"Emission offset" means a creditable emission reduction used to compensate for the increase in emissions resulting from a new major source or a major modification in accordance with Sections 203.302 and 203.303 of this Part.
Ill. Admin. Code tit. 35, § 203.121
Section 203.121 renumbered from Section 203.122 and amended at 17 Ill. Reg. 6973, effective April 30, 1993