Authority: IC 13-14-8-1; IC 13-14-9; IC 13-17-3-4

Affected: IC 13-14-8-8; IC 13-17-3

Sec. 7. (a) The requirements of this rule shall not apply to the following:

(1) Industrial boilers having a maximum heat input of less than or equal to twenty (20) mmBtu/hr.

(2) Standby boilers, standby stationary combustion turbines, or standby stationary internal combustion engines that operate less than five hundred (500) hours during any consecutive twelve (12) month period.

(A) The owner or operator of standby boilers, standby stationary combustion turbines, or standby stationary internal combustion engines shall maintain records for a period of not less than three (3) years in a format acceptable to the department. These records shall include the dates and number of hours the standby boilers, standby stationary combustion turbines, or standby stationary internal combustion engines operated.

(3) Stationary internal combustion engines having an energy output capacity of less than five hundred (500) horsepower.

(4) Stationary combustion turbines having an energy input capacity of less than twenty (20) mmBtu/hr.

(5) Space heating units.

(6) Auxiliary boilers.

(7) Carbon monoxide boilers.

(8) Research and development facilities.

(9) Jet engine test cells.

(10) Engine testing operations.

(11) Air pollution control devices.

(12) Municipal waste combustors.

(13) Facilities other than a boiler, stationary combustion turbine or stationary internal combustion engine that have the potential to emit less than twenty-five (25) tons per year of NOx.

(14) Affected facilities issued a valid air operating permit by the department in accordance with 326 IAC 2-7 that restricts such affected facility to twenty-five (25) tons per year or less of NOx emissions.

(15) Affected facilities issued a Part 70 operating permit by the department in accordance with 326 IAC 2-7 that is subject to best available control technology or lowest achievable emission rate standards.

(16) Affected facilities whose utilization is less than ten percent (10%) of its capacity factor on an annual average basis over a three (3) year rolling period and less than twenty percent (20%) of its capacity factor in any year of the three (3) year rolling period.

(b) The owner or operator of any affected facility that cannot comply with the applicable requirements set forth in this rule because of extraordinary reasons beyond the affected source's reasonable control may apply in writing to the department to request a variance. The variance application shall be prepared in accordance with the provisions specified in IC 13-14-8-8 and shall only be granted provided the requirements of this rule are met. No variance may be granted by the department that does not provide for eventual compliance with this rule.

(Air Pollution Control Division; 326 IAC 10-7-7; filed Oct 27, 2025, 10:54 a.m.: 20251126-IR-326250204FRA)