On March 19, 2026, a three-judge panel of the U.S. Court of Appeals for the D.C. Circuit denied EPA’s request to sever and stay challenges to drinking water standards, known as MCLs, for four PFAS (PFHxS, PFNA, HFPO‑DA, and mixtures of any of these three plus PFBS).  These four PFAS are referred to as “Index…