a) "Actual Emissions" means the actual rate of emissions of a regulated NSR pollutant from an emissions unit as determined in compliance with subsections (b) through (c), except that this definition shall not apply for calculating whether a significant emissions increase has occurred, or for establishing a PAL under Subpart Q. Instead, Section 203.1070 and Section 203.1320 shall apply for those purposes.

b) In general, actual emissions as of a particular date shall equal the average rate, in tons per year, at which the unit actually emitted the pollutant during a consecutive 24-month period which precedes the particular date and which is representative of normal source operation. The Agency shall allow the use of a different time period upon a demonstration by the applicant to the Agency that the time period is more representative of normal source operation. Such demonstration may include, but need not be limited to, operating records or other documentation of events or circumstances indicating that the preceding 24-month period is not representative of normal source operations. Actual emissions shall be calculated using the unit's actual operating hours, production rates, and types of materials processed, stored or combusted during the selected time period.

c) For any emissions unit which has not begun normal operations on the particular date, actual emissions shall equal the potential to emit of the unit on that date.

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