Updated July 13, 2022
Regulating Drinking Water Contaminants: EPA PFAS Actions
The detection of certain per- and polyfluoroalkyl substances
standards. In 2016, EPA issued Lifetime Health Advisory
(PFAS) in some public water supplies has generated public
levels for PFOA and PFOS in drinking water at 70 parts per
concern and increased attention to the U.S. Environmental
trillion (ppt) separately or combined. In June 2022, EPA
Protection Agency’s (EPA’s) actions to respond to PFAS
revised the advisories for PFOA and PFOS, and issued new
using Safe Drinking Water Act (SDWA) authorities. For
advisories for perfluorobutane sulfonic acid (PFBS) and
more than a decade, EPA has been evaluating PFAS under
GenX chemicals. EPA finalized Lifetime Health Advisory
SDWA to determine whether a national drinking water
levels for PFBS and GenX chemicals at 2,000 ppt and 10
regulation is warranted for one or more of these substances.
ppt, respectively. EPA issued interim Lifetime Health
In March 2021, EPA finalized determinations to develop
Advisory levels at 0.004 ppt for PFOA and 0.02 ppt for
SDWA regulations for the two most frequently detected
PFOS, significantly lower than the 2016 levels.
PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane
sulfonate (PFOS) (86 Federal Register 12272). EPA’s
Regulating Contaminants Under SDWA
determination triggers a SDWA requirement to propose a
SDWA authorizes EPA to regulate contaminants in water
regulation within 24 months (e.g., by March 2023 for
provided by public water systems and specifies a multistep
PFOA and PFOS), and finalize the rule within 18 months of
process for evaluating contaminants to determine whether a
the proposal. EPA’s 2021 PFAS Strategic Roadmap states
drinking water regulation is warranted (42 U.S.C. §300g-1).
that it intends to propose a PFOA and PFOS drinking water
As discussed below, the process includes identifying
regulation by fall 2022, and finalize the rule by fall 2023.
contaminants of potential concern, assessing health risks,
collecting occurrence data (and developing any necessary
In addition, the 116th Congress enacted legislation directing
test methods), and making determinations as to whether a
EPA to increase PFAS monitoring in water supplies, and
federal drinking water regulation is warranted.
authorizing appropriations for grants to address PFAS in
public water supplies, among other provisions. The 117th
Identifying Contaminants for Evaluation
Congress provided appropriations for such grants.
Every five years, EPA is required to publish a list of
contaminants that are known or anticipated to occur in
Background
public water systems and may warrant regulation under the
PFAS include thousands of diverse chemicals, some of
act (42 U.S.C. §300g-1(b)). In 2009, EPA placed PFOA and
which have been used for decades. The chemical
PFOS on the third such contaminant candidate list (CCL 3)
characteristics of PFAS led to their use in an array of
for evaluation (74 Federal Register 51850). In November
industrial, commercial, and U.S. military applications.
2016, EPA issued CCL 4, which carried over many CCL 3
These include use in fighting fuel-based fires and the
contaminants, including PFOA and PFOS, for further
processing and manufacturing of numerous products (e.g.,
evaluation (81 Federal Register 81103).
stain-resistant and waterproof fabrics, nonstick cookware,
and food containers). PFOA and PFOS were the most
Monitoring for Unregulated Contaminants
produced PFAS, historically. EPA worked with U.S.
To generate nationwide occurrence data for unregulated
manufacturers as they voluntarily phased out production of
contaminants, SDWA directs EPA to promulgate, every
PFOS, PFOA, and related substances.
five years, an unregulated contaminant monitoring rule
(UCMR) that requires water systems operators to test for up
In 2016, EPA reported that PFOA and/or PFOS were
to 30 contaminants (42 U.S.C. §300j-4). EPA generally
detected in at least one public water system in 24 states.
requires monitoring by operators of all public water systems
Four other PFAS were also detected in some systems.
that serve more than 10,000 persons, plus a representative
SDWA provides EPA with several authorities to address
sample of smaller systems. (More than 80% of U.S.
contaminants in drinking water supplies and sources. These
residents receive water from public water systems that serve
include the authority to issue health advisories, regulate
more than 10,000 individuals. More than half of water
contaminants in public water supplies, and issue
systems serve fewer than 500 people.)
“emergency powers” orders in certain circumstances.
In 2012, EPA issued the UCMR 3, requiring roughly 5,000
Drinking Water Health Advisories
water systems to monitor for six PFAS—including PFOA
SDWA authorizes EPA to issue health advisories for
and PFOS—between January 2013 and December 2015.
contaminants (42 U.S.C. §300g-1(b)(1)(F)). Advisories
According to EPA, 63 water systems (1.3%) serving an
provide information on health effects, testing methods, and
estimated 5.5 million individuals detected PFOA and/or
treatment techniques, as well as identify nonenforceable
PFOS at levels above EPA’s 2016 health advisory level of
levels to help water suppliers and others address
70 ppt (separately or combined). UCMR 4 did not require
contaminants that lack federal (or state) drinking water
monitoring for PFAS.
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Regulating Drinking Water Contaminants: EPA PFAS Actions
As directed by the National Defense Authorization Act for
as is “feasible” using best available technology or other
FY2020 (2020 NDAA; P.L. 116-92), EPA included on the
means available, taking costs into consideration. SDWA
next UCMR (i.e., UCMR 5) every PFAS for which EPA
requires that regulations include analytical methods and
had identified a validated test method. (EPA has validated
feasible treatment methods that public water systems can
test methods for 29 PFAS.) In December 2021, EPA
use to monitor for contaminants and comply with the MCL.
finalized UCMR 5, which requires all water systems
They also include monitoring and reporting requirements
serving 3,300 or more people to monitor for 29 PFAS
(42 U.S.C. §300f(1), §300g-1).
(including the 6 PFAS identified in UCMR 3) and a metal
Drinking Water Regulation Enforcement
(i.e., lithium) between 2023 and 2025, and report the data
Drinking water regulation enforcement is generally a state
by 2026 (86 Federal Register 73131). As amended by
responsibility. SDWA requires EPA to delegate
America’s Water Infrastructure Act of 2018 (P.L. 115-270),
enforcement authority for SDWA regulations to states that
SDWA requires EPA to pay the reasonable costs of testing
meet certain criteria (42 U.S.C. §300g-2). Currently, 49
and laboratory analysis for systems serving between 3,300
states, the territories, and the Navajo Nation have applied
and 10,000 individuals (42 U.S.C. §300j-4(j)). Accordingly,
for and received primacy for the drinking water program.
EPA stated in its rule that the inclusion of such systems in
EPA retains enforcement authority for Wyoming, the
UCMR 5 is dependent on appropriations. For FY2023, EPA
District of Columbia, and other Indian tribes.
requests $12 million to support such monitoring.
Emergency Powers
Regulatory Determinations
SDWA authorizes EPA to take actions it deems necessary
SDWA requires EPA to make a regulatory determination
to abate an imminent and substantial endangerment to
(RD) of whether or not to promulgate a national drinking
public health from a contaminant (regulated or unregulated)
water regulation for at least five contaminants every five
that is present in or likely to enter a public water system or
years. In selecting contaminants for RDs, SDWA directs
an underground source of drinking water, if state and local
EPA to prioritize those that present the greatest health
authorities have not acted (42 U.S.C. §300i). EPA may
concern while considering a contaminant’s effects on
issue orders to require persons who caused or contributed to
subgroups that may be at greater risk of adverse health
the endangerment to provide alternative water supplies or to
impacts from exposure (e.g., infants, pregnant women).
treat contamination. Since 2002, EPA has used this
authority to require responses to PFOA and/or PFOS
To make a positive RD, SDWA directs EPA to find the
contamination of water supplies associated with four sites,
following: (1) a contaminant may have an adverse health
including three Department of Defense (DOD) sites.
effect; (2) it is known to occur or there is a substantial
likelihood that it will occur in water systems at a frequency
MCLs and Remedial Actions
and at levels of public health concern; and (3) in the sole
judgment of the EPA Administrator, regulation of a
Under the Comprehensive Environmental Response,
contaminant presents a meaningful opportunity for reducing
Compensation, and Liability Act (CERCLA, or “Superfund”),
health risks. EPA finalized positive RDs for PFOA and
MCLs may be considered in selecting remedial actions for
PFOS in March 2021 (86 Federal Register 12272). Since
releases of hazardous substances, pol utants, and other
1996, EPA has finalized positive RDs for three
contaminants (42 U.S.C. §9621(d)). CERCLA establishes
contaminants (i.e., PFOA, PFOS, and perchlorate). (In
liability only for releases of hazardous substances. No PFAS
2020, EPA withdrew the positive RD for perchlorate [85
has been designated as a hazardous substance, though the
Federal Register 43990.])
PFAS Strategic Roadmap states that EPA plans to propose to
designate PFOA and PFOS as hazardous substances in spring
Developing Drinking Water Regulations
2022, and finalize by summer 2023. (See CRS Report R45986,
Once EPA makes a final determination to regulate a
Federal Role in Responding to Potential Risks of Per- and
substance, SDWA prescribes a schedule for promulgating
Polyfluoroalkyl Substances (PFAS) for more information.)
regulations. EPA is required to propose a rule within 24
months and promulgate a final drinking water regulation
Recent Congressional Action
within 18 months after the proposal. EPA may extend the
Numerous bills have been introduced in recent Congresses
deadline to publish a final rule for up to nine months (42
to address PFAS in drinking water, and some have been
U.S.C. §300g-1(b)(1)). Regulations generally take effect
enacted. The Infrastructure Investment and Jobs Act (IIJA;
three years after promulgation. EPA may allow up to two
P.L. 117-58) Division J, Title VI appropriates $4 billion
additional years if the Administrator determines that water
over FY2022-FY2026 to address emerging contaminants
system capital improvements are needed. States have the
with a focus on PFAS in drinking water through a grant
same authority to allow two additional years on a system-
program within the Drinking Water State Revolving Fund
by-system basis (42 U.S.C. §300g-1(b)(10)).
added by the 2020 NDAA. IIJA also appropriates $5 billion
over FY2022-FY2026 for a SDWA grant program to
For each regulation, EPA is required to establish a
address emerging contaminants in small and disadvantaged
nonenforceable maximum contaminant level goal (MCLG)
communities. See CRS Report R45793, PFAS and Drinking
at a level at which no known or anticipated adverse health
Water: Selected EPA and Congressional Actions for more
effects occur, with an adequate margin of safety. For each
information on EPA actions and recent bills.
contaminant covered by the regulation, EPA generally
specifies a maximum contaminant level (MCL)—an
Elena H. Humphreys, Analyst in Environmental Policy
enforceable standard applicable to public water suppliers.
SDWA directs EPA to set the MCL as close to the MCLG
IF11219
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Regulating Drinking Water Contaminants: EPA PFAS Actions


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https://crsreports.congress.gov | IF11219 · VERSION 11 · UPDATED

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