Updated August 6, 2019
Regulating Drinking Water Contaminants: EPA PFAS Actions
Detections of per- and polyfluoroalkyl substances (PFAS)
nonenforceable levels to help water suppliers and others
in drinking water supplies and uncertainty about potential
address contaminants that lack federal (or state) drinking
health effects associated with exposure to PFAS have
water standards. In 2016, EPA issued Lifetime Health
increased congressional attention to the U.S. Environmental
Advisory levels for PFOA and PFOS in drinking water at
Protection Agency’s (EPA) efforts to address these
70 parts per trillion (ppt) separately or combined. These
substances in public water supplies. Over the past decade,
levels are intended to protect the most sensitive population
EPA has been evaluating several PFAS under the Safe
groups, with a margin of protection, over a lifetime of
Drinking Water Act (SDWA) to determine whether national
exposure. They replaced provisional advisory levels for
drinking water regulations may be warranted. EPA has not
short-term exposures to PFOA and PFOS that EPA had
issued SDWA regulations for any PFAS but has taken
issued in 2009.
various actions to address PFAS in drinking water.
Regulating Contaminants under SDWA
In the 116th Congress, bills have been introduced to direct
SDWA authorizes EPA to regulate contaminants in water
EPA to issue drinking water regulations and standards,
provided by public water systems and specifies a multistep
increase monitoring and research, and take other actions to
process for evaluating contaminants to determine whether a
address these substances. In February 2019, EPA issued a
national primary drinking water regulation is warranted (42
PFAS Action Plan (EPA 823R18004), which discusses
U.S.C. §300g-1). The evaluation process includes
EPA’s efforts to address PFAS under multiple
identifying contaminants of potential concern, assessing
environmental laws. This In Focus outlines the agency’s
health risks, collecting occurrence data (and developing
PFAS-related activities using SDWA authorities, with
reliable analytical methods necessary to do so), and making
particular focus on the process for evaluating contaminants
determinations as to whether a national drinking water
for regulation under SDWA. (For more details, see CRS
regulation is warranted for a contaminant.
Report R45793, PFAS and Drinking Water: Selected EPA
and Congressional Actions.)
To make a positive determination to regulate a contaminant,
SDWA directs EPA to find the following: (1) a contaminant
Background
may have an adverse health effect; (2) it is known to occur
PFAS include thousands of diverse chemicals, some of
or there is a substantial likelihood that it will occur in water
which have been used for decades in an array of industrial,
systems at a frequency and at levels of public health
commercial, and U.S. military applications. The chemical
concern; and (3) in the sole judgment of the Administrator,
characteristics of PFAS have led to the use of various PFAS
regulation of the contaminant presents a meaningful
for beneficial purposes (such as firefighting) and to process
opportunity for reducing health risks. Below is an overview
and manufacture numerous commercial products (e.g.,
of each step and related EPA efforts regarding the
stain-resistant and waterproof fabrics, nonstick cookware,
assessment of specific PFAS.
and food containers).The two PFAS that have been detected
in water most often are perfluorooctanoic acid (PFOA) and
Contaminant Selection
perfluorooctane sulfonate (PFOS). In 2016, EPA reported
Every five years, EPA is required to publish a list of
that PFOA and/or PFOS were detected in at least one public
contaminants that are known or anticipated to occur in
water system in 24 states. Four other PFAS were also
public water systems and may warrant regulation under the
detected in some systems. U.S. manufacturers have phased
act (42 U.S.C. §300g-1(b)). In 2009, EPA placed PFOA and
out the production and most uses of PFOA and PFOS.
PFOS on the third such contaminant candidate list (CCL 3)
for evaluation (74 Federal Register 51850). In November
SDWA provides EPA with several authorities to address
2016, EPA issued CCL 4, which carried over many CCL 3
unregulated contaminants in drinking water supplies and
contaminants, including PFOA and PFOS, for further
sources. As briefly discussed below, these include the
evaluation (81 Federal Register 81103).
authority to issue health advisories, regulate contaminants
in public water supplies, and issue enforcement orders in
Monitoring for Unregulated Contaminants
certain emergency circumstances.
To generate nationwide occurrence data for unregulated
contaminants, SDWA directs EPA to promulgate, every
Drinking Water Health Advisories
five years, an unregulated contaminant monitoring rule
SDWA authorizes EPA to issue health advisories for
(UCMR) that requires water systems operators to test for no
contaminants that are not regulated under the act (42 U.S.C.
more than 30 contaminants (42 U.S.C. §300j-4). EPA
§300g-1(b)(1)(F)). Health advisories provide information
generally requires monitoring by operators of all public
on health effects, testing methods, and treatment techniques
water systems that serve more than 10,000 persons, plus a
for unregulated contaminants of concern. They also include
representative sample of smaller systems. (Roughly 82% of
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Regulating Drinking Water Contaminants: EPA PFAS Actions
the U.S. population is provided water from public water
provide alternative water supplies or to treat contamination,
systems that serve more than 10,000 individuals.)
among other actions. Since 2002, EPA has used this
authority to require responses to PFOA and/or PFOS
In 2012, EPA issued the UCMR 3, requiring roughly 5,000
contamination of water supplies associated with four sites,
water systems to monitor for six PFAS—including PFOA
including three Department of Defense (DOD) sites.
and PFOS—between January 2013 and December 2015.
According to EPA, 63 water systems (1.3%) serving an
MCLs and Remedial Actions
estimated 5.5 million individuals detected PFOA and/or
Under the Comprehensive Environmental Response,
PFOS at levels above EPA’s health advisory level of 70 ppt
Compensation, and Liability Act (CERCLA, or “Superfund”),
(separately or combined).
MCLs may be considered in selecting remedial actions for
releases of hazardous substances, pol utants and other
Regulatory Determinations
contaminants (42 U.S.C. §9621(d)). However, CERCLA
SDWA requires EPA, every five years, to make a
establishes liability only for releases of hazardous substances.
regulatory determination—a determination of whether or
No PFAS has been designated as a hazardous substance. In the
not to promulgate a national primary drinking water
116th Congress, several bil s (e.g., H.R. 2500, H.R. 535, and S.
regulation—for at least five contaminants on the CCL.
638) would direct EPA to designate PFAS as hazardous
substances under CERCLA. Additionally, H.R. 2500, Section
In selecting contaminants for a regulatory determination,
330A, and H.R. 3616 would have the effect of making PFAS
SDWA directs EPA to prioritize those that present the
hazardous substances under CERCLA.
greatest health concern while considering a contaminant’s
effects on subgroups that may be at greater risk of adverse
health impacts from exposure to a contaminant (e.g.,
PFAS Action Plan: Drinking Water
infants, pregnant women). SDWA directs EPA to publish a
In addition to the actions described above, EPA’s Action
preliminary determination and seek public comment before
Plan identifies efforts related to evaluating PFAS for
finalizing a determination. In 2016, EPA included PFOA
potential regulation under SDWA. Among others, EPA is
and PFOS on its “short list” of contaminants identified for
(1) developing new analytical test methods to support
regulatory determinations in CCL 4 (81 Federal Register
monitoring of more PFAS and at lower levels (EPA has
81103). EPA plans to propose preliminary regulatory
validated test methods for 18 PFAS), (2) preparing to use
determinations for PFOA and PFOS by the end of 2019 and
new test methods to include other PFAS in the next UCMR
to make final determinations by the end of 2020.
in 2020 to assess their occurrence, and (3) expanding PFAS
toxicity information and providing more information about
Developing Drinking Water Regulations
PFAS treatment and costs.
Once the Administrator determines to regulate a substance,
EPA is required to propose a rule within 24 months and
Legislation in the 116th Congress
promulgate a national primary drinking water regulation
In the 116th Congress, numerous bills would address PFAS
within 18 months after the proposal. EPA may extend the
through various authorities and agencies. Among drinking-
deadline for up to nine months (42 U.S.C. §300g-1(b)(1)).
water-related bills, H.R. 2377 and S. 1473 would direct
EPA to issue an MCL for PFAS. H.R. 2800 would expand
For each regulation, EPA is required to establish a
monitoring for PFAS in drinking water. Several bills (e.g.,
nonenforceable maximum contaminant level goal (MCLG)
H.R. 2741, S. 611, H.R. 1417, H.R. 2533, and H.R. 2570)
at a level at which no known or anticipated adverse health
would authorize grants for systems and/or households to
effects occur, with an adequate margin of safety. For each
treat PFAS in drinking water.
contaminant covered by the regulation, EPA generally
specifies a maximum contaminant level (MCL)—an
Both the House- and Senate-passed National Defense
enforceable standard applicable to public water suppliers.
Authorization Acts for FY2020 (H.R. 2500 and S. 1790)
SDWA directs EPA to set the MCL as close to the MCLG
would address PFAS through several federal agencies and
as is “feasible” using best available technology or other
authorities. Title III and VII of both bills include PFAS
means available, taking costs into consideration. SDWA
provisions specific to DOD. Amending SDWA, Title
requires that regulations include analytical methods and
LXVII, Subtitle B, of S. 1790 would direct EPA to (1) issue
feasible treatment methods that public water systems can
MCLs for PFOA and PFOS (and potentially other PFAS)
use to monitor for contaminants and comply with the MCL.
within two years of enactment, (2) require monitoring for
They also include monitoring and reporting requirements
all PFAS with validated test methods in the next UCMR,
(42 U.S.C. §300f(1), §300g-1).
(3) issue health advisories for additional PFAS, and (4)
Emergency Powers
authorize use of Drinking Water State Revolving Funds to
provide grants to water systems to address PFAS and other
SDWA authorizes EPA to take actions it deems necessary
emerging contaminants and authorize funding for this
to abate an imminent and substantial endangerment to
purpose. Among the PFAS provisions of H.R. 2500, none
public health from a contaminant (regulated or unregulated)
would amend SDWA. Other provisions of both bills would
that is present in or likely to enter a public water system or
direct EPA to address PFAS under other environmental
an underground source of drinking water (42 U.S.C. §300i).
statutes or take other actions to address PFAS
This authority is available if state and local authorities have
contamination of water resources.
not acted. EPA actions may include issuing orders requiring
persons who caused or contributed to the endangerment to
Mary Tiemann, Specialist in Environmental Policy
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Regulating Drinking Water Contaminants: EPA PFAS Actions

IF11219
Elena H. Humphreys, Analyst in Environmental Policy


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