Regulating Drinking Water Contaminants: EPA PFAS Actions
Updated August 2, 2023
Regulating Drinking Water Contaminants: EPA PFAS Actions
The detection of certain per- and polyfluoroalkyl substances
Advisory levels at 0.004 ppt for PFOA and 0.02 ppt for
(PFAS) in some public water supplies has generated public
PFOS, significantly lower than the 2016 levels.
concern and increased attention to the U.S. Environmental
Protection Agency’s (EPA’s) actions to respond to PFAS
Regulating Contaminants Under SDWA
using Safe Drinking Water Act (SDWA) authorities. In
SDWA authorizes EPA to regulate contaminants in water
March 2021, EPA finalized a positive regulatory
provided by public water systems and specifies a multistep
determination (RD) to develop SDWA regulations for the
process for evaluating contaminants to determine whether a
two most frequently detected PFAS, perfluorooctanoic acid
drinking water regulation is warranted (42 U.S.C. §300g-1).
(PFOA) and perfluorooctane sulfonate (PFOS) (86 Federal
As discussed below, the process includes identifying
Register 12272). On March 29, 2023, EPA proposed a
contaminants of potential concern, assessing health risks,
national primary drinking water regulation (NPDWR) for
collecting occurrence data (and developing any necessary
PFOA and PFOS, and issued a preliminary positive RD
test methods), and making determinations as to whether a
and a proposed NPDWR for several other PFAS (88
federal drinking water regulation is warranted.
Federal Register 18638). Under SDWA, EPA is required to
finalize the rule within 18 months of the proposal.
Identifying Contaminants for Evaluation
Every five years, EPA is required to publish a list of
Background
contaminants that are known or anticipated to occur in
PFAS include thousands of diverse chemicals, some of
public water systems and may warrant regulation under the
which have been used for decades. The chemical
act (42 U.S.C. §300g-1(b)). In 2009, EPA placed PFOA and
characteristics of PFAS led to their use in an array of
PFOS on the third such contaminant candidate list (CCL 3)
industrial, commercial, and U.S. military applications.
for evaluation (74 Federal Register 51850). In November
These include use in fighting fuel-based fires and the
2016, EPA issued CCL 4, which carried over many CCL 3
processing and manufacturing of numerous products (e.g.,
contaminants, including PFOA and PFOS, for further
stain-resistant and waterproof fabrics, nonstick cookware,
evaluation (81 Federal Register 81103).
and food containers). PFOA and PFOS were the most
produced PFAS, historically. EPA worked with U.S.
Monitoring for Unregulated Contaminants
manufacturers as they voluntarily phased out production of
To generate nationwide occurrence data for unregulated
PFOS, PFOA, and related substances.
contaminants, SDWA directs EPA to promulgate, every
five years, an unregulated contaminant monitoring rule
In 2016, EPA reported that PFOA and/or PFOS were
(UCMR) that requires water systems operators to test for up
detected in at least one public water system in 24 states.
to 30 contaminants (42 U.S.C. §300j-4). EPA generally
Four other PFAS were also detected in some systems.
requires monitoring by operators of all public water systems
SDWA provides EPA with several authorities to address
that serve more than 10,000 persons, plus a representative
contaminants in drinking water supplies and sources. These
sample of smaller systems. (More than 80% of U.S.
include the authority to issue health advisories, regulate
residents receive water from public water systems that serve
contaminants in public water supplies, and issue
more than 10,000 individuals. More than half of water
“emergency powers” orders in certain circumstances.
systems serve fewer than 500 people.)
Drinking Water Health Advisories
In 2012, EPA issued the UCMR 3, requiring roughly 5,000
SDWA authorizes EPA to issue health advisories for
water systems to monitor for six PFAS—including PFOA
contaminants (42 U.S.C. §300g-1(b)(1)(F)). Advisories
and PFOS—between January 2013 and December 2015.
provide information on health effects, testing methods, and
According to EPA, 63 water systems (1.3%) serving an
treatment techniques, as well as identify nonenforceable
estimated 5.5 million individuals detected PFOA and/or
levels to help water suppliers and others address
PFOS at levels above EPA’s 2016 health advisory level of
contaminants that lack federal (or state) drinking water
70 ppt (separately or combined). UCMR 4 did not require
standards. In 2016, EPA issued Lifetime Health Advisory
monitoring for PFAS.
levels for PFOA and PFOS in drinking water at 70 parts per
trillion (ppt) separately or combined. In June 2022, EPA
As directed by the National Defense Authorization Act for
revised the advisories for PFOA and PFOS, and issued new
FY2020 (2020 NDAA; P.L. 116-92), EPA included on the
advisories for perfluorobutane sulfonic acid (PFBS) and
next UCMR (i.e., UCMR 5) every PFAS for which EPA
GenX chemicals. EPA finalized Lifetime Health Advisory
had identified a validated test method. (EPA has validated
levels for PFBS and GenX chemicals at 2,000 ppt and 10
test methods for 29 PFAS.) In December 2021, EPA
ppt, respectively. EPA issued interim Lifetime Health
finalized UCMR 5, which requires all water systems
serving 3,300 or more people to monitor for 29 PFAS
https://crsreports.congress.gov
Regulating Drinking Water Contaminants: EPA PFAS Actions
(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
NPDWR enforcement is generally a state responsibility.
by 2026 (86 Federal Register 73131). As amended by P.L.
SDWA requires EPA to delegate enforcement authority for
115-270, SDWA requires EPA to pay the reasonable costs
SDWA to states that meet certain criteria (42 U.S.C. §300g-
of testing and laboratory analysis for systems serving
2). Currently, 49 states, the territories, and the Navajo
between 3,300 and 10,000 individuals (42 U.S.C. §300j-
Nation have received primacy for the drinking water
4(j)). Accordingly, EPA stated that the inclusion of such
program. EPA retains enforcement authority for Wyoming,
systems in UCMR 5 is dependent on appropriations, and the
the District of Columbia, and other Indian tribes.
agency’s FY2024 budget request notes that the 5,200
systems that serve between 3,300 and 10,000 individuals
Proposed PFAS Drinking Water Regulation
and a sample of 800 systems serving fewer than 3,300
In March 2023, EPA proposed an NPDWR for PFOA and
individuals will be required to monitor under UCMR 5.
PFOS. At the same time, the agency proposed a positive
regulatory determination for perfluorobutane sulfonic acid
Regulatory Determinations
(PFBS), perfluorononanoic acid (PFNA), perfluorohexane
SDWA requires EPA to make a regulatory determination
sulfonic acid (PFHxS), and hexafluoropropylene oxide
(RD) of whether or not to promulgate an NPDWR for at
dimer acid (HFPO-DA) and its ammonium salt (also known
least five contaminants every five years. In selecting
as the GenX chemicals). EPA also proposed a regulation for
contaminants for RDs, SDWA directs EPA to prioritize
these substances (88 Federal Register 18638). For more
those that present the greatest health concern while
information about EPA’s proposal, see CRS In Focus
considering a contaminant’s effects on subgroups that may
IF12367, Safe Drinking Water Act: Proposed National
be at greater risk of adverse health impacts from exposure.
Primary Drinking Water Regulation for Specified PFAS.
To make a positive RD, SDWA directs EPA to find the
Emergency Powers
following: (1) a contaminant may have an adverse health
SDWA authorizes EPA to take actions it deems necessary
effect; (2) it is known to occur or there is a substantial
to abate an imminent and substantial endangerment to
likelihood that it will occur in water systems at a frequency
public health from a contaminant (regulated or unregulated)
and at levels of public health concern; and (3) in the sole
that is present in or likely to enter a public water system or
judgment of the EPA Administrator, regulation of a
an underground source of drinking water, if state and local
contaminant presents a meaningful opportunity for reducing
authorities have not acted (42 U.S.C. §300i). EPA may
health risks. EPA finalized positive RDs for PFOA and
issue orders to require persons who caused or contributed to
PFOS in March 2021 (86 Federal Register 12272). In
the endangerment to provide alternative water supplies or to
March 2023, EPA proposed positive RDs for PFBS, PFNA,
treat contamination. Since 2002, EPA has used this
PFHxS, and GenX chemicals (88 Federal Register 18638).
authority to require responses to PFOA and/or PFOS at five
Developing Drinking Water Regulations
sites, including three Department of Defense (DOD) sites.
Once EPA makes a final determination to regulate a
MCLs and Remedial Actions
substance, SDWA prescribes a schedule for promulgating
Under the Comprehensive Environmental Response,
NPDWRs. EPA is required to propose a rule within 24
Compensation, and Liability Act (CERCLA, or “Superfund”),
months and promulgate an NPDWR within 18 months after
MCLs may be considered in selecting remedial actions for
the proposal. EPA may extend the deadline to publish a
releases of hazardous substances, pol utants, and other
final rule for up to nine months (42 U.S.C. §300g-1(b)(1)).
contaminants (42 U.S.C. §9621(d)). CERCLA establishes
NPDWRs generally take effect three years after
liability only for releases of hazardous substances. No PFAS
promulgation. EPA may allow up to two additional years if
has been designated as a hazardous substance, though EPA
the Administrator determines that water system capital
proposed to designate PFOA and PFOS as hazardous
improvements are needed. States have the same authority to
substances in September 2022 (87 Federal Register 54415). See
allow two additional years on a system-by-system basis (42
CRS Report R45986, Federal Role in Responding to Potential
U.S.C. §300g-1(b)(10)).
Risks of Per- and Polyfluoroalkyl Substances (PFAS) for more
information.
For each NPDWR, EPA is required to establish a
nonenforceable maximum contaminant level goal (MCLG)
at a level at which no known or anticipated adverse health
Recent Congressional Action
effects occur, with an adequate margin of safety. For each
Numerous bills have been introduced in recent Congresses
contaminant covered by the rule, EPA generally specifies a
to address PFAS in drinking water, and some have been
maximum contaminant level (MCL)—an enforceable
enacted. The Infrastructure Investment and Jobs Act (IIJA;
standard applicable to public water suppliers. SDWA
P.L. 117-58) Division J, Title VI appropriates $4 billion
directs EPA to set the MCL as close to the MCLG as is
over FY2022-FY2026 to address emerging contaminants
“feasible” using best available technology or other means
with a focus on PFAS in drinking water through a grant
available, taking costs into consideration. SDWA requires
program within the Drinking Water State Revolving Fund
that NPDWRs include analytical methods and feasible
added by the 2020 NDAA. IIJA also appropriates $5 billion
treatment methods that public water systems can use to
over FY2022-FY2026 for an SDWA grant program to
monitor for contaminants and comply with the MCL. They
address emerging contaminants in small and disadvantaged
also include monitoring and reporting requirements (42
communities. See CRS Report R45793, PFAS and Drinking
U.S.C. §300f(1), §300g-1).
Water: Selected EPA and Congressional Actions, for more
information on EPA actions and recent bills.
https://crsreports.congress.gov
Regulating Drinking Water Contaminants: EPA PFAS Actions
IF11219
Elena H. Humphreys, Analyst in Environmental Policy
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
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https://crsreports.congress.gov | IF11219 · VERSION 13 · UPDATED