EPA Proposes Two More Years for PFAS Drinking Water Compliance
The 4.0 parts per trillion limits for PFOA and PFOS stay, but systems could request an extension from April 2029 to April 2031 — with monitoring and reporting obligations unchanged.
The US Environmental Protection Agency announced a proposed rule on 18 May 2026 under docket EPA-HQ-OW-2025-1742, with the public comment period closing on 20 July. The proposal keeps the maximum contaminant levels set in the April 2024 National Primary Drinking Water Regulation — 4.0 parts per trillion each for PFOA and PFOS — but would let systems request two additional years to comply, moving the enforceable deadline from April 2029 to April 2031.
The obligations that do not move are the ones that matter to anyone building monitoring. Systems granted an exemption must still follow the monitoring and reporting timeframes set in the April 2024 final rule. Community water systems measuring at or above 4.0 ppt must report results to customers annually or biannually. Systems at or above 12 ppt would have to implement short-term mitigation actions to reduce exposure during the exemption period. A companion proposed rule would rescind the drinking water regulations for PFHxS, PFNA, HFPO-DA and the hazard index mixture that also includes PFBS.
The shape of this is familiar from other deferred regulations: the deadline for treatment moves, the deadline for knowing does not. A utility that reads the headline as two more years of quiet is still obliged to sample, still obliged to report what it finds to its customers, and — above 12 ppt — obliged to do something about it in the meantime.
For anyone working on utility instrumentation and data systems, that is where the work sits. Parts per trillion is not a concentration you monitor with an inline analyser; it is laboratory work, which means the engineering problem is sample chain of custody, result ingestion, retention, and generating a customer-facing report that matches what was submitted to the regulator. The gap between a laboratory information system and a utility's SCADA historian is exactly the seam where these programmes usually fail an audit, and a two-year extension is a reasonable window in which to close it properly rather than a reason to stop.