On October 3, 2025, the U.S. Court of Appeals for the D.C. Circuit granted EPA’s unopposed motion to hold the PFAS drinking water standards litigation in abeyance due to the lapse in appropriations as a result of the government shutdown. The order directed the parties to file motions governing further proceedings within ten days after appropriations are restored and the DOJ attorneys are permitted to resume their usual civil litigation functions.
Previously, on September 11, 2025, EPA filed a motion for partial vacatur seeking to set aside the regulatory determinations and MCLs for perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and hexafluoropropylene oxide dimer acid (HFPO-DA), and mixtures consisting of PFNA, PFHxS, HFPO-DA, and PFBS. EPA requested to retain and continue to defend the portions of the rule addressing PFOA and PFOS. The agency argued that parts of the rulemaking process for the regulatory determinations of PFNA, PFHxS, HFPO-DA, and the hazard index mixture were procedurally inconsistent with the requirements of the Safe Drinking Water Act (SDWA).
Respondent-Intervenors, comprised of public health and environmental groups, opposed EPA’s motion arguing that there was no procedural error in EPA’s rulemaking process, and that any alleged error was harmless. Respondent-Intervenors further argued that the Court must first determine that those provisions are unlawful before vacating them. Respondent-Intervenors requested leave to file a revised and expanded brief.
Separately, in the litigation concerning the hazardous substance designations of PFOA and PFOS, after over six months in abeyance, the Court approved a revised briefing schedule, with Petitioners’ Joint Reply Brief due November 14, 2025, and final briefs due December 5, 2025.