8 CAR § 43-301
For projects that only involve existing emissions units, a significant emissions increase of a regulated NSR pollutant is projected to occur if the sum of the difference between the projected actual emissions (as defined in Subpart 1 of this part) and the baseline actual emissions (as defined in Subpart 1 of this part, as applicable), for each existing emissions unit, equals or exceeds the significant amount for that pollutant (as defined in Subpart 1 of this part).
Codification Notes: “NSR” means new source review.