35 Ill. Adm. Code 217.180
Applicability Exemptions
Section 217.180 Applicability Exemptions
Before July 1, 2025, the provisions of this Subpart do not
apply to a process heater operating under a federally enforceable limit of NO
x
emissions from the heater to less than 15 tons per year and less than five tons
per ozone season.