EPA Emissions Offset Interpretive Ruling

On Thursday, March 16, 2012, the Environmental Protection Agency (“EPA”) took the almost unprecedented step of publishing in the Federal Register a correction to its prior definition of “regulated new source review pollutant” (“Rule”) contained in two sets of Prevention of Significant Deterioration (“PSD”) regulations, 40 C.F.R. §§ 51.166 and 52.21, and in EPA’s Emissions Offset Interpretative Ruling, 40 C.F.R. Part 51, Appendix S, 77 Fed.Reg. 15,656. The purpose of the revision is to correct an “inadvertent error” dating back to the Rule’s promulgation in 2008 when the then-existing definition was changed to require that particulate matter emissions, both PM10 and PM2.5, representing three separate size ranges of particulates, must include “gaseous emissions, source or activity which condense to form particulate matter at ambient temperatures,” i.e., condensable particulate matter.  See, e.g., 40 C.F.R. § 51.166(b)(49)(vi).  Previously, EPA’s regulations only required the filterable fraction, not the condensable particulate matter, to be considered for new source review purposes.  The 2008 change therefore imposed an unintended new requirement on State and local agencies and the regulated community.Continue Reading EPA Issues “Amendment” to Definition of Condensable Particulate Matter as Regulated New Source Review Pollutant