35 Ill. Adm. Code 204.690
Stationary Source
Section 204.690 Stationary Source
"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.