On April 23, 2020, the United States Supreme Court issued its decision in County of Maui, Hawaii v. Hawaii Wildlife Fund et al., No. 18-260, 590 U.S. __ (April 23, 2020), ruling that the federal Clean Water Act (CWA) may require a permit when a point source discharges pollutants to navigable waters through groundwater. This decision has been eagerly awaited by industry, government, and the bar.

The federal Clean Water Act (CWA) does not require a permit for the discharge of pollutants to groundwater that is hydrologically connected to navigable waters of the United States. That is the upshot of the federal District Court’s recent ruling upholding the Environmental Protection Agency’s (EPA) interpretation of the CWA as conferring no authority to regulate discharges to groundwater, regardless whether pollutants therein reach navigable waters of the United States. Judge William G. Young determined this to be a “permissible construction” of the statute.