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WYOMING DEPARTMENT OF ENVIRONMENTAL QUALITY

AIR QUALITY DIVISION

STANDARDS AND REGULATIONS 

CHAPTER 6

PERMITTING REQUIREMENTS

Section 9. Best available retrofit technology (BART).

(a) Applicability. The provisions of this regulation apply to existing stationary 

facilities, as defined in Section 9(b) of this chapter.

(b) Definitions.

“Adverse impact on visibility” means visibility impairment which interferes with 

the management, protection, preservation, or enjoyment of the visitor’s visual experience 

of the Federal Class I area. This determination must be made on a case-by-case basis 

taking into account the geographic extent, intensity, duration, frequency and time of 

visibility impairments, and how these factors correlate with 1) times of visitor use of the 

Federal Class I area, and 2) the frequency and timing of natural conditions that reduce 

visibility. This term does not include effects on integral vistas.

“Applicable technology” means a commercially available control option that has 

been or is soon to be deployed (e.g., is specified in a permit) on the same or a similar 

source type or a technology that has been used on a pollutant-bearing gas stream that is 

the same or similar to the gas stream characteristics of the source.

“Available technology” means that a technology is licensed and available through 

commercial sales.

“Average cost effectiveness” means the total annualized costs of control divided 

by annual emissions reductions (the difference between baseline annual emissions and 

the estimate of emissions after controls). For the purposes of calculating average cost 

effectiveness, baseline annual emissions means a realistic depiction of anticipated annual 

emissions for the source. The source or the Division may use State or Federally 

enforceable permit limits or estimate the anticipated annual emissions based upon actual 

emissions from a representative baseline period.

“BART alternative” means an alternative measure to the installation, operation, 

and maintenance of BART that will achieve greater reasonable progress toward national 

visibility goals than would have resulted from the installation, operation, and 

maintenance of BART at BART-eligible sources within industry source categories 

subject to BART requirements.
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“Best available retrofit technology (BART)” means an emission limitation based 

on the degree of reduction achievable through the application of the best system of 

continuous emission reduction for each pollutant that is emitted by an existing stationary 

facility. The emission limitation must be established, on a case-by-case basis, taking into 

consideration the technology available, the costs of compliance, the energy and non air 

quality environmental impacts of compliance, any pollution control equipment in use or 

in existence at the source or unit, the remaining useful life of the source or unit, and the 

degree of improvement in visibility which may reasonably be anticipated to result from 

the use of such technology.

“Deciview” means a measurement of visibility impairment. A deciview is a haze 

index derived from calculated light extinction, such that uniform changes in haziness 

correspond to uniform incremental changes in perception across the entire range of 

conditions, from pristine to highly impaired. The deciview haze index is calculated based 

on the following equation (for the purposes of calculating deciview, the atmospheric light 

extinction coefficient must be calculated from aerosol measurements):

Deciview haze index = 10 lne (bext/10 Mm-1)

Where bext = the atmospheric light extinction coefficient, expressed in inverse 

megameters (Mm-1).

“Existing stationary facility” means any of the following stationary sources of air 

pollutants, including any reconstructed source, which was not in operation prior to 

August 7, 1962, and was in existence on August 7, 1977, and has the potential to emit 

250 tons per year or more of any visibility impairing air pollutant. In determining 

potential to emit, fugitive emissions, to the extent quantifiable, must be counted.

(i) Fossil fuel-fired steam electric plants of more than 250 million British 

thermal units (BTU) per hour heat input that generate electricity for sale.

(A) Boiler capacities shall be aggregated to determine the heat 

input of a plant.

(B) Includes plants that co-generate steam and electricity and 

combined cycle turbines.

(ii) Coal cleaning plants (thermal dryers).

(iii) Kraft pulp mills.

(iv) Portland cement plants.

(v) Primary zinc smelters.

(vi) Iron and steel mill plants.
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(vii) Primary aluminum ore reduction plants.

(viii) Primary copper smelters.

(ix) Municipal incinerators capable of charging more than 250 tons of 

refuse per day.

(x) Hydrofluoric, sulfuric, and nitric acid plants.

(xi) Petroleum refineries.

(xii) Lime plants.

(xiii) Phosphate rock processing plants. Includes all types of phosphate 

rock processing facilities, including elemental phosphorous plants as well as fertilizer 

production plants.

(xiv) Coke oven batteries.

(xv) Sulfur recovery plants.

(xvi) Carbon black plants (furnace process).

(xvii) Primary lead smelters.

(xviii) Fuel conversion plants.

(xix) Sintering plants.

(xx) Secondary metal production facilities. Includes nonferrous metal 

facilities included within Standard Industrial Classification code 3341, and secondary 

ferrous metal facilities in the category “iron and steel mill plants”.

(xxi) Chemical process plants. Includes those facilities within the 2-digit 

Standard Industrial Classification 28, including pharmaceutical manufacturing facilities.

(xxii) Fossil fuel boilers of more than 250 million BTUs per hour heat 

input.

(A) Individual boilers greater than 250 million BTU/hr, 

considering federally enforceable operational limits.

(B) Includes multi-fuel boilers that burn at least fifty percent fossil 

fuels.
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(xxiii) Petroleum storage and transfer facilities with a capacity exceeding 

300,000 barrels.

(A) 300,000 barrels refers to total facility-wide tank capacity for 

tanks put in place after August 7, 1962 and in existence on August 7, 1977.

(B) Includes gasoline and other petroleum-derived liquids.

(xxiv) Taconite ore processing facilities.

(xxv) Glass fiber processing plants.

(xxvi) Charcoal production facilities. Includes charcoal briquette 

manufacturing and activated carbon production.

“Incremental cost effectiveness” means the comparison of the costs and 

emissions performance level of a control option to those of the next most stringent 

option, as shown in the following formula:

Incremental Cost Effectiveness (dollars per incremental ton removed) = [(Total 

annualized costs of control option) - (Total annualized costs of next control 

option)] ÷ [(Next control option annual emissions) - (Control option annual 

emissions)]

“In existence” means that the owner or operator has obtained all necessary 

preconstruction approvals or permits required by Federal, State, or local air pollution 

emissions and air quality laws or regulations and either has 1) begun, or caused to begin, 

a continuous program of physical on-site construction of the facility or 2) entered into 

binding agreements or contractual obligations, which cannot be cancelled or modified 

without substantial loss to the owner or operator, to undertake a program of construction 

of the facility to be completed in a reasonable time.

“In operation” means engaged in activity related to the primary design function 

of the source.

“Integral vista” means a view perceived from within the mandatory Class I 

Federal area of a specific landmark or panorama located outside the boundary of the 

mandatory Class I Federal area.

“Natural conditions” means naturally occurring phenomena that reduce visibility 

as measured in terms of light extinction, visual range, contrast, or coloration.

“Plant” means all emissions units at a stationary source.

“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 
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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 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.

“Visibility-impairing air pollutant” includes the following:

(i) Sulfur dioxide (SO2);

(ii) Nitrogen oxides (NOx); and

(iii) Particulate matter. (PM10 will be used as the indicator for particulate 

matter. Emissions of PM10 include the components of PM2.5 as a subset).

(c) Guidelines for BART Determinations.

(i) The U.S. Environmental Protection Agency regulations contained in 

40 CFR part 51, Appendix Y, are incorporated by reference into these regulations. The 

specific documents containing the complete text of the regulations are found in 40 CFR 

part 51, Appendix Y, as published on July 6, 2005 in the Federal Register beginning on 

page 39104, not including later amendments. Copies of the July 6, 2005 materials can be 

obtained from the Department of Environmental Quality, Division of Air Quality, 122 W. 

25th Street, Cheyenne, Wyoming 82002.

(ii) The owner or operator of a fossil fuel-fired steam electric plant with a 

generating capacity greater than seven hundred fifty megawatts of electricity shall 

comply with the requirements of 40 CFR part 51, Appendix Y. All other facility owners 

or operators shall use Appendix Y as guidance for preparing their best available control 

retrofit technology determinations.

(d) Identification of Sources Subject to BART.

(i) Identification of sources subject to BART shall be performed by the 

Air Quality Division in accordance with EPA’s guidelines for BART determinations 

under the regional haze rule 40 CFR part 51, Appendix Y, and incorporated by reference 

under Section 9(c). A BART-eligible source is subject to BART unless valid air quality 

dispersion modeling demonstrates that the source will not cause or contribute to visibility 

impairment in any Class I area.

(A) A single source that is responsible for a 1.0 deciview change 

or more is considered to “cause” visibility impairment in any Class I area.

(B) A single source that is responsible for a 0.5 deciview change 

or more is considered to “contribute” visibility impairment in any Class I area.
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(C) A single source is exempt from BART if the 98th percentile 

daily change in visibility, as compared against natural background conditions, is less than 

0.5 deciviews at all Class I federal areas for each year modeled and for the entire multiyear modeling period.

(ii) The Division will provide written notice to each source determined to 

be subject to BART.

(e) BART Requirements.

(i) Submission of Best Available Retrofit Technology (BART) Permit 

Application. The owner or operator of each source subject to BART as determined under 

Section 9(d), shall submit a BART permit application to the Division. The permit 

application shall be submitted according to a schedule determined by the Division. 

Sources with a potential to emit less than 40 tons per year SO2 or NOx or less than 15 

tons per year PM10 may exclude those de minimis level pollutants from the BART 

analysis. The BART permit application shall include:

(A) The name and address (physical location) of the existing 

stationary facility subject to BART.

(B) A brief description of the source and identification of any 

listed source categories in which it is included.

(C) Information on de minimis levels if pollutants are excluded 

from the analysis.

(D) An analysis of control options performed in accordance with 

40 CFR part 51, Appendix Y, IV.

(E) A proposal and justification for BART emission limits and 

control technology that reflect the BART requirements established in 40 CFR part 51, 

Appendix Y.

(F) A description of the proposed emission control systems, 

including the estimated control efficiencies.

(G) A schedule to install and operate BART.

(H) Additional relevant information as the Administrator may 

request.

(ii) Administrative Procedures for Review of a BART Permit 

Application. The administrative procedures for review shall follow the procedures 

specified in Chapter 6, Section 2(g) of these regulations. 
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(iii) Proposed Permits. The Administrator shall prepare a proposed 

permit following the Division’s review of the BART permit application. The 

Administrator may approve, or amend the proposed emission limits, BART technology, 

and compliance schedule. Any proposed permit shall specify any notification, operation 

and maintenance, performance testing, monitoring, reporting and recordkeeping 

requirements determined by the Administrator to be reasonable and necessary. 

(iv) Opportunity for Public Comment. The opportunity for public 

comment shall follow the procedures specified in Chapter 6, Section 2(m) for permit 

review.

(v) Modifications to BART Permits. Any source seeking to modify the 

BART determination for that facility must obtain the Administrator’s approval.

(vi) Operating Permit Requirements. BART requirements established 

pursuant to any BART permit issued under this section shall be included in a Chapter 6, 

Section 3 Operating Permit according to the procedures established in Chapter 6, Section 

3.

(vii) Fees. Persons applying for a permit under this section shall pay a fee 

to cover the Department’s cost of reviewing and acting on permit applications in 

accordance with Chapter 6, Section 2(o).

(viii) Installation of Best Available Retrofit Technology. The owner or 

operator of any source required to operate under a BART permit issued under Section 

9(e)(iii), shall install and operate best available retrofit technology unless an alternative to 

the installation of BART as specified under Section 9(f) has been approved by the 

Division. Any control equipment required under a permit issued in this section shall be 

installed and operating as expeditiously as practicable but in no event later than five years 

after the United States Environmental Protection Agency’s approval of Wyoming’s State 

Implementation Plan revision for Regional Haze.

(ix) Operation and Maintenance of Best Available Retrofit Technology. 

The owner or operator of a facility required to install best available retrofit technology 

under Section 9(e)(viii) shall establish procedures to ensure such equipment is properly 

operated and maintained.

(f) BART Alternative.

(i) The Administrator may implement or require participation in an 

emissions trading program or other alternative measures developed in accordance with 40 

CFR 51.308(e) rather than to require sources subject to BART to install, operate and 

maintain BART. 

(g) Monitoring, Recordkeeping and Reporting. The owner or operator of any 

existing stationary facility that is required to install best available retrofit technology or 
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an approved BART alternative shall conduct monitoring, recordkeeping and reporting 

sufficient to show compliance or noncompliance on a continuous basis.