Today the U.S. Supreme Court issued its long-awaited opinion in County of Maui v. Hawaii Wildlife Fund, addressing whether the Clean Water Act (CWA) requires a permit when pollutants originate from a point source but are conveyed to navigable waters by a nonpoint source, such as groundwater. The issue has historically been controversial and subject to much litigation.

In a 6-3 split, with Justice Breyer delivering the opinion of the Court, the Court rejected the Ninth Circuit’s “fairly traceable” test for determining when discharges from point sources to groundwater that reach surface waters are subject to Clean Water Act (CWA) permitting, instead laying out a narrower test focusing on whether a discharge to groundwater is the “functional equivalent of a direct discharge.”  The CWA defines point sources as any “discrete conveyance . . . from which pollutants are or may be discharged,” including pipes, channels, and wells. The Court found middle ground on the issue, citing to EPA’s long history of permitting pollution discharges from point sources that reached navigable waters only after traveling through groundwater and to several factors that should be considered on a case-by-case basis.