35 Ill. Adm. Code 201.144
Operating Permits for Existing Sources
Section 201
Section 201.144 Operating
Permits for Existing Sources
No person shall cause or allow
the operation of any existing emission source or any existing air pollution
control equipment without first obtaining an operating permit from the Agency,
except as provided in Section 201.146. Dates on which permits were required
are shown in Appendix C.