Section 212.207 of this Subpart may be applied to the aggregate of all fuel combustion emission units for which construction or modification commenced prior to April 14, 1972, vented to a common stack provided that after January 26, 1972:
Ill. Admin. Code tit. 35, § 212.208
Amended at 20 Ill. Reg. 7605, effective May 22, 1996