Alaska Department of Environmental Conservation v. EPA
United States Supreme Court
540 U.S. 461 (2004)
A mining company sought a state permit under the Clean Air Act's Prevention of Significant Deterioration program for an expansion that would significantly increase emissions; the state permitting agency, ADEC (plaintiff), initially found that a 90%-effective control technology was the best available control technology (BACT) but then reversed course under pressure from the mine and issued a permit allowing weaker, 30%-effective controls, without adequately explaining the reversal. The EPA (defendant) intervened and ordered construction halted, and the court of appeals upheld that order.
Whether, under the Clean Air Act, the EPA may issue an order halting construction of an emissions-generating facility upon finding that a state permitting agency failed to comply with the Act's best-available-control-technology mandates.