Published June 27, 2026
On May 18, 2026, the U.S. Environmental Protection Agency announced two proposed rules that would significantly change the federal government's approach to PFAS in drinking water, less than two years after the agency finalized the country's first nationwide limits on these chemicals.
The first proposal would rescind the enforceable drinking water limits set in April 2024 for four PFAS compounds: PFHxS, PFNA, HFPO-DA (commonly known as GenX), and a "Hazard Index" standard covering mixtures of those three plus PFBS. The EPA's stated rationale is procedural — the agency says the Biden administration combined separate regulatory steps that the Safe Drinking Water Act requires to happen independently, and that the original determinations need to be redone correctly. The agency has said it intends to re-evaluate these four substances for future regulation but has not given a timeline for doing so.
The second proposal would keep the existing limits for PFOA and PFOS — the two PFAS compounds with the longest regulatory history and the most extensive health data — but extend the compliance deadline for water systems from 2029 to 2031.
If finalized, the four rescinded compounds would no longer have a federal floor. Enforcement would fall back to whatever each state has set on its own, and those levels vary widely. Michigan, for instance, currently allows PFHxS at 51 parts per trillion and GenX at 370 parts per trillion — both several times higher than the federal limits being rescinded, which were 10 ppt each. Michigan's standard for PFNA is stricter than the federal one being removed, at 6 ppt. States without their own PFAS rules for these specific compounds would have no enforceable limit at all once the federal rule is gone, though water systems would remain subject to existing federal requirements covering other regulated contaminants, and states remain free to adopt their own PFAS standards at any time.
EPA Administrator Lee Zeldin has framed the changes as a correction to a flawed rulemaking process, not a retreat from PFAS oversight, and the agency has paired the announcement with close to $1 billion in new grant funding for PFAS treatment technology. Environmental groups have taken a different view. The Environmental Working Group has argued the rollback may violate the Safe Drinking Water Act's "anti-backsliding" provision, which restricts the EPA from issuing a rule weaker than one already in effect. The Great Lakes PFAS Action Network has pointed specifically to Grayling and Oscoda, Michigan, where former military fire-training sites contaminated local water with PFHxS — one of the four compounds losing its federal standard.
Both rules are open for public comment through July 20, 2026, with a virtual hearing scheduled for July 7. No final rule has been issued, and the EPA has not set a date for when one might be.