Ill. Admin. Code tit. 35, § 203.2230
"PAL major modification" means, notwithstanding Section 203.1220 and Section 203.1260 (the definitions for major modification and net emissions increase), any physical change in or change in the method of operation of the PAL source that causes it to emit the PAL pollutant at a level equal to or greater than the PAL.
(Source: Added at 49 Ill. Reg. 6237, effective April 23, 2025)