[Federal Register Volume 91, Number 97 (Wednesday, May 20, 2026)]
[Proposed Rules]
[Pages 29413-29425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-10085]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 141 and 142
[EPA-HQ-OW-2025-0654; FRL 12843-01-OW]
RIN 2040-AG53
Rescission of Regulatory Determinations and Removal of Related
Provisions for Four PFAS Substances (PFHxS, PFNA, HFPO-DA (GenX), and
the Mixture of These Three PFAS Plus PFBS)
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of proposed rule; request for public comment; notice of
public hearing.
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[[Page 29414]]
SUMMARY: The Environmental Protection Agency (EPA) is proposing to
rescind its regulatory determinations to regulate four per- and
polyfluoroalkyl substances (PFAS)--perfluorohexane sulfonic acid
(PFHxS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer
acid and its ammonium salt (HFPO-DA, commonly known as GenX chemicals),
and mixtures of these three PFAS plus perfluorobutane sulfonic acid
(PFBS)--under the Safe Drinking Water Act (SDWA). The EPA is also
proposing to rescind all associated regulatory provisions currently
codified in the EPA's 2024 PFAS National Primary Drinking Water
Regulations (NPDWR) exclusive to these PFAS that were promulgated
pursuant to the regulatory determinations that the EPA is now proposing
to rescind, including the final Maximum Contaminant Levels (MCLs) that
would have required monitoring, and where necessary, treatment by
public water systems (PWSs). This proposed action is necessary to
correct the unlawful procedure under which these regulations were
promulgated. Under the EPA's prior interpretation, the EPA proposed and
finalized regulatory determinations and regulations for these PFAS
simultaneously and in tandem. Under the best reading of the statute,
the EPA is not authorized to take such actions simultaneously and
therefore, the Agency proposes to rescind those regulatory
determinations, Maximum Contaminant Level Goals (MCLGs) and associated
portions of the 2024 PFAS NPDWR. The EPA is seeking public comment on
this proposal.
DATES: Comments must be received on or before July 20, 2026.
Public hearing: The EPA will hold a virtual public hearing on July
7, 2026. Please refer to the SUPPLEMENTARY INFORMATION section for
additional information on the public hearing.
ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OW-2025-0654, by any of the following methods:
Federal eRulemaking Portal: https://www.regulations.gov/
(our preferred method). Follow the online instructions for submitting
comments.
Email: [email protected]. Include Docket ID No. EPA-HQ-OW-
2025-0654 in the subject line of the message.
Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Office of Water Docket, Mail Code 28221T, 1200 Pennsylvania
Avenue NW, Washington, DC 20460.
Hand Delivery or Courier: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operations are 8:30 a.m. to 4:30 p.m.,
Monday through Friday (except Federal Holidays).
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to https://www.regulations.gov, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.
Information related to the virtual hearing can be found at https://www.epa.gov/sdwa/proposed-pfas-rescission-rule. The hearing will
convene at 11:00 a.m. eastern time and will conclude at 7 p.m. eastern
time, or at the conclusion of public testimony, whichever is sooner.
Refer to the SUPPLEMENTARY INFORMATION section below for additional
information.
FOR FURTHER INFORMATION CONTACT: Nicole Shao, Office of Ground Water
and Drinking Water, Standards and Risk Management Division (Mail Code
4601M), Environmental Protection Agency, 1200 Pennsylvania Avenue NW,
Washington, DC 20460; telephone number: 202-564-6779; email address:
[email protected].
SUPPLEMENTARY INFORMATION:
Table of Contents
I. General Information
A. Does this action apply to me?
B. What action is the Agency proposing?
C. What is the Agency's authority for proposing this action?
D. What are the incremental costs and benefits of this action?
II. Safe Drinking Water Act (SDWA) Legal Background
III. Procedural Background
IV. Basis for This Proposal
V. Proposed Rescission of Regulatory Determinations for PFHxS, PFNA,
HFPO-DA, and the Mixture of PFHxS, PFNA, HFPO-DA, Plus PFBS, and
Associated Regulatory Provisions
VI. Economic Analysis
VII. Primacy Requirements
VIII. Public Participation
A. Request for Public Comment
B. Written Comments
C. Participation in Virtual Public Hearing
IX. Statutory and Executive Orders Reviews
A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
B. Executive Order 14192: Unleashing Prosperity Through
Deregulation
C. Paperwork Reduction Act (PRA)
D. Regulatory Flexibility Act (RFA)
E. Unfunded Mandates Reform Act (UMRA)
F. Executive Order 13132: Federalism
G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
H. Executive Order 13045: Protection of Children From
Environmental Health & Safety Risks
I. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
J. National Technology Transfer and Advancement Act (NTTAA)
K. Consultations With the National Drinking Water Advisory
Council (NDWAC) and the Secretary of Health and Human Services (HHS)
1. NDWAC
2. HHS
X. References
I. General Information
A. Does this action apply to me?
Entities impacted by this action include PWSs that are community
water systems (CWSs) or non-transient non-community water systems
(NTNCWSs). A PWS, as defined in 40 CFR 141.2, provides water to the
public for human consumption through pipes or ``other constructed
conveyances, if such system has at least fifteen service connections or
regularly serves an average of at least twenty-five individuals daily
at least 60 days out of the year.'' A PWS is either a CWS or a non-
community water system. A CWS, as defined in 40 CFR 141.2, is ``a
public water system which serves at least 15 service connections used
by year-round residents or regularly serves at least 25 year-round
residents.'' The definition in 40 CFR 141.2 for a NTNCWS is ``a public
water system that is not a [CWS] and that regularly serves at least 25
of the same persons over 6 months per year.'' The following table
provides examples of the regulated entities under this rulemaking:
------------------------------------------------------------------------
Examples of potentially
Category affected entities
------------------------------------------------------------------------
PWSs......................................... CWSs; NTNCWSs.
State and Tribal agencies.................... Agencies responsible for
drinking water
regulatory development
and enforcement.
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[[Page 29415]]
If you have questions regarding the applicability of this action to
a particular entity, consult the person listed in the FOR FURTHER
INFORMATION CONTACT section.
B. What action is the Agency proposing?
The EPA is proposing to rescind its determinations to regulate
three PFAS individually--PFHxS, PFNA, HFPO-DA--and any mixture
containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS through a
hazard index (HI) (collectively, the Index PFAS).
In conjunction with this proposed rulemaking, the EPA is also
proposing to rescind the MCLGs and the 2024 Final PFAS NPDWR
requirements resulting from the regulatory determinations for the
contaminants described above. This includes the regulatory text in 40
CFR part 141 setting MCLGs and MCLs for PFHxS, PFNA, HFPO-DA, and the
Index PFAS. The proposal includes the removal of entries from the MCL
table, compliance provisions, and relevant sections including 40 CFR
141.900 specifically related to regulation of PFHxS, PFNA, HFPO-DA, and
the Index PFAS. This action does not impact the MCLGs, MCLs or the
regulatory provisions associated with monitoring or reporting from 40
CFR part 141 related to perfluorooctanoic acid (PFOA) and
perfluorooctane sulfonate (PFOS).
C. What is the Agency's authority for proposing this action?
The EPA proposes to rescind the relevant regulatory determinations,
MCLGs, and MCLs because they were promulgated using an unlawful
procedure which resulted in unlawful regulatory determinations, MCLGs
and NPDWRs for these contaminants.
D. What are the incremental costs and benefits of this action?
The EPA estimates that this proposed action would result in a
reduction of previously expected national compliance costs and would
relieve regulated entities, particularly PWSs, of specific monitoring,
treatment, and reporting obligations related specifically to these
drinking water contaminants. Removing the PFHxS NPDWR is estimated to
save $11.6 million (in 2022 dollars) in annualized quantified costs per
year. There are additional nonquantifiable costs: see section VI of
this preamble for further discussion.
This proposed deregulatory action is expected to yield a reduction
in previously expected benefits of approximately $6.7 million. There
are additional nonquantifiable reductions in previously expected
benefits in addition to other potential foregone benefits. See section
VI of this preamble for further discussion.
II. Safe Drinking Water Act (SDWA) Legal Background
SDWA section 1412 authorizes the EPA to regulate drinking water
contaminants through a carefully enumerated and sequential process. See
SDWA Sec. 1412(b). The EPA must issue a Contaminant Candidate List
(CCL) every five years with priority contaminants that are not yet
regulated but occur or are anticipated to occur in PWSs. Id. Sec.
1412(b)(1)(B)(i). Every five years, the EPA must also issue
determinations as to whether to regulate five or more contaminants on
the CCL based on statutory criteria. Id. Sec. 1412(b)(1)(B)(ii). The
EPA may also make a regulatory determination outside of the candidate
listing process. Id. Sec. 1412(b)(1)(B)(ii)(III).
The Act provides a specific process by which the EPA can determine
to regulate a new contaminant. Id. The EPA must publish a preliminary
determination and provide an opportunity for public comment before
making its determination to regulate the contaminant. Id. Sec.
1412(b)(1)(B)(ii), (iii). When making its final regulatory
determination, the EPA must determine that (i) ``the contaminant may
have an adverse effect on the health of persons;'' (ii) ``the
contaminant is known to occur or there is a substantial likelihood that
the contaminant will occur in public water systems with a frequency and
at levels of public health concern;'' and (iii) ``in the sole judgment
of the Administrator, regulation of such contaminant presents a
meaningful opportunity for health risk reduction for persons served by
public water systems.'' Id. Sec. 1412(b)(1)(A).
For each contaminant that the EPA ``determines to regulate,'' the
Agency must publish an MCLG and NPDWR for that contaminant through
notice-and-comment rulemaking. Id. Sec. 1412(a)(3), (b)(1)(A), (d),
(E). An NPDWR generally includes enforceable standards known as MCLs
that establish the ``maximum permissible level of a contaminant in
water which is delivered to any user of a public water system.'' Id.
Sec. 1401(1), (3).
The Act imposes express limits on the sequencing of and deadlines
for the EPA's regulatory determination and standard-setting processes.
It states that the EPA ``shall propose the maximum contaminant level
goal and national primary drinking water regulation for a contaminant
not later than 24 months after the determination to regulate . . . and
may publish such proposed regulation concurrent with the determination
to regulate.'' Id. Sec. 1412(b)(1)(E) (emphasis added). The Act thus
requires, in addition to the iterative listing of candidate
contaminants, sequencing: (1) a preliminary regulatory determination, a
public comment period, and a final regulatory determination; and (2) a
proposed substantive regulation no earlier than the final regulatory
determination, a second public comment period, and then a final
regulation. Id. The Act provides the EPA 18 months to promulgate a
final MCLG and NPDWR after it issues its proposal, with a possible
nine-month extension. Id.
The EPA's promulgation of an NPDWR triggers the Agency's ongoing
obligation to ``review and revise, as appropriate, each [NPDWR]
promulgated under this subchapter.'' The EPA must conduct the review
not less than every six years. Id. Sec. 1412(b)(9). The statute
provides further that ``[a]ny revision of a [NPDWR] . . . shall
maintain, or provide for greater, protection of the health of
persons.'' Id. The D.C. Circuit--which has exclusive jurisdiction to
review NPDWRs promulgated under SDWA--has interpreted this language to
mean that ``[r]evised regulations may increase but not decrease health
protections.'' Arizona v. EPA, 77 F.4th 1126, 1127 (D.C. Cir. 2023);
see, e.g., City of Waukesha v. EPA, 320 F.3d 228, 257 (D.C. Cir. 2003)
(``accept[ing] as reasonable the EPA's reading of the section as
barring any revision to an existing MCL that does not maintain the
level of protection the current MCL actually provides'' (emphasis
omitted)).
III. Procedural Background
For PFOA and PFOS, the EPA followed the statutorily prescribed
sequencing by proposing and finalizing a regulatory determination
through notice-and-comment before proposing and finalizing a regulation
through a further round of notice-and-comment. The EPA added PFOA and
PFOS to the CCL in 2009 for evaluation. 74 FR 51850 (October 8, 2009).
In 2020, the EPA proposed affirmative regulatory determinations for
PFOA and PFOS after tentatively concluding that both may have an
adverse effect on the health of persons, are known to or are
substantially likely to occur in PWSs, and that regulation could
meaningfully reduce health risks. 85 FR 14098, 14107, 14116 and 14117
(March 10, 2020). In 2021, the EPA finalized the regulatory
determinations for PFOA and PFOS after soliciting and responding to
public comment. 86 FR 12272 (March 3, 2021).
[[Page 29416]]
In 2023, the EPA proposed an MCLG of zero and an NPDWR that included an
MCL of 4 nanograms per liter (ng/L) or parts per trillion (ppt) based
on findings in the final regulatory determination, confirmed in the
PFOA and PFOS Human Health Toxicity Assessments informing the NPDWR,
that PFOA and PFOS have carcinogenic properties. 88 FR 18638 (March 29,
2023). In 2024, the EPA finalized an MCLG of zero and an NPDWR that
included the MCL of 4.0 ppt. 89 FR 32532, 32532 through 32557 (April
26, 2024).
Although the EPA followed the statutorily required process for PFOA
and PFOS, the EPA followed an unlawful procedure to propose and
finalize regulatory determinations, MCLGs, and NPDWR for PFHxS, PFNA,
HFPO-DA and the Index PFAS. Specifically, the EPA issued five
preliminary regulatory determinations for PFHxS, PFNA, HFPO-DA, PFBS,
and the mixture of one or more of these four PFAS on March 29, 2023.
Simultaneously, the EPA proposed an MCLG and an NPDWR for the mixture
of one or more of these four PFAS. 88 FR 18638 (March 29, 2023). On
April 26, 2024, after considering public comment, the EPA issued four
final regulatory determinations for PFHxS, PFNA, HFPO-DA, and the Index
PFAS and simultaneously promulgated a final NPDWR for these four
contaminants. 89 FR 32532, April 26, 2024. The EPA deferred its
individual regulatory determination to regulate PFBS in drinking water.
Id. at 32539.
The EPA's final regulatory determinations and portions of the EPA's
NPDWR issued April 26, 2024 are the subject of pending litigation. Am.
Water Works Ass'n, et al. v. EPA, et al., No. 24-1188 (D.C. Cir.).
IV. Basis for This Proposal
After reconsidering the Agency's rulemaking record, the relevant
issues raised in litigation and evaluating the Supreme Court's
intervening decision in Loper Bright Enterprises v. Raimondo, 603 U.S.
369 (2024), the EPA has concluded that the Agency promulgated an
unlawful drinking water standard by proposing and finalizing a drinking
water standard for PFHxS, PFNA, HFPO-DA and the Index PFAS without
following the stepwise process mandated by Congress. The EPA's unlawful
promulgation thwarted the fundamental processes required under the
statute and affects not just the NPDWR but also the simultaneously
issued regulatory determinations for these contaminants.
SDWA specifically requires the Agency to take a seriatim approach
to regulation in which the Agency must first propose to regulate a
particular drinking water contaminant and seek public comment on
whether regulation is appropriate. SDWA section 1412(b)(1)(E). Only
after the public has had the opportunity to comment on that proposal
and when the EPA has finalized a determination to regulate may the EPA
publish a proposed regulation of that contaminant, either
simultaneously with the final regulatory determination or after that
final determination. Id. Thus, the Act specifically requires two
sequential public comment periods before an NPDWR may be finalized.
During its rulemaking process for PFHxS, PFNA, HFPO-DA, PFBS and
the Index PFAS, the EPA interpreted the statute for the first time as
authorizing the Agency to simultaneously publish a preliminary
regulatory determination and a proposed regulation for public comment,
and to simultaneously publish a final regulatory determination with a
final regulation. See 88 FR 18644, 89 FR 32540 and 32541. After further
considering the statute, the EPA concludes that the best reading of
SDWA section 1412(b)(1)(E) is that the soonest the EPA may publish a
proposed regulation is with the final regulatory determination, not
with the preliminary regulatory determination.
The relevant phrase, ``determination to regulate,'' only appears
twice in this statutory provision, in the same sentence. The first
occurrence explicitly cross-references ``the determination to regulate
under subparagraph (B)'' of section 1412. Subparagraph (B) indisputably
sets forth the specific steps the EPA must take when issuing the final
``determination to regulate.'' Id. Sec. 1412(b)(1)(B)(ii). One of the
intermediate steps subparagraph (B) identifies in the progression to
the ``determination to regulate'' is providing ``notice of the
preliminary determination and opportunity for public comment. . .'' Id.
Sec. 1412(b)(1)(B)(ii)(I) (emphasis added). Because the reference to
the ``preliminary determination'' is a step necessary to the
``determination to regulate,'' the only valid reading of ``the
determination to regulate under subparagraph (B)'' is that it is the
final determination. See also id. Sec. 1412(b)(1)(E) (requiring that
``[f]or each contaminant that the Administrator determines to regulate
under subparagraph (B)'' the EPA must publish an MCLG and promulgate an
NPDWR, which are statutory obligations only triggered when the EPA
issues a final determination).
In its second occurrence of ``determination to regulate'' in the
Act's provision sequencing the regulatory determination and the
regulation, the statute provides that the EPA ``may publish [a]
proposed regulation concurrent with the determination to regulate.''
Id. The EPA previously interpreted this second usage of ``determination
to regulate'' to refer to a preliminary regulatory determination rather
than a final regulatory determination.
After further review of the statutory text, the EPA concludes that
the best reading of the precise term ``determination to regulate'' only
refers to the final determination. See, e.g., Id. Sec.
1412(b)(1)(B)(ii), (b)(1)(E). The statute only refers to
``determination to regulate'' in subsections 1412(b)(1)(B) when
outlining the steps necessary for the final regulatory determination
and in subsection 1412(b)(1)(E) when setting forth the sequencing of
the final regulatory determination and the regulation.
The EPA's further consideration of the precise language in
1412(b)(1)(B)(ii) also supports its changed interpretation. Subsection
1412(b)(1)(B)(ii)(I) states that, after receiving public comments, the
EPA shall make ``determinations of whether or not to regulate
[particular] contaminants.'' Because these determinations are made
after notice and comment are completed, it is clear from the context
that ``determinations'' referred to here are final determinations,
though they may be determinations either for or against regulation.
Subsection 1412(b)(1)(B)(ii)(II) and (III) then use the term
``determination to regulate a contaminant'' to refer to a final
determination--not a preliminary determination--that the statutory
criteria are satisfied and that regulation is warranted. Finally,
subsection 1412(b)(1)(B)(ii)(IV) states that ``[a] determination under
this clause not to regulate a [particular] contaminant shall be
considered final agency action and subject to judicial review.'' That
provision also refers to a final determination, made after the Agency
has considered public comments, that a particular contaminant should
not be regulated.
To support its prior interpretation, the EPA noted that the
statute's use of the term ``determination'' in section
1412(b)(1)(B)(iii) to refer to a preliminary determination elsewhere in
the statute demonstrates that Congress did not use the term
``determination to regulate'' to consistently refer to a final
determination. 89 FR 32541. Upon further analysis, the EPA acknowledges
the context of that provision obviates
[[Page 29417]]
the need for the word ``preliminary.'' Because section
1412(b)(1)(B)(iii) specifically addresses the requirement for public
comment on ``the determination,'' the context makes clear that it
refers to a preliminary determination without requiring the specific
term ``preliminary.'' Moreover, this provision refers to a
``determination'' put out for public comment; it does not use the
specific term ``determination to regulate'' at issue subsection
1412(b)(1)(E).
Although SDWA section 1412 sometimes uses the term
``determination'' to refer to a preliminary determination, it uses the
specific phrase ``determination to regulate'' (as well as the phrase
``determination under this clause not to regulate'' and the umbrella
phrase ``determinations of whether or not to regulate'') only to refer
to the final determinations that the EPA makes after completing notice
and comment on the preliminary determination. Because courts
``generally presume differences in language . . . convey differences in
meaning,'' Rudisill v. McDonough, 601 U.S. 294, 308 (2024), Congress's
specific use of ``determination to regulate'' should be construed to
refer to the final determination to regulate here.
By expressly authorizing the EPA to concurrently publish a proposed
rule with a final regulatory determination, Congress made clear that it
wanted the EPA to act within a certain window--immediately and up to 24
months later--only after determining that the statutory standard for
regulation is satisfied. Given the breadth of the EPA's authority to
list, evaluate, and regulate drinking water contaminants, this
requirement plays a critical role in the statutory scheme and in
ensuring that the Agency proceeds stepwise in a transparent and
scientifically sound manner. This conclusion is further bolstered by
Congress' imposition of a carefully constructed systematic approach to
the regulation of contaminants under SDWA.
In addition to previously arguing that Congress was inconsistent in
its terminology and that the meaning of ``determination'' must be
inferred from context, the EPA also supported its prior interpretation
because: (1) it is the only reading that gives the language independent
meaning because no provision in SDWA or general principle of
administrative law would otherwise preclude the EPA from issuing a
final regulatory determination concurrent with a proposed rule; and (2)
this reading best reflects Congress' goal of accelerating the
regulatory process for contaminants that present meaningful public
health risks, which is the apparent purpose of its allowance for
``concurrent'' processes. 89 FR at 32540 through 32542.
First, the EPA argued that interpreting the second usage of
``determination to regulate'' in SDWA section 1412(b)(1)(E) as a final
determination would render that clause null because no provision in
SDWA would otherwise preclude the EPA from issuing a final
determination concurrently with a proposed rule. In support of this
argument, the EPA explained that SDWA requirement to propose
regulations ``not later than 24 months after'' a final regulatory
determination establishes when the EPA's deadline begins to run; it was
not the beginning of an exclusive window for the EPA to propose a
NPDWR. 89 FR 32541. After further careful analysis of this subsection,
the EPA has now concluded that reading the second usage of
``determination to regulate'' as the final determination is, in fact,
the only reading that gives independent meaning to this phrase when
considered as part of subsection 1412(b)(1)(E) as a whole. The best
reading of subsection 1412(b)(1)(E) demonstrates that it provides a
very specific 24-month window in which a regulation may be proposed.
The first usage of subsection 1412(b)(1)(E) provides that the latest
the EPA can propose a regulation is 24 months after a final regulatory
determination. The second usage provides that the earliest the EPA can
propose a regulation is concurrent with a final regulatory
determination. Put differently, the statute provides that the EPA has
exactly 24 months to propose a regulation starting from the date the
final regulatory determination is published. The EPA's prior reading
failed to give full effect to this statutorily prescribed window.
Second, reading both the first and second usages of ``determination
to regulate'' as referring to the final regulatory determination
effectuates Congress' goal in enacting this provision. See 89 FR 32541.
This reading maintains the EPA's deadline to propose a regulation
within 24 months of the final regulatory determination, while also
maintaining Congress's commitment to ensuring the EPA's ultimate
regulation benefits from the required consultations and public input.
See, e.g., SDWA section 1412(b)(1)(B)(ii), (b)(1)(B)(iii), (b)(3)(C),
(b)(6)(A), (e). Thus, under the EPA's changed interpretation,
subsection 1412(b)(1)(E) accelerates the rulemaking process while
ensuring that the resulting regulation affords the public and regulated
entities multiple rounds of opportunity to inform its analysis and
contents.
V. Proposed Rescission of Regulatory Determinations for PFHxS, PFNA,
HFPO-DA, and the Mixture of These PFHxS, PFNA, HFPO-DA, Plus PFBS, and
Associated Regulatory Provisions
The EPA erred by issuing an MCLG and promulgating an NPDWR without
first completing the regulatory determination as a necessary
prerequisite to rulemaking. The EPA's legal error was based on an
incorrect interpretation of 1412(b)(1)(E) to authorize the EPA to issue
a proposed rule simultaneously with a preliminary determination. The
EPA now concludes that the best reading of SDWA section 1412(b)(1)(E)
is, in adherence to the plain language of the statute, that the soonest
the EPA may publish a proposed regulation is with the final regulatory
determination, not with the preliminary regulatory determination. As a
result, the EPA's rule regulating PFHxS, PFNA, HFPO-DA and the Index
PFAS was issued without the proper authorizing action, and because of
this error the resulting regulatory determinations, MCLGs and NPDWRs
are unlawful. Through this proposed rulemaking, the EPA is proposing to
rescind the regulatory determinations for PFHxS, PFNA, HFPO-DA and the
Index PFAS, as well as the MCLGs and the associated portions of the
NPDWR because they were unlawful and should be rescinded. Specifically,
the EPA proposes to remove the regulatory text in 40 CFR parts 141 and
142 for PFHxS, PFNA, HFPO-DA and the Index PFAS, as regulated through
the HI approach. This action does not impact the numeric MCLs, or the
regulatory provisions associated with monitoring or reporting from 40
CFR part 141 related to two other PFAS: PFOA and PFOS.
The EPA's proposal is solely based on its conclusion that the
Agency legally erred for the reasons described in this notice of
proposed rulemaking and is seeking comment on those reasons. The EPA's
proposal is not based on any reassessment of the substantive findings
included in its regulatory determinations or associated NPDWR
provisions. As a result, the EPA is not seeking comment on its
substantive findings supporting either its regulatory determinations or
its associated NPDWR provisions, including any information about health
risks associated with PFAS, cost of regulation, or occurrence
information.
The EPA's rescission of the regulatory determinations is not in
conflict with D.C. Circuit's decision holding that the EPA lacks
authority to withdraw a
[[Page 29418]]
regulatory determination. NRDC v. Regan, 67 F.4th 397 (D.C. Cir. 2023).
The NRDC decision addressed the EPA attempted withdrawal of its
determination to regulate perchlorate based on scientific information
and analysis that became available between the final regulatory
determination and the initiation of rulemaking to promulgate an NPDWR.
The D.C. Circuit did not address the EPA's interpretation of paragraph
(b)(1)(E). In this situation, unlike NRDC, the regulatory determination
is based on the EPA's exceedance of its SDWA authority which denied
interested parties the benefits of the full stepwise procedure
established by Congress. That is fundamentally different from the
Agency reversing based on information collected after the
determination, and this situation therefore would not be governed by
the NRDC decision.
Similarly, the EPA's proposal to rescind unlawful regulatory
determinations, MCLGs and NPDWR for PFHxS, PFNA, HFPO-DA and the Index
PFAS does not trigger SDWA's anti-backsliding requirements. Section
1412(b)(9) of the SDWA directs the EPA to ``review and revise'' each
NPDWR ``not less often than every 6 years'' and that ``[a]ny revision
of a [NPDWR] . . . shall maintain, or provide for greater, protection
of the health of persons'' SDWA section 1412(b)(9). The context and
structure of this provision makes clear that SDWA section 1412(b)(9)
applies to a ``revision'' of a lawfully promulgated NPDWR made after a
``review'' of that NPDWR. Section 1412(b)(9) of the SDWA does not
govern the rescission of unlawfully promulgated NPDWRs. In the instance
where a court vacates an NPDWR for failing to meet SDWA's requirements,
vacatur of an unlawful NPDWR does not trigger the SDWA section
1412(b)(9) anti-backsliding requirements. So here too, where the EPA
has determined that it unlawfully issued a proposed NPDWR
simultaneously with preliminary regulatory determinations for PFHxS,
PFNA, HFPO-DA, PFBS and mixtures of the PFAS, and ultimately
promulgated a final NPDWR with final regulatory determinations for
PFHxS, PFNA, HFPO-DA and the Index PFAS, rescission of unlawful
portions of the PFAS NPDWR does not trigger SDWA section 1412(b)(9)
anti-backsliding requirements. Even if the EPA's proposal to rescind
unlawful portions of the PFAS NPDWR trigger SDWA section 1412(b)(9)
requirements, the EPA's proposal ``maintain[s] . . . protection of the
health of persons.'' Id. The D.C. Circuit has interpreted the ``anti-
backsliding'' requirements of SDWA section 1412(b)(9) to mean that
``[r]evised regulations may increase but not decrease health
protections.'' Arizona v. EPA, 77 F.4th 1126, 1127 (D.C. Cir. 2023).
Furthermore, the Court has ``accept[ed] as reasonable EPA's reading of
the section as barring any revision to an existing M.C.L. that does not
maintain the level of protection the current M.C.L. actually
provides.'' City of Waukesha v. EPA, 320 F.3d 228, 257 (D.C. Cir.
2003). The statute does not prescribe how the EPA should determine if a
revision to an NPDWR ``maintain[s] protection of the health of
persons.'' Where the EPA revises an NPDWR and the compliance deadline
for the NPDWR has not passed, it is appropriate to determine if the
revised NPDWR maintains human health protection as compared to what
actually exists at the time the EPA makes its revision (i.e., the level
of protection the current MCL actually provides). In this instance,
none of the MCL compliance deadlines for PFHxS, PFNA, HFPO-DA, and the
Index PFAS have passed. Because there are currently no enforceable MCL
compliance deadlines for PFHxS, PFNA, HFPO-DA, and the Index PFAS,
rescission of these portions of the NPDWR will not change the level of
public health protection from current levels. This proposed rule
``maintain[s] protection of the health of persons,'' because the
baseline for comparison is no regulation for these contaminants. Thus,
the EPA's rescission of portions of the NPDWR for PFHxS, PFNA, HFPO-DA
and the Index PFAS is consistent with SDWA section 1412(b)(9) because
it simply maintains the status quo protection that is currently
afforded to the public.
VI. Economic Analysis
As discussed above, this action proposes to rescind the regulatory
text in 40 CFR part 141 setting MCLGs and NPDWRs related to PFHxS,
PFNA, HFPO-DA, and the Index PFAS regulated through the HI. SDWA
requires the EPA to conduct a Health Risk Reduction and Cost Analysis
(HRRCA) ``[w]hen proposing any national primary drinking water
regulation that includes a maximum containment level.'' SDWA section
1412(b)(3)(C)(i). SDWA also requires that the Administrator ``publish a
determination as to whether the benefits of the maximum contaminant
level justify, or do not justify, the costs based on the analysis
conducted under paragraph 3(C)'' when proposing an NPDWR. Id. Sec.
1412(b)(4)(C). Because the EPA is not proposing an enforceable NPDWR
that includes an MCL but instead proposes to rescind portions of an
NPDWR (including MCLs) that were promulgated without following the
statutorily-prescribed process, the EPA's obligations to prepare a
HRRCA and make a determination under SDWA section 1412 are not
triggered. The purpose of a HRRCA is to provide transparency to the
public, through public comment, of the costs and benefits of regulating
contaminants in drinking water at a particular level (and alternative
levels, if any) and for the EPA to use this analysis ``for the purposes
of paragraphs (4), (5) and (6)'' to make the required determination and
set alternatives levels as appropriate. Id. Sec. 1412(b)(3)(C)(i).
None of these purposes are relevant to the EPA's proposal to rescind
unlawful portions of enforceable regulations. Nonetheless, the EPA's
economic analysis, which was conducted pursuant to Executive Order
12866, addresses the substance of paragraphs 1412(b)(3)(C).
The EPA estimates that this proposed action would result in a
reduction of national compliance costs and would relieve regulated
entities, particularly PWSs, of specific monitoring, treatment, and
reporting obligations related specifically to these drinking water
contaminants.
The estimation of regulatory cost differences between the April
2024 Final PFAS NPDWR and the regulatory requirements of this proposed
rule were calculated using the estimated cost difference between the
April 2024 Final PFAS NPDWR, which represents the baseline for this
proposed rule and includes PFOA and PFOS MCLs of 4.0 ppt each; PFHxS,
PFNA, and HFPO-DA MCLs of 10 ppt each; and an HI of 1 (unitless), and
an alternative regulatory option that was considered during the
development of the 2024 Final PFAS NPDWR, ``Option 1a'' which is
representative of compliance requirements for this proposed rule
setting only PFOA and PFOS MCLs of 4.0 ppt. The estimated costs for
both the 2024 Final PFAS NPDWR and Option 1a can be found in the
Federal Register for the 2024 Final PFAS NPDWR (USEPA, 2024a) and/or
the Economic Analysis for the Final Per- and Polyfluoroalkyl Substances
National Primary Drinking Water Regulation (USEPA, 2024b) and
Appendices (USEPA, 2024c).
Given PFAS occurrence data available in USEPA 2024a, the EPA's
quantified total national-level annualized costs for the 2024 Final
PFAS NPDWR represent only the implementation of PFOA and PFOS MCLs of
4.0 ppt each, and the costs for PFHxS individual MCL (10 ppt)
exceedances, and HI MCL exceedances where PFHxS is present
[[Page 29419]]
above its Health Based Water Concentration (HBWC) while one or more
other HI PFAS is also present in that same mixture.\1\ The 2024 final
PFAS NPDWR annualized quantified national expected value cost estimate
for regulating PFOA, PFOS, and PFHxS was estimated to be $1.549 billion
(in 2022 dollars discounted at two percent), of which approximately
$11.6 million was attributable to the increased costs of regulating
PFOA, PFOS, and PFHxS, as compared to PFOA and PFOS alone.\2\ In other
words, including PFHxS in the regulation was estimated to add $11.6
million in annualized costs per year. This action now results in cost
savings, as those regulatory costs will no longer be attributable to
the part of the NPDWR that the EPA now proposes to rescind. See section
XII.D of the Federal Register for the PFAS NPDWR finalized in April
2024 for additional background information (USEPA, 2024a).
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\1\ Note, the EPA could not estimate the costs associated with
individual PFNA and HFPO-DA MCL exceedances, and HI MCL exceedances
resulting from non PFHxS HBWC exceedances due to a lack of
occurrence data.
\2\ Note at the time the PFAS NPDWR was finalized the EPA
followed the Office of Management and Budget's (OMB's) 2023 Circular
A-4 guidance (OMB, 2023) on discounting which indicated the
regulatory cost benefit analysis should use a two percent discount
rate. Executive Order 14192 now directs government agencies to use
the three and seven percent discount rates from OMB's 2003 Circular
A-4 guidance (OMB, 2003). The three and seven percent discounted
costs and benefits of the April 2024 Final PFAS NPDWR and regulatory
Option 1a are provided in the Economic Analysis for the Final Per-
and Polyfluoroalkyl Substances National Primary Drinking Water
Regulation Appendices, Appendix P.4 (USEPA, 2024c). The expected
value national annualized costs of the final April 2024 Final PFAS
NPDWR are $1,546 million, at the three percent discount rate, and
$1,554 million, at the seven percent discount rate, in 2022 dollars.
The cost of including the regulation of PFHxS in the rule (comparing
the estimated April 2024 final rule cost to the cost of Option 1a)
was estimated to range from $11.6 to $11.4 million in 2022 dollars
discounted at three and seven percent, respectively. For additional
information also see the USEPA, 2025a (Memorandum: Overview of Costs
and Benefits for the Rescission of Regulatory Determinations and
Removal of Related Provisions for Four PFAS Substances (PFHxS, PFNA,
HFPO-DA (GenX), and the mixture of these three PFAS plus PFBS)
Proposed Rule) providing additional detail on the economic analysis
conducted for this proposed rule in the EPA docket ID No. EPA-HQ-OW-
2025-0654.
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The quantified cost savings are relatively modest for the following
reasons: (1) PFHxS is observed to strongly co-occur with PFOA and PFOS;
therefore, significantly more systems are estimated to have two or more
of these PFAS in concentrations above their respective MCLs than
systems with solely PFHxS exceedances; (2) the PFHxS MCL of 10 ppt is
2.5 times higher than either the PFOA or PFOS MCLs of 4.0 ppt; and (3)
the PFHxS regulatory thresholds are one significant figure, whereas
PFOA and PFOS are two significant figures; therefore, for purposes of
estimating compliance, water systems with PFHxS occurrence would not be
deemed to be in exceedance of the standard until at or above 15 ppt.
The EPA estimated that 3 water systems with 50 entry points will be
triggered into corrective action for PFHxS alone while 212 systems (375
entry points) will treat for PFHxS in addition to PFOA and/or PFOS, and
the national annualized expected marginal costs of all PFHxS
exceedances, including at systems with and without PFOA/PFOS
exceedances, was $11.57 million in 2022 dollars, at a two percent
discount rate.\3\ See section 5.1.3 of the Economic Analysis for the
Final Per- and Polyfluoroalkyl Substances National Primary Drinking
Water Regulation (USEPA, 2024a). Note the treatment cost impacts
associated with potential exceedances of the PFNA and HFPO-DA MCLs, and
the HI MCL (except for exceedances that result solely from PFHxS where
two or more Index PFAS are present) are not accounted for in the
national quantified analysis; therefore, national level cost savings
associated with this proposed rule is likely underestimated.
---------------------------------------------------------------------------
\3\ The national annualized expected marginal costs of all PFHxS
exceedances, including at systems with and without PFOA/PFOS
exceedances range from $11.58 to $11.41 million in 2022 dollars
discounted at three and seven percent, respectively.
---------------------------------------------------------------------------
Additionally, the EPA developed a sensitivity analysis to determine
the national level potential cost impacts of exceedance of the Index
PFAS (mixtures of two or more of PFHxS, PFNA, HFPO-DA, and PFBS) and
the individual PFNA and HFPO-DA MCLs in addition to exceedances of the
PFOA, PFOS and PFHxS MCLs (see the Economic Analysis for the Final Per-
and Polyfluoroalkyl Substances National Primary Drinking Water
Regulation Appendices, Appendix N.3 (USEPA, 2024c)). While national-
level costs specific to each of these PFAS were not quantified due to
limitations in occurrence data available at that time, the EPA's
sensitivity analysis suggests that full compliance costs would increase
by approximately five percent if water systems were required to treat
for PFNA, HFPO-DA, and PFBS in addition to PFHxS. Accordingly, removing
the standards for PFNA, HFPO-DA, and the Index PFAS may result in
annualized cost savings of approximately $82 million, in 2022 dollars
discounted at two percent.\4\ This estimate is sensitive to system-
level variability and regional occurrence patterns. Note, the
occurrence data for HFPO-DA, PFBS, and PFNA used in the development of
the sensitivity analysis estimates were modeled using aggregated state-
level data that was extrapolated to the nation; thus, the derived
values from the sensitivity analysis lack the same level of precision
as the national cost estimates. This results in significantly greater
uncertainty in these numbers, and therefore the Agency provides the
results of this sensitivity analysis solely to demonstrate that
potential cost savings may exist as a result of rescinding the Index
PFAS and the individual PFNA and HFPO-DA MCLs.
---------------------------------------------------------------------------
\4\ Because the sensitivity analysis occurrence information is
based on non-UCMR 3 targeted state data which provided data based on
UCMR 5 minimum reporting levels (MRLs), these cost savings have a
higher degree of uncertainty and may be overestimated. See section
10.3.2. of Per- and Polyfluoroalkyl Substances (PFAS) Occurrence and
Contaminant Background Support Document for the Final PFAS National
Primary Drinking Water Regulation (USEPA, 2024d).
---------------------------------------------------------------------------
The primary cost savings stem from avoided capital, and operation
and maintenance expenditures for installing and operating treatment
technologies, primarily granular activated carbon (GAC) or ion exchange
(IX). The EPA anticipated a small number of systems would choose a non-
treatment option to comply with the rule, including drilling a new well
or interconnecting with another system. Systems that would have
otherwise installed a treatment technology or taken a non-treatment
action solely to address MCL exceedances of PFHxS, PFNA, and HFPO-DA,
or to remain below the HI MCL, would no longer be required to do so.
Systems that will install treatment technologies to address exceedances
of PFOA and/or PFOS will likely experience some marginal cost savings,
as they would not be required to operate those technologies to also
remove PFHxS, PFNA, HFPO-DA, and PFBS. The expected value for total
annualized treatment costs at PWSs will decrease by $11.3 million in
2022 dollars discounted at two percent. Additionally, monitoring and
administrative costs associated with ongoing compliance monitoring,
laboratory analysis, and reporting and recordkeeping would be
eliminated for those drinking water systems solely exceeding the
Trigger Levels and/or MCLs of PFHxS, PFNA, HFPO-DA, and/or the HI. This
would result in a reduced number of overall compliance sampling events
and therefore expected annual savings of approximately $240,000 in 2022
dollars discounted at two percent. Primacy agencies are also projected
to experience annualized cost savings of
[[Page 29420]]
approximately $20,000 (in 2022 dollars discounted at two percent) as a
result of reduced implementation and administrative burdens. See
section 5.1.3 of the Economic Analysis for the Final Per- and
Polyfluoroalkyl Substances National Primary Drinking Water Regulation
(USEPA, 2024b).
The rescission of the PFHxS, PFNA, and HFPO-DA individual MCLs of
10 ppt, and the Index PFAS regulatory standard may lead to forgone
benefits. Section XII.F of the Federal Register for the PFAS NPDWR
finalized in April 2024 (USEPA, 2024a) provides estimated quantified
total national-level annualized benefits which represent the
implementation of the PFOA and PFOS MCLs of 4.0 ppt each, and the
resultant increased benefits of co-removal of PFOA and PFOS at systems
required to treat for PFHxS because either the individual MCL of 10 ppt
was exceeded, or the HI MCL was exceeded where PFHxS is present above
its HBWC and one or more other HI PFAS is also present in that same
mixture. The annualized quantified national expected value benefit
estimate for regulating PFOA, PFOS, and PFHxS was estimated to be
$1.549 billion (in 2022 dollars discounted at two percent), of which
approximately $6.7 million was attributable to the increased benefits
of regulating PFOA, PFOS, and PFHxS as compared to PFOA and PFOS
alone.5 6
---------------------------------------------------------------------------
\5\ The estimation of forgone benefits between the April 2024
Final PFAS NPDWR and the regulatory requirements of this proposed
rule were calculated using the estimated benefit difference between
the April 2024 Final PFAS NPDWR (PFOA and PFOS MCLs of 4.0 ppt each,
PFHxS, PFNA, HFPO-DA MCLs of 10 ppt each and HI of 1) and Option 1a
(PFOA and PFOS MCLs of 4.0 ppt). These estimated benefits can be
found in the Federal Register for the PFAS NPDWR finalized in April
2024 (USEPA, 2024a) or the Economic Analysis for the Final Per- and
Polyfluoroalkyl Substances National Primary Drinking Water
Regulation (USEPA, 2024b) and Appendices (USEPA, 2024c).
\6\ The expected value national annualized benefits of the April
2024 Final PFAS NPDWR are $1,394 million, at the three percent
discount rate, and $916 at the seven percent discount rate, in 2022
dollars. The benefit of including the regulation of PFHxS in the
rule (comparing the estimated April 2024 final rule benefits to the
benefits of Option 1a) was estimated to range from $6.1 to $4.1
million in 2022 dollars discounted at three and seven percent,
respectively.
---------------------------------------------------------------------------
While quantified benefits were not available for PFHxS, PFNA, HFPO-
DA, and PFBS due to data limitations, the scientific literature and the
EPA's health assessments have identified evidence linking these
substances to adverse health effects. These include developmental and
reproductive toxicity, immune system suppression, liver damage, and
thyroid disruption. See the Economic Analysis for the Final Per- and
Polyfluoroalkyl Substances National Primary Drinking Water Regulation
Appendices, Appendix K.4 (USEPA, 2024c). The EPA cannot say with
certainty the degree to which nonquantifiable benefits will decrease as
a result of this action.
In summary, this proposed deregulatory action is expected to yield
greater quantified cost savings than quantified forgone benefits. The
EPA further recognizes there are additional non-quantified cost savings
and forgone benefits.
Exhibit 1--Quantifiable and Nonquantifiable Cost Savings and Forgone
Benefits of the Rescission of Related Provisions for Four PFAS
Substances
[PFHxS, PFNA, HFPO-DA, and the mixture of PFHxS, PFNA, HFPO-DA plus
PFBS]
------------------------------------------------------------------------
Cost savings and forgone
benefits category
------------------------------------------------------------------------
Quantifiable (2022 dollars,
2% discount rate):
Total Expected Annualized $11.57.\a\
Cost Savings.
Total Expected Annualized $6.66.\b\
Forgone Benefits.
Nonquantifiable:
Cost Savings............... The EPA performed a sensitivity analysis
of the national cost impacts associated
with HI exceedances resulting from PFNA,
PFBS, and HFPO-DA, and the PFNA and HFPO-
DA MCLs. Based on the results of this
analysis the EPA found the potential for
an additional $82.4 million in cost
savings per year.\c\ The EPA did not
consider the cost savings associated
with the reduced potential for hazardous
waste disposal.
Forgone Benefits........... Adverse health effects including
developmental and reproductive toxicity,
immune system suppression, liver damage,
thyroid disruption, and elevated risk of
kidney and liver cancers associated with
PFHxS, PFNA, HFPO-DA, PFBS, and other co-
occurring PFAS.
------------------------------------------------------------------------
Notes:
a. The quantifiable national annualized expected costs savings range
from $11.58 to $11.41 million in 2022 dollars discounted at three and
seven percent, respectively.
b. The quantifiable reduction in national annualized forgone benefits
range from $6.1 to $4.1 million in 2022 dollars discounted at three
and seven percent, respectively.
c. Note, the occurrence data for HFPO-DA, PFBS, and PFNA used in the
development of the sensitivity analysis estimates were modeled using
aggregated state-level data that was extrapolated to the nation; thus,
the derived values from the sensitivity analysis lack the same level
of precision as the national quantified cost savings estimates. This
results in significantly greater uncertainty in these numbers.
VII. Primacy Requirements
If the EPA takes final action to rescind portions of the PFAS
regulation, under SDWA, states/territories/Tribes will need to submit a
primacy program revision application or request an extension for those
portions of the PFAS rule that remain in effect following the
rescission. If finalized, states will not be required to adopt the
rescinded portions of the 2024 PFAS NPDWR. By requesting an extension
to submit a primacy revision package, primacy agencies can conserve
resources until there is certainty regarding the scope of the PFAS rule
that they must adopt. The EPA intends to take final action on this
proposed rescission rule in 2026. Those primacy agencies that choose to
submit an extension request should consult the extension criteria
detailed in 40 CFR 142.12(b)(2). For example, under 40 CFR
142.12(b)(2)(i)(C), a state could request an extension on the premise
that it intends ``to group two or more program revisions in a single
legislative or regulatory action,'' such as the original PFAS rule and
any revisions to that rule.
VIII. Public Participation
A. Request for Public Comment
The EPA seeks public comment on:
The legal interpretation of ``determination to regulate''
as used in SDWA 1412(b)(1)(E);
The rescission of the regulatory determinations for PFHxS,
PFNA, HFPO-DA and the Index PFAS;
[[Page 29421]]
The EPA's economic analysis described in section VI of
this preamble and in the associated memorandum (see Memorandum:
Overview of Costs and Benefits for the Rescission of Regulatory
Determinations and Removal of Related Provisions for Four PFAS
Substances (PFHxS, PFNA, HFPO-DA (GenX), and the mixture of these three
PFAS plus PFBS) Proposed Rule available in the docket), including
additional costs, cost savings, benefits, and forgone health benefits
of the action (USEPA, 2025a); and
The rescission of associated MCLGs, MCLs and related
regulatory provisions from 40 CFR part 141.
This rulemaking is being proposed solely on legal grounds. Any
comments not limited to the basis of the EPA's proposal or specific
regulatory edits associated with removing requirements related to
PFHxS, PFNA, HFPO-DA and the Index PFAS from the Code of Federal
regulations are considered beyond the scope of this rulemaking. The EPA
is not seeking comment on its substantive findings supporting either
its regulatory determinations or its associated NPDWR provisions,
including any information about health risks associated with PFAS, cost
of regulation, or occurrence information. If the Agency proceeds with
making a future regulatory determination on these or other PFAS in the
future, the Agency will provide an opportunity for public comment.
The EPA invites feedback from the public on all aspects of this
proposed rulemaking. Comments will inform whether the Agency proceeds
with finalizing the rescission of the regulatory determinations and
associated NPDWR.
B. Written Comments
Submit your comments, identified by Docket ID No. EPA-HQ-OW-2025-
0654, at https://www.regulations.gov (our preferred method), or the
other methods identified in the ADDRESSES section. Once submitted,
comments cannot be edited or removed from the docket. The EPA may
publish any comment received to its public docket. Do not submit to the
EPA's docket at https://www.regulations.gov any information you
consider to be Confidential Business Information (CBI), Proprietary
Business Information (PBI), or other information whose disclosure is
restricted by statute. Multimedia submissions (audio, video, etc.) must
be accompanied by a written comment. The written comment is considered
the official comment and should include discussion of all points you
wish to make. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). Please visit https://www.epa.gov/dockets/commenting-epa-dockets for additional submission methods; the
full EPA public comment policy; information about CBI, PBI, or
multimedia submissions; and general guidance on making effective
comments.
C. Participation in Virtual Public Hearing
The EPA will hold a public hearing on July 7, 2026 to receive
public comment and will present the proposed regulatory rescission of
the NPDWR for PFHxS, PFNA, HFPO-DA, and any mixtures containing two or
more of these PFHxS, PFNA, HFPO-DA, and PFBS as regulated through the
HI. The hearing will be held virtually from approximately 11:00 a.m. to
7:00 p.m. eastern time, or at the conclusion of public testimony,
whichever is sooner. The EPA will begin pre-registering speakers for
the hearing upon publication of this document in the Federal Register.
To attend and register to speak at the virtual hearing, please use the
online registration form available at https://www.epa.gov/sdwa/proposed-pfas-rescission. The last day to pre-register to speak at the
hearing will be July 1, 2026. On July 6, 2026, the EPA will post a
general agenda for the hearing that will list pre-registered speakers
in approximate order at: https://www.epa.gov/sdwa/proposed-pfas-rescission. The number of online connections available for the hearing
is limited and will be offered on a first-come, first-served basis. To
submit visual aids to support your oral comment, please contact
[email protected] for guidelines and instructions. Registration will
remain open for the duration of the hearing itself for those wishing to
provide oral comment during unscheduled testimony; however, early
registration is strongly encouraged to ensure proper accommodations and
adequate timing.
The EPA will make every effort to follow the schedule as closely as
possible on the day of the hearing; however, please plan for the
hearings to run either ahead of schedule or behind schedule. Please
note that the public hearing may close early if there are no more
people awaiting the opportunity to provide comment.
The EPA encourages commenters to provide the EPA with a copy of
their oral testimony electronically by emailing it to
[email protected]. Oral comments will be time limited to allow for
maximum participation, which may result in the full statement not being
heard. Therefore, the EPA also recommends submitting the text of your
oral comments as written comments to the rulemaking docket.
The EPA may ask clarifying questions during the oral presentations
but will not respond to the presentations at that time. Any person not
making an oral statement may also submit a written statement. Written
statements and supporting information submitted during the comment
period will be considered with the same weight as oral comments and
supporting information presented at the public hearing.
Please note that any updates made to any aspect of the hearing are
posted online at https://www.epa.gov/sdwa/proposed-pfas-rescission.
While the EPA expects the hearing to go forward as set forth above,
please monitor our website or contact [email protected] to determine if
there are any updates. The EPA does not intend to publish a document in
the Federal Register announcing updates.
If you require any accommodations such as language translation,
captioning, or other special accommodations for the day of the hearing,
please indicate this as part of your registration and describe your
needs by June 30, 2026. The EPA may not be able to arrange
accommodations without advance notice. Please contact [email protected]
with any questions related to the public hearing.
IX. Statutory and Executive Orders Reviews
Additional information about these statutes and Executive Orders
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review
This action is a significant regulatory action that was submitted
to the Office of Management and Budget (OMB) for review. Any changes
made in response to OMB recommendations have been documented in the
docket. The EPA prepared an analysis of the potential costs and
benefits associated with this action. This analysis can be found in
section VI of this Federal Register preamble.
B. Executive Order 14192: Unleashing Prosperity Through Deregulation
This action is expected to be an Executive Order 14192 deregulatory
action. The expected quantified annualized cost savings is $12 million,
in 2024 dollars, at a 7 percent discount
[[Page 29422]]
rate and an in-perpetuity time horizon. Details on the estimated cost
savings of this proposed rule can be found in the EPA's analysis of the
potential costs and benefits associated with this action. See the
appendix entitled Executive Order 14192 Information in the EPA's
memorandum (Memorandum: Overview of Costs and Benefits for the
Rescission of Regulatory Determinations and Removal of Related
Provisions for Four PFAS Substances (PFHxS, PFNA, HFPO-DA (GenX), and
the mixture of these three PFAS plus PFBS) Proposed Rule) in the EPA
Docket ID No. EPA-HQ-OW-2025-0654.
C. Paperwork Reduction Act (PRA)
This action does not impose any new information collection burden
under the PRA. The following is a summary of the information collection
activities associated with the existing regulation (i.e., the 2024
Final PFAS NPDWR) as amended by this proposed rescission rule which has
been submitted for approval to OMB under the PRA. The Information
Collection Request (ICR) document that the EPA prepared has been
assigned the EPA ICR number 7818.01. You can find a copy of the ICR in
the docket for the proposed rule or the PRA section of the proposed
rule Overview of Costs and Benefits Memorandum (USEPA, 2025a).
The proposed rule ICR being considered would cover information
collection burden and cost associated with the 2024 Final PFAS NPDWR
ICR (OMB control number 2040-0307, the EPA ICR #: 2732.02), as modified
in response to the proposed rescission of the MCLs for PFHxS, PFNA,
HFPO-DA and the Index PFAS, for the three year period from April 2026
to April 2029, or until such time as the burden and costs from the
proposed rule are added to the total operational burden and cost of the
national drinking water program under the Information Collection
Request for the Disinfectants/Disinfection Byproducts, Chemical, and
Radionuclides Rules (OMB control number 2040-0204) and the Information
Collection Request for the Public Water System Supervision Program (OMB
control number 2040-0090). The EPA notes that a portion of the burden
and cost estimates reported under this ICR, specifically those
associated with compliance monitoring, are also reported in the ICR for
the Extending the Compliance Deadline for the PFOA and PFOS Maximum
Contaminant Levels (EPA-HQ-OW-2025-1742; the EPA ICR #: 7817.01)
because each of these actions modifies the same underlying rule (i.e.,
the 2024 Final PFAS NPDWR) and covers the same three years after
promulgation (i.e., April 2026 to April 2029). If the EPA takes final
action in both rulemaking efforts, the Agency will prepare and submit a
unified final rule ICR under one of the collections established for the
proposed rules (either the EPA ICR number 7817.01 or 7818.01) covering
the final regulatory requirements that will be applied to respondents
in the three years following the final rules' promulgation, as
applicable. This information collection does not require respondents to
disclose confidential information.
Respondents/affected entities: The respondents/affected entities
are PWSs and primacy agencies.
Respondent's obligation to respond: The collection requirements are
mandatory under SDWA 1418.
Estimated number of respondents: For the first three years after
publication of the rule, information requirements apply to an average
of 17,206 respondents annually, including 17,150 PWSs and 56 primacy
agencies.
Frequency of response: Varies. Details can be found in the ICR for
the proposed rule and Chapter 5 of the Economic Analysis for the 2024
Final PFAS NPDWR.
Total estimated burden: 483,581 hours (per year) on average, as
required by the total burden of the 2024 Final PFAS NPDWR. Over the
April 2026 to April 2029 period the EPA estimates that the rescission
rule will result in an ICR burden reduction of 87,177 hours compared to
the 2024 Final PFAS NPDWR if the EPA were not amending this rule.
Burden is defined at 5 CFR 1320.3(b).
Total estimated cost: $98.9 million per year (simple average over
three years). Over the April 2026 to April 2029 period the EPA
estimates that the rescission rule will result in ICR cost savings of
$7.3 million compared to the requirements of the 2024 Final PFAS NPDWR
if the EPA were not amending this rule.
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
Submit your comments on the Agency's need for this information, the
accuracy of the provided burden estimates and any suggested methods for
minimizing respondent burden to the EPA using the docket identified at
the beginning of this rule. The EPA will respond to any ICR-related
comments in the final rule. You may also send your ICR-related comments
to OMB's Office of Information and Regulatory Affairs using the
interface at www.reginfo.gov/public/do/PRAMain. Find this particular
information collection by selecting ``Currently under Review--Open for
Public Comments'' or by using the search function. OMB must receive
comments no later than June 22, 2026.
D. Regulatory Flexibility Act (RFA)
The EPA certifies that this action will not have a significant
economic impact on a substantial number of small entities under the
RFA. In making this determination, the EPA concludes that the impact of
concern for this proposed rule is any significant adverse economic
impact on small entities and that the agency is certifying that this
proposed rule will not have a significant economic impact on a
substantial number of small entities because the proposed rule has no
new net burden on the small entities subject to the rule. The proposed
action alleviates requirements from an existing rule and is
deregulatory, as defined in Executive Order 14192, and will result in
expected national annualized total cost savings of approximately $11.6
million in 2022 dollars discounted at two percent.\7\ This estimated
value includes cost savings to small PWSs. See section VI of this
Federal Register preamble for additional information. The estimated
annualized total cost savings for small PWSs, defined under SDWA as
those serving 10,000 or fewer persons, is estimated to be $0.47 million
at the two percent discount rate, in 2022 dollars. These estimated
small system savings represent approximately 4.1 percent of total
proposed rule estimated annualized savings.\8\ The EPA has therefore
concluded that this action will relieve regulatory burden for all
directly regulated small entities.
---------------------------------------------------------------------------
\7\ Expected national annualized total cost savings are $11.6 to
$11.4 million in 2022 dollars discounted at three and seven percent,
respectively.
\8\ The annualized total cost savings for small PWSs are
estimated to be $0.47 and $0.48 million in 2022 dollars discounted
at three and seven percent, respectively. These estimated small
system savings represent approximately 4.3 percent (at the seven
percent discount rate) to 4.1 percent (at the three percent discount
rate) of total proposed rule estimated annualized savings.
---------------------------------------------------------------------------
E. Unfunded Mandates Reform Act (UMRA)
This action does not contain an unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small governments. UMRA does not apply to this action because it is
deregulatory, as defined in Executive Order 14192, and will reduce
regulatory costs to state, local or Tribal governments or the private
sector. The action imposes no
[[Page 29423]]
enforceable duty on any state, local or Tribal governments or the
private sector.
F. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the states, on the relationship between
the national government and the states, or on the distribution of power
and responsibilities among the various levels of government.
G. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This action does not have Tribal implications as specified in
Executive Order 13175. The Executive Order defines Tribal implications
as ``actions that have substantial direct effects on one or more Indian
Tribes, on the relationship between the Federal Government and Indian
Tribes, or on the distribution of power and responsibilities between
the Federal Government and Indian Tribes.'' The proposed action is
deregulatory, as defined in Executive Order 14192 and will not have a
new substantial direct effect on one or more Tribes, change the
relationship between the Federal Government and Tribes, or affect the
power and responsibilities between the Federal Government and Indian
Tribes. Thus, Executive Order 13175 does not apply to this action.
H. Executive Order 13045: Protection of Children From Environmental
Health & Safety Risks
The EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that the EPA has reason to believe may disproportionately affect
children, per the definition of ``covered regulatory action'' in
section 2-202 of the Executive Order. This action solely corrects a
legal error, and environmental health and safety risks, including those
that present a disproportionate risk to children, are beyond the scope
of this action. Therefore, this action is not subject to Executive
Order 13045 because it does not concern an environmental health risk or
safety risk. Since this specific action does not address human health
risks, the EPA's policy on Children's Health also does not apply.
I. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use
This action is not because it is not likely to have a significant
adverse effect on the supply, distribution, or use of energy. The
public and private water systems affected by this action do not, as a
rule, generate power. This action does not regulate any aspect of
energy distribution as the water systems that are proposed to be
impacted by this rule already have electrical service.
J. National Technology Transfer and Advancement Act (NTTAA)
This proposed rulemaking does not involve technical standards. The
proposed action is deregulatory, as defined in Executive Order 14192,
and will not require the implementation of technical standards.
K. Consultations With the National Drinking Water Advisory Council
(NDWAC) and the Secretary of Health and Human Services (HHS)
1. NDWAC
In accordance with SDWA 1412(d), ``the Administrator shall consult
with . . . the National Drinking Water Advisory Council'' prior to
proposing and promulgating a regulation under 1412. The Agency
consulted with the NDWAC during the Council's July 28, 2025, virtual
meeting. A summary of the NDWAC recommendations is available in the
docket for this proposed rule (USEPA, 2025b). The EPA considered NDWAC
recommendations during the development of this proposed rule.
2. HHS
In accordance with SDWA 1412(d), ``the Administrator shall consult
with the [HHS] Secretary'' prior to proposing and promulgating a
regulation under 1412. On March 19, 2026, the EPA consulted with the
Department of HHS. The EPA provided information to HHS officials on the
draft proposed rule and considered HHS input as part of the interagency
review.
X. References
OMB. 2003. Circular A-4: Regulatory Analysis. Washington, DC: OMB.
Available at: https://obamawhitehouse.archives.gov/omb/circulars_a004_a-4/.
OMB. 2023. Circular No. A-4. Regulatory Analysis. Washington, DC:
OMB. Available at: https://bidenwhitehouse.archives.gov/wp-content/uploads/2023/11/CircularA-4.pdf.
USEPA. 2024a. PFAS National Primary Drinking Water Regulation.
Federal Register. 89 FR 32532. April 26, 2024.
USEPA. 2024b. Economic Analysis for the Final Per- and
Polyfluoroalkyl Substances National Primary Drinking Water
Regulation. EPA-815-R-24-001.
USEPA. 2024c. Economic Analysis for the Final Per- and
Polyfluoroalkyl Substances National Primary Drinking Water
Regulation Appendices. EPA-815-R-24-002.
USEPA. 2024d. Per- and Polyfluoroalkyl Substances (PFAS) Occurrence
and Contaminant Background Support Document for the Final PFAS
National Primary Drinking Water Regulation (NPDWR). EPA-815-R-24-
013.
USEPA. 2025a. Memorandum: Overview of Costs and Benefits for the
Rescission of Regulatory Determinations and Removal of Related
Provisions for Four PFAS Substances (PFHxS, PFNA, HFPO-DA (GenX),
and the mixture of these three PFAS plus PFBS) Proposed Rule. EPA-
HQ-OW-2025-0654.
USEPA. 2025b. National Drinking Water Advisory Council (NDWAC)
Virtual Public Meeting--Summary of July 25, 2025, Consultation.
List of Subjects
40 CFR Part 141
Environmental protection, Monitoring and analytical requirement,
Per- and polyfluoroalkyl substances, Reporting and recordkeeping
requirements, Water supply.
40 CFR Part 142
Environmental protection, Monitoring and analytical requirements,
Per- and polyfluoroalkyl substances, Reporting and recordkeeping
requirements, Water supply.
Lee Zeldin,
Administrator.
For the reasons set forth in the preamble, the EPA proposes to
amend 40 CFR parts 141 and 142 as follows:
PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS
0
1. The authority citation for part 141 continues to read as follows:
Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.
Sec. 141.2 [AMENDED]
0
2. Amend Sec. 141.2 by removing the definitions for ``Hazard index
(HI)'', ``Hazard quotient (HQ)'', ``Health-based water concentration
(HBWC)'', ``HFPO-DA or GenX chemicals'', ``PFBS'', ``PFHxS'', and
``PFNA''.
Sec. 141.50 [AMENDED]
0
3. Amend Sec. 141.50, in the table to paragraph (b), by removing the
entries ``(34),'' ``(35),'' ``(36),'' and ``(37)'' and footnote 1.
0
4. Amend Sec. 141.60 by revising paragraph (a)(4) to read as follows:
Sec. 141.60 Effective dates.
(a) * * *
(4) The effective date for Sec. 141.61(c)(2)(i) and (ii) is April
26, 2029.
* * * * *
[[Page 29424]]
0
5. Amend Sec. 141.61 by:
0
a. Revising paragraph (c) introductory text and paragraph (c)(2);
0
b. Under ``Table 3 to Paragraph (d)'', removing the entries for
``Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA)'', ``HFPO-DA'',
``PFHxS'', and ``PFNA''.
The revisions read as follows:
Sec. 141.61 Maximum contaminant levels for organic contaminants.
* * * * *
(c) The following maximum contaminant levels (MCLs) in paragraphs
(c)(1) and (2) of this section for synthetic organic contaminants apply
to community water systems and non-transient, non-community water
systems.
* * * * *
(2) MCLs for PFAS.
----------------------------------------------------------------------------------------------------------------
MCL (mg/l) (unless
CAS. No. Contaminant otherwise noted)
----------------------------------------------------------------------------------------------------------------
(i) 45285-51-6................................. PFOA.............................. 0.0000040
(ii) 45298-90-6................................ PFOS.............................. 0.0000040
----------------------------------------------------------------------------------------------------------------
(d) * * *
Table 3 to Paragraph (d)--Best Available Technologies for PFAS Listed in Paragraph (c) of This Section
----------------------------------------------------------------------------------------------------------------
Contaminant BAT
----------------------------------------------------------------------------------------------------------------
PFOA................................................ Anion exchange, GAC, reverse osmosis, nanofiltration.
PFOS................................................ Anion exchange, GAC, reverse osmosis, nanofiltration.
----------------------------------------------------------------------------------------------------------------
* * * * *
Sec. 141.153 [AMENDED]
0
6. Amend Sec. 141.153 by removing paragraph (c)(3)(v).
Appendix A to Subpart O of Part 141--Regulated Contaminants [AMENDED]
0
7. Amend appendix A to subpart O by removing the entries for ``Hazard
Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA) (unitless)'', ``HFPO-DA
(ng/l)'', ``PFHxS (ng/l)'', and ``PFNA (ng/l)'', respectively.
Appendix A to Subpart Q of Part 141--NPDWR Violations and Other
Situations Requiring Public Notice [AMENDED]
0
8. Amend appendix A to subpart Q under the Contaminant heading ``D.
Synthetic Organic Chemicals (SOCs)'' by:
0
a. Removing entries for ``31'', ``32'', ``33'', ``34'';
0
b. Redesignating entries for ``35'' and ``36'' as entries ``31'' and
``32''; and
0
c. Removing footnote 23.
Appendix B to Subpart Q of Part 141--Standard Health Effects Language
for Public Notification [AMENDED]
0
9. Amend appendix B to subpart Q by removing the entries for ``55'',
``56'', ``57'', and ``58''; and redesignating entries ``59'' through
``95'' as ``55'' through ``92'', respectively, to read as follows:
* * * * *
----------------------------------------------------------------------------------------------------------------
Standard health effects
Contaminant MCLG \1\ mg/L MCL \2\ mg/L language for public
notification
----------------------------------------------------------------------------------------------------------------
* * * * * * *
----------------------------------------------------------------------------------------------------------------
E. Synthetic Organic Chemicals (SOCs)
----------------------------------------------------------------------------------------------------------------
* * * * * * *
55. PFOA........................ Zero........................... 0.0000040 Some people who drink water
containing PFOA in excess of
the MCL over many years may
have increased health risks
such as cardiovascular,
immune, and liver effects, as
well as increased incidence of
certain types of cancers
including kidney and
testicular cancer. In
addition, there may be
increased risks of
developmental and immune
effects for people who drink
water containing PFOA in
excess of the MCL following
repeated exposure during
pregnancy and/or childhood.
56. PFOS........................ Zero........................... 0.0000040 Some people who drink water
containing PFOS in excess of
the MCL over many years may
have increased health risks
such as cardiovascular,
immune, and liver effects, as
well as increased incidence of
certain types of cancers
including liver cancer. In
addition, there may be
increased risks of
developmental and immune
effects for people who drink
water containing PFOS in
excess of the MCL following
repeated exposure during
pregnancy and/or childhood.
* * * * * * *
----------------------------------------------------------------------------------------------------------------
* * * * *
Appendix B--Endnotes
* * * * *
1. MCLG--Maximum contaminant level goal.
2. MCL--Maximum contaminant level.
* * * * *
[[Page 29425]]
Appendix C to Subpart Q of Part 141--List of Acronyms Used in Public
Notification Regulation [AMENDED]
0
10. Amend appendix C to subpart Q by removing the entries for ``HI
Hazard Index'' and ``PFAS Per- and Polyfluoroalkyl Substances''.
Sec. 141.901 [AMENDED]
0
11. Amend Sec. 141.901 as follows:
0
a. Under ``Table 1 to Paragraph (b)(1)-Analytical Methods for PFAS
Contaminants'' by removing the entries for ``Perfluorobutane Sulfonate
(PFBS)'', ``Perfluorohexane Sulfonate (PFHxS)'', ``Perfluorononanoate
(PFNA)'', and ``2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy)propanoate
(HFPO-DA or GenX Chemicals)''; and
0
b. Under ``Table 2 to Paragraph (b)(2)(ii)-Acceptance Limits for PFAS
Performance Evaluation Samples'' by removing the entries for
``Perfluorobutane Sulfonate (PFBS)'', ``Perfluorohexane Sulfonate
(PFHxS)'', ``Perfluorononanoate (PFNA)'', and ``2,3,3,3-Tetrafluoro-2-
(heptafluoropropoxy)propanoate (HFPO-DA or GenX Chemicals)''.
Sec. 141.902 [AMENDED]
0
12. Amend Sec. 141.902, ``Table 1 to Paragraph (a)(5)-Trigger Levels
for PFAS Contaminants'', by removing the entries for ``Hazard Index
PFAS (HFPO-DA, PFBS, PFHxS, PFNA)'', ``HFPO-DA'', ``PFHxS'', and
``PFNA''.
0
13. Amend Sec. 141.903 by:
0
a. Revising paragraph (d); and
0
b. Removing paragraph (f)(2).
The revisions read as follows:
Sec. 141.903 Compliance requirements.
* * * * *
(d) Systems monitoring triennially whose sample result equals or
exceeds the trigger level of 2.0 ng/l for either PFOS or PFOA must
begin quarterly sampling for all regulated PFAS in the next quarter at
the sampling point. Systems monitoring annually whose sample result
equals or exceeds the MCL of 4.0 ng/l for either PFOS or PFOA must
begin quarterly sampling for all regulated PFAS in the next quarter at
the sampling point.
* * * * *
0
14. Amend Sec. 141.905 by revising paragraph (a) and removing
paragraph (e) to read as follows:
Sec. 141.905 Violations.
* * * * *
(a) PFAS MCL violations for both the PFOA and PFOS MCL, as listed
in Sec. 141.61(c), are based on a running annual average, as outlined
under Sec. 141.903.
* * * * *
PART 142--NATIONAL PRIMARY DRINKING WATER REGULATIONS
IMPLEMENTATION
0
15. The authority citation for part 142 continues to read as follows:
Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.
Sec. 142.62 [AMENDED]
0
16. Amend Sec. 142.62,``Table 1 to Paragraph (a)-BATs for PFAS Listed
in Sec. 141.61(c)'' by removing the entries for ``Hazard Index PFAS
(HFPO-DA, PFBS, PFHxS, and PFNA)'', ``HFPO-DA'', ``PFHxS'', and
``PFNA''.
[FR Doc. 2026-10085 Filed 5-19-26; 8:45 am]
BILLING CODE 6560-50-P