Darcy's Law and the Supreme Court.

In a historic 6-3 decision, the U.S. Supreme Court (SCOTUS) ruled in April 2020 that some groundwater is now regulated under the Clean Water Act (CWA) and a National Pollutant Discharge and Elimination System (NPDES) permit is required when it can be demonstrated there is a "functional equivalent" of a direct discharge of a pollutant from a point source into navigable waters via groundwater. The pertinent question is, when is a discharge of groundwater containing pollutants from a point source "functionally equivalent" to a NPDES direct discharge into navigable waters? SCOTUS apparently has left it to the groundwater community to provide a scientific basis for evaluating functionally equivalent NPDES discharges. [Extracted from the article]