EPA Announces Proposed PFAS Rules

Written by Kimberley Hale, Jennifer Simon, and Kate Hopkins

On May 18, 2026, EPA announced two long-anticipated proposed rules related to the PFAS MCLs for public drinking water systems it originally promulgated in April 2024. The rules are available at https://www.epa.gov/sdwa/proposed-pfas-rescission-rule and https://www.epa.gov/sdwa/proposed-pfoa-and-pfos-compliance-extension-rule. The first rule proposes to rescind drinking water regulations for PFHxS, PFNA, HFPO-DA (commonly known as GenX), and the Hazard Index mixture of these three PFAS plus PFBS. As EPA previously articulated both in court filings and to the public, EPA is rescinding those regulations because it did not follow the regulatory sequencing required under the rule that would allow for public comment at each phase of the process, from a preliminary determination of an adverse health effect and need for regulation through a final determination and proposed substantive rule. EPA has stated it intends to continue evaluating these and other PFAS for potential future regulation pursuant to the prescribed regulatory process, but any such efforts are unlikely to occur in the near term.

As states are obligated to do under the regulations still in effect, they are continuing to request that the implicated community water systems and non-community, non-transient water systems monitor for all six regulated PFAS measures per 40 CFR 141, Subpart Z.  Until the proposed rules are finalized, public water systems remain subject to the currently applicable testing obligations. However, once finalized, which EPA promises to complete this year, public water systems would only be obligated to test for PFOA and PFOS and not the remaining four PFAS. Given the five-month spacing requirement between samples and the April 27, 2027 deadline to submit PFAS monitoring results to the state, EPA would need to move quickly to impact those obligations. It may be a consideration that, for those states that have requested an extension on implementing the 2024 MCLs (as Georgia and most states have), EPA would be the enforcing authority for those testing obligations.

EPA is accepting written comments on the proposed rules through July 17, 2026, and will hold a virtual public hearing on July 7, 2026.