1. (a) The minimum good engineering practice stack height value allowable for any source, regardless of size or location of any structures or terrain features, shall be 65 meters.

   (b)(1) Except as provided in subsection (c) of this regulation, the maximum good engineering practice stack height value allowable for any source shall be determined using one of the following mathematical formulas:

   1. (A) for stacks that were in existence on January 12, 1979 and provided that the owner or operator presents evidence that this equation was relied upon when establishing an emission limit:

      Hg=2.5H

   2. (B) for stacks constructed after January 12, 1979 and provided that the owner or operator, at the department's request, presents evidence through a field study or fluid modeling to verify that the height arrived at by the following formula is valid:

      Hg=H+1.5L

      1. (2) When using formula (A) or (B), the terms and values used shall be as follows:
   3. (A) Hg = good engineering practice stack height, measured from the ground level elevation at the base of the stack;
   4. (B) H = height of any nearby structures measured from the ground level at the base of the stack; and
   5. (C) L = lesser dimension of the height or projected width of any nearby structures.
2. (c) A source may obtain good engineering practice stack height credit in excess of that calculated by K.A.R. 28-19-18c(b)(1)(A) or K.A.R. 28-19-18c(b)(1)(B) provided that it demonstrates by fluid modeling or a field study approved by the department that the emissions from a stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures or nearby terrain features.

(Authorized by and implementing K.S.A. 65-3005, 65-3010; effective May 1, 1983; amended, T-88-2, Jan. 23, 1987; amended May 1, 1988.)