Court of Appeals Order Denying Motion for Partial Vacatur

On January 21, 2026 the U.S. Court of Appeals for the District of Columbia denied EPA's motion to vacate portions of the National Primary Drinking Water Regulations for PFAS relating to "hazard index" PFAS, but allowing EPA to notify the court of portions of the rule that it no longer plans to defend. The order also establishes a schedule for future briefings on the case.