This morning, in a lengthy per curiam opinion, the U.S. Court of Appeals for the D.C. Circuit granted petitions of review filed by states and environmental groups against primary and secondary National Ambient Air Quality Standards (NAAQS) for fine particulate matter and remanded the standards to the Environmental Protection Agency (EPA). At the same time, the court denied both industry and environmental petitions challenging the NAAQS for coarse particulates. The decision in American Farm Bureau Federation v. EPA is here.
As I have noted before, it is remarkable how poorly the Bush Administration's air pollution regulations have fared in federal court, even before the relatively conservative D.C. Circuit. In related news, yesterday the Supreme Court denied the petition for certiorari seeking review of the D.C. Circuit's decision invalidating the Bush administration's regulations governing mercury emissions.