US Supreme Court Issues Decision in Pivotal Clean Water Act Case That Addresses Discharges to Groundwater

On Thursday of last week, the United States Supreme Court issued its long-awaited decision in the County of Maui v. Hawaii Wildlife Fund regarding the application of Clean Water Act permitting requirements to discharges to groundwater. In its decision, the Supreme Court rejected the Ninth Circuit Court of Appeal’s “fairly traceable” test, and also rejected the “bright line” test advocated by the State of Hawaii and the United States Environmental Protection Agency. Rather, the Supreme Court has created a new test to determine when discharges to groundwater from point sources may be subject to National Pollutant Discharge Elimination System Permit (NPDES) requirements. In its 6-3 decision, the Court found that the CWA requires an NPDES permit “when there is a direct discharge from point source into navigable waters or when there is a functional equivalent of a direct discharge.”

With respect to what constitutes a functional equivalent of a direct discharge, the Court recognized that the test provided may be vague and that the facts of each case will vary. The decision lists factors it considered relevant for consideration, but also caveats that these factors are dependent on the circumstances of each case. Since the decision does not provide clear guidance for application of the new test, the Court noted that the lower courts will play a role in providing future guidance and suggested that EPA should also provide administrative guidance.

Notably, as part of the decision, the Court shared its view that when Congress adopted the CWA, it specifically intended to leave responsibility and autonomy to the States as it pertained to groundwater pollution and nonpoint source pollution. Accordingly, the decision does not weaken the exemptions for discharges from nonpoint sources of pollution like agriculture, and only applies to discharges from point sources. With regard to Maui’s actual discharge, the Court remanded the case to the Ninth Circuit for further proceedings consistent with the opinion. View Update