Environmental Alert — PFAS Drinking Water Standards Recalibrated: EPA Retains PFOA/PFOS Limits, Rescinds Other Standards, and Extends Compliance Deadline

May 27, 2025 | By: Tim Sowecke and Tyler Self

On May 14, 2025, the U.S. Environmental Protection Agency (“EPA”) announced plans to revise federal drinking water standards for certain per- and polyfluoroalkyl substances (“PFAS”). This announcement builds on EPA’s April 28, 2025, policy update, which outlined the Agency’s broader regulatory approach to PFAS under the Safe Drinking Water Act (“SDWA”).

Background: Drinking Water PFAS Regulation Finalized in 2024

In April 2024, EPA finalized the first-ever federal drinking water standards for six PFAS, including PFOA and PFOS, under the SDWA—marking a significant step in national efforts to address PFAS exposure through public water systems. These National Primary Drinking Water Regulations (“NPDWR”) set legally enforceable maximum contaminant levels (“MCLs”) and established monitoring, treatment, and reporting obligations for public water systems, with an original compliance deadline of 2029.

The Latest from EPA: PFOA and PFOS Standards Will Remain Intact

In its latest announcement, EPA reaffirmed its commitment to 4 parts per trillion (“ppt”) MCLs for PFOA and PFOS. These two PFAS compounds have been extensively studied and are widely recognized as posing significant health risks, including developmental, immunological, and potential carcinogenic effects. Despite ongoing litigation challenging the rule, EPA has indicated it will defend the rule as it applies to PFOA and PFOS, signaling to public water system operators that these standards remain a top enforcement priority.

Rescission of Certain PFAS Standards

In a significant shift, EPA will rescind the MCLs for PFHxS, PFNA, HFPO-DA (or GenX Chemicals), and the novel Hazard Index for mixtures of these compounds and/or PFBS. EPA stated its rationale for the rescission is to “ensure that the [regulatory] determinations and any resulting drinking water regulation follow the legal process laid out in the [SDWA].” This decision aligns with arguments advanced by petitions challenging the 2024 rule and may help mitigate regulatory exposure and litigation risk for affected stakeholders. Notably, in a Subcommittee on Environment congressional hearing held on May 19, Administrator Zeldin testified that the other MCL calculations were done incorrectly and the outcome of the review of these other MCLs could actually result in more stringent MCLs.

Compliance Deadline Extended to 2031

To reduce implementation burdens, EPA will extend the compliance deadline for PFOA and PFOS standards from 2029 to 2031. While this change provides short-term relief, public water systems must continue to meet monitoring and planning obligations in the interim. Stakeholders should remain proactive in compliance preparations.

EPA plans to issue a proposed rule this fall and to finalize the above-listed changes by spring 2026.

Launch of the PFAS OUTreach Initiative

To assist utilities during the extended compliance timeline, EPA also announced the PFAS OUTreach Initiative (or PFAS OUT). This program will deliver technical assistance through EPA’s existing WaterTA program, facilitate access to federal funding for PFAS mitigation projects, and guide utilities— particularly in underserved or rural areas—through the evolving regulatory landscape. This initiative provides a good opportunity for water systems to engage with EPA and secure necessary support.

Broader Enforcement Commitment: Targeting Upstream Polluters

EPA again emphasized its intent to hold polluters accountable by pairing drinking water regulations with other regulatory tools like establishing effluent limitation guidelines for PFAS discharges to water bodies. This upstream approach signals EPA’s focus on holding polluters—not just public water systems—accountable for contamination, and signals EPA’s expansion of PFAS regulation beyond end-of-pipe regulation that has occurred to date.

Legal and Regulatory Implications

By preserving core standards for PFOA and PFOS while withdrawing more ambiguous provisions, EPA aims to maintain public health protections while minimizing legal challenges. The rescission may alleviate liability concerns for utilities and industries wary of cumulative PFAS regulation, a concern that has been at the forefront of stakeholders in opposition to increased PFAS regulation.

Conclusion: PFAS Regulations Evolve, But Momentum Remains

While EPA’s announcement offers important compliance relief for drinking water systems and reduces some regulatory uncertainties, it also signals the Agency’s intent to hold firm where it has determined it matters most: PFOA and PFOS. Stakeholders should not take their eye off the ball with these regulations, as we can expect the number of regulated PFAS to continue to grow across administrations. With past as prologue, PFAS continues to be a bipartisan issue.

For ongoing insights and practical guidance, be sure to check out GableGotwals’ PFAS Pulse—our dedicated resource for tracking regulatory developments, compliance deadlines, and legal impacts. We will continue to keep our clients informed as the PFAS landscape evolves.

Tim Sowecke
405-568-3308
tsowecke@gablelaw.com

Tyler A. Self
405-235-5589
tself@gablelaw.com

This article is provided for educational and informational purposes only and does not contain legal advice or create an attorney-client relationship. The information provided should not be taken as an indication of future legal results; any information provided should not be acted upon without consulting legal counsel.