The court affirms a district court decision that New York Air Pollution Mitigation Law §66-k is preempted by the Clean Air Act (CAA) Title IV cap-and-trade system and violates the…

The court held that a 2002 U.S. Environmental Protection Agency (EPA) rule specifying that Nevada was divided into more than 250 baseline areas for the Clean Air Act (CAA) prevention of…

The court affirms a district court holding that the Clean Air Act (CAA) does not preempt California's ban of the use of methyl tertiary butyl ether (MTBE) in oxygenated fuel. CAA §…

The court holds that the U.S. Environmental Protection Agency's (EPA's) approval of Georgia's state implementation plan (SIP) mooted environmental groups' claims that Atlanta…

The court grants an environmental group's motion for partial summary judgment against Pennsylvania officials for failing to implement the state-enhanced vehicle inspection and maintenance (I/…

The court vacates a district court decision that the U.S. Environmental Protection Agency (EPA) violated its statutory obligations under the Radon Gas and Indoor Air Quality Act (Radon Act) by…

The court holds that the Secretary of the Pennsylvania Department of Transportation and the Secretary of the Pennsylvania Department of Environmental Protection violated the Clean Air Act (CAA) by…

The court denies a petition for review seeking reversal of the U.S. Environmental Protection Agency (EPA) Administrator's decision not to object to a state agency's determination that…

The court holds that the U.S. Environmental Protection Agency (EPA) did not abuse its discretion or act arbitrarily or capriciously in invalidating a state-granted prevention of significant…

The court holds that a gas and electric company violated the Clean Air Act (CAA) by failing to obtain a preconstruction permit before making modifications to its facility even though there were no…