EPA Proposes to Extend PFOA and PFOS Compliance Date for Qualifying Water Systems

The Environmental Protection Agency (EPA) has proposed to extend the compliance date to implement the federal drinking water Maximum Contaminant Levels (MCLs) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). The current rule requires public water systems to meet MCLs of 4 parts per trillion (PPT) for both PFOA and PFOS by April 26, 2029. Under the proposed rule, qualifying public water systems (PWS) may request two additional years to comply with these enforceable limits by April 26, 2031. 91 Fed. Reg. 29425 (May 20, 2026). For those that want to participate in the rule making process, the EPA will accept written comments until July 20, 2026, and hold a virtual public hearing on July 7, 2026. The public docket can be accessed at www.regulations.gov under Docket ID: EPA-HQ-OW-2025-1742. 

The EPA has also proposed a rule to rescind MCLs previously established for PFHxS, PFNA, HFPO-DA, and Hazard Index mixtures of these three PFAS and PFBS as well as the regulatory determinations relied upon to establish those limits. 91 Fed. Reg. 29413 (May 20, 2026). The EPA’s proposal to rescind these standards appears to be driven primarily by EPA’s position that the 2024 rule did not follow the sequencing requirements of the Safe Drinking Water Act. American Water Works Ass’n v. EPA, No. 24-1188 (D.C. Cir. Sept. 11, 2025) (EPA Motion for Partial Vacatur).

With respect to PFOA and PFOS, states with primary enforcement authority (49 states not including Wyoming) have two years from the publication of a final National Primary Drinking Water Regulation to adopt and enforce MCLs at least as stringent as the federal limit. States had until April 27, 2026 to either adopt the 4 PPT limit or request an extension of time. States with less stringent PFOA and PFOS limits will need to revise their limits.

The EPA is relying on the exemption provisions of the Safe Drinking Water Act in section 1416 which allows states with primacy to exempt PWS from complying with MCLs when all of the following are established: economic and other “compelling factors” prevent compliance; the PWS was operating prior to the MCL or, if it was not in operation at the time, there are no reasonable alternative drinking water sources available; granting the exemption will not result in an unreasonable health risk; and there are no management or structural changes that would achieve compliance or improve drinking water quality. See SDWA 1416(a). PWS seeking to apply for the exemption would have to follow their state’s application processes. The EPA has proposed that PWS with PFOA or PFOS levels at or above 12 PPT that seek a compliance extension be required to implement interim control measures during the two-year period.

Should this proposed rule become final, PWS including municipal systems may find it helpful if not necessary to determine whether they may qualify for this exemption. Regardless, understanding the availability, cost, and implementation timeline of feasible treatment technologies needs to be evaluated now to avoid compliance issues in the future.

Attorneys at West Group Law (“WGL”) have represented municipalities and public entities across the country for more than 30 years in connection with water and wastewater matters, litigation, environmental and regulatory matters, solid waste issues, transportation, general municipal law, civic projects, structuring requests for proposals, contract negotiations, alternative project delivery methods, land use development, construction law, animal management services, and more. WGL attorneys have a wealth of knowledge and can assist municipalities and public entities in a variety of matters.

For more information, please contact Managing Partner Teno West at:

 twest@westgrouplaw.com or at 917-922-6226.