Ill. Admin. Code tit. 35 § 211.6130
"Source" means any stationary source (or any group of stationary sources)that are located on one or more contiguous or adjacent propertiesthatare under common control of the same person(or persons under common control)and that belongsto a single major industrial grouping. For the purposes of defining "source," a stationary source or group of stationary sources shall be considered part of a singlemajorindustrial grouping if all of the pollutant emitting activities at such source or group of sourceslocatedon contiguous or adjacentproperties and under common controlbelong to the same Major Group (i.e., all have the same two-digit code) as described in the Standard Industrial Classification Manual, 1987 (incorporated by reference in 35 Ill. Adm. Code 218.112 and 219.112 ), or such pollutant emitting activities at a stationary source (or group of sources) located on contiguous or adjacent properties and under common control constitute a support facility as defined in Section 39.5 of the Environmental Protection Act [415 ILCS 5/39.5 ]. The determination as to whether any group of stationary sources are located on contiguous or adjacent properties, and/or are under common control, and/or whether the pollutant emitting activities at such group of stationary sources constitute a support facility shall be made on a case by case basis. [415 ILCS 5/39.5 ]
Ill. Admin. Code tit. 35, § 211.6130
Amended at 25 Ill. Reg. 5900, effective April 17, 2001