The County of Maui, Hawai‘i operates the Lahaina Wastewater Reclamation Facility, a water treatment facility that disposes of treated sewage by releasing it from injection wells into groundwater, which then carries the discharge to the Pacific Ocean.  The Clean Water Act (CWA) prohibits “the discharge of any pollutant by any person” without a permit, and it defines such a discharge as “any addition of any pollutant to navigable waters from any point source,” like a well.  In 2012, four Maui-based nonprofits (Hawaii Wildlife Fund, Sierra Club – Maui Group, Surfrider Foundation, and West Maui Preservation Association) sued the County, alleging that it had violated the CWA by discharging the treated sewage without a permit.  Everyone agreed that the treated sewage from the injection wells enters the Pacific Ocean and that this treated sewage is a “pollutant,” the Pacific Ocean constitutes “navigable waters,” and the County’s injection wells are “point sources,” all within the meaning of the CWA.  The County argued, however, that it did not need a permit for this discharge because it sent the pollutant through groundwater on its way to the ocean.  The district court disagreed and granted summary judgment for the nonprofits.  The Ninth Circuit affirmed.  The County filed a petition for certiorari with the Supreme Court, which the Court granted in February 2019.

CAC filed an amicus curiae brief in support of respondents (the nonprofits) arguing that the CWA prohibits the pollution of navigable waters from any point source without a permit, regardless of whether the point source delivers the pollutant directly.  First, we emphasized that the CWA’s plain text prohibits “any addition of any pollutant to navigable waters from any point source” and that it does not provide an exception for indirect point-source pollution.  In particular, we argued that the statutory language is broad and, as a plurality of the Supreme Court had already recognized, “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.’”  Second, we argued that the structure and purpose of the CWA are consistent with the meaning of its plain text and that the County’s arguments to the contrary are unpersuasive.  Finally, we argued that no “clear-statement rule” requires a different result.  Although the County argued that Congress must “speak clearly” when it intends to expand an agency’s authority, that rule is inapplicable here.  And Congress could hardly have been clearer that the CWA prohibits any addition of any pollutant to navigable waters from any point source without a permit, regardless of whether the pollutant travels directly from Point A to Point B.

The Supreme Court held that the CWA requires a permit for either a direct discharge or the functional equivalent of a direct discharge of a pollutant from a point source to navigable waters, so the CWA prohibited Maui from polluting the Pacific Ocean through groundwater without a permit.  The Court echoed our arguments that the language, structure, and history of the CWA, along with the Court’s prior interpretation of that statute, compel this result.  This decision, issued by a cross-ideological majority, was a significant win for environmental protection.