Can citizen plaintiffs in federal court sue the same violator for the same water pollution violation against which the U.S Environmental Protection Agency (EPA) or state agency is taking or has taken administrative enforcement? 

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.