Submitted via Regulations.gov
Docket ID No. EPA-HQ-OW-2025-0654
Re: 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)
Lee Zeldin
Office of the Administrator
US Environmental Protection Agency
1200 Pennsylvania Avenue, N.W .
Washington, DC 20460
Clean Water Action / Clean Water Fund respectfully submits the following comments in reference to Docket ID No. EPA-HQ-OW-2025-0654 Rescission of Regulatory Determinations and Removal of Related Provisionsfor Four PFAS Substances (PFHxS, PFNA, HFPO-DA (GenX), and the mixture of these three PFAS plus PFBS). We submit these comments urging the Environmental Protection Agency (EPA) to withdraw this proposal and maintain the drinking water protections established under the 2024 PFAS National Primary Drinking Water Regulation.
Clean Water Action/Fund are national organizations of members and supporters across the country working to protect clean water, public health, and environmental justice. For decades, we have advocated for strong implementation of the Safe Drinking Water Act (SDWA), improved drinking water protections, and policies that prevent toxic contaminants from entering source waters in the first place. We believe that EPA's proposal should be withdrawn.
At the outset, it is important to recognize what EPA is not claiming in this proposal. EPA does not argue that PFHxS, PFNA, HFPO-DA, or PFBS are harmless. EPA does not dispute the occurrence data supporting regulation. EPA does not challenge the toxicological record supporting the 2024 rule. EPA does not contend that regulation of these contaminants fails to provide meaningful public health benefits. Indeed, the proposal does not revisit the Agency's findings regarding adverse health effects, occurrence in public water systems, or the opportunity for meaningful health risk reduction. Those findings formed the basis for EPA's regulatory determinations in 2024 and remain largely undisturbed in the current proposal. The Agency therefore seeks to remove protections without demonstrating that the contaminants no longer satisfy the substantive criteria for regulation under SDWA Section 1412.
Rather, EPA proposes rescission based primarily on its revised interpretation of the procedural requirements governing regulatory determinations under SDWA Section 1412. As a result, the Agency seeks to remove enforceable drinking water protections without demonstrating that the scientific basis supporting those protections has changed. We believe such an outcome is inconsistent with the public health purposes of the SDWA and unsupported by the administrative record.
I. EPA Has Not Demonstrated That the Scientific Basis for Regulation Has Changed
The 2024 PFAS NPDWR was the result of years of scientific evaluation, occurrence monitoring, public review, and technical analysis. In promulgating the rule, EPA determined that PFHxS, PFNA, and HFPO DA satisfy the statutoiy criteria for regulation under SDWA and that regulating these contaminants would provide meaningful opportunities for reducing public health risks.
Nothing in the current proposal alters those findings.
EPA does not identify new toxicological evidence undermining the health assessments supporting the 2024 rule . EPA does not present new occurrence data demonstrating that these contaminants no longer occur in public water systems at levels of concern. EPA does not conclude that the contaminants fail the statutory regulatory determination criteria. Instead, EPA seeks rescission based on a revised interpretation of the procedural sequence by which the Agency adopted the rule.
Administrative agencies may revisit prior decisions, but where an agency changes course it must provide a reasoned explanation that addresses the factual findings underlying the prior action. Here, EPA's proposal leaves intact the scientific record supporting regulation while simultaneously eliminating the resulting protections. The proposal creates a disconnect between the Agency's scientific conclusions and its regulatory outcome.
The contaminants at issue remain highly persistent in the environment, continue to contaminate drinking water sources throughout the United States, and remain associated with serious adverse health effects. The administrative record supporting regulation has not materially changed since 2024.
II. EPA Has Failed to Adequately Consider Reliance Interests
EPA's proposal also fails to adequately address the substantial reliance interests generated by the 2024 PFASNPDWR.
Since promulgation of the rule, public water systems, state primacy agencies, engineers, consultants, and communities have invested significant resources preparing for implementation. Utilities have conducted monitoring, developed treatment plans, initiated engineering design work, evaluated treatment technologies , pursued Drinking Water State Revolving Fund financing, and incorporated PFAS compliance activities into long-term capital planning.
Many states have similarly devoted substantial resources to implementation planning, technical assistance, and coordination with public water systems.
These activities were undertaken in reliance on EPA's final rule and the Agency's determination that regulation of these contaminants was necessary to protect public health.
The proposal contains little discussion of these reliance interests and provides no meaningful assessment of the costs and disruption associated with abandoning implementation efforts already underway.
Regulatory certainty is particularly important for drinking water systems that must make infrastructure
investments years in advance. Reversing course after utilities and regulators have already begun implementation creates uncertainty while undermining confidence in the stability of federal drinking water standards.
III. The Proposal Provides No Scientific Basis for Eliminating the Hazard Index
The proposed rescission is particularly troubling with respect to the Hazard Index. The Hazard Index reflects a fundamental principle of modem risk assessment: that people are exposed to multiple contaminants simultaneously instead of one chemical at a time. Communities affected by PFAS contamination frequently experience exposure to multiple PFAS compounds in drinking water, groundwater, and other environmental media.
EPA appropriately recognized in the 2024 rule that PFHxS, PFNA, HFPO-DA, andPFBS may contribute to cumulative health risks through shared or overlapping health endpoints. The Hazard Index framework was developed to account for those combined risks.
The current proposal does not identify new scientific evidence demonstrating that cumulative exposure is no longer a concern. Nor does EPA present evidence that the Hazard Index methodology is scientifically invalid.
Instead, EPA proposes removing the Hazard Index solely because it was promulgated pursuant to regulatory determinations that EPA now seeks to rescind. This procedural rationale does not address the underlying scientific justification for considering cumulative exposure.
Abandoning the Hazard Index would move federal drinking water regulation away from real-world exposure conditions and away from established principles of cumulative risk assessment.
IV. Rescission Would Shift Costs and Risks to Communities
The practical consequences of rescission should not be overlooked.
PFAS contamination imposes substantial costs on drinking water systems and their customers. When contamination occurs, utilities must identify sources, conduct monitoring, install treatment technologies, and operate those systems indefinitely. These costs are often borne by ratepayers despite the fact that contamination originates from industrial activities, manufacturing, military uses, or other sources beyond the control of drinking water providers.
Removing federal standards does not eliminate contamination. It simply shifts more risk and uncertainty onto states, local governments, utilities, and affected communities.
Communities facing PFAS contamination need stronger federal protections, greater investment in treatment and monitoring, and more aggressive efforts to prevent PFAS pollution at its source. They do not benefit from the elimination of health-based drinking water standards.
V. EPA Has Not Adequately Addressed SDWA's Anti-Backsliding Requirements
The proposal also raises significant concerns regarding the SDWA's longstanding protections against regulatory backsliding.
Congress directed EPA to periodically review and revise National Primary Drinking Water Regulations as appropriate. However, the statute further provides that any revision of an existing NPDWR "shall maintain, or provide for greater, protection of the health of persons." EPA acknowledges this requirement in the proposal and further acknowledges that the United States Court of Appeals for the District of Columbia Circuit has interpreted this provision to prohibit revisions that reduce public health protections.
The current proposal will unquestionably reduce public health protections. Rescinding the MCLs, MCLGs, monitoring requirements, compliance obligations, and Hazard Index provisions applicable to PFHxS, PFNA, HFPO-DA, and PFBS mixtures would eliminate federal drinking water protections that currently exist under the 2024 rule. Communities currently protected by these standards would be left with fewer safeguards than they possess today.
EPA attempts to distinguish this proposal from a revision of an existing NPDWR by characterizing the action as a rescission of regulatory determinations that were allegedly promulgated through an unlawful procedure. However, the Agency's characterization does not alter the practical consequences of the proposal. Regardless of how the action is described proced urally, the result is the elimination of existing health-based drinking water protections.
Moreover, EPA has not identified any change in the underlying science that would justify reducing protections. The proposal does not conclude that PFHxS, PFNA, HFPO-DA, or PFBS mixtures present less risk than EPA previously determined. Nor does the Agency contend that the contaminants no longer satisfy the statutory criteria for regulation. Instead, EPA seeks to remove protections while leaving the scientific basis for those protections largely intact.
We are are concerned that the proposal effectively elevates an alleged procedural defect above the substantive public health objectives that Congress embedded throughout the SDWA. Congress established the Act to protect drinking water consumers from contaminants that pose health risks. The anti-backsliding provision reflects a clear legislative judgment that public health protections should generally move forward, not backward, as scientific understanding improves.
At a minimum, EPA should provide a more comprehensive analysis explaining how the proposed rescission is consistent with the anti-backsliding principles embodied in SDWA Section l 4 l 2(b)(9). The current proposal does not adequately address the tension between eliminating existing protections and Congress's directive that revisions maintain or increase protection of public health.
VI. EPA Should Address Any Procedural Concerns Without Eliminating Public Health Protections
Even assuming EPA's revised interpretation of SDWA Section 1412 is correct, rescission is not the only available response. EPA has failed to explain why less disruptive alternatives, including supplemental rulemaking, reissuance of the regulatory determinations through a sequential notice-and-comment process, maintaining existing protections during any corrective proceeding, or other narrowly tailored remedies, would be insufficient to address the Agency's stated procedural concerns while avoiding the loss of critical public health protections.
The Agency could pursue supplemental rulemaking to address any perceived procedural deficiencies while maintaining existing protections. EPA could preserve the current standards during any additional regulatory process rather than eliminating them entirely. Such an approach would better reflect SDWA's
core public health mission while minimizing disruption for states and water systems already implementing the 2024 rule.
The proposal before the Agency instead seeks to remove protections despite leaving the underlying scientific record largely untouched . We do not believe that outcome is justified by either the administrative record or the public health purposes of the SDWA.
Conclusion
For the reasons discussed above, we urge EPA to withdraw its proposal to rescind the regulatory detenn inations, MCLGs, MCLs, and associated regulatory provisions applicable to PFHxS, PFNA, HFPO-DA, and the Hazard Index.
The scientific evidence supporting regulation remains compelling. Communities continue to face significant risks from PFAS contamination. Drinking water systems and states have already begun implementation in reliance on the 2024 rule. EPA should maintain these protections and continue strengthening efforts to prevent PFAS contamination at its source, ensure polluter accountability, and protect public health.
Thank you for the opportunity to comment. Sincerely,
Sean Jackson
National Water Campaigns Coordinator
Clean Water Action and Clean Water Fund