County of Maui, HI v. Hawaii Wildlife Fund

Whether the Clean Water Act requires a permit when pollutants originate from a point source but are conveyed to navigable waters by a nonpoint source, such as groundwater.

The Clean Water Act (CWA) requires National Pollutant Discharge Elimination System (NPDES) permits, which are managed by the Environmental Protection Agency (EPA), for any pollutant discharge into navigable waters from point sources. Petitioner’s wastewater management company injects effluent into its underground injection control wells. Upon injection it mixes with groundwater which migrates toward the ocean, about 90% entering the ocean through diffuse flow, meaning it has no identifiable ocean entry point. Hawai'i’s nonpoint source pollution management program controls the migration of effluent from these wells to the ocean. The Hawai'i Department of Health and the EPA have never required the County to obtain an NPDES permit for well disposal. The district court granted summary judgment for Respondent holding the County liable for failure to have permits because the wells are a point source which discharges pollutants indirectly through a “groundwater conduit.” The Ninth Circuit affirmed holding that NPDES permitting is required even where pollutants are discharged from a nonpoint source, rejecting the district court’s conduit theory. Petitioner argues in its brief to the Supreme Court, that the Ninth Circuit’s decision parted with precedent by expanding NPDES point source permitting to include nonpoint source pollution. Petitioner further argues that this expansion is akin to that of the Clean Air Act permitting, which the Court reversed in Util. Air Regulatory Grp. v. EPA, 134 S. Ct. 2427 (2014).