Judges Probe Scope of Supreme Court’s Clean Water Act Ruling

An Illinois pollution dispute could shed light on the practical impacts of a recent U.S. Supreme Court ruling on the scope of the Clean Water Act.

The U.S. Court of Appeals for the Seventh Circuit heard virtual oral arguments Friday in a long-running clash over alleged contamination from an old coal-fired power station. At issue is whether Dynegy Midwest Generation is liable for alleged discharges from coal ash ponds through groundwater into a local river.

The Clean Water Act requires permits for pollution that moves from discrete sources to surface waterways, and a district court in 2018 ruled that the ...