Although it has received thousands of comments, EPA has declined to extend the comment period on its proposed mandatory greenhouse gas (GHG) reporting rule citing a need to begin collecting data in 2010 in order to implement future GHG policy - including cap and trade legislation, if enacted. If, as expected, the rule is adopted essentially as EPA has proposed, it will impose yearly reporting requirements on GHG emissions from more than 13,000 facilities (those with annual GHG emissions of 25,000 tons or more of CO2 equivalent), covering 85 to 90 percent of U.S. GHG emissions. Facilities in 19 source categories (including petroleum refineries and cement production), however, will have to report regardless of their emission levels. The rule requires covered sources to begin tracking their GHG emissions on Jan. 1, 2010, and submit their first annual report by March 31, 2011.