Committee for a Better Arvin v. U.S. Environmental Protection Agency

Petitioners, a contingent of environmental and community groups, bring serious challenges to the State of California’s plans to improve air quality in the San Joaquin Valley, an area with some of the worst air quality in the United States. We must consider whether these state plans are sufficient'in law, specifically, whether the regulating United States Environmental Protection Agency (“EPA”) erred in approving California’s State Implementation Plans (“SIPs”) to comply with National Ambient Air Quality Standards (“NAAQS”) enacted under the federal Clean Air Act (“CAA”) concerning ozone and fine particulate matter in the San Joaquin Valley. We do this in the context of a cooperative federalism regime in which the federal agency sets required air quality standards but the state is a primary actor in creating plans to achieve them, followed by potential enforcement at both state and federal levels and by private citizens.

Petitioners contend: (1) that the approved plans calculate the necessary emissions reductions and forecasts in part based on state-adopted measures that are not themselves incorporated into the federally enforceable plan, in violation of the CAA; (2) that…