Section 203.1340  Regulated NSR Pollutant

"Regulated NSR pollutant" means the following:

a)         NO_X or VOM;

b)         Any pollutant for which a NAAQS has been promulgated;

c)         Any pollutant that is identified under this Section as a constituent or precursor of a general pollutant listed under subsection (a) or (b), provided that such constituent or precursor pollutant may only be regulated under NSR as part of regulation of the general pollutant.  Precursors for purposes of NSR are the following:

1)         Except as provided in Section 203.1450, VOM and NO_X are precursors to ozone in all ozone nonattainment areas.

2)         SO₂ and NO_X are precursors to PM_2.5 for a stationary source located in a PM_2.5 nonattainment area or, for purposes of Subpart R, a stationary source which would cause or contribute to a violation of a PM_2.5 NAAQS.

3)         VOM and ammonia are precursors to PM_2.5 in any PM_2.5 nonattainment area.

d)         Direct PM_2.5 emissions and PM₁₀ emissions shall include gaseous emissions from a source or activity that condense to form particulate matter at ambient temperatures.  On or after January 1, 2011, such condensable particulate matter shall be accounted for in applicability determinations and in establishing emissions limitations for direct PM_2.5 emissions and PM₁₀ emissions in NA NSR permits.  Compliance with emissions limitations for direct PM_2.5 emissions and PM₁₀ emissions issued prior to this date shall not be based on condensable particulate matter unless required by the terms and conditions of the permit.  Applicability determinations made prior to this date without accounting for condensable particulate matter shall not be considered as a violation of this Part.

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)