"Stationary source" means any building, structure, facility, or installation that emits or may emit a regulated NSR pollutant. Emissions resulting directly from an internal combustion engine for transportation purposes or from a nonroad engine or nonroad vehicle as defined in section 216 of the CAA (42 USC 7550) are not a part of a stationary source.
Ill. Admin. Code tit. 35, § 204.690