The Tenth Circuit Court of Appeals has dismissed as moot a Clean Air Act (CAA) citizen suit brought by environmental groups alleging that the Public Service Co. of Colorado (PSCo) violated the CAA by failing to obtain a valid construction permit for a coal-fired power plant in Pueblo, Colorado. WildEarth Guardians v. PSCo, No. 11-1400 (10th Cir. 8/10/12).

Plaintiffs claimed that PSC o’s construction of the Comanche Generating Station, a new coal-fired power plant, violated the CAA because the company’s construction permit lacked required mercury emissions provisions. Although the project complied with federal and state laws when construction began in 2005, a 2008 federal appeals court decision required regulators to impose additional CAA mercury emissions requirements for new plant construction. New Jersey v. EPA, No. 05-1097 (D.C. Cir. 2/08/08). Plaintiffs sought civil penalties and an injunction to halt construction until PSC o came into compliance.  

The district court dismissed the complaint, ruling that the D.C. Circuit decision was not retroactive. Plaintiffs appealed, and the appeals court dismissed under the jurisdictional doctrine of constitutional mootness. According to the court, because PSC o has shown that its CAA violations, if any, are not likely to recur, plaintiffs’ lawsuit “can serve no cognizable deterrent purpose.”