Luminant Generation Co. v. EPA
Two sets of petitioners sought review of the EPA's final rule partially approving and partially disapproving the most recent revision to Texas's State Implementation Plan (SIP) submitted by the Texas Commission on Environmental Quality pursuant to the Clean Air Act. The portion of the SIP at issue created an affirmative defense against civil penalties for excess emissions during both planned and unplanned startup, shutdown, and maintenance/malfunction (SSM) events. The EPA approved the portion of the SIP revision providing an affirmative defense against civil penalties for unplanned SSM events and disapproved the portion of the SIP revision providing an affirmative defense against civil penalties for planned SSM events. The Fifth Circuit Court of Appeals denied both petitions for review, holding that the EPA did not act arbitrarily or capriciously, or contrary to law, or in excess of its statutory authority, in its partial approval and partial disapproval of Texas's SIP revision.