On April 23, 2020, the U.S. Supreme Court issued a 6-3 opinion in County of Maui v. Hawaii Wildlife Fund, which established a new test to determine the permitting requirements under the Clean Water Act (CWA). The case centered on the County of Maui’s Lahaina Wastewater Reclamation Facility, which treats millions of gallons of waste each day and then injects it into deep wells underground. A 2013 study ordered by the Environmental Protection Agency (EPA) showed that 90% of this waste ultimately ends up in the Pacific Ocean, after traveling through groundwater.

The CWA prohibits the “addition” of any pollutant from a “point source” to “navigable waters” without the appropriate permit from the EPA. See Federal Water Pollution Control Act, §§ 301(a), 502(12)(A), as amended by the Federal Water Pollution Control Act Amendments of 1972 (Clean Water Act) § 2, 86 Stat. 844, 886, 33 U.S.C. §§ 1311(a), 1362(12)(A). The question in this case was whether the CWA requires a permit when the pollutants originate from a point source, but are conveyed to navigable waters by a nonpoint source, such as groundwater.

Previously, the 9^th Circuit held that a permit is required when “the pollutants are fairly traceable from the point source to a navigable water such that the discharge is the functional equivalent of a discharge into the navigable water.” SCOTUS adopted a narrower interpretation than the 9^th Circuit, concluding that a permit is required when there is “a direct discharge from a point source into the navigable waters or when there is the functional equivalent of a direct discharge.” The Court emphasizes that time, distance, the nature of material through which the pollutant travels, the extent to which the pollutant is diluted or changed as it travels, the amount of pollutant, the manner by which the pollutant enters the navigable waters, and the degree to which the pollution has maintained its specific identity could be important considerations when making this determination.

The County of Maui argued for a bright-line test known as the “means-of-delivery” test, which would find that no permit was required here because groundwater, not the point source, delivered the pollutant to navigable waters. The Court disagreed, using a hypothetical to explain the issues with the means-of-delivery test: a pipe spewing pollution directly into coastal waters clearly requires a permit, but if the County of Maui’s argument was accepted, moving the pipe back a few yards so that the pollution travels through groundwater before it meets the sea would avoid this permitting requirement. The Court said, “[w]e do not see how Congress could have intended to create such a large and obvious loophole.”

The Court recognizes that their test, which is a middle ground, is more difficult to administer. However, they reason that taking an absolute stance is inconsistent with congressional objectives. Therefore, they conclude that “the permitting requirement, § 301, as applicable to a discharge (from a point source) of pollutants that reach navigable waters after traveling through groundwater if that discharge is the functional equivalent of a direct discharge from the point source into navigable waters.” The Court vacated the 9^th Circuit’s judgment and remanded the case for further proceedings consistent with this new test.