D.C. Circuit Denies EPA’s Request to Vacate Drinking-Water Limits for Four PFAS

A D.C. Circuit motions panel denied the EPA’s motion to vacate four of six PFAS limits for drinking water. Industry groups and water utilities had challenged the EPA’s final rule setting maximum contaminant levels in drinking water for certain PFAS chemicals. The EPA sought to vacate four of the six PFAS limits (for HPFO-DA, PFNA, PFHxS, and PFBS), arguing they were invalid due to procedural errors by the previous administration, but did not walk back the limits for PFOA or PFOS. In denying the EPA’s request to vacate, the court found the merits of the parties’ positions were “not so clear as to warrant summary action.” As a result of the denial, the six PFAS limits remain in place while the litigation proceeds on the merits, creating uncertainty for water utilities because any final decision is unlikely before the rule’s deadlines take effect.

January 21, 2026 | American Water Works Association v. Environmental Protection Agency, No. 24-1188 (D.C. Cir.).