The United States Supreme Court agreed to consider the issue of whether a Federal Clean Water Act (“CWA”) permit is required for discharges of pollutants from point sources that reach CWA navigable waters through a groundwater conduit. By taking up this case, the Supreme Court will hopefully resolve a current Circuit Court split between the 9th and 4th Circuits, which have both held that discharges of pollutants through groundwater require a CWA permit, and the 6th Circuit which has rejected that theory.

The case before the Court is County of Maui v. Hawaii Wildlife Fund, et al., No. 18-260, in which the 9th Circuit ruled that pollutants found in CWA navigable waters that are “fairly traceable” to a point source discharge to groundwater are a basis for liability under the Act and would require a CWA permit. In County of Maui, the point sources at issue were underground injection wells that discharged sanitary effluent via groundwater to the Pacific Ocean.

The Supreme Court’s decision could have far-reaching impacts on a variety of industries and practices, including those which may not be currently regulated under the CWA. The decision also has the potential to bring an added layer of complexity and reopener risk to groundwater cleanups.