The AMWA’s and AWWA’s petition for review is focused on the initial EPA’s PFAS rule “PFAS National Primary Drinking Water Regulation” that was issued April 10, 2024 (and made available on the Federal Register on April 26, 2024). The rule sets drinking water standards for PFAS substances of from 4.0 parts per trillion to 10 parts per trillion. Those PFAS substances are perfluorooctanoic acid (PFOA); perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PENA); perfluorohexanesulfonic acid (PFHxS); perfluorobutanesulfonic acid (PFBS); and hexafluoropropylene oxide dimer acid (HFPO-DA, also known as GenX chemicals).

In addition, On April 19, 2024, the EPA issued a second PFAS regulation designating PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the “Superfund.”

The AMWA and AWWA’s petition challenges the science and methods used by EPA to justify the regulation, as well as its potential financial impact on communities and water suppliers. The petition says, “EPA did not rely on the best available science and the most recent occurrence data, and used novel approaches as the basis for certain portions of the rule.”

Furthermore, the associations argue that when the EPA finalized the PFAS rule, the agency deviated from the process imposed by Congress for finalizing a regulation, and that the public did not receive enough time to provide input on the rule. The petition says “EPA finalized this rule without following the process mandated by Congress, without allowing the public an adequate opportunity to provide comment, and without addressing the concerns raised by those who work to deliver safe and affordable drinking water to their communities.”

The EPA seems to partly agree with the claim in the AMWA and AWWA’s petition for on Sept. 11, 2025 the agency filed a motion saying that portions of the EPA’s PFAS rulemaking process were unlawful, thereby invalidating some of the rule.