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:

( printed 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 § 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. § 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. § 1412(b)(1)(B)(ii). The EPA may also make a regulatory determination outside of the candidate listing process. Id. § 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. § 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. § 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. § 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. § 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. § 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. § 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). ( printed 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. See88 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. § 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. § 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. § 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. § 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 ( printed 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. See89 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 ( printed 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. § 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. § 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 ( printed 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).

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.

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.

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 ( printed 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]

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.

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; ( printed 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 from40 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 PFASNPDWR@epa.gov 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 PFASNPDWR@epa.gov. 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 PFASNPDWR@epa.gov 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 PFASNPDWR@epa.gov 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 ( printed 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.

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 ( printed 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.

For the reasons set forth in the preamble, the EPA proposes to amend 40 CFR parts 141 and 142 as follows:

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.

2. Amend § 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”.

3. Amend § 141.50, in the table to paragraph (b), by removing the entries “(34),” “(35),” “(36),” and “(37)” and footnote 1.

4. Amend § 141.60 by revising paragraph (a)(4) to read as follows:

5. Amend § 141.61 by:

a. Revising paragraph (c) introductory text and paragraph (c)(2);

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:

6. Amend § 141.153 by removing paragraph (c)(3)(v).

Appendix A to Subpart O of Part 141—Regulated Contaminants [AMENDED]

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]

8. Amend appendix A to subpart Q under the Contaminant heading “D. Synthetic Organic Chemicals (SOCs)” by:

a. Removing entries for “31”, “32”, “33”, “34”;

b. Redesignating entries for “35” and “36” as entries “31” and “32”; and

c. Removing footnote 23.

Appendix B to Subpart Q of Part 141—Standard Health Effects Language for Public Notification [AMENDED]

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:

Appendix B—Endnotes

1. MCLG—Maximum contaminant level goal.

2. MCL—Maximum contaminant level.

( printed page 29425)

Appendix C to Subpart Q of Part 141—List of Acronyms Used in Public Notification Regulation [AMENDED]

10. Amend appendix C to subpart Q by removing the entries for “HI Hazard Index” and “PFAS Per- and Polyfluoroalkyl Substances”.

11. Amend § 141.901 as follows:

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

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)”.

12. Amend § 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”.

13. Amend § 141.903 by:

a. Revising paragraph (d); and

b. Removing paragraph (f)(2).

The revisions read as follows:

14. Amend § 141.905 by revising paragraph (a) and removing paragraph (e) to read as follows:

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.

16. Amend § 142.62,“Table 1 to Paragraph (a)-BATs for PFAS Listed in § 141.61(c)” by removing the entries for “Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA)”, “HFPO-DA”, “PFHxS”, and “PFNA”.

91 FR 29413