Section 326 IAC 1-7-3 - Actual stack height provisionsAuthority: IC 13-1-1-4; IC 13-7-7
Affected: IC 13-1-1
Sec. 3.
(a) All exhaust gas stacks subject to this rule ( 326 IAC 1-7) for which construction commenced after June 19, 1979, shall be constructed using good engineering practice (GEP). Stack height shall be sufficient to insure that emissions from said stack will not cause excessive ground level concentrations due to atmospheric downwash, wakes, and eddies. The GEP stack height shall be calculated by adding the height of the supporting or the nearby structure, whichever is largest, to 1.5 times the lesser dimension (height or width) of the supporting or nearby structure. The nearby structure shall be within five (5) times the lesser dimension (width or height) of that structure, but shall in no event exceed 0.8 kilometers (one-half (1/2) mile). A greater or lesser stack height may be allowed through wind tunnel, field studies or other methods that show to the satisfaction of the commissioner that no such excessive concentrations, due to less than adequate stack height, will result.(b) A source for which construction or modification commenced prior to June 19, 1979, may request the commissioner to allow an increase in stack height up to GEP as defined in subsection (a) above. Such increase shall be allowed if:(1) the source demonstrates to the commissioner that said increase will not cause a violation of the ambient air quality standards as set forth in 326 IAC 1-3 or PSD increments as set forth in 326 IAC 1-2; and(2) the source demonstrates to the commissioner that such increase is necessary to prevent downwash.(c) All sources constructed before January 12, 1979, which received full GEP credit, must submit evidence of actual reliance on the 2.5 H formula before full GEP credit may be granted.(d) All sources constructed after December 31, 1970, that are tied into grandfathered stacks, and all sources constructed prior to December 31, 1970, but for which major modifications have been carried out subsequent to that date, will be prohibited from stack height credit greater than GEP stack height. Air Pollution Control Board; 326 IAC 1-7-3; filed Mar 10, 1988, 1:20 pm: 11 IR 2383; readopted filed Jan 10, 2001, 3:20 p.m.: 24 IR 1477