Virginia v. EPA
United States Court of Appeals for the District of Columbia Circuit
108 F.3d 1397 (1997)
Under 1990 Clean Air Act amendments, each state formulated an EPA-approved implementation plan (SIP) to meet national ozone standards, and every state in a designated Northeast Ozone Transport Region, including Virginia (plaintiff), had an SIP already meeting national standards and approved under section 110. The EPA (defendant) then declared each Region state's SIP "substantially inadequate" and required them to adopt California's more restrictive Low Emission Vehicle (LEV) standards to further cut ozone pollution. Virginia and automobile-manufacturer associations petitioned the D.C. Circuit to challenge the EPA's rule, with several Region states intervening to defend it.
Whether, under section 110 of the Clean Air Act, the Environmental Protection Agency possesses the authority to condition approval of a state implementation plan on the state's adoption of a particular control measure.