PFAS and Drinking Water: Selected EPA and Congressional Actions

July 2, 2019 – July 18, 2022 R45793

PFAS and Drinking Water: Selected EPA and
July 18, 2022
Congressional Actions
Elena H. Humphreys
Per- and polyfluoroalkyl substances (PFAS) are fluorinated chemicals that have been used in an
Analyst in Environmental
array of commercial, industrial, and U.S. military applications for decades. Some of the more
Policy
common applications include nonstick coatings, food wrappers, waterproof materials, and fire

suppressants. Detections of some PFAS in drinking water supplies and uncertainty about
potential health effects associated with exposure to particular PFAS above certain concentrations

have increased calls for the U.S. Environmental Protection Agency (EPA) to control these
substances in public water supplies. For those few PFAS for which scientific information is available, animal studies suggest
that exposure to particular substances above certain levels may be linked to various adverse health effects, including
developmental effects; changes in liver, immune, and thyroid function; and increased risk of some cancers. In 2009, EPA
listed certain PFAS for formal evaluation under the Safe Drinking Water Act (SDWA) to determine whether regulations may
be warranted. In 2016, EPA issued nonenforceable lifetime health advisory levels for two PFAS—perfluorooctanoic acid
(PFOA) and perfluorooctane sulfonate (PFOS) in drinking water at 70 parts per trillion (ppt), separately or combined. In
March 2021, EPA made a determination to issue drinking water regulations for PFOA and PFOS. In 2022, EPA issued
revised interim lifetime health advisory levels for PFOA (i.e., 0.004 ppt) and PFOS (i.e., 0.02 ppt), as well as finalized
lifetime health advisory levels for hexafluoropropylene oxide dimer acid and its ammonium salt (together referred to as
“GenX chemicals”) at 10 ppt and perfluorobutane sulfonic acid and its related compound potassium perfluorobutane
sulfonate (together referred to as “PFBS”) at 2,000 ppt. Among other actions, EPA issued a PFAS Action Plan, formed the
EPA Council on PFAS to better understand the potential risks of PFAS, and issued a revised plan, a “PFAS Strategic
Roadmap,” which further identifies EPA planned actions using several statutory authorities.
EPA’s determination to issue drinking water regulations for PFOA and PFOS has increased congressional attention to the
SDWA regulation development process. The act requires a risk- and science-based process for evaluating and regulating
contaminants in drinking water. The evaluation process includes identifying contaminants of potential concern, assessing
health risks, collecting occurrence data (and developing reliable analytical methods necessary to do so), and making
determinations as to whether a national drinking water regulation is warranted for a contaminant. Under SDWA, EPA is
required to propose a regulation within 24 months of finalizing a regulatory determination (e.g., by March 2023 for PFOA
and PFOS), and finalize the regulation within 18 months of publishing the proposal. The PFAS Strategic Roadmap states that
the agency plans to propose a PFOA and PFOS drinking water regulation by fall 2022, and finalize by fall 2023.
PFAS include thousands of diverse chemicals, and setting drinking water standards for individual or groups of PFAS raises
technical and scientific challenges. For example, SDWA requires EPA to make determinations and set standards using the
best available peer-reviewed science and occurrence data. However, data on the potential health effects and occurrence are
available for few of these substances. Contamination of drinking water by various PFAS can pose challenges for states and
communities, and some have called for EPA to establish enforceable standards for these substances. State drinking water
regulators have noted that many states may face significant obstacles in setting their own standards.
SDWA also authorizes EPA to take actions it deems necessary to abate an imminent and substantial endangerment to public
health from a contaminant present in or likely to enter a public water system or an underground source of drinking water.
Actions may include issuing orders requiring persons who caused or contributed to the endangerment to provide alternative
water supplies or to treat contamination. Since 2002, EPA has used this authority to require responses to PFOA and/or PFOS
contamination of water supplies associated with four sites, including three Department of Defense (DOD) sites.
In recent Congresses, numerous bills would address PFAS through various authorities and agencies. The 117th Congress has
taken up legislation to address PFAS in a range of contexts. On July 21, 2021, the House passed H.R. 2467, the PFAS Action
Act of 2021. As passed, H.R. 2467 would direct EPA to promulgate PFAS drinking water regulations on an accelerated
timeline. Additionally, the Infrastructure Investment and Jobs Act (IIJA; P.L. 117-58), enacted in November 2021, provides
emergency appropriations for a grant program for public water systems to address PFAS and other emerging contaminants
that was authorized by the National Defense Authorization Act (NDAA) for FY2020 (P.L. 116-92). The NDAA for FY2020
included multiple PFAS provisions regarding primarily the DOD, but several involve EPA and other federal agencies.
Among the EPA provisions, Title LXXIII, Subtitle A, directs EPA to require public water systems to conduct additional
monitoring for PFAS. Title LXXIII, Subtitle A, also authorizes the aforementioned grant program for public water systems to
address PFAS and other emerging contaminants.
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PFAS and Drinking Water: Selected EPA and Congressional Actions

Introduction
The detection of certain per- and polyfluoroalkyl substances (PFAS) in some public water
supplies has generated public concern and increased congressional attention to the U.S.
Environmental Protection Agency’s (EPA’s) efforts to address these substances. Over the past
decade, EPA has been evaluating several PFAS under the Safe Drinking Water Act (SDWA) to
determine whether national drinking water regulations may be warranted. Using SDWA
authorities, EPA issued nonenforceable health advisories for two PFAS—perfluorooctanoic acid
(PFOA) and perfluorooctane sulfonate (PFOS)—in drinking water in 2016.1 In March 2021, EPA
made a determination to issue drinking water regulations for PFOA and PFOS.
PFAS are a large, diverse group of fluorinated compounds, some of which have been used for
decades in a wide array of commercial, industrial, and U.S. military applications.2 Since the
1940s, more than 1,200 PFAS compounds have been used in commerce, and about 600 are still in
use today.3 The chemical characteristics of PFAS have led to the widespread use of these
substances for beneficial purposes (such as firefighting) and in the processing and manufacture of
many commercial products, such as nonstick cookware, food wrapper coatings, stain-resistant
carpets, waterproof clothing, and food containers.
The two PFAS most frequently detected in water supplies are PFOA and PFOS. Since 2002, U.S.
manufacturers have phased out the production and most uses of PFOS.4 In coordination with
EPA, manufacturers completed the phase-out of PFOA production by 2015.5 EPA reports that
food and consumer products represent a large portion of exposure to PFOA and PFOS, while
drinking water can be an additional source in the relatively small percentage of communities with
contaminated water supplies.6

1 In May 2016, EPA established Lifetime Health Advisory levels for PFOA and PFOS at 70 parts per trillion (ppt),
separately or combined. These nonenforceable levels are expected to protect the most sensitive subpopulations (e.g.,
nursing infants), with a margin of protection, over a lifetime of exposure. Health advisories are nonregulatory and are
intended to help states, water suppliers, and others address contaminants for which federal (or state) drinking water
standards have not been established.
2 These chemical compounds consist of a chain of carbon atoms generally attached to varying numbers of fluorine
atoms. Fully fluorinated chemicals are referred to as perfluoroalkyl substances, while partially fluorinated chemicals
are referred to as polyfluoroalkyl substances. Among potentially thousands of PFAS, differences in the length of the
carbon chain, number of fluorine atoms, and other structural parts of the PFAS suggest that there may also be
differences in terms of their properties, uses, interactions with other chemicals in the environment, and health effects in
humans. More information regarding the chemical and physical properties of certain PFAS are available in Chapter 4 of
Agency of Toxic Substances and Disease Registry, Toxicological Profile for Perfluoroalkyls, May 2021,
https://www.atsdr.cdc.gov/ToxProfiles/tp200.pdf.
3 EPA, EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan, February 2019, p. 12, https://www.epa.gov/
pfas/epas-pfas-action-plan.
4 EPA, “Perfluoroalkyl Sulfonates; Significant New Use Rule,” 67 Federal Register 11007, March 11, 2002.
5 EPA initiated the 2010/2015 PFOA stewardship program in January 2006 (EPA-HQ-OPPT-2006-0621). EPA invited
the eight companies manufacturing PFOA and associated chemicals to reduce their PFOA product content and
emission by 95% by 2010 and eliminate their PFOA emissions and product content by 2015. EPA reported that all
companies met the stewardship program’s goals.
6 EPA, Health Effects Support Document for Perfluorooctane Sulfonate (PFOS), May 2016; EPA, Health Effects
Support Document for Perfluorooctanoic Acid (PFOA), May 2016; and EPA, PFOA & PFOS Drinking Water Health
Advisories, Fact Sheet, November 2016, p. 1. EPA required roughly 5,000 water systems (that serve approximately
82% of U.S. population) to monitor for six PFAS—including PFOA and PFOS—between January 2013 and December
2015. According to EPA, 63 water systems (1.3%) serving an estimated 5.5 million individuals detected PFOA and/or
PFOS at levels above EPA’s health advisory level of 70 ppt (separately or combined). Monitoring results for individual
water systems are available at https://www.epa.gov/dwucmr/third-unregulated-contaminant-monitoring-rule.
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PFAS and Drinking Water: Selected EPA and Congressional Actions

Among the thousands of different PFAS, few have sufficient health effects studies for
determining a threshold below which adverse effects are not expected to occur. Most studies of
potential health effects of PFAS have focused on PFOA and PFOS because of their predominant
historical use. For those PFAS for which scientific information is available, animal studies
suggest that exposure to particular substances above certain levels may be linked to various health
effects, including developmental effects; changes in liver, immune, and thyroid function; and
increased risk of some cancers.7 A discussion of these studies and their results is beyond the scope
of this report.
In 2016, EPA reported that public water systems in 29 states had detected at least one PFAS in
their water supplies.8 In total, 63 public water systems serving approximately 5.5 million people
reported detections of PFOA and PFOS (separately or combined) above EPA’s 2016 health
advisory level of 70 parts per trillion (ppt).9 EPA has reported that PFAS contamination of
drinking water “is typically localized and associated with a specific facility.”10 According to the
Agency for Toxic Substances and Disease Registry, PFAS may have been released to surface or
ground water from manufacturing sites, industrial use, use and disposal of PFAS-containing
consumer products (e.g., unlined landfills), fire/crash training areas, wastewater treatment
facilities, and the spreading of contaminated biosolids.11 A discussion of PFAS use, including at
U.S. military installations, and PFAS disposal is not included in this report.
Uncertainty about potential health effects that may be associated with exposure to specific PFAS
above particular concentrations—combined with the absence of a federal health-based drinking
water standard—has posed challenges and created uncertainty for states, water suppliers and their
customers, homeowners using private wells, and others regarding treatment or other potential
responses.12 State drinking water regulators and others have called for greater federal leadership
to address these substances through several federal laws and, specifically, have urged EPA to set
federal drinking water standards for one or more PFAS under SDWA.13 Representatives of public
water systems have supported EPA’s commitment to follow the statutory process for regulating
contaminants in drinking water, which prioritizes regulating those that occur at levels and
frequency of public health concern.14

7 EPA, Health Effects Support Document for Perfluorooctane Sulfonate (PFOS), May 2016; EPA, Health Effects
Support Document for Perfluorooctanoic Acid (PFOA), May 2016.
8 Monitoring results for individual water systems are available at EPA, “Third Unregulated Contaminant Monitoring
Rule,” https://www.epa.gov/dwucmr/third-unregulated-contaminant-monitoring-rule.
9 Email communication with EPA, May 30, 2019. This health advisory level is expected to be protective of sensitive
subpopulations, with a margin of protection, assuming daily ingestion at this concentration over a lifetime (70 years).
10 EPA, PFOA & PFOS Drinking Water Health Advisories, Fact Sheet, November 2016, p. 1.
11 Agency for Toxic Substances and Disease Registry, Toxicological Profile for Perfluoroalkyls, May 2021,
https://www.atsdr.cdc.gov/ToxProfiles/tp200.pdf.
12 See, for example, testimony of Tracy Mehan for the American Water Works Association before the Senate
Committee on Environment and Public Works, hearing on Examining Legislation to Address the Risks Associated with
Per- and Polyfluoroalkyl Substances (PFAS), May 22, 2019, https://www.epw.senate.gov/public/index.cfm/2019/5/
examining-legislation-to-address-the-risks-associated-with-per-and-polyfluoroalkyl-substances-pfas.
13 See, for example, Association of State Drinking Water Administrators, comment letter to EPA on PFAS National
Leadership Summit and Engagement, July 20, 2018, https://www.asdwa.org/pfas/.
14 See, for example, testimony of Tracy Mehan for the American Water Works Association before the Senate
Committee on Environment and Public Works, hearing on Examining Legislation to Address the Risks Associated with
Per- and Polyfluoroalkyl Substances (PFAS), May 22, 2019, https://www.epw.senate.gov/public/index.cfm/2019/5/
examining-legislation-to-address-the-risks-associated-with-per-and-polyfluoroalkyl-substances-pfas.
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link to page 20 PFAS and Drinking Water: Selected EPA and Congressional Actions

SDWA provides EPA with several authorities to address emerging contaminants in public water
supplies and drinking water sources. These include the authority to (1) issue health advisories, (2)
regulate contaminants in water provided by public water systems, and (3) issue enforcement
orders in certain circumstances.15 For more than a decade, EPA has been using SDWA authorities
to evaluate several PFAS—particularly PFOA and PFOS—to determine whether national
drinking water regulations may be warranted.16 To date, EPA has not promulgated drinking water
regulations for any PFAS but has taken a number of related actions.
In February 2019, EPA issued a PFAS Action Plan, which identifies and discusses the agency’s
current and proposed efforts to address PFAS through several statutory authorities, including
SDWA.17 These actions range from potential regulatory actions to public outreach on PFAS.
Many of these actions support EPA’s evaluation of various PFAS for regulation under SDWA.
These include research and development of analytical methods needed to accurately measure
substances in drinking water, development of additional toxicity information to increase
understanding of potential health risks associated with exposures to different PFAS, and research
on drinking water treatment effectiveness and costs for individual or groups of PFAS. EPA also
plans to generate occurrence data for more PFAS to determine their frequencies and
concentrations in public water supplies. Further, EPA is working with federal, state, and tribal
partners to develop risk communication materials on PFAS and plans to develop an interactive
map on potential PFAS sources and occurrence. Table A-1 includes EPA’s selected actions and
associated timelines relevant to addressing PFAS in drinking water.
In April 2021, EPA announced the formation of the EPA Council on PFAS to build on the
agency’s ongoing work, as outlined in the PFAS Action Plan, to better understand the potential
risks of PFAS.18 As outlined in the announcement memorandum, the council is tasked with
coordinating EPA activities using existing authorities, expertise, and partnerships to reduce the
potential risk of PFAS to public health. The council is to develop a multiyear strategy to address
PFAS; coordinate within EPA to address regionally specific PFAS challenges or to address PFAS
in the range of environmental media; support the use of EPA financial assistance programs for
PFAS treatment and “cleanup”; and engage with federal, state, and tribal partners to coordinate
efforts, communication strategies, and identify solutions.
In October 2021, EPA issued a “PFAS Strategic Roadmap.”19 The PFAS Strategic Roadmap
builds on the 2019 PFAS Action Plan. Among the SWDA-related actions, the roadmap states that

15 SDWA Section 1412(b)(1)(F)—Title 42, Section 300g-1(b)(1)(F) of the United States Code—authorizes EPA to
establish health advisories for emerging drinking water contaminants. SDWA Section 1412 (42 U.S.C. §300g-1)
authorizes EPA to regulate contaminants in drinking water. SDWA Section 1431 (42 U.S.C. §300i) authorizes EPA to
issue emergency orders to address drinking water contamination, under certain circumstances. SDWA provides
additional tools to address emerging contaminants, such as source water assessment and protection programs.
16 Using Toxic Substance Control Act (TSCA) authorities, EPA has issued several significant new use rules that require
manufacturers (including importers) and processors of certain PFAS to notify EPA at least 90 days prior to resuming
use of these substances. EPA then would review the potential health and environmental effects of the activity and make
a determination whether to authorize the new use.
17 EPA, EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan, February 2019, https://www.epa.gov/pfas/
epas-pfas-action-plan. The plan also notes the agency’s actions under the authority of other environmental statutes,
including the Clean Air Act; the Clean Water Act; the Comprehensive Environmental Response, Compensation, and
Liability Act; the Resource Conservation and Recovery Act; and TSCA.
18 Letter from Michael Regan, EPA Administrator, April 27, 2021, https://www.epa.gov/sites/default/files/2021-04/
documents/per-and_polyfluoroalkyl_substances.memo_.signed.pdf.
19 EPA, PFAS Strategic Roadmap: EPA’s Commitments to Action 2021-2024, October 18, 2021, https://www.epa.gov/
system/files/documents/2021-10/pfas-roadmap_final-508.pdf.
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EPA will issue a PFOS and PFOA drinking water regulation under an accelerated time frame;
require water systems to monitor for all PFAS for which a validated analytical method is
available, as required by the National Defense Authorization Act (NDAA) for Fiscal Year 2020
(P.L. 116-92); publish health advisories for additional PFAS; and publish updates to analytical
methods to detect additional PFAS in drinking water.20 Table B-1 includes EPA’s selected actions
and associated timelines relevant to addressing PFAS in drinking water.
The challenges of regulating individual substances or categories of PFAS in drinking water are
multifaceted and may raise several policy and scientific questions. Technical issues involve
availability of data, detection methods, and treatment techniques for related but diverse
contaminants. Scientific questions exist about health effects attributed to many individual PFAS
and whether health effects can be generalized from one or a category of PFAS to others. Policy
and regulatory considerations may involve setting priorities among numerous unregulated
contaminants, the value of establishing uniform national drinking water standards, and the ability
to demonstrate the relative risk-reduction benefits compared to compliance costs to communities
associated with regulating individual or multiple PFAS.21 The absence of a federal health-based
standard can pose challenges for states and communities with PFAS contamination. State
drinking water regulators have noted that many states may face significant obstacles in setting
their own standards.
The 117th Congress has taken up legislation to address PFAS in a range of contexts. On July 21,
2021, the House passed H.R. 2467, the PFAS Action Act of 2021. As passed, H.R. 2467 would
direct EPA to promulgate PFAS drinking water regulations on an accelerated timeline.
Additionally, some bills would establish grant programs to assist communities in addressing
PFAS. Enacted in November 2021, the Infrastructure Investment and Jobs Act (IIJA; P.L. 117-58)
provides emergency appropriations for a grant program for public water systems to address PFAS
and other emerging contaminants that was authorized by the 2020 NDAA.
The 116th Congress held hearings on PFAS issues and passed legislation to address PFAS use,
disposal, contamination, and regulation through several departments and agencies. The National
Defense Authorization Act (NDAA) for Fiscal Year 2020 (P.L. 116-92) included several PFAS
provisions involving the Department of Defense (DOD) and other federal agencies.22 Of the EPA
provisions related to drinking water, Title LXXIII, Subtitle A, directs EPA to require public water
system operators to conduct additional monitoring for PFAS and authorizes a grant program for
public water systems to address PFAS and other emerging contaminants. The NDAA for FY2021
(P.L. 116-283) included a number of DOD PFAS provisions.
This report provides an overview of EPA’s actions to address PFAS under SDWA authorities,
with particular focus on the statutory process for evaluating and regulating two PFAS—PFOA
and PFOS—in drinking water. This report does not address the status of scientific research on
health effects that may be associated with exposure to one or more PFAS, nor does it discuss

20 EPA, PFAS Strategic Roadmap: EPA’s Commitments to Action 2021-2024, October 18, 2021, https://www.epa.gov/
system/files/documents/2021-10/pfas-roadmap_final-508.pdf.
21 When developing regulations, SDWA requires EPA to (1) use the best available peer-reviewed science and
supporting studies and data and (2) make publicly available a risk assessment document that discusses estimated risks,
uncertainties, and studies used in the assessment. When proposing drinking water regulations, EPA must publish a
“health risk reduction and cost analysis.” For each drinking water standard and each alternative standard being
considered for a contaminant, EPA must publish and take comment on quantifiable and nonquantifiable health-risk-
reduction benefits and costs and also conduct other specified analyses (SDWA §1412(b); 42 U.S.C. §300g-1(b)).
22 See CRS Report R45986, Federal Role in Responding to Potential Risks of Per- and Polyfluoroalkyl Substances
(PFAS), coordinated by David M. Bearden.
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federal actions regarding other environmental statutes, such as the Toxic Substances Control Act
(TSCA) and the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA).23
Addressing PFAS Using SDWA Authorities
SDWA provides EPA with several authorities to address contaminants in drinking water supplies
and sources. The act authorizes EPA to promulgate regulations that include enforceable standards
and monitoring requirements for contaminants in water provided by public water systems.24
Under this authority, EPA finalized determinations to regulate two PFAS in drinking water in
March 2021. For contaminants that are not regulated under the act, SDWA authorizes EPA to
issue contaminant-specific health advisories that include technical guidance and identify
concentrations that are expected to be protective of sensitive populations.25 In addition, SDWA
authorizes EPA in certain circumstances to take actions to abate an “imminent and substantial
endangerment” to public health from “a contaminant that is present in or is likely to enter a public
water system or an underground source of drinking water.”26 This emergency authority is
available if the appropriate state and local authorities have not acted to address substantial threats
to public health.
Evaluating Emerging Contaminants for Regulation
SDWA specifies a multistep process for evaluating contaminants to determine whether a national
primary drinking water regulation is warranted.27 The evaluation process includes identifying
contaminants of potential concern, assessing health risks, collecting occurrence data (and
developing reliable analytical methods necessary to do so), and making determinations as to
whether or not regulatory action is needed for a contaminant.
To make a positive determination that a national drinking water regulation is warranted for a
contaminant, EPA must find that
 a contaminant may have an adverse health effect;
 it is known to occur or there is a substantial likelihood that it will occur in public
water systems with a frequency and at levels of public health concern; and
 in the sole judgment of the EPA Administrator, regulation of the contaminant
presents a meaningful opportunity for health risk reduction for persons served by
water systems.28

23 For more information on the regulation of chemicals in commerce under TSCA, see CRS Report RL31905, The
Toxic Substances Control Act (TSCA): A Summary of the Act and Its Major Requirements, by Jerry H. Yen.
24 SDWA §1412; 42 U.S.C. §300g-1. SDWA does not cover residential wells.
25 SDWA §1412(b)(1)(F); 42 U.S.C. §300g-1(b)(1)(F).
26 SDWA §1431; 42 U.S.C. §300i.
27 SDWA §1412; 42 U.S.C. §300g-1. The 104th Congress established the current regulatory structure with the Safe
Drinking Water Amendments of 1996 (P.L. 104-182).
28 SDWA §1412(b)(1)(A); 42 U.S.C. §300g-1(b)(1)(A). The Administrator’s determination not to regulate a
contaminant is subject to judicial review (SDWA §1412(b)(1)(B)(ii)(IV); 42 U.S.C. §300g-1(b)(1)(B)(ii)(IV)). For a
detailed discussion of the federal process for regulating contaminants in drinking water, see CRS Report R46652,
Regulating Contaminants Under the Safe Drinking Water Act (SDWA), by Elena H. Humphreys.
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PFAS and Drinking Water: Selected EPA and Congressional Actions

Identifying Contaminants That May Warrant Regulation
SDWA Section 1412(b) requires EPA to publish, every five years, a list of contaminants that are
known or anticipated to occur in public water systems and may require regulation under the act.29
Before publishing a final contaminant candidate list (CCL), EPA is required to provide an
opportunity for public comment and consult with the scientific community, including the Science
Advisory Board.30
In 2009, EPA placed PFOA and PFOS on the third such list (CCL 3) for evaluation.31 In preparing
the CCL 3, EPA considered over 7,500 chemical and microbial contaminants and screened these
contaminants based on their potential to occur in public water systems and potential health
effects. EPA selected 116 of the contaminants on the proposed CCL based on more detailed
evaluation of occurrence, health effects, expert judgement, and public input.32
In 2016, EPA published the fourth list, CCL 4, which carried over many CCL 3 contaminants,
including PFOA and PFOS. EPA carried forward these contaminants to continue evaluating health
effects, gathering national occurrence data, and developing analytical methods.33
Monitoring for Emerging Contaminants in Public Water Systems
To generate data on the nationwide occurrence of emerging contaminants in public water
supplies, EPA is required to administer a monitoring program for unregulated contaminants.
SDWA directs EPA to promulgate, every five years, an unregulated contaminant monitoring rule
(UCMR) that requires public water systems to test for no more than 30 contaminants.34 Only a
representative sample of systems serving 10,000 or fewer people is required to conduct
monitoring.35 EPA uses data collected through UCMRs to estimate whether the occurrence of the
contaminant in public water supplies is local, regional, or national in scope.
UCMRs set a minimum reporting level (MRL) for each contaminant. MRLs are not health based;
rather, they establish concentrations for reporting and data collection purposes. EPA makes the
UCMR monitoring results available to the public and reports the number of detections above the
MRL and also detections above EPA’s health-based reference levels (discussed below), where

29 SDWA §1412(b)(1)(B)(i); 42 U.S.C. §300g-1(b)(1)(B)(i). Nothing in statute precludes EPA from modifying the list
outside the five-year timeline. See EPA, “Announcement of the Drinking Water Contaminant Candidate List,” 63
Federal Register 10274, March 2, 1998, https://www.govinfo.gov/content/pkg/FR-1998-03-02/html/98-5313.htm.
30 The 1978 Environmental Research, Development, and Demonstration Authorization Act (P.L. 95-477) directed EPA
to establish the Science Advisory Board to provide scientific advice to the Administrator (42 U.S.C. §4365).
31 EPA, “Drinking Water Contaminant Candidate List 3—Final,” 74 Federal Register 51850, October 8, 2009. For
more information on CCL 3, see EPA, “Contaminant Candidate List 3—CCL 3,” https://www.epa.gov/ccl/
contaminant-candidate-list-3-ccl-3.
32 EPA, “Drinking Water Contaminant Candidate List 4—Final,” 81 Federal Register 81101-81103, November 17,
2016. Discussion of the CCL 3 process is included in this Federal Register notice.
33 EPA, “Drinking Water Contaminant Candidate List 4—Final,” 81 Federal Register 81099, November 17, 2016. For
more information on CCL 4, see EPA, “Contaminant Candidate List 4—CCL 4,” https://www.epa.gov/ccl/
contaminant-candidate-list-4-ccl-4-0.
34 SDWA §1445(a)(2); 42 U.S.C. §300g-4(a)(2).
35 SDWA §1445(a)(2); 42 U.S.C. §300g-4(a)(2). EPA estimates that approximately 82% of the population receives
water from public water systems that serve more than 10,000 individuals. Section 2021 of America’s Water
Infrastructure Act (P.L. 115-270) amended Section 1445 to require public water systems serving between 3,300 and
10,000 individuals to monitor for unregulated contaminants—subject to the availability of appropriations—to support
costs associated with monitoring for these systems. This requirement enters into effect three years after the date of
enactment of P.L. 115-270 (i.e., October 23, 2021).
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PFAS and Drinking Water: Selected EPA and Congressional Actions

available. The act includes an authorization of appropriations to cover monitoring and related
costs for small systems (serving 10,000 persons or fewer). However, large systems pay UCMR
monitoring and laboratory costs.36
In 2012, EPA issued the third UCMR (UCMR 3), under which 4,864 public water systems tested
their drinking water for six PFAS—including PFOA and PFOS—between January 2013 and
December 2015.37 Among these systems, EPA reported the following monitoring results for
PFOA and PFOS:
 117 of the public water systems reported detections of PFOA at levels above the
MRL of 20 ppt, and
 95 reported detections of PFOS at concentrations above the MRL of 40 ppt.38
Overall, 63 of the 4,864 (1.3%) water systems that conducted PFAS monitoring reported at least
one sample with PFOA and/or PFOS (separately or combined) concentrations exceeding EPA’s
2016 health advisory level of 70 ppt for PFOA and PFOS.39 Actual exposures among individuals
served by these systems would be expected to vary depending on water use and consumption.
EPA estimates that these 63 water systems serve approximately 5.5 million individuals. Of the 63
systems,
 9 reported detections of both PFOS and PFOA above 70 ppt;
 4 reported detections of PFOA above 70 ppt;
 37 reported detections of PFOS above 70 ppt; and
 13 reported detections of PFOA and PFOS (combined but not separately) above
70 ppt.40
Systems with PFOA or PFOS detections above 70 ppt were located in 21 states, the Pima-
Maricopa Indian community, and 2 U.S. territories.41

36 SDWA Section 1445(a)(2)(H)—Title 42, Section 300g-4(a)(2)(H) of the United States Code—authorizes
appropriations of $10 million for each of FY2019-FY2021 for EPA to pay the reasonable costs of testing and
laboratory analysis for small systems. Additionally, SDWA directs EPA to reserve $2 million from the Drinking Water
State Revolving Fund appropriation to pay the costs of small system UCMR monitoring (SDWA §1452(o); 42 U.S.C.
§300j-12(o)).
37 EPA, “Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems: Final
Rule,” 77 Federal Register 26072-26101, May 2, 2012. This rule required monitoring for 29 unregulated contaminants.
The PFAS for which monitoring was conducted include PFOA, PFOS, perfluorononanoic acid,
perfluorohexanesulfonic acid, perfluoroheptanoic acid, and perfluorobutanesulfonic acid (PFBS).
38 EPA, Data Summary of the Third Unregulated Contaminant Monitoring Rule, January 2017, p. 11,
https://www.epa.gov/dwucmr/data-summary-third-unregulated-contaminant-monitoring-rule.
39 Testimony of Peter Grevatt, Director, Office of Ground Water and Drinking Water, EPA, before the House
Committee on Energy and Commerce, Subcommittee on Environment; hearing on Perfluorinated Chemicals in the
Environment: An Update on the Response to Contamination and Challenges Presented, September 6, 2018. In May
2016, EPA issued nonenforceable health advisory levels for lifetime exposure, with a margin of safety, to PFOA and
PFOS in drinking water. EPA established the Lifetime Health Advisory level for PFOA and PFOS at 70 ppt, separately
or combined.
40 Email communication with EPA, May 30, 2019.
41 Monitoring results for individual water systems (listed by state) are available on EPA’s UCMR 3 website,
https://www.epa.gov/dwucmr/third-unregulated-contaminant-monitoring-rule. This report does not correlate levels of
exposure based on individuals served by these water systems.
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EPA’s PFAS Action Plan noted that the agency intended to propose monitoring requirements for
other PFAS in the next UCMR (UCMR 5).42 Further, the 2020 NDAA directs EPA to include on
UCMR 5 every PFAS for which EPA has identified a validated test method. EPA’s plan also
states that the agency would use the monitoring data gathered through UCMR 5 to evaluate the
national occurrence of additional PFAS.43 In December 2021, EPA finalized UCMR 5, which
would require all water systems serving 3,300 or more people to monitor for 29 PFAS and
lithium.44 As amended by America’s Water Infrastructure Act of 2018 (P.L. 115-270), SDWA
requires EPA to pay the reasonable costs of testing and laboratory analysis for water systems
serving between 3,300 and 10,000 individuals.45 Accordingly, the agency stated that the inclusion
of such systems would be dependent on appropriations.46 Public water systems are required to
conduct monitoring during a 12-month period from January 2023 through December 2025, and
report final results through 2026.47
Regulatory Determinations
SDWA requires EPA, every five years, to make a regulatory determination—a determination of
whether or not to promulgate a national primary drinking water regulation—for at least five
contaminants on the CCL.48 In March 2021, EPA finalized positive regulatory determinations for
PFOA and PFOS.49 To consider a contaminant for a regulatory determination (RD), EPA requires,
at a minimum, a peer-reviewed risk assessment and nationally representative occurrence data. In
selecting contaminants for an RD, SDWA requires EPA to give priority to those that present the
greatest public health concern while considering a contaminant’s health effects on specified
subgroups of the population (e.g., infants, children, pregnant women) who may be at greater risk
of adverse health effects due to exposure to a contaminant.50
As noted above, to make a positive determination to regulate a contaminant, EPA must find that
(1) a contaminant may have an adverse health effect; (2) it is known to occur or there is a
substantial likelihood that it will occur in public water systems with a frequency and at levels of
public health concern; and (3) in the sole judgment of the EPA Administrator, regulation of the
contaminant presents a meaningful opportunity for health risk reduction for persons served by
water systems. SDWA directs EPA to publish a preliminary determination and seek public

42 EPA did not require monitoring for any PFAS in UCMR 4.
43 EPA, EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan, February 14, 2019, p. 21,
https://www.epa.gov/pfas/epas-pfas-action-plan.
44 EPA, “Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems and
Announcement of Public Meeting,” 86 Federal Register 73131-73157, December 27, 2021.
45 SDWA §1445(j); 42 U.S.C. §300j-4(j). Section 2021(a) of America’s Water Infrastructure Act of 2018 (AWIA; P.L.
115-270) expanded unregulated contaminant monitoring requirements to include public water systems serving 3,300-
10,000 individuals—subject to the availability of appropriations for this purpose and lab capacity. This section
authorizes $15.0 million to be appropriated for each year from FY2019 through FY2021 to support the expanded
monitoring.
46 EPA, “Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems and
Announcement of Public Meeting,” 86 Federal Register 73131-73157, December 27, 2021.
47 EPA, “Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems and
Announcement of Public Meeting,” 86 Federal Register 73131-73157, December 27, 2021.
48 SDWA §1412(b)(1)(B)(ii); 42 U.S.C. §300g-1(b)(1)(B)(ii).
49 EPA, “Announcement of Final Regulatory Determinations for Contaminants on the Fourth Drinking Water
Contaminant Candidate List,” 86 Federal Register 12272-12291, March 3, 2021.
50 SDWA §1412(b)(1)(C); 42 U.S.C. §300g-1(b)(1)(C).
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comment prior to making an RD.51 EPA may also make RDs for contaminants not listed on the
CCL if EPA finds that the statutory criteria regarding health effects and occurrence are satisfied.52
In 2014, when EPA published preliminary RDs for contaminants on CCL 3 (including PFOA and
PFOS), UCMR 3 monitoring was under way and national occurrence data were not available.
EPA did not include any PFAS among the contaminants selected for the third RD. In November
2016, EPA included PFOA and PFOS on the agency’s list of unregulated contaminants for which
sufficient health effect and occurrence data were available to make RDs.53 For the fourth cycle,
EPA proposed and finalized regulatory determinations for contaminants on CCL 4, determining to
regulate PFOA and PFOS and not to regulate six other chemicals.
Developing Regulations and Standards for Emerging Contaminants
Once the Administrator makes a determination to regulate a contaminant, SDWA allows EPA 24
months to propose a “national primary drinking water regulation” and request public comment.
EPA is required to promulgate a final rule within 18 months after the proposal.54 SDWA
authorizes EPA to extend the deadline to publish a final rule for up to nine months, by notice in
the Federal Register.55 With the SDWA time frame triggered by the March 2021 RDs, EPA is
required to propose PFOA and PFOS drinking water regulations within 24 months—by March
2023—and finalize such regulations within 18 months of publishing the proposed rule. While
SDWA outlines time frames for EPA to follow to propose and finalize a regulation, EPA notes in
its PFAS Strategic Roadmap that the agency intends to propose a PFOA and PFOS drinking water
regulation by fall 2022, and finalize such regulation by fall 2023.56
For each contaminant that EPA determines to regulate, EPA is required to establish a
nonenforceable maximum contaminant level goal (MCLG) at a level at which no known or
anticipated adverse health effects occur and which allows an adequate margin of safety.57 An
MCLG is based solely on health effects data and does not reflect cost or technical feasibility
considerations. EPA derives an MCLG based on an estimate of the amount of a contaminant that a
person can be exposed to on a daily basis that is not anticipated to cause adverse health effects
over a lifetime.58 This amount is derived using the best available peer-reviewed studies and
incorporates uncertainty factors to provide a margin of protection for sensitive subpopulations. In
developing an MCLG, EPA also estimates the general population’s exposure to a contaminant
from drinking water and other sources (e.g., food, dust, soil, and air). After considering other

51 SDWA §1412(b)(1)(B)(ii); 42 U.S.C. §300g-1(b)(1)(B)(ii). The act authorizes EPA to promulgate an interim
national primary drinking water regulation without making a regulatory determination or completing the other analyses
to respond to an urgent threat to public health (SDWA §1412(b)(1)(D); 42 U.S.C. §300g-1).
52 SDWA §1412(b)(1)(B)(ii)(III); 42 U.S.C. §300g-1(b)(1)(B)(ii)(III).
53 EPA, “Drinking Water Contaminant Candidate List 4—Final,” 81 Federal Register 81102-81104, November 17,
2016. For more information on CCL 4, see EPA, “Contaminant Candidate List 4—CCL 4.”
54 SDWA §1412(b)(3); 42 U.S.C. §300g-1(b)(3).
55 SDWA §1412(b)(1)(E); 42 U.S.C. §300g-1(b)(1)(E).
56 EPA, PFAS Strategic Roadmap: EPA’s Commitments to Action 2021-2024, October 18, 2021, p. 12,
https://www.epa.gov/system/files/documents/2021-10/pfas-roadmap_final-508.pdf.
57 When developing regulations, EPA is required to (1) use the best available peer-reviewed science and supporting
studies and data and (2) make publicly available a risk assessment document that discusses estimated risks,
uncertainties, and studies used in the assessment. Concurrent with proposing a regulation, SDWA requires EPA to
publish a “health risk reduction and cost analysis.” SDWA §1412(b)(4)(A); 42 U.S.C. §300g-1(b)(4)(A).
58 EPA follows this process to evaluate noncarcinogenic effects. For contaminants that may have carcinogenic effects,
EPA typically sets the MCLG at zero.
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exposure routes, EPA estimates the proportion of exposure attributable to drinking water (i.e., the
relative source contribution). When exposure information is not available, EPA uses a default
assumption that 20% of exposure to a contaminant is attributable to drinking water. EPA applies
the relative source contribution to ensure that an individual’s total exposure from all sources
remains within the estimated protective level.59
The MCLG provides the basis for calculating a drinking water standard. Thus, EPA’s ability to
develop a drinking water regulation for a contaminant is dependent, in part, on the availability of
peer-reviewed scientific studies.
Drinking water regulations generally specify a maximum contaminant level (MCL)—an
enforceable limit for a contaminant in public water supplies.60 SDWA requires EPA to set the
MCL as close to the MCLG as feasible.61 When assessing feasibility, the law directs EPA to
consider the best available (and field-demonstrated) treatment technologies, taking cost into
consideration.62 If the treatment of a contaminant is not feasible—technologically or
economically—EPA may establish a treatment technique in lieu of an MCL.63 Each regulation
also establishes associated monitoring, treatment, and reporting requirements. These regulations
can cover multiple contaminants and, generally, establish an MCL for each contaminant covered
by the regulation.
Regulations generally take effect three years after promulgation. EPA may allow up to two
additional years if the Administrator determines that more time is needed for public water systems
to make capital improvements. (States have the same authority for individual water systems.64)
The law directs EPA to review—and if necessary revise—each regulation every six years and
requires that any revision maintain or provide greater health protection.65
Health Advisories
For emerging contaminants of concern, data may be limited, particularly regarding a
contaminant’s potential health effects and occurrence in public water supplies. SDWA authorizes
EPA to issue health advisories for contaminants in drinking water that are not regulated under the
act.66 These advisories provide information on a contaminant’s health effects, chemical
properties, occurrence, and exposure. They also provide technical guidance on identifying,
measuring, and treating contaminants, but are not enforceable by EPA under SDWA.
Health advisories include nonenforceable levels for concentrations of contaminants in drinking
water. EPA sets health advisories at levels that are expected to protect the most sensitive
subpopulations (e.g., nursing infants) from any deleterious health effects, with a margin of
protection, over specific exposure durations (e.g., 1-day, 10-day, or lifetime).67 These
nonregulatory levels are intended to help states, water suppliers, and others address contaminants

59 EPA, Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA), May 2016, p. 32, https://www.epa.gov/
ground-water-and-drinking-water/supporting-documents-drinking-water-health-advisories-pfoa-and-pfos.
60 SDWA does not prohibit states from setting stricter standards.
61 SDWA §1412(b)(4)(B); 42 U.S.C. §300g-1(b)(4)(B).
62 SDWA §1412(b)(4)(D); 42 U.S.C. §300g-1(b)(4)(D).
63 SDWA §1412(b)(7)(A); 42 U.S.C. §300g-1(b)(7)(A).
64 SDWA §1412(b)(10); 42 U.S.C. §300g-1(b)(10).
65 SDWA §1412(b)(9); 42 U.S.C. §300g-1(b)(9).
66 SDWA §1412(b)(1)(F); 42 U.S.C. §300g-1(b)(1)(F).
67 EPA, 2018 Edition of the Drinking Water Standards, pp. 17-25.
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for which federal (or state) drinking water standards have not been established. Some states may
use health advisories to inform their own state-specific drinking water regulations.
Health advisories may be used to address various circumstances: to provide interim guidance
while EPA evaluates a contaminant for possible regulation, to provide information for
contaminants with limited or localized occurrence that may not warrant regulation, and to address
short-term incidents or spills. EPA has issued health advisories for more than 200 contaminants to
address different circumstances and subsequently established regulations for many of these
contaminants.68
In May 2016, EPA issued health advisory levels for lifetime exposure to PFOA and PFOS in
drinking water.69 EPA established the Lifetime Health Advisory level for PFOA and PFOS at 70
ppt, separately or combined.70 In calculating the health advisory level, EPA applied a relative
source contribution of 20% (i.e., an assumption that 20% of PFOS and/or PFOA exposure is
attributable to drinking water and 80% is from diet, dust, air, or other sources).71 These levels are
intended to protect the most sensitive subpopulations (e.g., nursing infants), with a margin of
safety, over a lifetime of daily exposure. The Lifetime Health Advisories replaced Provisional
Health Advisories that EPA issued in 2009 to address short-term exposures to PFOA and PFOS.72
In June 2022, EPA announced revised interim Lifetime Health Advisories for PFOA and PFOS,
and final Lifetime Health Advisories for hexafluoropropylene oxide dimer acid and its
ammonium salt (together referred to as “GenX chemicals”) and perfluorobutane sulfonic acid and
its related compound potassium perfluorobutane sulfonate (together referred to as “PFBS”).73 As
with the 2016 Lifetime Health Advisories, the revised and new advisories identify specific levels
of PFAS that are intended to protect the most sensitive subpopulations (e.g., lactating women,
childbearing women, or children), with a margin of protection, from adverse health effects over a
lifetime of daily exposure.
EPA finalized Lifetime Drinking Water Health Advisory levels for PFBS and GenX chemicals at
2,000 ppt and 10 ppt, respectively. EPA issued interim Lifetime Drinking Water Health Advisory
levels at 0.004 ppt for PFOA and 0.02 ppt for PFOS, significantly lower than the 2016 Lifetime
Advisory levels of 70 ppt, separately or combined. Similar to the 2016 advisories, in calculating
the health advisory levels, EPA applied a relative source contribution of 20% (i.e., an assumption
that 20% of PFOA, PFOS, PFBS, or GenX chemical exposure is attributable to drinking water
and 80% is from diet, dust, air, or other sources). The interim PFOA and PFOS Lifetime Drinking

68 EPA, Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA), p. 11. See also EPA, 2018 Edition of the
Drinking Water Standards and Health Advisories Tables, March 2018, https://www.epa.gov/sites/production/files/
2018-03/documents/dwtable2018.pdf.
69 EPA, “Fact Sheet: PFOA and PFOS Drinking Water Health Advisories,” 2016, https://www.epa.gov/sites/
production/files/2016-06/documents/drinkingwaterhealthadvisories_pfoa_pfos_updated_5.31.16.pdf.
70 EPA, “Lifetime Health Advisories and Health Effects Documents for Perfluorooctanoic Acid and Perfluorooctane
Sulfonate,” 81 Federal Register 33250, May 25, 2016.
71 Also in May 2016, EPA released health effects support documents for these two PFAS, which summarize the
scientific literature that EPA evaluated to establish the 2016 advisories. For the accompanying health effects documents
for PFOA and PFOS, see EPA, “Supporting Documents for Drinking Water Health Advisories for PFOA and PFOS.”
72 In 2009, EPA established a Provisional Health Advisory level of 400 ppt for PFOA and 200 ppt for PFOS. For more
information on these health advisories, see EPA, “Provisional Health Advisories for Perfluorooctanoic Acid (PFOA)
and Perfluorooctane Sulfonate (PFOS),” https://www.epa.gov/sites/production/files/2015-09/documents/pfoa-pfos-
provisional.pdf.
73 EPA, “Lifetime Drinking Water Health Advisories for Four Perfluoroalkyl Substances,” 87 Federal Register 36848,
June 21, 2022.
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Water Health Advisory levels are based on draft health effect analyses under review by the EPA
Science Advisory Board (SAB).74 Using new and existing human epidemiological and
experimental animal study data, EPA developed draft health effect analyses that identified a
different “most sensitive non-cancer effect” (i.e., decreased immunity) than the health effect (i.e.,
developmental effects) that the agency used to derive the 2016 Lifetime Drinking Water Health
Advisories.75 As these analyses are still under SAB review, EPA notes that the interim PFOA and
PFOS levels may change based on potential revisions after the SAB completes its review, and
other feedback.76 Such interim levels are below the level at which analytical methods can detect
PFOS or PFOA in drinking water.77
Emergency Powers Orders
SDWA Section 1431 grants EPA “emergency powers” to issue orders to abate an imminent and
substantial endangerment to public health from “a contaminant that is present in or is likely to
enter a public water system or an underground source of drinking water” and if the appropriate
state and local authorities have not acted to protect public health.78 This authority is available to
address both regulated and unregulated contaminants. The EPA Administrator “may take such
actions as he may deem necessary” to protect the health of persons who may be affected. Actions
may include issuing orders requiring persons who caused or contributed to the endangerment to
provide alternative water supplies or to treat contamination. When using this authority, EPA
generally coordinates closely with states.
EPA reports that it has used its emergency powers under Section 1431 to require responses to
PFOA and/or PFOS releases and related contamination of drinking water supplies at four sites,
three of which involved DOD.79
1. Warminster Naval Warfare Center, Pennsylvania. In 2014, EPA issued an
administrative enforcement order directing the U.S. Navy to address PFOS in
three drinking water supply wells at and near this National Priorities List site.80

74 Ibid.
75 EPA, Technical Fact Sheet: Drinking Water Health Advisories for Four PFAS (PFOA, PFOS, GenX chemicals, and
PFBS), EPA 822-F-22-002, Washington, DC, June 2022, https://www.epa.gov/system/files/documents/2022-06/
technical-factsheet-four-PFAS.pdf. In May 2016, EPA released health effects support documents for these two PFAS,
which summarize the scientific literature that EPA evaluated to establish the 2016 advisories. For the accompanying
health effects documents for PFOA and PFOS, see EPA, “Supporting Documents for Drinking Water Health
Advisories for PFOA and PFOS.”
76 EPA, Technical Fact Sheet: Drinking Water Health Advisories for Four PFAS (PFOA, PFOS, GenX chemicals, and
PFBS), EPA 822-F-22-002, Washington, DC, June 2022, https://www.epa.gov/system/files/documents/2022-06/
technical-factsheet-four-PFAS.pdf.
77 Ibid.
78 42 U.S.C. §300i.
79 EPA, EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan, pp. 55-56. In April 2019, EPA responded to
CRS, listing specific federal and state enforcement actions taken to address PFAS under various statutory authorities.
These actions include the four examples of the use of SDWA Section 1431 emergency powers and also orders under
the authority of TSCA and the Resource Conservation and Recovery Act. According to EPA’s Enforcement and
Compliance History Online tool, which identifies enforcement actions since 2009, EPA has issued 119 orders using the
SDWA Section 1431 authority to respond to imminent and substantial endangerment as of May 2019. Of the 119
orders, EPA issued 113 orders to public water systems for a variety of circumstances, including corrosive pipes,
discovery of disease vectors in finished water storage, and MCL violations, among others.
80 CERCLA directs EPA to maintain a National Priorities List to identify the most hazardous sites for the purpose of
prioritizing cleanup actions.
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2. Former Pease Air Force Base, New Hampshire. In August 2015, EPA issued an
administrative enforcement order to require the U.S. Air Force to design and
construct a system to treat water systems contaminated from releases of PFOA
and PFOS at the former Pease Air Force Base in New Hampshire.
3. Horsham Air Guard Station/Willow Grove, Pennsylvania. In 2015, EPA
issued an order directing the Air Guard/Air Force to treat onsite drinking water
wells and to provide treatment for private offsite wells.
4. Chemours Washington Works Facility, West Virginia/Ohio. EPA issued three
emergency orders to this facility in 2002, 2006, and 2009—and amended the
2009 order in 2017 to incorporate the 2016 Lifetime Health Advisory level—
requiring DuPont and Chemours to offer water treatment, connection to a public
water system, or bottled water where PFOA concentrations exceeded 70 ppt.
MCLs and Remedial Actions
Under CERCLA (or “Superfund”), MCLs may be considered in selecting remedial actions for releases of hazardous
substances, pol utants, and other contaminants (42 U.S.C. §9621(d)). However, CERCLA establishes liability only
for releases of hazardous substances, as defined in CERCLA (42 U.S.C. §9601(14)). No PFAS has been federally
designated as a hazardous substance (42 U.S.C. §9602(a)). EPA’s PFAS Strategic Roadmap states that EPA plans to
propose to designate PFOA and PFOS as hazardous substances in spring 2022, and finalize by summer 2023.
EPA issued interim recommendations in December 2019 for PFOA and PFOS groundwater screening levels and
preliminary remediation goals for evaluating potential risks at sites under CERCLA and sites subject to corrective
action under the Resource Conservation and Recovery Act. EPA recommends using PFOA and PFOS screening
levels of 40 ppt and preliminary remediation goals of 70 ppt (EPA’s 2016 Lifetime Health Advisory level). This
guidance would supplement existing CERCLA guidance, which EPA uses to assess risks and inform the selection of
site-specific response actions. In May 2022, EPA issued additional screening levels for several PFAS that
supplement the December 2019 groundwater recommendations. For more information regarding PFAS and other
environmental statutes, see CRS Report R45986, Federal Role in Responding to Potential Risks of Per- and
Polyfluoroalkyl Substances (PFAS), coordinated by David M. Bearden.
Recent Congressional Action
Recent Congresses have held hearings and introduced and passed legislation to address PFAS in
drinking water. In the 117th Congress, more than 60 bills have been introduced to address PFAS in
a broad range of contexts. Several bills would authorize financial assistance programs to help
communities pay for infrastructure improvements to treat PFAS in wastewater effluent and/or
drinking water. The National Defense Authorization Act (NDAA) for Fiscal Year 2022 (P.L. 117-
81) includes several provisions related to PFAS that would build upon certain requirements
enacted in prior NDAAs, which are specific to DOD or related to DOD activities.
Enacted in November 2021, the Infrastructure Investment and Jobs Act (P.L. 117-58) includes
water-related PFAS provisions:
 Division J, Title VI provides $4 billion in emergency appropriations over five
fiscal years to address emerging contaminants with a focus on PFAS in drinking
water through the grant program within the DWSRF that was added to SDWA by
the National Defense Authorization Act for Fiscal Year 2020 (P.L. 116-92) within
EPA’s State and Tribal Assistance Grants (STAG) account.81

81 SDWA §1452(a)(2)(G); 42 U.S.C. §300j-12(a)(2)(G).
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 Division J, Title VI provides $1 billion in emergency appropriations over five
fiscal years to address emerging contaminants in wastewater in EPA’s STAG
account.82
Among the drinking water-related bills, the PFAS Action Act of 2021 (H.R. 2467), which
parallels H.R. 535 from the 116th Congress, contains a range of provisions that would address
PFAS using multiple authorities, including several EPA-administered laws. Passed by the House
on July 22, 2021, the bill includes several drinking water provisions, some of which would amend
SDWA:
 Section 5 would amend SDWA to require EPA, within two years of enactment, to
promulgate a national primary drinking water regulation for PFAS with standards
for PFOA and PFOS at a minimum. It would establish a separate regulatory
process for PFAS with shorter time frames to accelerate EPA’s promulgation of
drinking water standards. Among other provisions, this section would require
EPA to propose a regulation for a PFAS within 18 months (rather than 24
months) of making a determination to regulate it. This section would allow EPA,
when developing regulations, to rely on health risk information for one PFAS to
“extrapolate reasoned conclusions” regarding the health risks of other PFAS. It
would also direct EPA to issue a health advisory within a year of finalizing a
toxicity value for a single PFAS or class of PFAS.
 Section 6 would prohibit EPA (but not states) from imposing penalties for
violations of PFAS drinking water regulations until five years after the date of
promulgation (to allow systems time to make capital improvements as needed for
compliance).
 Section 7 would add SDWA Section 1459E to direct EPA to establish a
competitive grant program to assist community water systems with installing
treatment technologies to address PFAS contamination. To support this program,
Section 7 would authorize annual appropriations of $125 million for FY2020 and
FY2021 and $100 million for FY2022-FY2024. EPA would be required to give
funding priority to community water systems that (1) serve a “disadvantaged
community or a disproportionately exposed community,” (2) provide at least a
10% cost share, or (3) demonstrate the capacity to maintain the treatment
technology.83
In the 116th Congress, more than 40 bills were introduced to address PFAS through a broad range
of actions and federal agencies.84 The NDAA for FY2020 (P.L. 116-92) contains PFAS provisions
specific to DOD, EPA, and several other federal agencies. Some NDAA provisions involve the
use of aqueous film-forming foam, while others address DOD remediation of PFAS-contaminated

82 For additional discussion, see CRS Report R46892, Infrastructure Investment and Jobs Act (IIJA): Drinking Water
and Wastewater Infrastructure, by Elena H. Humphreys and Jonathan L. Ramseur.
83 Section 14 would direct EPA to establish a household well water testing website to host various resources for private
well owners to identify services and test and treat their well water for PFAS.
84 In the conference report accompanying the Consolidated Appropriations Act, 2019 (P.L. 116-6, enacted February 15,
2019), the conferees directed EPA to brief the committees within 60 days of enactment (i.e., April 16, 2019) on the
agency’s plans to evaluate the need for an MCL for PFAS. U.S. Congress, House of Representatives, Conference
Committee, Conference Report to Accompany H.J.Res. 31, Making Further Continuing Appropriations for the
Department of Homeland Security for Fiscal Year 2019, and for Other Purposes, committee print, 116th Cong., 1st
sess., February 13, 2019, H.Rept. 116-9 (Washington: GPO, 2019), p. 741.
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drinking water, groundwater, and surface water.85 Among the EPA provisions, the FY2020 NDAA
addresses drinking water as follows:
 Section 7311 requires EPA to add to UCMR 5 all PFAS or categories of PFAS
with validated test methods.
 Section 7312 amended SDWA to authorize appropriations for grants within the
Drinking Water State Revolving Fund to assist water systems in addressing
emerging contaminants, with an emphasis on PFAS. Section 7312 authorized
appropriations of $100 million annually for FY2020 through FY2024 for this
purpose.
Among other bills in the 116th Congress, House-passed H.R. 535 included provisions intended to
reduce exposures to PFAS in drinking water and to prevent or remediate the contamination of
groundwater, surface water, and drinking water supplies from releases of these substances.86 The
Senate did not act on H.R. 535. Further, the NDAA for FY2021 (P.L. 116-283) included DOD-
specific PFAS provisions.87
In the context of SDWA, congressional attention has focused primarily on EPA setting of drinking
water standards (MCLs) for PFOA and PFOS, or potentially other PFAS. SDWA directs EPA to
follow a regulatory development process for contaminants, which includes consideration of
technical feasibility and the assessment of health-risk-reduction benefits and costs, among other
factors.
Several bills have proposed a separate, and accelerated, regulatory development process for
PFAS. In the 117th Congress, provisions of H.R. 2467 and H.R. 3684 would allow EPA to
extrapolate the health effects from one PFAS to a group of PFAS, thereby potentially reducing the
number of peer-reviewed health effects studies needed to evaluate such substances. These bills
would also direct EPA to finalize drinking water regulations for PFAS in shorter time frames than
what is currently required under SDWA.88
On occasion, Congress has directed EPA to promulgate a regulation for a particular contaminant
within a specified time frame.89 Congress has used this approach to prompt EPA to regulate

85 For further discussion of DOD-related PFAS legislation, see CRS Report R45986, Federal Role in Responding to
Potential Risks of Per- and Polyfluoroalkyl Substances (PFAS), coordinated by David M. Bearden.
86 In the 115th Congress, the Agriculture Improvement Act of 2018 (P.L. 115-334)—known as the 2018 farm bill—
contains several provisions to address PFAS in rural communities’ drinking water. P.L. 115-334, Section 6404,
expands an existing program to authorize qualified nonprofit entities to provide technical assistance to rural
communities to address contamination of drinking water and surface water supplies by emerging contaminants,
including PFAS (7 U.S.C. §1926(a)(14)); Section 6409 authorizes loans and grants for installation of water treatment to
address ground well water contamination at individual households (7 U.S.C. §1926e); Section 6407(a) authorizes the
use of U.S. Department of Agriculture (USDA) Emergency Water Assistance grants to address contamination that
poses human health or environmental risks and was caused by circumstances beyond the control of the applicant (7
U.S.C. §1926a); and Section 6407(b) directs USDA to coordinate an interagency task force on drinking water in rural
communities located near military bases. For more information on USDA water infrastructure assistance programs, see
CRS Report RL30478, Federally Supported Water Supply and Wastewater Treatment Programs, coordinated by
Jonathan L. Ramseur.
87 See CRS Report R46714, FY2021 National Defense Authorization Act: Context and Selected Issues for Congress, by
Pat Towell, for an additional discussion.
88 See CRS Report R46652, Regulating Contaminants Under the Safe Drinking Water Act (SDWA), by Elena H.
Humphreys, for a discussion of SDWA regulatory development provisions.
89 For example, in the Safe Drinking Water Amendments of 1996 (P.L. 104-182), the 104th Congress directed EPA to
regulate radon, propose a new arsenic standard, and evaluate sulfate for regulation (SDWA §1412(b)(12); 42 U.S.C.
§300g(b)(12); SDWA §1412(b)(13); 42 U.S.C. §300g(b)(13)).
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PFAS and Drinking Water: Selected EPA and Congressional Actions

certain contaminants already under review and/or to specify a deadline for issuing regulations
under development. In the case of PFAS, representatives of public water systems and others have
cautioned against bypassing SDWA’s science-based and risk-driven process.90 As regulatory
compliance costs are borne by communities, public water suppliers have urged that regulations be
data-driven to better ensure risk-reduction benefits.91 Others have urged “federal leadership” to
provide more certainty to states and communities with contaminated water supplies.92 State
drinking water regulators have noted that some states may lack the resources to assess and/or the
authority to regulate drinking water contaminants that are not federally regulated, including
PFAS. As with certain other contaminants, some states have urged EPA to set national standards.
A further concern is that state-by-state actions could create public confusion regarding the safety
of drinking water.93

90 See, for example, testimony of Tracy Mehan for the American Water Works Association before the House
Committee on Energy and Commerce, Subcommittee on Environment and Climate Change, hearing on Protecting
Americans at Risk of PFAS Contamination and Exposure, May 15, 2019, https://energycommerce.house.gov/
committee-activity/hearings/hearing-on-protecting-americans-at-risk-of-pfas-contamination-exposure.
91 See, for example, American Water Works Association, Association of Metropolitan Water Agencies, National
Association of Water Companies, and the National Rural Water Association, joint letter to the House Committee on
Armed Services and the Senate Committee on Armed Services, on the 2020 National Defense Authorization Act,
August 8, 2019, https://www.awwa.org/AWWA-Articles/awwa-and-partners-send-pfas-letter-to-us-congress.
92 See, for example, testimony of Lisa Daniels for the Association of State Drinking Water Administrators before the
Senate Committee on Environment and Public Works, hearing on Examining Legislation to Address the Risks
Associated with Per- and Polyfluoroalkyl Substances (PFAS), May 22, 2019, https://www.epw.senate.gov/public/
index.cfm/2019/5/examining-legislation-to-address-the-risks-associated-with-per-and-polyfluoroalkyl-substances-pfas.
93 Association of State Drinking Water Administrators, comment letter to EPA on draft human health toxicity
assessments for GenX chemicals and PFBS, EPA Docket No. #EPA-HQ-OW-2018-0614, January 22, 2019.
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Appendix A. Selected PFAS Drinking-Water-
Related Actions in EPA’s PFAS Action Plan
Table A-1. Selected Drinking-Water-Related Actions in EPA’s PFAS Action Plan
Action
Description
Time Frame
Provisional Health Advisories
Developed provisional health
Completed January 2009
advisory values for short-term
exposure to PFOA and PFOS at
400 ppt and 200 ppt, respectively
Analytical Method Development
Developed an analytical method
Completed September 2009
(Method 537) for measuring PFOA,
PFOS, and 12 other PFAS in
drinking water
Contaminant Candidate List 3
Included PFOS and PFOA on the
Completed October 2009
third contaminant candidate list
Unregulated Contaminant
Monitored for unregulated
Completed between 2013 and 2015
Monitoring Rule 3
contaminants, including six PFAS in
public water supplies using analytical
methods developed by EPA
Lifetime Health Advisories for
Developed Health Advisories for
Completed May 2016
PFOA and PFOS
PFOA and PFOS that identify
nonenforceable levels at or below
which adverse health effects are not
anticipated to occur
Contaminant Candidate List 4
Included PFOS and PFOA on the
Completed November 2016
fourth contaminant candidate list
Analytical Method Development
Expanded Method 537 to Method
Completed November 2018
537.1, which measures four short-
chain PFAS, including GenX
compoundsa
Water Contaminant Information
Developed contaminant profiles for
Completed December 2018
Tool: Profiles for PFOA and PFOS
PFOA and PFOS for EPA’s Water
Contaminant Information Tool,
which is used by the water sector
to prepare for, respond to, or
recover from drinking water
incidents
Point-of-Entry and Point-of-Use
Evaluated commercially available
Completed October 2018
Home Treatment Systems
reverse osmosis and granular
activated carbon units that can
serve households through point-of-
use or point-of-entry treatment
applications for PFAS
Treatability Cost Models
Update Drinking Water PFAS
Ongoing
Treatability cost models
Drinking Water Treatability
Update Drinking Water Treatability
Ongoing
Database
Database for effective drinking
water treatment processes for
PFOA, PFOS, and additional PFAS
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Action
Description
Time Frame
Research for Drinking Water
Conducted experiments to evaluate Completed October 2020b
Treatment
performance and cost (capital and
maintenance operations) of
treatment and potential unintended
effects of using specific
technologies; tested granular
activated carbon and ion exchange
treatment technologies
Regulatory Determination 4
Proposed a regulatory
Completed March 2021
determination for PFOA and PFOS
Analytical Method Development
Develop new validated analytical
Ongoing. As of July 2021, EPA had
method for short-chain PFAS, which developed Method 533 that
are currently not measured by the
measures 11 short-chain PFAS.
Method 537 or Method 537.1
Unregulated Contaminant
Developed unregulated
On December 27, 2021, EPA issued
Monitoring Rule (UCMR) 5
contaminant monitoring rule for
UCMR 5 to require water systems
additional PFAS using the new
to monitor for 29 PFAS and lithium
validated analytical method to
between 2023 and 2025.
detect more PFAS at lower
concentrations
Source: Compiled by CRS from EPA’s PFAS Action Plan.
Notes: This table includes only EPA’s actions directly related to drinking water. The Action Plan includes other
EPA efforts to address PFAS under other environmental statutes.
a. GenX is a chemical process used to create fluoropolymers.
b. See EPA website “Treating PFAS in Drinking Water” at https://www.epa.gov/pfas/treating-pfas-drinking-
water.
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Appendix B. Drinking-Water-Related Actions in
EPA’s PFAS Strategic Roadmap
Table B-1. Selected Drinking-Water-Related Actions in EPA’s PFAS Strategic
Roadmap
Action
Description
Time Frame
Unregulated Contaminant
Col ect additional data on PFAS
Expected fall 2021 (on December 27,
Monitoring Rule (UCMR) 5
occurrence through an unregulated
2021, EPA finalized UCMR 5)a
contaminant monitoring rule to
determine the frequency that 29
PFAS are found in drinking water
systems and at what levels
National Primary Drinking Water
Develop, propose, and finalize a
Propose a regulation by fall 2022,
Regulations
National Primary Drinking Water
and finalize such a regulation by fall
Regulation for PFOA and PFOS
2023
Publish Health Advisories
Develop nonenforceable and
June 2022
for GenXb and Perfluorobutane
nonregulatory drinking water health
sulfonic acid (PFBS)
advisories GenX and PFBS to help
inform whether state and local
actions are required.
Analytical Methods for Additional
Update and validate analytical
Expected fall 2024
PFAS
methods to monitor additional
PFAS in drinking water
Source: Compiled by CRS from EPA’s PFAS Strategic Roadmap.
Notes: This table includes only EPA’s actions directly related to drinking water. The Strategic Roadmap includes
other EPA efforts to address PFAS under other environmental statutes.
a. EPA, “Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 5) for Public Water Systems and
Announcement of Public Meeting,” 86 Federal Register 73131-73157, December 27, 2021.
b. GenX is a chemical process used to create fluoropolymers.

Author Information

Elena H. Humphreys

Analyst in Environmental Policy

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PFAS and Drinking Water: Selected EPA and Congressional Actions

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan
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under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other
than public understanding of information that has been provided by CRS to Members of Congress in
connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not
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