T « 7 ^ UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

^ ;'«^bS»»/ REGION 8 

999 18TM STREET- SUITE 200 

DENVER, CO 80202-2466 

Phone 800-227-8917 

http://www.epa.gov/region08 

Ref: 8P-AR 

MEMORANDUM 

DATE: 

SUBJECT: Submission to Revisions to the State Implementation Plan for Montana for 

Incorporation by Reference 

FROM: Regulation Management Staff EPA 

TO: Officeof the Federal Register 

Please add this document to the "Montana Implementation Plan'" file and tab it in the 

appropriate sequence. 

40 CFR part 52 is amended to read as follows: 

PART 52 [AMENDED] 

1. The authority citation for Part 52 continues to read as follows: 

Authority: 42 U.S.C. 7401 et seq. 

Subpart BB'- Montana 

2. Section 52.13 7 0 is amended by adding paragraph (c)(68) to read as 

follows: 

§ 52.1370 Identification of plan. 

+ • * • * * 

(c.) * * * 

(69) Revisions to the State Implementation Plan which were submitted by the 

State of Montana on January 16, 2009 and May 4, 2009. The revisions are to 

the Administrative Rules of Montana; they malce minor editorial and grammatical 

changes, update the citations and references to federal laws and. regulations, 

and make other minor changes to conform to federal regulations. 

(i) Incorporation by reference. 

(A) Administrative Rules of Montana (ARM)' sections 17.8.102 
Incorporation by.Reference -- Publication Dates, 17.8.301 Definitions, 

17.8.901 Definitions, and 17.8.1007- Baseline for Determining Credit, for 

Emissions and Air Quality Offseits, effective October 24, 2008. 

(B) Administrative Rules of Montana (ARM) section 17.8.308 Particulate 

Matter, Airborne,•effective February 13, 2009. 
AIR QUALITY 17.8.102 

17.8.102 INCORPORATION BY REFERENCE-PUBLICATION DATES 

(1) Unless expressly provided otherwise, in this chapter where the board has: 

(a) adopted a federal regulation by reference, the reference is to the July 1, 

2007, edition ofthe Code of Federal Regulations (CFR); 

(b) adopted a section of the United States Code (USC) by reference, the 

reference Is to the 2000 edition ofthe USC and Supplement V (2005); 

(c) adopted another rule of the department or of another agency of the state 

of Montana by reference, the reference is to the December 31, 2007, edition of the 

Administrative Rules of Montana (ARM). 

(2) The following subparts, or portions thereof, of 40 CFR Part 60, are 

excluded from Incorporation by reference: 

(a) 40 CFR 60, Subpart CCCC, Standards of Performance for Commercial 

and Industrial Solid Waste Incineration Units for which Construction Is Commenced 

After November 30, 1999, or for which Modification or Reconstruction Is 

Commenced on or After June 1, 2001 (40 CFR 60.2000 through 60.2265, and all 

associated appendices and tables), as vacated June 8, 2007, by the U.S. Circuit 

Court of Appeals, D.C. Circuit, ruling. 

(3) The following subparts, or portions thereof, of 40 CFR Part 63 are 

excluded from incorporation by reference: 

(a) 40 CFR 63, Subpart JJJJJ, National Emission Standards for Hazardous 

Air Pollutants for Brick and Structural Clay Products Manufacturing (40 CFR 63.8380 

through 63.8515, and all associated appendices and tables), as vacated March 13, 

2007, by the U.S. Circuit Court of Appeals, D.C. Circuit; 

(b) 40 CFR 63, Subpart KKKKK, National Emission Standards for Hazardous 

Air Pollutants for Clay Ceramics Manufacturing (40 CFR 63.8530 through 63.8665, 

and all associated appendices and tables), as vacated March 13, 2007, by the U.S. 

Circuit Court of Appeals, D.C. Circuit; 

(c) 40 CFR 63, Subpart DDDDD, National Emission Standards for Hazardous 

Air Pollutants for Industrial, Commercial, and Institutional Boilers and Process 

Heaters (40 CFR 63.7480 through 63.7575, and all associated appendices and 

tables), as vacated June 8, 2007, by the U.S. Circuit Court of Appeals, D.C. Circuit; 

(d) portions of 40 CFR 63, Subpart DDDD, National Emission Standards for 

Hazardous Air Pollutants for Plywood and Composite Wood Products, as vacated 

June 19, 2007, by the U.S. Circuit Court of Appeals, D.C. Circuit. (History: 75-2-

111, MCA; IMP, Title 75, chapter 2, MCA; NEW, 1996 MAR p. 1844, Eff. 7/4/96; 

TRANS, from DHES, 1996 MAR p. 2285; AMD, 1997 MAR p. 1581, Eff. 9/9/97; 

AMD. 1998 MAR p. 1725, Eff. 6/26/98; AMD. 1999 MAR p. 2250, Eff. 10/8/99; AMD, 

2000 MAR p. 2696, Eff. 10/6/00; AMD. 2001 MAR p. 1468, Eff. 8/10/01: AMD. 2002 

MAR p. 1747, Eff. 6/28/02; AMD, 2003 MAR p. 645, Eff. 4/11/03; AMD. 2004 MAR p. 

724, Eff. 4/9/04; AMD. 2005 MAR p. 959, Eff. 6/17/05; AMD. 2006 MAR p. 1956, Eff. 

8/11/06; AMD, 2007 MAR p. 1663, Eff. 10/26/07; AMD. 2008 MAR p. 2267, Eff. 

10/24/08.) 

ADMINISTRATIVE RULES OF MONTANA 12/31/08 17-233 
AIR QUALITY 17.8,301 

Subchapter 3 

. Emission Standards 

17:8.301 DEFINITIONS For purposes of this subchapter, the following 

definitions apply: 

(1) "112(g) exemption" means a document issued by the department on a 

case-by-case basis, finding that a major source of HAP meets the criteria contained 

in 40 CFR 63.41 (definition of "construct a major source", (2)(l) through (vi)), and is 

thus exempt from the requirements of 42 USC 7412(g). 

(2) "Airborne particulate matter" means any particulate matter discharged 

into the outdoor atmosphere which is not discharged from the normal exit of a stack 

or chimney for which a source test can be performed in accordance with 40 CFR 

Part 60, Appendix A, method 5 (determination of particulate emissions from 

stationary sources). 

(3) "Best available control technology (BACT)" means an emission limitation 

(including a visible emission standard), based on the maximum degree of reduction 

for each air pollutant which would be emitted from any source or alteration which the 

department, on a case-by-case basis, taking into account energy, environment, and 

economic impacts and other costs, determines is achievable for such sources or 

alterations through application of production processes or available methods, 

systems, and techniques, including fuel cleaning or treatment or innovative fuel 

combustion techniques for control of such air contaminant. In no event shall 

•application of BACT result in emission of any air contaminant which would exceed 

the emissions allowed by any applicable standard under this chapter. If the 

department determines that technological or economic limitations on the application 

of measurement methodology to a particular class of sources or alterations would 

make the imposition of an emission standard infeasible, it may instead prescribe a 

design, equipment, work practice or operational standard or combination thereof, to 

require the application of BACT. Such standard shall, to the degree possible, set 

forth the emission reduction achievable by implementation of such design, 

equipment, work practice or operation and shall provide for compliance by means 

which achieve equivalent results. 

ADMINISTRATIVE RULES OF MONTANA 9/30/06 17-301 
17.8.301 ENVIRONMENTAL QUALITY 

(4) "Beginning actual construction" means, in general, initiation of physical 

on-site construction activities of a permanent nature. Such activities include, but are 

not limited to, installation of building supports and foundations, laying of 

underground pipework, and construction of permanent storage structures. 

(5) "Building, structure, facility, or installation" meians all ofthe pollutantemitting activities which belong to the same industrial grouping, are located on one 

or more contiguous or adjacent properties, and are under the control of the same 

person (or persons under common control) except the activities of any vessel. 

Pollutant-emitting activities shall be considered as part of the same industrial . 

grouping if they belong to the same major group (i.e., which have the same two-digit 

code) as described in the standard industrial classification manual, 1987. 

(6) "Construct a major source of HAP" means: 

(a) to fabricate, erect, or install a major source of HAP; or 

(b) to reconstruct a major source of HAP, by replacing components at an 

existing process or production unit that in and of itself emits or has the potential to 

emit ten tons per year of any HAP, or 25 tons per year of any combination of HAP, 

whenever: 

(i) the fixed capital cost of the new components exceeds 50% of the fixed 

capital cost that would be required to construct a comparable process or production 

unit; and 

(ii) it is technically and economically feasible for the reconstructed major 

source to meet the applicable maximum achievable control technology emission 

limitation for new sources established under 40 CFR ?3 Subpart B. 

(7) "Existing fuel burning equipment" means fuel burning equipment 

constructed or installed prior to November 23, 1968. 

(8) "Greenfield site" means a contiguous area under common control that is 

an undeveloped site'. 

(9) "Hazardous air pollutant" ("HAP") means any air pollutant listed in or 

pursuant to 42 USC 7412(b). 

(10) "Lowest achievable emission rate" ("LAER") means, for any source, that 

rate of emissions which reflects: 

(a) the most stringent emission limitation which is contained in the 

implementation plan of any state for such class or category of source, unless the 

owner or operator of the proposed source demonstrates that such limitations are not 

achievable; or 

(b) the most stringent emission limitation which is achieved in practice by 

such class or category of source, whichever is more stringent. In no event shall the 

application of this term permit a proposed new or modified source to emit any 

pollutant in excess ofthe amount allowable under applicable new source standards 

of performance under 40 CFR Parts 60 and 61. 

17-302 9/30/06 ADMINISTRATIVE RULES OF MONTANA 
AIR QUAUTY 17.8.301 

(11) "Major source of HAP" means: 

(a) at any greenfield site, a stationary source or group of stationary sources 

which is located within a contiguous area and under common control and which 

emits or has the potential to emit ten tons per year of any HAP or 25 tons per year of 

any combination of HAP; or 

(b) at any developed site, a new process or production unit which in and of 

itself emits or has the potential to emit ten tons per year of any HAP or 25 tons per 

year of any combination of HAP. 

(12) "Maximum achievable control technology" ("MACT") means the emission 

limitation which is not less stringent than the emission limitation achieved in practice 

by the best controlled simitar source, and which reflects the maximum degree of 

reduction in emissions that the department, taking into consideration the cost of 

achieving such emission reduction, and any nonair quality health and environmental 

impacts and energy requirements, determines is achievable by the constructed or 

reconstructed major source of HAP. 

(13) "New fuel burning equipment" means fuel burning equipment 

constructed, installed or altered after November 23, 1968. 

(14) "Notice of MACT approval" means a document issued by the 

department containing all federally enforceable conditions necessary to enforce 

MACT or other control technologies such that the MACT emission limitation is. met. 

(15) "Process or production unit" means any collection of structures and/or 

equipment, that processes, assembles, applies, orotherwise uses material inputs to 

produce or store an intermediate or final product. A single facility may contain more 

than one process or production unit. 

(16) "Process weight" means the total weight of all materials introduced into 

any specific process which may cause emissions. Solid fuels charged will be 

considered as part of the process weight, but liquid and gaseous fuels and 

combustion air will not. 

ADMINISTRATIVE RULES OF MONTANA 9/30/06 17-303 
17.8.302 ENVIRONMENTAL QUALITY 

(17) "Process weight rate" means the rate established as follows: 

(a) for continuous or long-run steady-state operations, the total process 

weight for the entire period of continuous operation or for a typical portion thereof, 

divided by the number of hours of such period or portion thereof; . 

(b) for cyclical or batch operations, the total process weight for a period that 

covers a complete operation or an integral number df cycles, divided by the hours of 

actual process operation during such a period. Where the nature of any process or 

operation or the design of any equipment is such as to pennit more than one 

interpretation of this definition, the interpretatio'n that results in the minimum value for 

allowable emissions shall apply. 

(18) "Reasonable precautions" mean any reasonable measures to control 

emissions of airborne particulate matter. Determination of what is reasonable will be 

accomplished on a case-by-case basis taking into account energy, environmental, 

economic, andothercosts. 

(19) "Reasonably available control technology" means devices, systems, 

process modifications, or other apparatus or techniques that are determined on a 

case-by-case basis to be reasonably available, taking into account the necessity of 

imposing such controls in order to attain and maintain a national or Montana ambient 

air quality standard, the social, environmental, and economic,impact of such 

controls, and alternative means of providing for attainment and maintenance of such 

standard. (History: 75-2-111, 75-2-203, 75-2-204, MCA; IMP, 75-2-203, MCA; 

NEW, 1993 MAR p. 2530, Eff. 10/29/93; TRANS, from DHES, 1996 MAR p, 2285; 

AMD. 1999 MAR p. 1658, Eff. 7/23/99; AMD. 2001 MAR p. 976, Eff. 6/8/01; AMD, 

2008 MAR p..2267, Eff. 10/24/08.) 

17.8.302 INCORPORATION BY REFERENCE (1) For the purposes of^fiis 

[pter, the board adopts and incorporates by reference the following:^/^ 

.40 CFR Part 60, pertaining to standards of performance fqiy^w 

stationary sbfcii;ces and modifications, with the following exceptior 

(i) 40 m^O.150 0 through 1940 and tables 1 throupirs (subpart BBBB), 

emission guideline^^ existing small municipal waste ^orfiDustion units, are not 

incbrporated by referenb^and 

(ii) 40 CFR 60.4141^442, pertaining toj^i^rcury allowance allocations; 

(b) 40 CFR Part 61, pertsiining to ejipt^on standards for hazardous air 

pollutants; 

(c) 40 CFR Part 63, pertaii>P(^^tl>>emission standards for hazardous air 

pollutant source categories; 

(d) _40 CFR 81.327^Jp^rtaining to the aihqjjality attainment status 

designations for Montaij: 

(e) ARM Titl)S^7, chapter 53, subchapter 5, pertg|ning to the identification 

and listing of ha^^dous waste; and 

(f) th^'^andard Industrial Classification Manual (1987)>^ice of 

Managep^t and Budget (PB 87-100012), pertaining to a systerrhstjndustrial 

classiftcation and definition based upon the composition and structure^the 

eoemomy. 

17-304 12/31/08 ADMINISTRATIVE RULES OF MONTANA. 
AIR QUALITY 17.8.308 

17.8.308 PARTICULATE MATTER. AIRBORNE (1) No person shall cause 

or authorize the production, handling, transportation, or storage of any material 

unless reasonable precautions to control emissions of airborne particulate matter are 

taken. Such emissions of airborne particulate matter from any stationary source 

shall not exhibit an opacity of 20% or greater averaged over six consecutive 

minutes, except for emission of airborne particulate matter originating from any 

transfer ladle or operation engaged in the transfer of molten metal which was 

installed or operating prior to November 23, 1968. 

(2) No person shall cause or authorize the use of any street, road, or parking 

lot without taking reasonable precautions to control emissions of airborne particulate 

matter. 

(3) No person shall operate a construction site or demolition project unless 

reasonable precautions are taken to control emissions of airborne particulate matter. 

Such emissions of airborne particulate matter from any stationary source shall not 

exhibit an opacity of 20% or greater averaged over six consecutive minutes. 

(4) Within any area designated nonattainment in 40 CFR 81.327 for PM, any 

person who owns or operates: 

(a) any existing source of airborne particulate matter shall apply reasonably 

available control technology (RACT); 

(b) any new source of airborne particulate matter that has a potential to emit 

less than 100 tons per year of particulate matter shall apply best available control 

technology (BACT); 

(c) any new source of airborne particulate matter that has a potential to emit 

more than 100 tons per year of particulate matter shall apply lowest achievable 

emission rate (LAER). 

(5) The provisions of this rule shall not apply to emissions of airborne 

particulate matter originating from: 

(a) any agricultural activity or equipment that is associated with the use of 

agricultural land or the planting, production, processing, harvesting, or storage of 

agricultural crops by an agricultural producer and that is not subject to the 

requirements of 42 USC 7475, 7503, or 7661, as set forth in 75-2-111(1)(a), MCA; or 

(b) a business relating to the activities or equipment referred to in (5)(a) that 

remains in a single location for less than 12 months and is not subject to the 

requirements of 42 USC 7475, 7503, or 7661, as set forth in 75-2-111 (1 )(b), MCA. 

(History: 75-2-111, 75-2-203, MCA; MP, 75-2-203, MCA; Eff. 12/31/72; AMD, 1979 

MAR p. 145, Eff. 2/16/79; AMD. 1993 MAR p. 2530, Eff. 10/29/93; TRANS, from 

DHES, 1996 MAR p. 2285; AMD, 2000 MAR p. 836, Eff. 3/31/00; AMD. 2009 MAR 

p. 142, Eff. 2/13/09.) 

ADMINISTRATIVE RULES OF MONTANA 3/31/09 17-309 
AIR QUALITY 17.8.901 

Subchapter 9 

Permit Requirements for Major Stationary Sources or 

Major Modifications Locating Within Nonattainment Areas 

17.8.901 DEFINITIONS In this subchapter the following definitions apply: 

(1) "Actual emissions" means the actual rate of emissions of a pollutant from 

an emissions unit as determined in accordance with (1)(a) through (c). 

(a) Actual emissions as of a particular date shall equal the average rate, in 

tons per year, at which the unit actually emitted the pollutant during a two-year 

period which precedes the particular date and which Is representative of normal 

source operation. The department may determine that a different time is more 

representative of normal source operation. Actual emissions shall be calculated 

using the unit's actual operating hours, production rates, and types of materials 

processed, stored, or combusted during the selected time period. 

(b) If the department is unable to determine actual emissions consistent with 

(1)(a), the department may presume that the source-specific allowable emissions for 

the unit are equivalent to the actual emissions of the unit. 

(c) For any emissions unit which has not begun normal operations on the 

particular date, actual emissions shall equal the potential to emit of the unit on that 

date. 

(2) "Allowable emissions" means the emissions rate of a stationary source 

calculated using the maximum rated capacity ofthe source (unless the source is 

subject to federally enforceable limits which restrict the operating rate or hours of 

operation, or both) and the most stringent of the following: 

(a) the applicable standards as set forth in ARM 17.8.340 or 17.8.341; 

(b) the applicable emissions limitation contained in the Montana State 

Implementation Plan, including those with a future compliance date; or 

(c) the emissions rate specified as a federally enforceable permit condition, 

including those with a future compliance date. 

(3) "Begin actual construction" means, in general, Initiation of physical on-site 

construction activities of a permanent nature on an emissions unit. Such activities 

include, but are not limited to, installation of building supports and foundations, 

laying of underground pipework, and construction of permanent storage structures. 

With respect to a change In method of operation, this term refers to those on-site 

activities other than preparatory activities which mark the initiation of the change. 

(4) "Building, structure, facility, or installation" means all ofthe pollutantemitting activities which belong to the same industrial grouping, are located on one 

or more contiguous or adjacent properties, and are under the control ofthe same 

person (or persons under common control), except the activities of any vessel. 

Pollutant-emitting activities shall be considered as part ofthe same industrial 

grouping if they belong to the same major group (i.e., having the same two-digit 

code) as described in the Standard Industrial Classification Manual, 1987. 

ADMINISTRATIVE RULES OF MONTANA 9/30/06 17-521 
17.8.901 ENVIRONMENTAL QUALITY 

(5) "Commence", as applied to construction of a major stationary source or 

major modification, means that the owner or operator has all necessary 

preconstruction approvals or permits and either has: 

(a) begun, or caused to begin, a continuous program of actual on-site 

construction of the source, to be completed within a reasonable time; or 

(b) entered into binding agreements or contractual obligations, which cannot 

be canceled or modified without substantial loss to the owner or operator, to 

undertake a program of actual construction of the source to be completed within a 

reasonable time. 

(6) "Construction" means any physical change or change in the method of 

operation (including fabrication, erection, installation, demolition, or modification of 

an emissions unit) which would result in a change in actual emissions. 

(7) "Emissions unit" means any part of a stationary source which emits or 

would have the potential to emit any pollutant subject to regulation under the FCAA. 

(8) "Federally enforceable" means all limitations and conditions which are 

enforceable by the administrator, including those requirements developed pursuant 

to 40 CFR Parts 60 and 61, requirements within the Montana State Implementation 

Plan, and any permit requirement established pursuant to 40 CFR 52.21 or under 

regulations approved pursuant to 40 CFR Part 51, subpart I, including operating 

permits issued under an EPA-approved program that is incorporated into the 

Montana State Implementation Plan and expressly requires adherence to any permit 

issued under such program. 

(9) "Fugitive emissions" means those emissions which could not reasonably 

pass through a stack, chimney, vent, or other functionally equivalent opening. 

(10) "Lowest achievable emission rate" means, for any source, the more 

stringent rate of emissions based on the following: 

(a) the most stringent emissions limitation which is contained in the 

implementation plan of any state for such class or category of stationary source, 

unless the owner or operator of the proposed stationary source demonstrates that 

such limitations are not achievable; or 

(b) the most stringent emissions limitation which is achieved in practice by 

such class or category of stationary sources. This limitation, when applied to a 

modification, means the lowest achievable emissions rate for the new or modified 

emissions units within a stationary source. In no event shall the application ofthe 

term permit a proposed new or modified stationary source to emit any pollutant in 

excess of the amount allowable under applicable new source standards of 

performance under 40 CFR Parts 60 and 61. 

17-522 9/30/06 ADMINISTRATIVE RULES OF MONTANA 
AIR QUALITY 17.8.901 

(11) "Major modification" means any physical change in, or change in the 

method of, operation of a major stationary source that would result in a significant 

net emissions increase of any pollutant subject to regulation under the FCAA. 

(a) Any net emissions increase that is considered significant for volatile 

organic compounds Is considered significant for ozone. 

(b) A physical change in, or change in the method of, operation does not 

include: 

(i) routine maintenance, repair, and replacement; 

(ii) use of an alternative fuel or raw material by reason of an order under 

(2)(a) and (2)(b) ofthe Energy Supply and Environmental Coordination Act of 1974, 

15 USC 791, et seq. (1988), or by reason of a natural gas curtailment plan pursuant 

to the Federal Power Act, 16 USC 791a, etseq. (1988 and Supp. Ill 1991); 

(iii) use of an alternative fuel by reason of an order or rule under section 125 

of the FCAA; 

(iv) use of an alternative fuel at a steam generating unit to the extent that the 

fuel is generated from municipal solid waste; 

(v) use of an alternative fuel or raw material by a stationary source which: 

(A) the source was capable of accommodating before December 21, 1976, 

unless such change would be prohibited under any federally enforceable permit 

condition which was established after December 12, 1976, pursuant to 40 CFR 

52.21 or under regulations approved pursuant to 40 CFR Part 51, subpart I, or 

section 51.166; or 

(B) the source Is approved to use under any permit issued under regulations 

approved pursuant to 40 CFR 51.165; 

(vi) an increase in the hours of operation or In the production rate, unless 

such change is prohibited under any federally enforceable air quality preconstruction 

permit condition which was established after December 21, 1976 pursuant to 40 

CFR 52.21 or under regulations approved pursuant to 40 CFR Part 51, subpart I, or 

section 51.166; 

(vii) any change in ownership at a stationary source. 

(12) The following apply to the definition of the term "major stationary 

source": 

(a) "major stationary source" means: 

(i) any stationary source of air pollutants which emits, or has the potential to 

emit, 100 tons per year or more of any pollutant subject to regulation under the 

FCAA; or 

(ii) any stationary source of air pollutants located In a serious particulate 

matter (PM-10) nonattainment area which emits, or has the potential to emit, 70 tons 

per year or more of PM-10; or 

(iii) any physical change that would occur at a stationary source not 

qualifying under (12)(a)(i) or (ii) as a major stationary source, if the change would 

constitute a major stationary source by itself. 

ADMINISTRATIVE RULES OF MONTANA 12/31/08 17-523 
17.8.901 ENVIRONMENTAL QUALITY 

(b) The fugitive emissions of a stationary source will not be included in 

determining, for any ofthe purposes of this subchapter, whether It is a major 

stationary source, unless the source belongs to one of the following categories of 

stationary sources: 

(i) coal cleaning plants (with thermal dryers); 

(ii) kraft pulp mills; 

(ill) Portland cement plants; 

(iv) primary zinc smelters; 

(v) iron and steel mills; 

(vi) primary aluminum ore reduction plants; 

(vii) primary copper smelters; 

(viii) municipal incinerators capable of charging more than 250 tons of refuse 

per day; 

(ix) hydrofluoric, sulfuric, or nitric acid plants; 

(x) petroleum refineries; 

(xi) lime plants; 

(xii) phosphate rock processing plants; 

(xiii) coke oven batteries; 

(xiv) sulfur recovery plants; 

(xv) carbon black plants (furnace process); 

(xvi) primary lead smelters; 

(xvii) fuel conversion plants; 

(xviii) sintering plants; 

(xix) secondary metal production plants; 

(xx) chemical process plants; 

(xxi) fossil-fuel boilers (or combination thereof) totaling more than 250 million 

British thermal units per hour heat input; 

(xxii) petroleum storage and transfer units with a total storage capacity 

exceeding 300,000 barrels; 

(xxiii) taConite ore processing plants; 

(xxiv) glass fiber processing plants; 

(xxv) charcoal production plants; 

(xxvi) fossil fuel-fired steam electric plants of more than 250 million British 

thermal units per hour heat input; and 

(xxvii) any other stationary source category which, as of August 7, 1980, is 

being regulated under sections 111 or 112 of the FCAA. 

(13) "Necessary preconstruction approvals or permits" means those permits 

or approvals required under federal air quality control laws and regulations and 

those air quality control laws and regulations which are part of the Montana State 

Implementation Plan. 

17-524 9/30/06 ADMINISTRATIVE RULES OF MONTANA 
AIR QUALITY 17.8.901 

(14) The following apply to the definition ofthe term "net emissions increase": 

(a) "net emissions increase" means the amount by which the sum ofthe 

following exceeds zero: 

(i) any increase In actual emissions from a particular physical change or 

change in the method of operation at a stationary source; and 

(ii) any other increases and decreases in actual emissions at the source that 

are contemporaneous with the particular change and are otherwise creditable. 

(b) An increase or decrease in actual emissions is contemporaneous with the 

increase from the particular change only if it occurs between the date five years 

before construction on the particular change commenced, and the date that the 

increase from the particular change occurs. 

(c) An increase or decrease in actual emissions Is creditable only if the 

department has not relied on it in issuing a permit for the source under regulations 

approved pursuant to 40 CFR 51.165, which permit is in effect when the increase in 

actual emissions from the particular change occurs. 

(d) An Increase In actual emissions is creditable only to the extent that the 

new level of actual emissions exceeds the old level. 

(e) A decrease in actual emissions is creditable only to the extent that: 

(i) the old level of actual emissions or the old level of allowable emissions, 

whichever is lower, exceeds the new level of actual emissions; 

(ii) it is federally enforceable at and after the time that actual construction on 

the particular change begins; 

(iii) the department has not relied on it in issuing any Montana air quality 

permit under regulations approved pursuant to 40 CFR Part 51, subpart I (July 1, 

1993 ed.), or the state has not relied on it in demonstrating attainment or reasonable 

further progress; and 

(iv) it has approximately the same qualitative significance for public health 

and welfare as that attributed to the increase from the particular change. 

(f) An increase that results from a physical change at a source occurs when 

the emissions unit on which construction occurred becomes operational and begins 

to emit a particular pollutant. Any replacement unit that requires shakedown 

becomes operational only after a reasonable shakedown period, not to exceed 180 

days. 

ADMINISTRATIVE RULES OF MONTANA 9/30/06 17-525 
17.8.901 ENVIRONMENTAL QUALITY 

(15) "Potential to emit" means the maximum capacity of a stationary source 

to emit a pollutant under its physical and operational design. Any physical or 

operational limitation on the capacity of the source 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, shall be treated as part of its 

design only if the limitation or the effect it would have on emissions is federally 

enforceable. Secondary emissions do not count in determining the potential to emit 

of a stationary source. 

(16) "Reasonable further progress" means annual incremental reductions in 

emissions of the applicable air pollutant which are required by the FCAA or the 

administrator for attainment of the applicable national ambient air quality standard by 

the date required in section 172(a) of the FCAA. 

(17) "Secondary emissions" means emissions which would occur as a result 

of the construction or operation of a major stationary source or major modification, 

but do not come from the major stationary source or major modification Itself For 

the purpose of this chapter, secondary emissions must be specific, well defined, 

quantifiable, and impact the same general area as the stationary source or 

modification which causes the secondary emissions. Secondary emissions include 

emissions from any offsite support facility which would not be constructed or 

increase its emissions except as a result of the construction or operation of the 

major stationary source or major modification. Secondary emissions do not include 

any emissions which come directly from a mobile source such as emissions from the 

tailpipe of a motor vehicle, from a train, or from a vessel. 

(18) "Significant" means, in reference to a net emissions increase or the 

potential of a source to emit any of the following pollutants, a rate of emissions that 

would equal or exceed any of the following rates: 

Pollutant and Emission Rate 

Carbon monoxide: 100 tons per year (tpy) 

Nitrogen oxides: 40 tpy 

Sulfur dioxide: 40 tpy 

Particulate matter: 25 tpy of particulate matter emissions 

or 15 tpy of PM-10 emissions 

Lead: 0.6 tpy 

(19) "Stationary source" means any building, structure, facility, or installation 

which emits or may emit any air pollutant subject to regulation under the FCAA. 

(20) "Volatile organic compounds (VOC)" means the same as defined in 40 

CFR 51.100(s). (History: 75-2-111, 75-2-203, MCA; IMP, 75-2-202, 75-2-203, 75-2-

204, MCA; NEW. 1993 MAR p. 2919, Eff. 12/10/93; AMD, 1995 MAR p. 2410, Eff. 

11/10/95; AMD, 1996 MAR p. 1843, Eff. 7/4/96; AMD. 1996 MAR p. 1844, Eff. 

7/4/96; TRANS, from DHES, 1996 MAR p. 2285; AMD, 1998 MAR p. 1725, Eff. 

6/26/98; AMD. 2002 MAR p. 1747, Eff. 6/28/02; AMD. 2002 MAR p. 3567, Eff. 

12/27/02; AMD. 2003 MAR p. 645, Eff. 4/11/03; AMD. 2007 MAR p. 1663, Eff. 

10/26/07; AMD. 2008 MAR p. 2267, Eff. 10/24/08.) 

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17-526 12/31/08 ADMINISTRATIVE RULES OF MONTANA 
17.8.1007 ENVIRONMENTAL QUALITY 

17.8.1007 BASELINE FOR DETERMINING CREDIT FOR EMISSIONS AND 

AIR QUALITY OFFSETS (1) For the purposes of this subchapter, the following 

requirements shall apply: 

(a) the requirements of ARM 17.8.906, except that 17.8.906(7) through (9) 

are not applicable to offsets required under this subchapter; 

(b) emission offsets must be reductions in actual emissions for the same 

pollutant obtained from the same source or other sources which are located in the 

same general area of the proposed major stationary source or modification, and that 

contribute to or would contribute to the violation ofthe national ambient air quality 

standard; 

(c) in the case of emission offsets involving volatile organic compounds and 

oxides of nitrogen, offsets will generally be acceptable if they are obtained from 

within the areas specified in (1)(b). If the proposed offsets would be from sources 

located at considerable distances frorti the new source, the department shall 

increase the ratio of the required offsets and require a showing by the applicant that 

nearby offsets were investigated and reasonable alternatives were not available; 

(d) in the case of emission offsets involving sulfur dioxide, particulates, and 

carbon monoxide, areawide mass emission offsets are not acceptable, and the 

applicant shall perform atmospheric simulation modeling to ensure that emission 

offsets provide a positive net air quality benefit. The department may exempt the 

applicant from the atmospheric simulation modeling requirement if the emission 

offsets provide a positive net air quality benefit, are obtained from an existing source 

on the same premises or in the immediate vicinity of the new source, and the 

pollutants disperse from substantially the same effective stack height; and 

(e) no emissions credit shall be allowed for replacing one hydrocarbon 

compound with another of lesser reactivity, except for those compounds listed in 

Table 1 of EPA's "Recommended Policy on Control of Volatile Organic Compounds" 

(42 FR 35314, July 8, 1977). (History: 75-2-111, 75-2-203, MCA; MP, 75-2-202, 

75-2-203, 75-2-204, MCA; NEW, 1993 MAR p. 2919, Eff. 12/10/93; TRANS, from 

DHES, 1996 MAR p. 2285; AMD. 2007 MAR p. 1663, Eff. 10/26/07; AMD. 2008 

MARp. 2267, Eff. 10/24/08.) 

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17-556 12/31/08 ADMINISTRATIVE RULES OF MONTANA