R 336.1224 Best available control technology for toxics (T-BACT); requirements for new and modified sources of air toxics; exemptions.

Rule 224. (1) A person who is responsible for any proposed new or modified emission unit or units for which an application for a permit to install is required by R 336.1201 and which emits a toxic air contaminant shall not cause or allow the emission of the toxic air contaminant from the proposed new or modified emission unit or units in excess of the maximum allowable emission rate based on the application of best available control technology for toxics (T-BACT), except as provided in subrule (2) of this rule. (2) The requirement for T-BACT in subrule (1) of this rule does not apply to any of the following: (a) An emission unit or units for which standards have been promulgated under section 112(d) of the clean air act or for which a control technology determination has been made under section 112(g) or 112(j) for any of the following: (i) The hazardous pollutants listed in section 112(b) of the clean air act. (ii) Other toxic air contaminants that are volatile organic compounds, if the standard promulgated under section 112(d) of the clean air act or the determination made under sections 112(g) or 112(j) controls similar compounds that are also volatile organic compounds. (iii) Other toxic air contaminants that are particulate matter, if the standard promulgated under section 112(d) of the clean air act or the determination made under section 112(g) or 112(j) controls similar compounds that are also particulate matter. (b) An emission unit or units that is in compliance with all of the following: (i) The maximum allowable emissions of each toxic air contaminant from the proposed new or modified emission unit or units is 0.1 pound per hour or less for a carcinogen or 1.0 pound per hour or less for any other toxic air contaminant. (ii) The applicable initial threshold screening level for the toxic air contaminant is more than 200 micrograms per cubic meter. (iii) The applicable initial risk screening level is more than 0.1 micrograms per cubic meter. (c) An emission unit or units which only emits toxic air contaminants that are particulates or volatile organic compounds and which is in compliance with best available control technology requirements, including R 336.1702, or lowest achievable emission rate requirements for particulates and volatile organic compounds. (d) Engines, turbines, boilers and process heaters burning solely natural gas, diesel fuel (No. 2 fuel oil), or biodiesel, of up to 100 MMBTU per hour, provided that the effective stack is vertical and unobstructed and is at least 1.5 times the building height, and the building setback is at least 100 feet from the property line. (e) Natural gas fuel burning equipment or natural gas fired equipment that meet all the following: (i) A maximum natural gas usage rate of 50,000 cubic feet per hour or less. (ii) Emissions from the source are discharged from an unobstructed stack oriented vertically upwards. (iii) With a stack height at least 1.5 times the height of the building most influential in determining the predicted ambient impacts of the emissions. (f) Air pollution control equipment that combusts only natural gas as fuel.