Is A NPDES Permit Needed For Groundwater Discharge? It Depends

On April 23, the U.S. Supreme Court finally answered the question that has plagued environmental attorneys for years with its decision in County of Maui v. Hawaii Wildlife Fund  (Slip Op 18-260, April 23, 2020): whether point source discharges of pollutants to groundwater with a hydrologic connection to navigable waters are or should be regulated under the Clean Water Act's (CWA) National Pollutant Discharge Elimination System (NPDES) program. This issue has been debated since before the County of Maui, Hawaii, filed its cert. petition on Aug. 27, 2018, seeking to overturn the U.S. Court of Appeals for the Ninth Circuit's decision in Hawaii Wildlife Fund v. County of Maui, 886 F.3d 737 (9th Cir. 2018). That decision held that a point source discharge into groundwater that ultimately flows into navigable waters should be regulated under the NPDES program, creating a split with the U.S. Court of Appeals for the Fourth Circuit's contrary decision in Upstate Forever v.