(1) Actual 1990 baseline emissions. An emissions baseline established from 1990 actual emissions as reported in response to the department's survey of major facilities.

(2) Forced outage. An unplanned component failure that requires the source or major electrical inter-tie (345 kV or greater) be removed from service immediately or before the next weekend. Such failures must not include those attributable to improperly designed equipment, lack of preventive maintenance, careless or improper operation, or operator error.

(3) Large boiler. A boiler with a maximum heat input capacity greater than 100 million Btu per hour and equal to or less than 250 million Btu per hour.

(4) Mid-size boiler. A boiler with a maximum heat input capacity greater than 25 million Btu per hour and equal to or less than 100 million Btu per hour.

(5) Peaking combustion turbine. A combustion turbine used intermittently to produce energy during periods of extremely high (i.e., peak) power demand.

(6) Regenerative combustion turbine. Any combustion turbine which recovers heat from the turbine exhaust gases to preheat combustion air.

(7) Shutdown. The permanent removal from service of an emission source as evidenced by either a permit condition or provision prohibiting the emission source from further operation, the surrender of the emission source's permit, or the complete deletion of mention of the emission source from the permit of the major facility of which it had formerly been a part with no authorization for operation of the emission source appearing in any other permit.

(8) Small boiler. A boiler with a maximum heat input capacity equal to or greater than one million Btu per hour and equal to or less than 25 million Btu per hour.

(9) Small combustion turbine. A combustion turbine with a maximum heat input capacity less than 10 mmBtu per hour.

(10) Small stationary internal combustion engine. A stationary internal combustion engine with a maximum mechanical output rating of less than 200 brake horsepower in any severe ozone nonattainment area and less than 400 brake horsepower in the remainder of the State.

(11) System. As used in the term system averaging plan, a combination of operating emission sources that are located within the same ozone nonattainment area. A system may consist of multiple emission sources at multiple facilities having different owners and/or operators.

(12) Tune-up. Adjustments made to a combustion installation in accordance with procedures supplied by the manufacturer (or an approved specialist) to optimize the combustion efficiency.

(13) Weighted average permissible emission rate. The average emission rate of all operating emission sources in a system averaging plan where the emission rate of the emission sources in operation is equivalent to the emission rate achieved if each emission source operated in compliance with the most stringent permissible emission rate applicable to that emission source.