### STATE OF MONTANA 

## AIR QUALITY CONTROL IMPLEMENTATION PLAN

AIR 

### QUALITY 17.8

.740 DEFINITIONS For the purposes ofthis subchapter: (1) "Best available control technology (BACT)" means an emission !.imitation (including a visible emission standard), based on the maximum degree ofreduction for eachpollutant subjectto regulation under42 U.S.c. 7410, ct seq. or75-2-1 01, et seq., MCA, thatwould be emitted from allYproposed emittingunit or modification which the department, on a case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, determines is achievable for such emitting unit ormodification through application ofproductionprocesses or available methods, systems, and techniques, including fuel cleaning or treatment or innovative fuel combustion techniques for control of such contaminant. In no event may application of BACT result in emission of any regulated air pollutant that would exceed the emissions allowed by any applicable standard under ARM Title 17, chapter 8, subchapter 3, and this subchapter. Ifthe departmentdetennines thattechnological oreconomic limitations on the application ofmeasurementmethodologyto aparticularclass ofemittingunits would make the imposition of an emission standard infeasible, it may instead prescribe a design, equipment, workpractice, oroperational standard orcombination thereof, to require the application ofBACT. Such standard must, to the degree possible, setforth the emission reduction achievable by implementation ofsuch design, equipment, work practice or operation and must provide for compliance by means that achieve equivalent results. (2) "Construct" or "construction" includes a reasonable period of time for startup and shakedown and means: (a) initiation of on-site fabrication, erection, or installation of an emitting unit or control equipment including, but not limited to: (i) installation ofbuilding supports or foundations; (ii) laying ofunderf,'Tound pipework; or (iii) construction ofstorage structures; or (h) tlle installation ofany portable or temporary equipment or facilities. (3) "Day" means calendar day unless otherwise stated. (4) "Emitting 

### unit" means: (a) allY equipment that emits orhas the potmtial to emit anyregulated airpollutantunder the CleanAir Act ofMontana through a stack(s) or vent(s); or (b) any equipment from which emissions consist solely offugitive emissions ofa regulated air pollutant under the Clean Air Act ofMontana.

17-427 ADMINISTRATIVE RULES OF MONTANA 12131/02



### Replaces Page:
Page 9.2.2.7 (4)

### STATE OF MONTANA AIR QUALITY CONT lMPLEM PLAN

17.8.740 ENVIRONMENTAL QUALITY (5) "Existing emitting unit" means an emitting unit that was in existence and operating or was capable of being operated on March 16, 1979, or for which the department had issued a permit by that date. (6) "Facility" means any real orpersonal property that is either stationary or portable and is located on one ormore contiguous oradjacent properties under the control ofthe same owner or operatorand that emits orhas the potential to emit any airpollutant subject to regulation under the Clean AirAct ofMontana or the Federal CleanAir Act, including associated control equipment that affect') orwould affect the nature, character, composition, amount, or environmental impacts ofail pollution and that has the same two-digit standard industrial classification code. A facility may consist ofone or more emitting units. (7) "Install" or "installation" means to set into position and connect or adjust for use. (8) "Modify" does not include routine maintenance, repair, or replacement but means: (a) construction or changes in operation at a facility oremitting unit for which the departmenthas issued a Montana air quality permit under this chapter, except when a permit is not required under ARM 17

.8.745; (b) construction orchanges in operation at a facility oremitting unitfor which aMontana air qualitypermit has not been issued under this chapter but that subjects the facility or emitting unit to the requirement') ofARM 17.8.743; (c) construction orchangesin operation at a facility oremittingunit that would violate any condition in the facility's Montana air quality permit, any board or court order, any control plan within the Montana state implementation plan, or any rule in this chapter, except as provided in ARM 17.8.745; (d) construction or changes in operation at a facility or emitting wlit that would qualify as a major modification ofa major stationary source under subchapters 8, 9, or 10 ofthis chapter; (e) construction or changes in operation at a facility or emitting unit that would affect the plUllle rise or dispersion characteristics ofemissions in a manner that would cause or contribute to a violation ofan ambient air quality standard or an ambient air increment, as defined in ARM 17.8.804; or (f) any change in operation that affects emissions and that was not previously permitted, except that a change in operation that does not result in an increase in emissions because ofthe change is not a modification.

17-428 12C, },'02 ADMINTSTRATfVE RULES OF MONTANA


### Replaces Page:
Page 9.2

.2.7 (5)

### STATE OF MONTANA 

### AIR QUALITY CONT IMPLEME PLAN

AIR QUALITY 17.8.740 (9) "Montana air quality pennit" means a preconstruction pennit issued under this subchapter that may include requirements for the construction and subsequent operation ofan emitting unites) or facility. (10) "Negligible risk to the public health, safety, and welfare and to the environment" means an increase in excess lifetime cancer risk of less than 1.0 x 10-6

, 

### for any individual pollutant, and 1

.0 x 10-5
, 

### for the aggregate ofall pollutants, and an increase in the sum ofthe non-cancer hazard quotients for all pollutants with similar toxic effects of less than 1.0, as detennined by a human health risk assessment conducted according to ARM 17.8.767. The department shall also consider environmental impacts identified in any environmental analysis conducted pursuant to the Montana Environmental Policy Act, Title 75, chapter 1, parts 1 through 3, MCA, in detennining compliance with all applicable rules or other requirements requiring protection ofpublic health, safety, and welfare and the environment. (11) "New ormodified emittingunit" meads an emitting unitthat was not constructed or upon which construction was not commenced prior to March 16, 1979. (12) "Owneroroperator" means the owner ofa facility or otherperson designated bythe owner as responsible for overall operation ofthe facility. (13) "Potential to emit" 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 ofoperation or on the type or amount of material combusted, stored, or processed, is treated as part ofits design onlyifthelimitation or the effect it would have on emissions is federally enforceable

. Secondary emissions are not considered in detenniningpotential to emit. (14) "Routine maintenance, repair, or replacement" means any action taken upon an emitting unit by the owner or operator that is necessary on a periodic basis to assure proper operation ofthe emitting unit. The tenn routine does not include activities that: (a) have associated fixed capital costs in excess of 50% of the fixed capital cost necessary to construct a comparable, entirely new emitting 

## unit;

ADMINISTRATIVE RUl

.ES OF MONTANA

. . 12/31/02 

### 17-429

Page9.2.2.7 (6)

### STATE OF MONTANA AIR QUALITY CONT**~LE** 

### PLAN

ENVIRONMENTAL QUALITY 

### (b) design ofthe emitting unit, including associated control c 

### (c) incrcase the p tial to emit ofthe emitting unit. (15) "Secondary emissl " means emissions that would oce s a result ofthe construction or operation ofa facility or emitting unit, 0 

### not corne from th cllity or emittingunit itself. Secondary emissions must be specific, well defined, qua impact the same general area as the facility or emitting unit which causes the secondary**emi~.** 

### _ ondary emissions mayinclude, but are not limitcd to:**~** 

### (a) emissions from trains ng to or from the facility 0 ' 

### itting unit; (b) 

### emissions fro y off-site support facility that otherwIse ould not be constructed or increase its emission ' a result ofthe construction or opcration ofthe facility 0 

### itting unit. (History: 75-2-111,75- 1 

### 4, MeA; lMP, 75-2-211, MeA; NEW, 2002 MAR p. 3567, Eff.

_ 77/02) 

### Rules 17.8.741 and 17.8.742 reserved 17

.8.743 MONTANA AIR QUALITY PERMn:S--WHEN REQUIRED (1) Except as provided in 

### ARM 17.8.744 and 17.8

.745, a person may nolconstruct, install, modify, or operate any ofthe following without first obtaining a Montana air qualitypcrmit issued bythe department: (a) 

### a new facility or emitting unit with the potential to emit airborne lead in an amount greater than five tons peryear or a modification to an existing facility oremitting unit that results in an increase in the facility or emitting unit's potential to emit airborne lead by an amount greater than 0.6 tons per year; (b)**a~~flBlt** 

### e6fterete piMa, 

### fflifwra!**effi~ftef8,** B:ne 

### mineral screens that have the potential to emit more than 15 tons peryear ofany airborne pollutant, other than lead, that is regulated under this chapter; (c) any incinerator, as defined in 75-2-103(11), MeA, and that is subject to the requirements of 75-2-215, MeA; (d) any facility oremitting unit upon which construction commenced, orthat was installed, before November 23 , 1968, when that facility or emitting unit is modified after that date and the modification increases the potential to emitbymore than 25 tons peryear ofany airbornepollutant, otherthan lead, that is regulated under this chapter; or

17-430 -12/31/02 

### ADMfNTSTRATIVE RULES OF 

### MONTANA


### Dated:
December 6, 2002 

### Page: 7 of30