In the Federal Register of 10/25/2012, EPA published a final rule regarding the definition of “particulate matter emissions” or PM, with respect to Prevention of Significant Deterioration (PSD) and New Source Review (NSR). The proposed rule was issued in March 2012. In the final rulemaking, EPA is correcting an inadvertent error in the May 2008 PM2.5 Implementation Rule, in which the definition of particulate matter, PM10, and PM2.5 required that condensable PM be included in determining emissions of the three pollutants. However, particulate matter (not PM10 or PM2.5) has historically represented only filterable emissions, and the addition of condensable PM to the definition of particulate matter was an error. Condensable PM will continue to be required to be included when calculating PM10 and PM2.5 emissions. And, if a regulation (e.g., NSPS) specifically requires that condensable PM be addressed in assessing compliance with a standard, today’s rulemaking does not affect those regulations.
Pending and future permit applications involving PSD, NSR, or avoidance of those programs will be impacted. Also, existing permits that required condensable PM to be included in total PM emissions may need to be reevaluated.