On May 14, 2025, the U.S. Environmental Protection Agency (EPA) announced it will retain the enforceable maximum contaminant levels (MCLs) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) at 4 parts per trillion, while also maintaining the nonenforceable MCL goals at zero. The EPA also indicated a significant shift in its Safe Drinking Water Act (SDWA) PFAS rule, proposing to rescind and reevaluate regulatory determinations for four additional per- and polyfluoroalkyl substances (PFAS): perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA or GenX), and perfluorobutane sulfonic acid (PFBS).
Additionally, the EPA plans to propose an extension of the compliance deadline for the PFOA and PFOS MCLs from 2029 to 2031. This change would give public water systems more time to implement necessary treatment and monitoring solutions.
Background
The first Trump Administration formally decided to regulate PFOA and PFOS in drinking water. But in April 2024, the EPA under the Biden Administration finalized the first-ever national drinking water standards for six PFAS. This included enforceable MCLs for PFOA, PFOS, PFHxS, PFNA, and HFPO-DA, along with a hazard index limit for mixtures containing PFHxS, PFNA, HFPO-DA, and PFBS. These rules aimed to address concerns over PFAS contamination.
However, industry groups, state agencies, and utilities raised questions about the technical feasibility, legal consistency, and financial impact of the original regulation, particularly the hazard index approach.
The EPA’s May 2025 announcement reflects an effort to balance regulatory goals with practical considerations for industry. According to the EPA, this action will address significant compliance challenges the agency has heard from public water systems and other stakeholders, while supporting actions to address the purported impacts of certain PFAS on drinking water supplies.
The EPA is also considering providing utilities with short-term waivers from the PFAS standards using Section 1416 of the SDWA.
In parallel, the agency introduced the PFAS OUTreach initiative, designed to provide technical and financial support to small and rural water systems affected by the PFAS requirements. This initiative will operate with the EPA’s water technical support, providing free assistance to small, rural, and disadvantaged communities to develop water infrastructure solutions and enhance capacity.
Implications for Stakeholders
For public water systems, the EPA’s decision to extend the compliance deadline for PFOA and PFOS standards to 2031 provides important flexibility in managing the operational and financial challenges of PFAS treatment technology deployment.
For industries involved in the manufacture or use of PFAS compounds, the EPA’s decision to reevaluate the regulatory determinations for PFHxS, PFNA, HFPO-DA, and PFBS introduces a period of regulatory uncertainty. While this reassessment may provide temporary relief from immediate compliance obligations, it also suggests the EPA is carefully considering both scientific evidence and legal processes before finalizing a comprehensive regulatory framework.
Companies should assess their current compliance strategies in light of these developments. The potential recission of certain MCLs may impact ongoing or planned remediation efforts and influence litigation strategies related to PFAS.
Next Steps
The EPA is expected to issue a proposed rule in fall 2025 extending the compliance deadline for PFOA and PFOS MCLs to 2031, with a final rule anticipated in spring 2026. Concurrently, the agency will undertake a comprehensive review of the regulatory framework for PFHxS, PFNA, HFPO-DA, and PFBS, which could result in revised proposals or further opportunities for public comment. The announcement also suggests that the EPA intends to use effluent limitations guidelines as an additional regulatory tool. Stakeholders are encouraged to monitor these developments closely and engage in the rulemaking process to ensure that their perspectives are considered.
Alston & Bird continues to track ongoing litigation, legislative actions, and regulatory shifts in the evolving PFAS landscape. To stay on top of these developments, please visit our PFAS Primer or contact an attorney on our PFAS Team.
If you have any questions, or would like additional information, please contact one of the attorneys on our Environment, Land Use & Natural Resources team.
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