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EPA Considering Whether Clean Water Act Applies to Groundwater

Earlier this year, the U.S. Environmental Protection Agency (“EPA”) requested comments about whether pollutant discharges to certain groundwater sources are subject to Clean Water Act (“CWA”) regulation. The specific question addresses “pollutant discharges from point sources that reach jurisdictional surface waters via groundwater or other subsurface flow that has a direct hydrologic connection to the jurisdictional surface water.”

Previously, EPA stated that the pollutant discharges in question may require National Pollutant Discharge Elimination System (“NDPES”) permits. Case law, however, has been mixed. Some courts had a narrow view of when CWA regulation applies and issued rulings that the CWA does not explicitly answer the question of hydrologically connected groundwater; that discharges do not extend to groundwater; that CWA only covers discharges to navigable waters, but not pollutants that travel from a point source to a navigable water; or that a hydrological connection between groundwater and surface water is not a sufficient justification for CWA regulation. Other courts have upheld applying CWA regulation when pollutants reach water of the U.S. through groundwater with a direct hydrological connection.

In its request for comments, EPA asked stakeholders to address not only “whether EPA should review and potentially revise its previous statements” regarding the applicability of CWA to pollutants that reach navigable waters via hydrologically connected groundwater, but also:

  • whether such regulations are consistent with the “text, structure, and purposes of the CWA;”
  • whether that type of regulation would be better addressed through other federal authorities; and
  • whether those types of releases are already adequately regulated through state programs or other federal regulations.

The comment period closed May 21, 2018.


Written by Marta L. Weismann