County of Maui v. Hawaii Wildlife Fund

Background

A county in Hawaii runs a wastewater treatment facility that pumps about four million gallons a day of treated sewage into underground wells. That water then travels through groundwater about a half mile to the Pacific Ocean. Several environmental groups sued under the Clean Water Act, saying the county was adding a pollutant to navigable waters without an EPA permit. Lower courts found for the groups, and the case reached the Supreme Court to decide whether pollution that moves through groundwater needs a federal permit.

Reasoning

The Court asked whether the statute’s words require a permit when pollution originates at an identifiable source but reaches the ocean only after passing through groundwater. In a majority opinion, the Court ruled that a permit is required for a direct discharge into navigable waters or when the underground release is the “functional equivalent” of a direct discharge. The majority said time and distance are usually the most important factors and listed other factors like dilution and the material the pollutant travels through.

Real world impact

This decision means some discharges that travel through groundwater can trigger federal permits, but not all will. Coastal sewage plants whose discharges quickly reach the ocean will be most affected. The ruling leaves room for regulators and courts to apply the new “functional equivalent” test case by case, and it notes that EPA and states can issue guidance or permits tailored to recurring situations. The Court also remanded the Maui case for further proceedings under this standard.

Dissents or concurrances

The concurring Justice emphasized that time and distance should guide most cases. Two dissenting Justices argued the Clean Water Act covers only direct discharges into navigable waters and would have reversed the Ninth Circuit.