Delaney v. Environmental Protection Agency

In 1978, the Environmental Protection Agency (EPA) (defendant) designated areas of Maricopa and Pima counties in Arizona as nonattainment areas for carbon monoxide under the Clean Air Act (CAA) for failing to achieve national ambient air quality standards. Arizona submitted revised state implementation plans for the counties in 1979, which were approved by the EPA in 1983. However, neither county attained the national standards for carbon monoxide by a 1982 deadline established by the 1977 amendments to the CAA. Arizona sought unsuccessfully to extend the deadline to 1987 and submitted revised plans to achieve national air quality standards by 1987. The EPA rejected the revised plans, a decision that was upheld by the court of appeals. Then, a group of residents from Maricopa and Pima counties (county residents) (plaintiffs) successfully sued the EPA, compelling the EPA to promulgate its own implementation plans for both counties by August 10, 1988, unless Arizona submitted an adequate plan before that date. Before the August deadline, Arizona submitted revised plans that the EPA approved. The EPA evaluated the plans on the basis of whether they provided for attainment of national standards by August 10, 1991, three years from the date of approval. The county residents again sued the EPA, arguing that the EPA’s approval of the revised plans was arbitrary and capricious.