On April 15, 2019, the U.S. Environmental Protection Agency (EPA) issued a prepublication draft of an Interpretative Statement clarifying the application of Clean Water Act (CWA) National Pollution Discharge Elimination System (NPDES) permitting requirements to discharges of pollutants to groundwater. EPA concluded that releases of pollutants to groundwater are categorically excluded from the CWA's permitting requirements because Congress explicitly left regulation of discharges to groundwater to the states and to EPA under other statutory authorities. As described in prior blogs, EPA published a Request for Comment in the Federal Register seeking comments on a broad range of topics related to the question of whether the CWA NPDES permitting requirement should be used to regulate discharges of pollutants to groundwater which have a direct hydrologic connection to surface water. EPA received over 50,000 comments from a wide range of stakeholders, many of which affirmed that additional clarity from EPA was necessary.

As described in the press release this decision "recognizes the state's leadership role in protecting groundwater and provides certainty to states and others who implement and enforce EPA's federal permitting programs." The Interpretive Statement goes to great length to describe the current posture of recent cases, as well as the lengthy history of the CWA, including its legislative history. It also describes with particularity some of the key positions by commenters and why EPA rejected certain of those positions. EPA will be seeking further comment in Docket No. EPA-HQ-OW-2019-0166 for a period of 45 days after publication in the Federal Register, which has not yet occurred. More information is available on EPA's webpage.

This decision comes while the Ninth Circuit decision in Hawaii Wildlife Fund v. County of Maui, 886 F.3d 737 (9th Cir. 2018) is pending before the Supreme Court of the United States (SCOTUS) in docket no. 18-260 and was forecast by the Brief for the United States as Amicus Curiae filed Jan. 3, 2019. Only time will tell whether SCOTUS finds EPA's position persuasive.