Environmentalists scored a rare and somewhat muddled victory in the U.S. Supreme Court on Thursday. For the court's newest justice, Brett Kavanaugh, victory belonged to the late Justice Antonin Scalia.

In County of Maui v. Hawaii Wildlife Fund, the justices were asked if the Clean Water Act requires a permit when pollutants originate from a point source, such as a sewage treatment plant, but are conveyed to navigable waters by a nonpoint source, such as groundwater.

Parties on both sides claimed their positions were supported by Scalia's 2006 plurality opinion in the case Rapanos v. United States, an opinion described as a "quagmire" interpretation of "waters of the United States." The relevant part of the fractured 4-1-4 Rapanos opinion for the Maui case was that the CWA "does not forbid the 'addition of any pollutant directly to navigable waters from any point source,' but rather the 'addition of any pollutant to navigable waters.'"