Sierra Club Seeks To Vacate Affirmative Defenses Under Clean Air Act For Unavoidable Malfunctions

This month, the Sierra Club filed a petition for review challenging certain provisions of nine EPA rules that provide for affirmative defenses against alleged Clean Air Act violations in the case of unavoidable malfunctions. This petition results directly from Sierra Club's recent partial victory in Natural Resources Defense Council v. EPA, where the D.C. Circuit held in the context of a similar challenge to EPA's 2013 rule governing emissions standards for the Portland cement industry that "the affirmative defense for private civil suits exceeds EPA's statutory authority." 749 F.3d 1055, 1057 (D.C. Cir. 2014). A victory in this case could impact significantly a number of different industries regulated under Section 112 of the Clean Air Act.