EME Homer City Generation, L.P. v. EPA

The EPA (defendant) promulgated the Transport Rule under the Clean Air Act's "good neighbor" provision, requiring 28 upwind states to reduce emissions contributing to downwind states' air-quality nonattainment, but the Rule let the EPA itself quantify each state's obligations and impose EPA-designed Federal Implementation Plans rather than first giving states the statutorily contemplated opportunity to develop their own compliance plans; EME Homer City and various states, localities, and industry groups (plaintiffs) petitioned for review, arguing the Rule exceeded EPA's statutory authority.