On April 23, 2020, the U.S. Supreme Court decided County of Maui v. Hawaii Wildlife Fund, holding that the Clean Water Act requires a permit for a point source that emits pollutants into navigable waters through groundwater only if the emission is the “functional equivalent” of a direct discharge from the point source into navigable waters.
The Clean Water Act forbids the “addition” of any pollutant from a “point source” to “navigable waters” without a permit from the Environmental Protection Agency (or a state agency with a delegated program). Maui County, Hawaii, pumps partially treated sewage underground, where it travels about half a mile through groundwater to the ocean. The County does not have a permit for discharges into navigable waters, and environmental groups sued claiming that it should. The U.S. Court of Appeals for the Ninth Circuit held that a permit is required for non-direct discharges that “are fairly traceable from the point source to a navigable water.”
The Supreme Court vacated that decision by a 6-3 vote. It noted that “virtually all water, polluted or not, eventually makes its way to navigable water,” and held that Congress did not intend for the EPA to have “permitting authority over the release of pollutants that reach navigable waters many years after their release and in highly diluted forms” — especially because the relevant provisions of the Clean Water Act “say nothing at all about nonpoint source regulation or groundwater regulation,” but instead “left general groundwater regulatory authority to the States.”
On the other hand, the Court held that not “all releases of pollutants to groundwater are excluded from the scope of the permitting program.” That, said the Court, would allow the owner of a pipe leading directly into navigable waters to “simply move the pipe back, perhaps only a few yards, so that the pollution must travel through at least some groundwater before reaching the sea.” The Court could “not see how Congress could have intended to create such a large and obvious loophole.” The Court also noted that this interpretation is “difficult to reconcile … with the statute’s inclusion of ‘wells’ in the definition of ‘point source,’ for wells most ordinarily would discharge pollutants through groundwater.”
Instead, the Court concluded that the Clean Water Act requires a permit where “there is the functional equivalent of direct discharge.” The Court declined to elaborate a precise test for “functional equivalent,” but left the standard for elaboration “through decisions in individual cases.” It explained, however, that “in most cases” the “time and distance” between the point source and the navigable waters “will be the most important factors.” The Court also gave a non-exhaustive list of other “factors that may prove relevant:”
- “The nature of the material through which the pollutant travels,”
- “The extent to which the pollutant is diluted or chemically changed as it travels,”
- “The amount of pollutant entering the navigable waters relative to the amount of the pollutant that leaves the point source,”
- “The manner by or area in which the pollutant enters the navigable waters,” and
- “The degree to which the pollution (at that point) has maintained its specific identity.”
Justice Breyer authored the opinion of the Court, joined by Chief Justice Roberts and Justices Ginsburg, Sotomayor, Kagan, and Kavanaugh. Justice Kavanaugh filed a concurring opinion. Justice Thomas filed a dissent, joint by Justice Gorsuch; and Justice Alito filed a separate dissent.