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.

The now apparent rationale for the revision (besides political pressure from governmental agencies and the emitting community), is that EPA no longer regulates the ambient indicator, total suspended particulates, with which the indicator “particular matter emissions” is associated.  Therefore, there is no “compelling” reason for requiring the condensable PM portion to be counted toward the measure of particulate matter emissions from stationary sources for PSD applicability determinations and establishing emissions limitations. 

Finally, the revision will restore consistency in the regulation of these indictors for particulate matter under the PSD program with EPA’s original intent.  Specifically, this would mean PM10 and PM2.5 pollutants will be regulated as criteria pollutants, i.e, under the definition covering “any pollutant for which a National Ambient Air Quality Standard has been promulgated,” and would be required to include the condensable PM fraction emitted by the source.  In addition, “particulate matter emissions” would be regulated as a non-criteria pollutant (that is under the portion of the definition that refers to “any pollutant that is subject to any standard promulgated under § 111 of the Act”) without a general requirement to include the condensable PM fraction emitted by a source. 

While this change may seem insignificant to the general public, the regulated community that will be affected by it is not small, and includes, but is not limited to, miscellaneous chemical products, natural gas liquids, natural gas transportation, pulp and paper mills and automobile manufacturing.  These industry segments will be relieved of expensive and time consuming burdens caused by EPA’s “inadvertent error,” and, thus, will not be required to pass these costs on to the consumer.