A Murky Solution: The Supreme Court’s Ruling on Application of the Clean Water Act

Under the Clean Water Act, a National Pollutant Discharge Elimination System permit (“NPDES permit”) is necessary for the “discharge of any pollutant by any person” “into waters of the United States”.¹

“Person” broadly includes individuals, businesses, the State, State agencies, and political subdivisions.^₂ And “discharge of any pollutant” means “any addition of any pollutant to [waters of the United States] from any point source.”³ A point source is “any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.”⁴

These definitions—primarily what it means to discharge into waters of the United States—are subject to longstanding disputes in context of the Clean Water Act. Among these disputes was whether the Clean Water Act would apply to a discharge of pollutants into groundwater or indirect location that eventually reaches waters of the United States

On April 23, 2020 the U.S. Supreme Court addressed that very issue when it handed down its opinion in County of Maui, Hawaii v. Hawaii Wildlife Fund, No. 18-260, 590 U.S. ___ (2020). Here, the County of Maui’s wastewater treatment plant used injection wells to discharge partially treated sewage into groundwater. Those wells are about a half-mile from the Pacific Ocean, undoubtedly a water of the United States. The treatment plant generated around 4 million gallons of partially treated sewage a day, which migrated through the groundwater to the Pacific Ocean.

Several environmental groups filed a citizen Clean Water Act lawsuit claiming the County of Maui discharged pollutants to the Pacific Ocean without the necessary NPDES permit. The federal district court granted summary judgment in favor of the environmental groups. It found that the path to the ocean was “clearly ascertainable”. And the discharge from the County of Maui’s wells into nearby groundwater was “functionally one into navigable water.” Therefore, the court found the County of Maui liable.

On appeal the Ninth Circuit affirmed the district court. But it did so on a marginally different, yet critically important, basis. The Ninth Circuit required that the path from the point source to waters of the United States be “fairly traceable.” This requirement created a split in the various federal Courts of Appeals as to what “fairly traceable” means.

In a 6-3 decision penned by Justice Breyer, the Supreme Court held that the Ninth Circuit erred in its “fairly traceable” requirement. Instead, the Supreme Court found that the Clean Water Act only requires a permit for a discharge to groundwater that is the “functional equivalent” of a direct discharge to waters of the United States. The Supreme Court sent back, or remanded, the case to the Ninth Circuit in light of its Opinion.

Notably the Supreme Court declined to adopt either of the tests proposed by the parties in the case—the test proposed by the environmental groups was far too broad, and the bright line test proposed by the County of Maui and the United States (as amicus) was far too rigid and would create easy loopholes. The Court then adopted its own standard and guidance, setting forth a series of 7 factors to consider:

(1) transit time;

(2) distance traveled,

(3) the nature of the material through which the pollutant travels;

(4) the extent to which the pollutant is diluted or chemically changed as it travels;

(5) the amount of pollutant entering the navigable waters relative to the amount of the pollutant that leaves the point source;

(6) the manner by, or area in, which the pollutant enters the navigable waters; and

(7) the degree to which the pollution (at that point) has maintained its specific identity.

The Court likewise stated that the first two factors, time and distance, would more often than not be the predominant factors in determining liability under the Clean Water Act.

But the implications of this holding are not entirely clear. Since the Supreme Court declined to adopt a bright line test, or one with more definition, its holding in Maui serves to create future uncertainty. Also, adding to the uncertainty, the Supreme Court expressed the suggestion that federal district court judges be mindful of the penalties under the Clean Water Act, particularly when “a party could reasonably have thought that a permit was not required.”

This decision, while new precedent, ultimately creates more of the same: uncertainty and necessary litigation to further define the metes and bounds of the jurisdiction and application of the Clean Water Act. These future cases, alongside subsequent EPA guidance and NPDES permits, may provide further helpful guidance for potential litigants.

¹U.S.C. §§ 1311(a), 1362(12)(A).
²U.S.C. § 1362(5).
³U.S.C. §§ 1311(a), 1362(7), 1362(12)(A).
⁴Id. at § 1362(14).