Today the U.S. Supreme Court issued a long awaited decision in County of Maui, Hawaii v. Hawaii Wildlife Fund, 590 U.S. (2020), holding that point source discharges of pollutants that are the “functional equivalent of a direct discharge” into navigable waters require a permit under the Clean Water Act’s national pollutant discharge elimination system (NPDES) program. The NPDES program exclusively regulates discharges of pollutants from point sources (defined as a confined, discrete conveyance) to navigable waters, and therefore whether a permit is required for pollutants that flow from a point through intermediary conveyances is a crucial question. The court’s opinion, authored by Justice Breyer and joined by Chief Justice Roberts and Justices Ginsburg, Sotomayor, Kagan, and Kavanaugh, who wrote a separate concurrence, threatens to upend well-settled expectations around NPDES permitting and the regulation of pollutants in groundwater in general.

At issue in the case was the County of Maui’s use of Class IV underground injection wells (permitted under the state’s Underground Injection Control program) to discharge treated wastewater from its wastewater treatment plant. The wastewater eventually seeped through groundwater into the Pacific Ocean along approximately two miles of coastline over a period of approximately 10 months, and the Ninth Circuit held that because the discharge was “fairly traceable” to a point source and was more than de minimis, the discharge required an NPDES permit. County of Maui, Hawaii v. Hawaii Wildlife Fund, 886 F. 3d 737, 749 (2018). While the court today rejected the Ninth Circuit’s fairly traceable test as overly broad (and potentially requiring a permit in the ridiculous scenario where a discharge from a point source arrived in surface water 100 years later), it nonetheless held that where a discharge of pollutants to navigable waters originates from a point source that is the “functional equivalent” of a direct discharge, a NPDES permit is required.

The court acknowledged that this functional equivalent test provides little guidance to the Environmental Protection Agency (EPA) and the regulated community at large as to how far the NPDES program should actually extend, opining that “time and distance” will be crucial determinations. The court expressed little sympathy for the potential impact its decision will have, for example, on the owners of the “over 20 million septic systems used in many Americans’ homes.” Instead, the court suggested that EPA and the states can simply issue permits to address these discharges, without regard for the cost to individual permittees to apply for and comply with such permits and the regulatory burden of overseeing NPDES permit compliance at millions of individual residences. The court similarly breezed past the substantial risk of citizen suits posed by the decision (a substantial risk given the hefty penalties for failing to obtain an NPDES permit), suggesting that the issue can simply be worked out in litigation and that courts will exercise appropriate discretion in imposing civil penalties. Absent from the opinion was any discussion of how the decision will upend existing regulatory programs that already address the types of discharges at issue and upset well-settled expectations of compliance. The court did suggest that its interpretation left room for EPA to issue regulations addressing how its decision was to be interpreted and implemented, but in the meantime the regulated community will be left at risk of citizen suits under the Clean Water Act for discharges previously addressed under other environmental statues and state programs.