The Clean Water Act regulates the discharge of pollutants into “waters of the United States” pursuant to National Pollutant Discharge Elimination System (NPDES) permits issued by the U.S. Environmental Protection Agency (EPA) or an authorized state agency. This is not a new concept. However, what has come to be known as “the groundwater conduit theory” is disrupting the long-standing understanding of what is and what isn’t covered by the Clean Water Act. This new theory also creates questions for companies and attorneys dealing with Superfund sites and waste management units regulated under RCRA. This article discusses the circuit split on this theory and what I view as potential implications for Superfund sites and waste management units depending on how the U.S. Supreme Court rules.

Several federal cases have addressed the issue of the indirect discharge of pollutants into jurisdictional waters via groundwater transport, and the Supreme Court may weigh in on this question soon. This is an important issue with far-reaching ramifications because it is generally understood that all groundwater that is not otherwise removed (i.e., pumped for drinking water supply) will eventually discharge to a surface water. The Clean Water Act prohibits discharges of pollutants from a “point source” without a NPDES permit, 33 U.S.C. Section 1342. A “point source” is defined as “any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.” Based on this definition, discharges into and through groundwater have not been considered point source discharges because they are not the typical “end of the pipe” discharges. Recent case law out of the U.S. Courts of Appeal for the Fourth, Ninth and Sixth Circuit has resulted in a circuit split on coverage under the Clean Water Act.