EPA Maintains Current Drinking Water Standards for PFOA and PFOS but Plans To Reconsider Other PFAS Compounds

On May 14, 2025, the Environmental Protection Agency (“EPA”) announced that it will keep the current National Primary Drinking Water Regulations (“NPDWR”) for perfluorooctanoic acid (“PFOA”) and perfluorooctane sulfonic acid (“PFOS”) under the Safe Drinking Water Act (“SDWA”), while extending the compliance deadline from 2029 to 2031. EPA further announced it plans to rescind requirements in those regulations applicable to other PFAS and mixtures of certain PFAS in drinking water. The NPDWR consists of legally enforceable primary standards and treatment techniques that apply to public water systems and guide EPA’s enforcement of the SDWA. This announcement follows EPA’s April 28, 2025 press release outlining its priorities for PFAS enforcement, which included 21 actions EPA intends to take to address PFAS and “engage with Congress and industry to establish a clear liability framework that ensures the polluter pays and passive receivers are protected.”

PFAS is not one chemical—but rather a class of thousands of chemicals—which have been used for decades to make a wide range of products resistant to water, stains, extreme temperatures and harsh chemical environments. On April 10, 2024, the EPA under the Biden administration announced the original NPDWR, which established maximum contaminant levels (“MCLs”) for several individual PFAS, including PFOA and PFOS, in drinking water. It also set a compliance deadline of 2029 for public water utilities and required the development of systems for initial monitoring, as well as the installation of filtration systems. This rule was the first national limit on any PFAS in drinking water and established federal funding for PFAS treatment.

The rule was faced with steep opposition from public drinking water utilities and water systems and industry associations, who have alleged that compliance costs would outpace the annual $1.5 billion EPA cost estimate. Lawsuits contend that EPA violated its mandates under the SDWA when it evaluated the rule’s costs and benefits, bypassed statutory requirements for standard-setting, used an untested formula to regulate mixtures, and failed to properly use updated occurrence data. In the ongoing litigation, utilities have generally supported the decision to regulate specifically PFOA and PFOS, but at less stringent levels and on a more forgiving timeline.

Although the PFOA and PFOS MCLs will remain in place, the Agency is extending the compliance deadline from 2029 to 2031 and stated that it plans to issue a proposed rule this fall and a final rule by spring 2026 to codify the extension. The two-year delay is intended to give state and local water system managers additional time to identify affordable treatment technologies and make necessary improvements.

The Agency also plans to rescind the MCLs and reconsider the regulatory determinations for several other PFAS—namely, PFHxS, PFNA, and HFPO-DA (commonly known as GenX)—and for mixtures of two or more of PFHxS, PFNA, HFPO-DA, and PFBS. Some of these chemicals, were designed to replace PFOA and PFOS during their phase out. As part of its reconsideration, the Agency stated that it will determine if the regulatory determinations and any resulting drinking water regulations align with the SDWA.

Finally, EPA stated that it will pair the NPDWR, as modified, with effluent limitations guidelines (“ELGs”) for PFAS and “other tools to ensure that polluters are held responsible,” but did not specify the particular chemicals that would be subject to ELGs or when any ELGs would be developed. EPA encouraged states to ask it for additional time to develop applications for primacy while these MCLs are reconsidered. Notably, EPA remains silent on its intent with respect to the CERCLA regulation designating PFOA and PFOS as hazardous substances.

In addition to extending the compliance deadlines for meeting the PFOA and PFOS MCLs, EPA announced the launch of a new PFAS outreach initiative, PFAS OUT, to assist public water utilities address compliance challenges. The program will “connect with every public water utility known to need capital improvements to address PFAS in their systems.” PFAS OUT also establishes a federal exemption framework, which the announcement did not further define. The Agency stated that its changes to the PFAS program align with its goal of addressing PFAS in drinking water “while following the law and ensuring that regulatory compliance is achievable for drinking water systems.”