure is needed.
EPA’s 2003 drinking water infrastructure needs survey found that systems need to
invest $276.8 billion in infrastructure improvements over 20 years to comply with
drinking water regulations and to ensure the provision of safe water.24 The survey
includes funds needed for compliance with several recent rules (including the arsenic
rule and the disinfectants and disinfection byproducts rules) and several proposed
rules (including radon). The survey also identified $1 billion in security-related
needs. All infrastructure projects in the needs assessment promote the health
objectives of the act, but only $45.1 billion (16.3%) of the total need is attributable

23 See also CRS Report RS22037, Drinking Water State Revolving Fund: Program Overview
and Issues, by Mary Tiemann. For information on other assistance programs, see CRS
Report RL30478, Federally Supported Water Supply and Wastewater Treatment Programs.
24 U.S. Environmental Protection Agency, Drinking Water Infrastructure Needs Survey and
Assessment: Third Report to Congress, June 2005, EPA 816-R-05-001, available at
[ ht t p: / / saf e wat e r / needssur vey/ i ml ] .

to SDWA compliance. Although aging, deteriorated infrastructure often poses a
threat to drinking water safety, these needs occur independently of federal mandates.
Table 3. Drinking Water State Revolving Fund Program Funding,
(in millions of dollars, nominal dollars and adjusted for inflation)
Adjusted for
Inflation in 2007
Fiscal YearAuthorizations AppropriationsDollars
1997 $1,000.0 $1,275.0 $1,594.6
1998 $1,000.0 $725.0 $895.9
1999 $1,000.0 $775.0 $945.2
2000$1,000.0 $816.9$976.6
2001 $1,000.0 $823.2 $961.4
2002 $1,000.0 $850.0 $974.1
2003 $1,000.0 $844.5 $948.6
2004 — $845.0$925.1
2005 — $843.2$894.5
2006 — $837.5$859.9
2007 — $837.5$837.5
2008 — $829.0est. $813.3
2009 (req.) — $842.2est. $809.9
Sources: Prepared by CRS using information from the following sources: FY1997-FY2000 and
FY2002 enacted amounts are from the enacted appropriations bills for those fiscal years.
FY2001enacted amount is the prior year enacted amount specified in EPAs FY2002 congressional
budget justification. FY2003-FY2004 enacted amounts are from EPAs Office of Water. FY2005-
FY2006 enacted amounts are prior year enacted amounts specified in House Appropriations
Committee reports on subsequent year appropriations bills. FY2007 an d FY2008 enacted amounts,
and FY2009 President’s request, are as reported to CRS by the House Appropriations Committee. All
enacted amounts reflect rescissions. Nominal dollar amounts were converted into 2007 dollar values
using the GDP Chained Price Index from the Office of Management and Budget, Budget of the United
States Government for Fiscal Year 2009, Historical Tables.
EPA also has prepared a broader municipal wastewater and drinking water
infrastructure funding gap analysis, which identified potential funding gaps between25
projected needs and spending from 2000 through 2019. This analysis estimated the
potential 20-year funding gap for drinking water and wastewater infrastructure capital
and operations and maintenance (O&M), based on two scenarios: a “no revenue
growth” scenario and a “revenue growth” scenario that assumed infrastructure
spending would increase 3% per year. Under the “no revenue growth” scenario, EPA
projected a funding gap for drinking water capital investment of $102 billion ($5
billion per year) and an O&M funding gap of $161 billion ($8 billion per year).

25 U.S. Environmental Protection Agency, The Clean Water and Drinking Water
Infrastructure Gap Analysis Report, Report No. EPA 816-R-02-020, September 2002, 50

Using revenue growth assumptions, EPA estimated a 20-year capital funding gap of
$45 billion ($2 billion per year), and no gap for O&M. In response to the Gap
Analysis, EPA’s FY2004 budget request proposed that funding for the DWSRF
program be continued at a level of $850 million annually through FY2018. EPA
explained that this funding level would allow DWSRFs to revolve at a cumulative
level of $1.2 billion (more than double the previous goal of $500 million) and would
help close the funding gap for drinking water infrastructure needs.
Other assessments also have found a funding gap. In 2000, the Water
Infrastructure Network (WIN) (a coalition of state and local officials, water
providers, environmental groups and others) reported that over the next 20 years,
water and wastewater systems need to invest $23 billion annually more than current
investments to meet SDWA and Clean Water Act health and environmental priorities
and to replace aging infrastructure. WIN and other groups have proposed
multibillion dollar investment programs for water infrastructure. Others, however,
have called for more financial self-reliance within the water sector.
In the 109th Congress, the Senate Environment and Public Works Committee
reported the Water Infrastructure Financing Act, S. 1400 (S.Rept. 109-186), which
would have amended the SDWA and the Clean Water Act to reauthorize both SRF
programs (authorizing $15 billion over five years for the DWSRF). The bill also
would have directed EPA to establish grant programs for small or economically
disadvantaged communities for critical drinking water and water quality projects;
authorized loans to small systems for preconstruction, short-term, and small project
costs; and directed EPA to establish a demonstration program to promote new
technologies and approaches to water quality and water supply management. At
markup, the committee adopted an amendment to apply Davis-Bacon prevailing
wage requirements, in perpetuity, to projects receiving DWSRF assistance. The
Davis-Bacon measure remained contentious, and S. 1400 received no further action.
The 110th Congress returned to water infrastructure funding and needs issues.
On September 26, 2008, the House passed an emergency supplemental
appropriations bill, H.R. 7110 (the Job Creation and Unemployment Relief Act of
2008). This bill proposed to provide $1 billion for the DWSRF program, and another
$6.5 billion for the Clean Water SRF program. Also in September, the Senate
Environment and Public Works Committee reported several bills that would have
authorized funding for drinking water infrastructure. S. 3617 (S.Rept. 110-509), the
Water Infrastructure Financing Act, which was similar to the committee bill from the
109th Congress, would have authorized more funding for drinking water and
wastewater SRF programs (authorizing $15 billion over five years for the DWSRF),
and would have created a grant program at EPA for small or economically
disadvantaged communities for critical drinking water and water quality projects. S.
3617 included a Davis-Bacon prevailing wage provision, requiring that prevailing
wage requirements would apply to all projects financed in whole or part through an
SRF.) The other reported bills included S. 1933 (S.Rept. 110-475), which would have
created a grant program for small drinking water systems and would have authorized
$750 million annually for FY2008 through FY2014; and S. 199 (S.Rept. 110-476),
to increase the authorization of appropriations for water and wastewater grants for
Alaska’s rural and Native villages. None of the bills was enacted.

In the face of uncertainty over increased federal assistance for water
infrastructure, EPA, states, communities, and utilities have been examining
alternative management and financing strategies to address SDWA compliance costs
and broader infrastructure maintenance and repair costs. Such strategies include
establishing public-private partnerships (privatization options range from contracting
for services to selling system assets), improving asset management, and adopting
full-cost pricing for water services. Still, these strategies may be of limited use to
many small and/or economically disadvantaged communities, and stakeholders are
likely to continue to urge Congress to increase funding for water infrastructure.26
Small Systems Issues
An issue that has received considerable attention concerns the financial,
technical, and managerial capacity of small systems to comply with SDWA
regulations. Roughly 84% (44,000) of the nation’s 52,800 community water systems
are small, serving 3,300 persons or fewer, and 57% (30,000) of the community water
systems serve 500 persons or fewer. Many small systems face challenges in
complying with SDWA rules and, more fundamentally, in ensuring the quality of
water supplies. Major problems include deteriorated infrastructure, lack of access to
capital, limited customer and rate base, inadequate rates, diseconomies of scale, and
limited managerial and technical capabilities. Because of these same characteristics,
the DWSRF program has not been as successful for small systems, compared to
larger systems. Although these systems serve just 9% of the population served by
community water systems, the sheer number of small systems has created challenges
for policymakers and regulators.
In the earliest SDWA debates, Congress recognized that setting standards based
on technologies affordable for large cities could pose problems for small systems.
During the reauthorization debate leading up to the 1996 amendments, policymakers
gave considerable attention to the question of how to help small systems improve
their capacity to comply with SDWA mandates. The 1996 amendments added
provisions aimed at achieving this goal, including a requirement that states establish
strategies to help systems develop and maintain the technical, financial, and
managerial capacity to meet SDWA regulations. Congress also revised provisions
on standard-setting (§1412(b)), variances (§1415(e)), and exemptions (§1416) to
increase consideration of small system concerns.
Exemptions. The act’s exemption provisions are intended to provide
compliance flexibility in certain cases. States or EPA may grant temporary
exemptions from a standard if, due to certain compelling factors (including cost), a
system cannot comply on time. For example, all systems are required to comply with
the new arsenic standard five years after its promulgation date. An exemption would
allow three more years for qualified systems. Small systems (serving 3,300 persons
or fewer) may be eligible for up to three additional two-year extensions, for a total
exemption duration of nine years (and for a total of up to 14 years to achieve

26 For further discussion of infrastructure issues, see CRS Report RL31116, Water
Infrastructure Needs and Investment: Review and Analysis of Key Issues, by Claudia
Copeland and Mary Tiemann.

compliance). In the preamble to the arsenic rule published in January 2001, EPA
noted that exemptions will be an important tool to help states address the number of
systems needing financial assistance to comply with this rule and other SDWA rules
(66 Federal Register 6988).
However, to grant an exemption, the law requires a state to hold a public hearing
and make a finding that the extension will not result in an “unreasonable risk to
health.” Because of the administrative burden to the states, the act’s exemption
authority has seldom been used. Approximately 13 states had indicated that they
would likely use the exemption process for the arsenic rule, but it appears that many
states have not exercised this option.
Small System Variances and Affordability. In contrast to exemptions,
variances offer a more permanent form of compliance flexibility for small systems.
Since 1996, SDWA has required EPA, when issuing a regulation, to identify
technologies that meet the standard and that are affordable for systems that serve
populations of 10,000 or fewer. If EPA does not identify affordable “compliance”
technologies, then the agency must identify small system “variance” technologies.
A variance technology need not meet the standard, but must protect public health.
States may grant variances to systems serving 3,300 persons or fewer if a system
cannot afford to comply with a rule (through treatment, an alternative source of
water, or other restructuring) and if the system installs a variance technology. With
EPA approval, states also may grant variances to systems serving between 3,300 and
10,000 people. (Regulations addressing microbial contaminants are not eligible for
variances under the statute.)
In 1998, EPA published affordability criteria to establish guidelines for
determining whether a regulation is deemed affordable for small systems, and
whether small system variances would be available. Under the criteria, EPA
evaluates the affordability of a regulation by determining whether the compliance
cost would raise the total water cost above 2.5% of annual median household income
(MHI) in the three categories of small systems. Using this approach, EPA has
determined that affordable compliance technologies are available for every drinking
water regulation. Consequently, the agency has not identified any small system
variance technologies, and thus, no small system variances are available.
Several recent regulations (such as the revised arsenic and radium standards and
the Stage 2 Disinfectants and Disinfection Byproducts Rule) have heightened
concern, particularly among rural communities, that EPA has not used the tools
Congress provided to help small systems comply with SDWA regulations.
Affordability Criteria Review. Prompted by debate over the revised arsenic
standard and its potential cost to small communities, the conference report for EPA’s
FY2002 appropriations (H.Rept. 107-272) directed EPA to review its affordability
criteria and how small system variance programs should be implemented for the
arsenic rule. EPA began the review and sought the advice of the EPA’s National
Drinking Water Advisory Council (NDWAC) and Science Advisory Board (SAB).
After considering recommendations from its affordability work group, the
NDWAC reported to EPA in 2003. The council acknowledged the statutory basis for

small system variances and recommended changes, but cautioned that “significant
practical, logistical, and ethical issues mitigate against the use of variances.”27 The
National Rural Water Association, a member of the NDWAC work group, dissented
and issued a separate report urging EPA to adopt a safe and affordable variance
approach that would make variances available to small communities, as authorized
by Congress. The Science Advisory Board concluded that EPA’s basic approach was
justified on the basis of equity, efficiency and administrative practicality, but
recommended ways to improve the criteria. The SAB suggested that EPA consider
lowering its affordability threshold, noting that “the national affordability threshold
has never been exceeded, but some small water systems appear to have genuinely
struggled with costs, suggesting that the 2.5% rule is too high.”28 The SAB also
encouraged EPA to develop clear guidelines about when variances should be granted,
and recommended that EPA consider measures other than median income to better
capture impacts on disadvantaged households.
In March 2006, EPA proposed three options for revising its affordability criteria
for determining whether a compliance technology is unaffordable for small systems
(71 Federal Register 10671). EPA currently assumes that treatment technology costs
are affordable to the average household if they do not cause median annual water
bills to exceed about $1,000 (this threshold is calculated by taking 2.5% of median
household income among small systems). Based on this approach, EPA has
determined that affordable technologies are available for all standards. The three
proposed options are well below that level: 0.25%, 0.50%, and 0.75%. EPA also
requested comment on whether or not the agency should evaluate affordability
strictly on a national level, or use a two-step process that would include evaluations
of affordability first at the national level and then at the county level. A county level
analysis would be performed only when a standard was found to be affordable at the
national level. The revised criteria are further intended to address the issue of how
to ensure that a variance technology would be protective of public health — an issue
that has historically hampered the use of variances.
EPA is evaluating comments on its proposed revisions, and has noted its
intention to apply the revised criteria only to the recent Stage 2 DBP Rule and future
rules. States could use the criteria to grant small-system variances, on a case-by-case
basis, when systems cannot afford to comply with a standard. If these variances
become available, it is not clear how often they might be used. A key issue is that
variances allow systems to provide lower-quality water in lower-income
communities, and this could raise issues for states, communities, and consumers.
Small System Legislation. During the 110th Congress, various bills were
introduced to help small water systems comply with the arsenic standard and other

27 U.S. Environmental Protection Agency, Small Drinking Water Systems Variances:
Revision of Existing National-Level Affordability Methodology and Methodology to Identify
Variance Technologies that Are Protective of Public Health, (71 Fed. Reg. 10671), March

2, 2006, p. 10657.

28 U.S. Environmental Protection Agency, Science Advisory Board, Affordability Criteria
for Small Drinking Water Systems: An EPA Science Advisory Board Report, 2002, p. 4. The
SAB report is available at [].

drinking water regulations. Legislation has focused on promoting small system
compliance through funding assistance and compliance flexibility. The Senate
Environment and Public Works Committee reported S. 1933, the Small Community
Drinking Water Funding Act (S.Rept. 110-475) which would have directed EPA to
establish a small public water system grant program. As mentioned, the committee
also reported S. 3617 (S.Rept. 110-509) to authorize increased funding for the
DWSRF program, and to create a grant program at EPA for small or economically
disadvantaged communities for critical drinking water and water quality projects.
Additionally, S. 199 (S.Rept. 110-476) would have increased the authorization of
appropriations for grants to Alaska to build water and wastewater systems in rural
and Native villages. Among other small-system focused bills, H.R. 2141 would have
required primacy states to grant exemptions to eligible small systems for rules
covering naturally occurring contaminants, including arsenic, radon, radium,
uranium, and several disinfection byproducts. S. 2509, the Small System Safe
Drinking Water Act of 2007, proposed to provide more compliance assistance to
small communities and prevent the enforcement of certain drinking water regulations
unless sufficient funding was available or a variance technology had been identified.
S. 2509 also would have required EPA to establish a research program to explore
new compliance technologies, and would have established new requirements for
EPA’s affordability criteria. S. 1429 (S.Rept. 110-242) would have reauthorized
SDWA funding for small system technical assistance.
Underground Injection Control and Carbon Sequestration
Most public water systems rely on groundwater as a source of drinking water,
and the 1974 Safe Drinking Water Act authorized EPA to regulate the underground
injection of fluids (including solids, liquids, and gases) to protect underground
sources of drinking water.29 SDWA §1421 directed EPA to promulgate regulations
for state underground injection control (UIC) programs, and mandated that the
regulations contain minimum requirements for programs to prevent underground
injection that endangers drinking water sources.30 Section 1422 authorized EPA to
delegate primary enforcement authority (primacy) for UIC programs to the states,
provided that state programs prohibit any underground injection that is not authorized
by a state permit.31 Thirty-three states have assumed primacy for the program, EPA

29 Underground injection control provisions are contained in SDWA §1421 - §1426; 42
U.S.C. 300h - 300h-5.
30 § 1421(d)(2) states that
underground injection endangers drinking water sources if such injection may
result in the presence in underground water which supplies or can reasonably be
expected to supply any public water system of any contaminant, and if the
presence of such contaminant may result in such system’s not complying with
any national primary drinking water regulation or may otherwise adversely affect
the health of persons.
31 P.L. 93-523, SDWA §1421 (42 U.S.C. 300h).

has lead implementation and enforcement authority in 10 states, and authority is
shared in the remainder of the states.32
The 1974 law specified that the UIC regulations could not interfere with the
underground injection of brine from oil and gas production or recovery of oil unless
underground sources of drinking water would be affected.33 In the Energy Policy Act
of 2005, the 109th Congress amended SDWA to specify further that the definition of
“underground injection” excludes the injection of fluids or propping agents (other
than diesel fuels) used in hydraulic fracturing operations related to oil, gas, or
geothermal production activities.34
The UIC program regulations specify siting, construction, operation, closure,
financial responsibility, and other requirements for owners and operators of injection
wells. EPA has established five classes of injection wells based on similarity in the
fluids injected and activities, as well as common construction, injection depth,
design, and operating techniques.
Carbon Sequestration and Storage. In the 110th Congress, underground
injection received attention primarily regarding its role as a potential means for
sequestering carbon dioxide (CO2) emissions in geologic formations to control
greenhouse gas emissions. Geologic sequestration (GS) is the process of injecting
CO2 captured from a large stationary source (such as a coal-fired power plant)
through a well deep into the earth for long-term storage. Research indicates that
numerous geologic formations exist in the United States and worldwide that have the
capacity to store large volumes of CO2. Because coal is responsible for nearly half
of the electricity generated worldwide and its use is increasing, carbon capture and
storage (CCS) is attracting a growing number of proponents who believe that, with
proper site selection and management, geologic sequestration could play an important
role in controlling CO2 emissions.
Although considerable interest has emerged for the rapid, commercial-scale
development of carbon sequestration projects, questions exist regarding the long-term
safety and effectiveness of sequestration of large volumes of CO2. Issues include how
sequestration activities might affect underground sources of drinking water, what
local health and environmental risks could arise from slow leakage or sudden releases
of stored gas, and who would have long-term responsibility for water contamination
or other damages that might result from sequestration activities.

32 To receive primacy, a state, territory, or Indian tribe must demonstrate to EPA that its UIC
program is at least as stringent as the federal standards; the state, territory, or tribal UIC
requirements may be more stringent than the federal requirements. For Class II (oil and gas)
wells, states must demonstrate that their programs are effective in preventing pollution of
underground sources of drinking water (USDWs).
33 SDWA §1421(d) specifies that “underground injection” does not include the underground
injection of natural gas for storage purposes. In legislative history, Congress explained that
the natural gas exclusion applies only to “natural gas as it is commonly defined” and “not
to other injections of matter in a gaseous state.” U.S. House of Representatives, H.Rept. 96-

1348, 1980, USCCAN, p. 6080.

34 P.L. 109-58, H.R. 6, Section 322,amended SDWA section 1421(d).

A key public health and environment issue concerns the potential for stored
CO2 to contaminate underground water supplies or otherwise adversely affect human
health and the environment. According to a 2005 report by the United Nations
Intergovernmental Panel on Climate Change (IPCC), human and environmental risks
potentially could result from leaking injection wells, abandoned wells, or leakage
across faults in rock formations and ineffective confining layers. The IPCC report
noted that,
Avoiding or mitigating these impacts will require careful site selection, effective
regulatory oversight, an appropriate monitoring program that provides early
warning that the storage site is not functioning as anticipated and implementation
of remediation methods to stop or control CO2 releases. Methods to accomplish35
these are being developed and tested.
Noting that knowledge gaps exist and that more demonstration projects are
needed, the IPCC report concluded that, although “more work is needed to improve
technologies and decrease uncertainty, there appear to be no insurmountable
technical barriers to an increased uptake of geological storage as an effective
mitigation option.”36 However, uncertainties and research gaps involving the safety
and effectiveness of long-term carbon sequestration, the potential health and
environmental impacts, regulatory requirements, and long-term liability all pose
hurdles to the rapid deployment of this technology.37
Congress has acted on several bills that would facilitate and/or regulate the use
of underground injection wells for the purpose of carbon sequestration. Enacted in
December 2007, the Energy Independence and Security Act of 2007 (EISA, P.L. 110-
140) expands the Department of Energy (DOE) carbon sequestration research and
development program. EISA Section 702 requires DOE to conduct at least seven
large-volume sequestration tests, in addition to conducting research that promotes the
development of sequestration technologies. Section 706 specifies that the injection
and sequestration of CO2 under EISA will be subject to the requirements of the Safe
Drinking Water Act, including the act’s UIC provisions.
In addition to EISA, several bills in the 110th Congress that contained geologic
sequestration provisions would have required sequestration activities to be done in
conformance with SDWA requirements. Both S. 3036 and H.R. 6186 proposed to

35 United Nations Intergovernmental Panel on Climate Change, 2005, IPCC Special Report
on Carbon Dioxide Capture and Storage, p. 197.
36 Ibid, p. 198.
37 Commercial-scale deployment of CCS faces a range of technical, legal, economic,
regulatory, and public policy issues. Capturing carbon and preparing it for transport and
storage are generally considered the most economically and technologically challenging
aspects of CCS, and no commercial technology to capture these emissions is currently
available for large-scale coal-fired power plants. Moreover, carbon capture technologies
would markedly increase the cost of electricity generation. Consequently, few companies
may be inclined or able to install such technology unless they are required to do so, either
by regulation or by a carbon price. For further discussion see CRS Report RL34621,
Capturing CO2 from Coal-Fired Power Plants: Challenges for a Comprehensive Strategy,
by Peter Folger, Larry Parker, and Deborah D. Stein.

amend SDWA to require EPA to promulgate regulations to manage and facilitate
carbon sequestration.38
In July 2008, EPA proposed regulations to create a nationally consistent
framework for managing the underground injection of CO2 for geologic sequestration
purposes, thus taking a step toward providing certainty to industry and the public
about requirements that would apply to this activity.39 The rule proposes to create a
new class of injection wells (Class VI) for geologic sequestration, and establish
national requirements that would apply to these injection wells. The proposed rule
builds on the existing UIC program, including requirements for well owners and
operators to ensure that wells are appropriately located, constructed, tested,
monitored, and ultimately closed with proper funding.
EPA’s stated regulatory goal is to ensure that permitting regulations are in place
to ensure that GS can occur in a safe and effective manner in order to enable
commercial-scale CCS projects to move forward. After taking public comment on
the rule through December 2008, the agency expects to promulgate a final GS rule
under SDWA in December 2010 or 2011. EPA is coordinating with DOE on carbon
sequestration research, development, and demonstration activities.

38 For a detailed discussion of geologic sequestration and related legislation, see CRS Report
RL33801, Carbon Capture and Sequestration (CCS), and CRS Report RL34218,
Underground Carbon Dioxide Storage: Frequently Asked Questions, both by Peter Folger.
39 U.S. Environmental Protection Agency, Federal Requirements Under the Underground
Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic Sequestration (GS)
Wells, Proposed Rule, 73 Fed. Reg. 43491-43541, July 25, 2008.

Congressional Hearings and Reports,
and Documents
U.S. Congress. Senate. Committee on Environment and Public Works. Water
Infrastructure Financing Act. Report to accompany S. 1400. 109th Cong., 1st
sess. December 8, 2005. 52 p. (S.Rept. 109-186).
U.S. Congress. House. Committee on Government Reform. Public Confidence,
Down the Drain: the Federal Role in Ensuring Safe Drinking Water in the
District of Columbia. Hearing, March 5, 2004, 108th Cong., 2nd sess. 268 p.
(H.Rept. 108-161).
U.S. Congress. House. Committee on Government Reform. Subcommittee on Energy
Policy, Natural Resources and Regulatory Affairs. EPA Water Enforcement:
Are We on the Right Track? Hearing, October 14, 2003, 108th Cong., 1st sess.

201p. (H.Rept. 108-157).

U.S. Congress. House. Committee on Transportation and Infrastructure.
Subcommittee on Water Resources and Environment. Aging Water Supply
Infrastructure. Hearing, April 28, 2004, 108th Cong., 2nd sess. 78 p. (H.Rept.


Additional Reading
U.S. Environmental Protection Agency. Drinking Water State Revolving Fund
Program: Increasing Impact, 2006 Annual Report. Office of Water. Report No.
EPA 816-R-07-002, June 2007. 44 p. [
U.S. Environmental Protection Agency. Providing Safe Drinking Water in America:
2003 National Public Water Systems Compliance Report. Office of
Enforcement and Compliance Assurance. Report No. EPA 305-R-05-002.
September 2005. 19 p. plus appendices. [
resources/reports/accomplis hments/sdwa/sdwacom2003.pdf]
U.S. Environmental Protection Agency. The Clean Water and Drinking Water
Infrastructure Gap Analysis Report. Office of Water. Report No. EPA 816-R-

02-020. September 2002. 50 p.

National Research Council. Health Implications of Perchlorate Ingestion. Board on
Environmental Studies and Toxicology. National Academies Press. January

2005. 177 p.