EPA announces changes to PFAS Drinking Water Standard

The U.S. Environmental Protection Agency (EPA) announced a new plan for regulating per- and polyfluoroalkyl substances (PFAS) in drinking water on Wednesday, retaining its maximum contaminant levels for PFOA and PFOS but pulling back on its use of a hazard index and regulatory determinations for additional PFAS. EPA also indicated the steps it is taking is to ensure alignment with the legal processes outlined in the Safe Drinking Water Act.

In response to the announcement, AWWA and the Association of Metropolitan Water Agencies (AMWA), who jointly filed a petition for judicial review in 2024 regarding the original PFAS drinking water standard, issued a statement:

“AWWA and AMWA share EPA’s goal of protecting people from potentially harmful levels of PFAS in drinking water,” the associations said. “We appreciate EPA’s careful review of the PFAS Rule and commend the agency’s intention to make improvements to the previous rulemaking process.”

Key elements of the announcement include:

• No change to MCLs for PFOA and PFOS: The EPA does not anticipate revising the maximum contaminant levels (MCLs) for perfluorooctanoic acid (PFOA) or perfluorooctane sulfonic acid (PFOS), each of which remain at 4.0 parts per trillion.
• Extended compliance deadlines: The agency plans to extend the deadline for compliance with the PFOA and PFOS MCLs by two years, moving the deadline to 2031.
• Reconsideration of determinations and associated rule requirements: The EPA intends to rescind and reconsider the regulatory determinations for perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and hexafluoropropylene oxide dimer acid (HFPO-DA or GenX), as well as the associated individual MCLs and the hazard index MCL for mixtures of these three PFAS and perfluorobutanesulfonic acid (PFBS).
• Use of Safe Drinking Water Act (SDWA) exemptions: EPA anticipates working with state drinking water program administrators to develop a framework for applying exemptions under SDWA (42 U.S. Code § 300g-5). This provision allows states to grant temporary exemptions to public water systems that face compelling challenges such as economic hardship or lack of alternative water sources, provided that public health is not unreasonably at risk. These exemptions can give qualifying systems additional time to comply with drinking water standards.

EPA plans to issue a proposed rule in fall 2025 and a finalized rule in spring 2026.

“While today’s announcement does not appear to substantially reduce the costs of the PFAS rule, it does acknowledge the very substantial challenges communities face in finding alternative sources of water or installing treatment,” AWWA and AMWA said. “We welcome EPA’s recognition that compliance will require additional time and flexibility, particularly for small systems and those facing affordability challenges. Allowing communities time to make fiscally sound decisions based on thoughtful evaluation of compliance alternatives is simply good policy.

“We will continue to provide data to EPA as the new rulemaking moves forward while helping the nation’s water systems comply with the PFAS rule as it evolves.”

AWWA will evaluate details of EPA’s plan as they become available in the coming weeks and determine what that means for the petition going forward. For more information and resources about PFAS, visit www.awwa.org/pfas.