On February 20, 2018, the U.S. Environmental Protection Agency (EPA) requested comments on whether pollutant discharges from point sources that reach jurisdictional surface waters via groundwater or other subsurface flow with a direct hydrologic connection to the jurisdictional surface water may be subject to regulation under the Clean Water Act (CWA).
The answer to this question will have far reaching implications because the scope of the agency’s powers under the CWA determines the scope of:
- National Pollutant Discharge Elimination System (NPDES) permitting programs;
- Section 404 wetlands permitting programs;
- Section 311 oil/hazardous substance release requirements; and
- Spill Prevention Control and Countermeasure (SPCC) requirements.
As a result, the extent to which a discharge to groundwater that reaches jurisdictional surface waters is subject to regulation under the CWA is a significant issue for farmers, manufacturers, and anyone who discharges to groundwater.
The CWA regulates the discharge of pollutants and placement of fill into “navigable waters,” and defines navigable waters as “the waters of the United States.” Since the CWA was passed in 1972, there has been much debate over the extent to which waters that are not considered navigable in fact and wetlands may be regulated as waters of the United States. This uncertainty has given rise to a variety of CWA citizen suits alleging that discharges from point sources that migrate via groundwater to waters of the United States require NPDES permits.
Over the years, various federal courts have reached differing conclusions on the question of whether discharges to groundwater can be considered discharges to waters of the United States. Most recently, the Ninth Circuit addressed this issue in Hawaii Wildlife Fund v. County of Maui, 881 F.3d 754 (9th Cir. 2018). In that case, the County of Maui (the “County”) discharged treated effluent from its wastewater reclamation facility into injection wells. Tracer dye studies confirmed that this effluent migrated through the groundwater to the Pacific Ocean. A three-judge panel for the Ninth Circuit Court of Appeals ruled that the County’s discharge triggered Clean Water Act jurisdiction and the need for an NPDES permit because the groundwater was hydrologically connected to the Pacific Ocean, a water of the United States. Under the court’s ruling, an indirect discharge of contaminants from point sources that travels through groundwater and ultimately reaches navigable waters will now be subject to federal permitting requirements.