Sierra Club petitions the Environmental Appeals Board to review a Clean Air Act prevention of significant deterioration permit that Maricopa County Air Quality Department issued to Arizona Public Service Company in March 2016. The permit authorizes Arizona Public Service to construct five new natural gas-fired combustion turbines at its Ocotillo Power Plant in Tempe, Arizona. Maricopa County issued the final permit pursuant to a delegation agreement between it and the United States Environmental Protection Agency Region 9.