For decades, the precise scope of the Clean Water Act’s point source permitting program has been the subject of much controversy. Over the past several years, the question of whether that program—known as the National Pollution Discharge Elimination System (“NPDES”)—regulates discharges to groundwater that is hydrologically connected to surface water has produced a number of conflicting decisions and a torrent of commentary and public debate. The Fourth and Ninth Circuits recently concluded that the NPDES program regulates such discharges under certain circumstances, while the Sixth Circuit reached the opposite conclusion, setting up potential review of the issue in the United States Supreme Court. See Upstate Forever v. Kinder Morgan Energy Partners, L.P., 887 F.3d 637 (4th Cir. 2018); Haw. Wildlife Fund v. Cty. of Maui, 886 F.3d 737 (9th Cir. 2018); Ky. Waterways All. v. Ky. Utils. Co., No. 18-5115, 2018 WL 4559315 (6th Cir. Sept. 24, 2018); Tenn. Clean Water Network v. Tenn. Valley Auth., No. 17-6155, 2018 WL 4559103 (6th Cir. Sept. 24, 2018).