06-096-100 Me. Code R. § 1
"Actual emissions" means the actual rate of emissions of a pollutant from an emissions unit. In general, actual emissions as of a particular date shall equal the average rate, in tons per year (tpy), at which the unit actually emitted the pollutant. 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. The Department may presume that the source-specific allowable emissions for the unit are equivalent to the actual emissions of the unit. For any existing emissions unit that may be modified or affected by a modification, future actual emissions shall equal projected actual emissions. For any new source 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. For the purposes of determining baseline emissions from a source when calculating an emission reduction credit in accordance with 06-096 C. M. R. ch. 113, source-specific allowable emissions can only be used when the allowable emissions during the baseline period are lower than the actual emissions.
06-096 C.M.R. ch. 100, § 1