35 Ill. Adm. Code 202.104
Actual Emissions
Section 202
Section 202.104 Actual
Emissions
"Actual emissions"
means the actual rate of annual emissions of a pollutant from an operational
emission source for a particular date equal to the mean rate at which the
emission source actually emitted the pollutant during the two-year period which
immediately precedes the particular date and which is determined by the
Illinois Environmental Protection Agency (Agency) to be representative of
normal emission source operation; however:
a) The Agency shall allow the use of a different time period upon
a determination that it is more representative of normal emission source
operation. The burden shall be on the applicant to demonstrate that another
time period is more representative. Actual emissions shall be calculated using
the emission source's actual operating hours, production rates, and types of
materials processed, stored, or combusted during the selected time period.
b) If the Agency determines that there is inadequate information
to determine actual emissions as indicated in the preceding paragraphs, the
Agency shall use the potential to emit of the emission source.