Safe Drinking Water Act: Proposed National Primary Drinking Water Regulation for Specified PFAS

Safe Drinking Water Act: Proposed National Primary Drinking Water Regulation for Specified PFAS

March 30, 2023
Safe Drinking Water Act: Proposed National Primary Drinking
Water Regulation for Specified PFAS
Detections of per- and polyfluoroalkyl substances (PFAS)
Every five years, EPA is required to publish a list of
in public water supplies have heightened public and
contaminants that are known or anticipated to occur in
congressional interest in the U.S. Environmental Protection
public water systems and may warrant regulation under the
Agency’s (EPA’s) authorities under the Safe Drinking
act (42 U.S.C. §300g-1(b)). In 2009, EPA placed PFOA and
Water Act (SDWA) to limit PFAS in drinking water.
PFOS on the third such contaminant candidate list for
evaluation (74 Federal Register (FR) 51850).
PFAS are fluorinated chemicals that have been used in
commercial, industrial, and U.S. military applications since
To generate nationwide occurrence data for unregulated
the 1940s. Some of the more common applications include
contaminants, SDWA directs EPA to promulgate, every
nonstick coatings, food wrappers, waterproof materials, and
five years, an unregulated contaminant monitoring rule
fire suppressants. According to the Agency for Toxic
(UCMR) that requires water systems to test for up to 30
Substances and Disease Registry, PFAS may have been
contaminants (42 U.S.C. §300j-4). EPA generally requires
released to surface or ground water from manufacturing
monitoring by all public water systems that serve more than
sites, industrial operations, use and disposal of PFAS-
10,000 persons, plus a representative sample of smaller
containing consumer products, fire/crash training areas,
systems. In 2012, EPA issued UCMR 3, requiring roughly
wastewater treatment facilities, and the spreading of
5,000 water systems to monitor for 6 PFAS—including
contaminated biosolids, among other activities. Scientific
PFOA and PFOS—between January 2013 and December
information is available for a select number of PFAS. For
2015. Among the UCMR 3 results, 95 systems had PFOS
those select PFAS, studies suggest that exposure to specific
detections, and 117 systems detected PFOA. In 2020, the
PFAS above certain levels may be linked to adverse health
National Defense Authorization Act for FY2020 (P.L. 116-
effects, such as developmental effects; changes in liver,
92) directed EPA to include on the next UCMR (i.e.,
immune, and cardiovascular function; and increased risk of
UCMR 5) every PFAS for which EPA had identified a
some cancers. Two of the historically most studied PFAS
validated test method. (EPA has validated test methods for
are perfluorooctanoic acid (PFOA) and perfluorooctane
29 PFAS.) In December 2021, EPA finalized UCMR 5,
sulfonate (PFOS).
which requires monitoring for 29 PFAS (including the 6
PFAS identified in UCMR 3) between 2023 and 2025, with
PFAS and Drinking Water
data reporting by December 2026 (86 FR 73131).
For more than a decade, EPA has been evaluating certain
PFAS to determine if these substances warrant regulation
For EPA to make a regulatory determination—a positive
under SDWA. After finalizing a determination to regulate
RD—that regulation of a contaminant is warranted, SDWA
PFOA and PFOS in March 2021, EPA proposed a drinking
directs EPA to find the following: (1) the contaminant may
water regulation for these substances on March 14, 2023.
have an adverse health effect; (2) the contaminant is known
At the same time, EPA proposed that the regulation include
to occur or there is a substantial likelihood that it will occur
four other PFAS. Under SDWA, EPA has 18 months (i.e.,
in water systems at a frequency and at levels of public
until September 14, 2024) to finalize the proposal. The
health concern; and (3) in the sole judgment of the EPA
following sections provide a brief overview of the SDWA
Administrator, regulation of the contaminant presents a
regulatory development provisions and key elements of
meaningful opportunity for reducing health risks. EPA
EPA’s proposed regulation, and discuss this development in
finalized positive RDs for PFOA and PFOS in March 2021
the context of recent legislative activity.
(86 FR 12272). Since 1996, EPA has finalized a positive
RD for one other contaminant: perchlorate. In 2020, EPA
SDWA Regulatory Development
withdrew perchlorate’s positive RD (85 FR 43990).
As amended in 1996, SDWA specifies a multistep process
for evaluating contaminants to determine whether a national
Once EPA finalizes a positive RD, SDWA prescribes a
primary drinking water regulation is warranted (42 U.S.C.
schedule for promulgating regulations. EPA is required to
§300g-1). The evaluation process includes identifying
propose a rule within 24 months and promulgate a final
contaminants of potential concern, assessing health risks,
drinking water regulation within 18 months after the
collecting occurrence data (and developing reliable
proposal. For each contaminant, EPA is required to
analytical methods necessary to do so), and making
establish a maximum contaminant level goal (MCLG) at a
determinations as to whether or not regulatory action is
level at which no known or anticipated adverse health
needed for a contaminant. For more information, see CRS
effects occur and which allows an adequate margin of
Report R46652, Regulating Contaminants Under the Safe
safety (42 U.S.C. §300g-1(b)(4)(A)). Regulations also
Drinking Water Act (SDWA).
include a maximum contaminant level (MCL)—an
enforceable limit for a contaminant in public water
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Safe Drinking Water Act: Proposed National Primary Drinking Water Regulation for Specified PFAS
supplies—or a treatment technique if an MCL is not
the combined risk of potential noncancerous health effects
feasible (42 U.S.C. §300g-1(b)(4)(B)). Concurrent with
associated with these PFAS.
proposing a regulation, SDWA requires that EPA publish
and seek public comment on a “health risk reduction and
Treatment Technologies
cost analysis” (HRRCA) for each contaminant covered by
EPA notes that conventional and most advanced water
the proposed regulation (42 U.S.C. §300g-1(b)(6)(C)).
treatment options are ineffective at removing PFAS from
water. To meet the MCLs, EPA proposes that the best
For each drinking water regulation, SDWA requires EPA to
available treatment technologies are anion exchange (AIX),
identify a list of best available technologies, treatment
granular activated carbon (GAC), reverse osmosis (RO),
techniques, and other means that EPA finds to be feasible
and nanofiltration (NF). Operation of these technologies
for the purposes of meeting the MCL. SDWA requires EPA
would require either waste-stream disposal or treatment-
to identify treatment technologies that achieve the MCL and
residuals disposal. Nontreatment options available to water
are “affordable” for small systems (42 U.S.C. §300g-
systems to achieve compliance include (1) replacing a water
1(b)(4)(E)(ii)). Each regulation also establishes monitoring
source with a new water source that meets the MCLs or (2)
and reporting requirements. EPA may extend the deadline
buying water that meets the MCLs from another system.
to publish a final rule for up to nine months (42 U.S.C.
§300g-1(b)(1)). Regulations generally take effect three
As required by SDWA, EPA’s proposal identifies
years after promulgation. EPA may allow up to two added
technologies that are “affordable” for small systems. EPA
years if the Administrator finds that capital improvements
finds that GAC and AIX are affordable for systems that
are needed. On a system-by-system basis, states can provide
serve 10,000 or fewer individuals. For systems serving
the same two-year extension (42 U.S.C. §300g-1(b)(10)).
more than 3,300 individuals, RO and NF are considered
affordable. For systems serving 3,300 individuals or fewer,
EPA’s Proposed PFAS Regulation
EPA finds that RO or NF would be affordable when RO or
On March 14, 2023, EPA announced its proposed national
NF point-of-use devices that treat to the MCLs and meet the
primary drinking water regulation (NPDWR) for PFOA and
National Sanitation Foundation (NSF) International
PFOS. The agency also proposed a positive RD for several
/American National Standards Institute certification
other PFAS: perfluorohexane sulfonic acid (PFHxS),
standard become available. As of the date of EPA’s
perfluorobutane sulfonic acid (PFBS), hexafluoropropylene
proposal, such devices are not available; accordingly, the
oxide dimer acid (HFPO-DA) and its ammonium salt (also
affordable technologies for water systems serving 3,300 or
known as a GenX chemicals), and perfluorononanoic acid
fewer individuals are GAC and AIX.
(PFNA). In the same notice, EPA proposed that the
NPDWR include these PFAS. EPA’s proposal was
Infrastructure Investment and Jobs Act
published at 88 FR 18638 on March 29, 2023.
The Infrastructure Investment and Jobs Act (IIJA; P.L. 117-
58) provides supplemental appropriations for the Drinking
MCLGs and MCLs for PFOA and PFOS
Water State Revolving Fund (DWSRF) and for another
For PFOA and PFOS, EPA proposed to set the MCLG at
SDWA program dedicated to emerging contaminant
zero. In NPDWRs, EPA sets the MCLG at zero for
projects. IIJA provides $800 million annually for FY2022-
microbial contaminants and for a contaminant that EPA (1)
FY2026 through the DWSRF for grants to water systems
has evidence that it may cause cancer, and (2) cannot
for projects that address emerging contaminants with an
determine a dose that is considered “safe.” SDWA
emphasis on PFAS. For small and disadvantaged
generally requires EPA to establish the MCL as close to the
communities, IIJA provides $1.0 billion annually for
MCLG as feasible (42 U.S.C. §300g-1(b)(4)(B)). The
FY2022-FY2026 for projects to address emerging
proposed NPDWR includes MCLs for PFOA and PFOS
contaminants. The term “emerging contaminant” has no
each at 4.0 parts per trillion (ppt), which EPA finds to be
federal definition but is mainly understood to mean
the lowest level that can be reliably measured by existing
unregulated contaminants for which scientific information
analytical methods, referred to as the detection limit.
on potential risks is still evolving. As such, these IIJA funds
are intended for projects to address contaminants without
Hazard Index for Four Other PFAS
NPDWRs though EPA states that PFAS projects will
Instead of numerical MCLGs and MCLs for each of the
remain eligible for these funds.
other four PFAS in the agency’s proposed regulation, EPA
proposes to use a hazard index approach to evaluate the
Should EPA meet the SDWA timeframe to finalize the
potential risks of these chemicals in aggregate. This
PFAS NPDWR, the regulation would go into effect in
involves assessing concentrations of each substance relative
September 2027. EPA states that it intends to finalize the
to that substance’s “health based water concentration”
rule by the end of 2023 and does not plan to delay the
(HBWC) and combining those relative values together to
effective date of 2026. EPA’s proposal anticipates that
calculate the hazard index. EPA’s proposal includes
smaller systems that need to install treatment to meet the
HBWCs for PFHxS at 9.0 ppt; HFPO-DA at 10.0 ppt;
PFAS MCLs would use the IIJA emerging contaminant
PFNA at 10.0 ppt; and PFBS at 2,000 ppt. Water systems
funds for these projects. These funds could help offset
would divide the sampled concentrations of each PFAS by
capital costs, yet communities would remain responsible for
its respective HBWC, and then sum these relative values to
the operation and maintenance of these technologies.
calculate the aggregate hazard index value. EPA proposed a
MCLG and MCL for the combination of these four PFAS at
Elena H. Humphreys, Analyst in Environmental Policy
a hazard index of 1. The hazard index is intended to address
IF12367
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Safe Drinking Water Act: Proposed National Primary Drinking Water Regulation for Specified PFAS

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