EPA proposes rescinding SDWA regulatory determinations and related NPDWR provisions for PFHxS, PFNA, HFPO‑DA (GenX), and Hazard Index mixtures

EPA announced a proposed rule to rescind the SDWA regulatory determinations and remove related drinking-water regulatory provisions for PFHxS, PFNA, HFPO‑DA (GenX chemicals), and the Hazard Index mixture approach (PFHxS, PFNA, HFPO‑DA, and PFBS). The proposal is positioned as a revision to the federal PFAS drinking-water regulatory framework adopted in 2024, potentially reducing the set of PFAS subject to federal MCL/MCLG and associated monitoring/treatment obligations (while leaving the PFOA/PFOS portions unaffected per EPA’s proposal description). EPA indicates a 60-day public comment period will run after Federal Register publication and notes a virtual public hearing scheduled for July 7, 2026 (with pre-registration deadline July 1, 2026).