Greenhouse gas emissions are potentially subject to regulation under the Title V and Prevention of Significant Deterioration (PSD) program.  For newly subject Title V sources, the initial Title V application deadline is July 1, 2012.  For biogenic sources, EPA has granted a 3-year exemption; however, some states are not updating their rules but are instead relying on enforcement discretion for sources with biogenic CO2 that puts them over the threshold.  In April, Wisconsin legislators enacted 2011 Wisconsin Act 171, which created statutes 285.60(3m) and 285.63(3m), allowing for the federal deferral to apply to Wisconsin sources.