EPA proposes rescinding NPDWR determinations/provisions for PFHxS, PFNA, HFPO‑DA (GenX) and Hazard Index mixture (incl. PFBS)

EPA issued a proposed rule to rescind Safe Drinking Water Act regulatory determinations and remove associated provisions in the 2024 PFAS NPDWR that are exclusive to PFHxS, PFNA, HFPO‑DA (GenX chemicals), and the Hazard Index mixture approach (mixtures including these PFAS plus PFBS). If finalized, this would change the scope of federally regulated PFAS drinking-water requirements by removing/altering monitoring/treatment/other NPDWR obligations tied to these specific PFAS/HI components (while leaving PFOA/PFOS requirements outside the scope of this proposal). EPA opened a written public comment process (60-day comment period after Federal Register publication) and scheduled a virtual public hearing for July 7, 2026 (speaker pre-registration deadline July 1, 2026; docket EPA-HQ-OW-2025-0654).