326 IAC 1-2-6 "Best available control technology (BACT)" defined

Sec. 6. An emission limitation (including a visible emission standard) or equipment standard based on the maximum degree of reduction of each pollutant subject to regulation under the Clean Air Act and applicable Indiana laws or rules which would be emitted from or which results from any proposed major facility or modification thereto which the commissioner, on a case-by-case basis, taking into account energy, environmental and economic impacts and other costs, determines is achievable for such facility or modification through application of production processes and available methods, systems, and techniques, including fuel cleaning or treatment or innovative fuel combustion techniques for control of such pollutant. In no event shall application of best available control technology result in emissions of any pollutant which will exceed the emissions allowed by any applicable standard. If the commissioner determines that technological or economic limitations on the application of measurement methodology to a particular emissions unit would make the imposition of an emissions standard not feasible, a design, equipment, work practice, operational standard, or combination thereof, may be prescribed instead to satisfy the requirements for the application of best available control technology. Such standard shall, to the degree possible, set forth the emissions reduction achievable by implementation of such design, equipment, work practice or operation, and shall provide for compliance by means which achieve equivalent results.