AUTHORITY: Implementing Sections 9.1 and 10 and authorized by Sections 27 and 28 of the Environmental Protection Act [415 ILCS 5/9.1, 10, 27 and 28].POLLUTION CONTROL BOARD
a) The degree of emission limitation required for control of any air pollutant under this Part shall not be affected in any manner by:
1) So much portion of the stack height of any source that exceeds good engineering practice; or
2) Any other dispersion technique.
b) Subsection (a) shall not apply with respect to stack heights in existence before December 31, 1970 or to dispersion techniques implemented before then.