D.C. Circuit Vacates EPA’s Exemption for Excess Emissions During Startup, Shutdown and Malfunction Episodes for Major Sources of Air Toxics

On December 19, 2008, the U.S. Court of Appeals for the District of Columbia Circuit vacated a major Environmental Protection Agency rule exempting large industrial sources from the Clean Air Act’s standards for hazardous air pollutants (HAPs) during periods of startup, shutdown and malfunction (Sierra Club v. EPA, No. 02-1135 (D.C. Cir. Dec. 19, 2008). Unless the decision is vacated by the Court of Appeals on rehearing or by the Supreme Court on certiorari, the decision will dramatically change the regulatory framework for HAPs emitted by large industrial sources.