Brian McCarthy Gayle Hartmann Alma Williams Roberta Delaney v. Lee M. Thomas City of Tucson

Opinion by Judge WIGGINS.

Plaintiffs below (“Appellants”) sought from the district court an order requiring the cities of Tucson and Phoenix to enlarge their mass transit systems. Specifically, Appellants asserted that Tucson and Phoenix must comply with certain mass transit proposals that Arizona submitted to the EPA in the late 1970s and early 1980s. The district court disagreed with Appellants and entered summary judgment for the cities. We reverse.

I.

A. Statutory Framework

As amended in 1970, the Clean Air Act (“CAA”) required the EPA to establish national ambient air quality standards (“NAAQS”) for certain airborne pollutants. 42 U.S.C. § 7409 . Most relevant to this case, the CAA required the EPA to promulgate standards for carbon monoxide (“CO”). These standards were to be enforced by the states, under the direction of the EPA. Specifically, each state was to submit to the EPA plans designed to implement, maintain, and enforce the NAAQS within the state. Id. § 7410(a)(1). The EPA was to review the proposed plans and “approve or disapprove” them. Id. § 7410(a) (1988); see id. § 7410(k) (1994). EPA approval was to be given to submitted plans that complied with the CAA.…