On February 19, 2019, the U.S. Supreme Court agreed to hear a case addressing pollution that moves through groundwater before reaching waters subject to the Clean Water Act (CWA). Specifically, the Justices agreed to hear the County of Maui, Hawaii v. Hawaii Wildlife Fund case. The issue to be examined and resolved is whether the CWA requires a permit when pollutants originate from a point source but are conveyed to navigable waters of the U.S. by a nonpoint source such as groundwater.

Many interests, including environmental groups, states, and industry, are following the case closely, given its resolution could potentially narrow EPA’s historical interpretation of the types of pollution discharges subject to the CWA. John Cruden, Counselor at Beveridge & Diamond PC and former head of the Justice Department’s Environment Division, is quoted as saying, “This is the most significant environmental law case in the last few years.” The case involves the County of Maui’s wastewater treatment facility. The plaintiff alleged a link between the wastewater injection wells and pollution that seeped through groundwater and ended up in the Pacific Ocean. The 9th U.S. Circuit Court of Appeals sided with the plantiff, endorsing the so-called conduit theory, and found that the county should have had a Clean Water Act permit. If the Court rules in favor of the plantiff, a significant number of water pollution sources, including municipal water treatment plants, would be subject to strict new rules about where they could put waste and how to treat it.