Sierra Club v. EPA

The D.C. Circuit directed that the claim involving timing issues in this challenge to EPA's final Prevention of Significant Deterioration and Title V Greenhouse Gas Tailoring Rule be severed and consolidated with other pending cases challenging former EPA Administrator Stephen Johnson's December 2008 interpretive memo and EPA's reconsideration of the memo.

Sierra Club filed a lawsuit challenging the U.S. Environmental Protection Agency (EPA) final Prevention of Significant Deterioration and Title V Greenhouse Gas Tailoring Rule to the extent it codified former EPA Administrator Johnson's interpretive memo governing when pollutants become “subject to regulation” under the Clean Air Act. Sierra Club noted that it had intervened to defend other aspects of the rule in industry lawsuits challenging the final rule.

Center for Biological Diversity filed a petition for review challenging the U.S. Environmental Protection Agency's (EPA's) reconsideration of the interpretive memorandum issued by former EPA Administrator Stephen Johnson in December 2008.