The Environmental Protection Agency intends to propose to withdraw its regulatory determinations to regulate four per- and polyfluoroalkyl substances (PFAS)perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid and its ammonium salt (HFPO-DA, commonly known as GenX), and the mixture of these three PFAS plus perfluorobutane sulfonic acid (PFBS)under the Safe Drinking Water Act. EPA also intends to propose to rescind all associated regulatory provisions associated with the Final PFAS NPDWR (89 FR 32532) currently codified in 40 CFR part 141 and 142 exclusive to these PFAS that were promulgated pursuant to the regulatory determinations that EPA is now proposing to withdraw.