On April 15, 2019, U.S. Environmental Protection Agency (“EPA”) issued a new interpretation of the Clean Water Act (“CWA”), stating that the CWA does not require permits for groundwater pollution. The CWA regulates pollution to surface water and requires permits for point-source discharges. However, the question as to whether a discharge of pollutants into groundwater can potentially trigger the CWA’s permitting requirements has been the subject of conflicting federal appellate court decisions.
The Ninth Circuit has held that a county violated the CWA by allowing pollutants from four sewage wastewater injection wells to seep into the Pacific Ocean through groundwater without issuing a NPDES permit. In that case, the EPA filed a friend of the court brief, agreeing that the county was acting illegally. The Fourth Circuit has sided with the Ninth Circuit on this issue, while the Sixth Circuit has explicitly limited the CWA’s application to direct discharges to navigable waters from point sources. In February 2019, the Supreme Court granted certiorari in the Ninth Circuit case to resolve the circuit split on this issue.
EPA’s new interpretation is significant in that it comes just a few months after the Supreme Court granted the Petition for writ of certiorari and that it reverses the position EPA took in the Ninth Circuit case. The EPA is now of the position that “releases of pollutants to groundwater are categorically excluded from the act’s permitting requirements,” regardless of whether the groundwater is hydrologically connected to “navigable water” that is within the CWA’s justification. While EPA clarified that this interpretation would not be enforced in the Ninth and Fourth Circuits (pending the Supreme Court’s ruling on the matter), the new policy will be enforced in the rest of the country immediately.
This change will ultimately make it harder to enforce the CWA in cases that involve conveyance via groundwater. Likewise, for municipal and industrial facilities that discharge to groundwater, it provides some clarity over which federal laws are supposed to cover which types of water.