NSR Enforcement Lives On (For Now) — A Split Decision For Ameren

The 8^th Circuit Court of Appeals has largely affirmed a District Court order finding that Ameren Missouri violated the NSR provisions of the Clean Air Act in making major modifications to its Rush Island facility. The Appeals Court did reject the District Court's requirement that Ameren Missouri make improvements at its nearby Labadie facility that was not in violation of the CAA.

I have three thoughts about the decision.

First, the liability finding was pretty much plain vanilla.  I will note, however, that the combination of the decision here and the 3^rd Circuit decision in United States v. EME Homer City Generation results in a strong incentive for owners of power plants concerned about NSR liability to sell them quickly, since the courts have clearly landed on an interpretation of the CAA under which former owners are not subject to liability, while current owners (if they were owners at the time of a modification), remain liable.