On May 16, 2011, the Environmental Protection Agency (“EPA” or “Agency”) stayed indefinitely the effective date for the controversial final rules, “National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters” (the “Major Source Boiler MACT”) and “Standards of Performance for New Sources and Emission Guidelines for Existing Sources: Commercial and Industrial Solid Waste Incinerator Units” (the “CISWI Rule”). 

On May 20, 2011, eighty parties representing a cross-section of American business filed their opening brief in the U.S. Court of Appeals for the D.C. Circuit (“D.C. Circuit” or the “Court”) challenging EPA’s finding that greenhouse gases (“GHGs”) emitted by new motor vehicles endanger the public health and welfare by contributing to climate change.  A group of states filed separate briefs challenging that finding as well.