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 §211(c)(4)(A) preempts state regulation of fuel for purposes of motor vehicle emissions, but California is exempt fr...

The court invalidates a 1999 U.S. Department of Energy (DOE) order governing the disposal of high-level radioactive waste (HLW) at the Hanford site in Washington, the INEEL facility in Idaho, and the Savannah River site in South Carolina. Part of the order defines a process by which HLW that meets c...

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 significant deterioration (PSD) program was not arbitrary or capricious. Based on an ambiguous 1991 EPA regulation...

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 Supremacy Clause of the U.S. Constitution. Section 66-k requires the assessment of an air pollution mitigation offs...

The court holds that an electric utility violated the Clean Air Act (CAA) when it completed 11 construction activities that modified a coal-fired electric-generating facility without first calculating post-construction emissions and obtaining preconstruction CAA prevention of significant deteriorati...

The court largely upholds the U.S. Environmental Protection Agency's (EPA's) determination that Subtitle C of the Resource Conservation and Recovery Act (RCRA) does not apply to recycled materials used to make zinc fertilizers, or to the resulting fertilizers themselves, so long as they meet certain...

The Ninth Circuit holds that a district court erred in holding that residents living across from a county dump lacked standing to bring Clean Air Act (CAA) claims based on ozone degradation against a county health department and in granting the county summary judgment on the residents' Resource Cons...

The court holds that a local transportation control measure, adopted as part of California's state implementation plan to attain federal air quality standards in the San Francisco Bay Area, does not impose an enforceable obligation on the local transportation commission to increase public transit ri...

The D.C. Circuit held that on remand EPA must explain how the risk assessments it used in exempting certain recycled zinc fertilizer products from regulation under RCRA compare with the risk threshold estimates in a private study. Petitioners were limited to challenging EPA's claim that its study an...

The U.S. Supreme Court held that certain aspects of local fleet rules do not escape preemption under CAA §209(a) simply because they address the purchase of vehicles rather than their manufacture or sale. The fleet rules prohibit the purchase or lease of vehicles by fleet operators that do not ...