35 Ill. Adm. Code 204.1720
PAL Major Modification
Section 204.1720Â PAL Major Modification
"PAL major modification" means, notwithstanding
Sections 204.490 and 204.550 (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.