For the purposes of this subchapter:

(1) "Emitting unit" means:

(a) any equipment that emits or has the potential to emit any regulated air pollutant under the Clean Air Act of Montana through a stack(s) or vent(s) ; or

(b) any equipment from which emissions consist solely of fugitive emissions of a regulated air pollutant under the Clean Air Act of Montana.

(2) "Potential to emit (PTE) " means the maximum capacity of a facility or emitting unit, within physical and operational design, to emit a pollutant. Any physical or operational limitation on the capacity of the facility or emitting unit to emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, is treated as part of its design only if the limitation or the effect it would have on emissions is federally enforceable. Secondary emissions are not considered in determining potential to emit.

(3) "Registered facility" means any registration eligible facility that has been registered for operation under the requirements in this subchapter.

(4) "Registration" means identifying equipment and/or processes to the department in accordance with this subchapter.

(5) "Registration eligible facility" means an oil or gas well facility as defined in 75-2-103 (13) , MCA, and subject to the requirements of ARM 17.8.743.

(6) "VOC piping components" means valves, pumps, compressors, flanges, pressure relief valves and connectors, and other piping components that have VOC emissions.