EPA proposes rescinding drinking-water regulatory determinations/related NPDWR provisions for PFHxS, PFNA, HFPO‑DA (GenX) and Hazard Index mixtures (incl. PFBS)

EPA issued a proposed rule (signed May 18, 2026 per EPA materials) to rescind the SDWA regulatory determinations and remove related NPDWR provisions for PFHxS, PFNA, HFPO‑DA (GenX chemicals), and Hazard Index mixtures involving PFHxS/PFNA/HFPO‑DA plus PFBS. Compliance teams at water utilities and impacted stakeholders should track the proposed rollback of these components of the PFAS drinking water framework, prepare comments, and reassess compliance planning contingent on final rule outcomes. EPA materials indicate a public comment process and a virtual public hearing with pre-registration deadline details.