1

A. Analysis of 309(g) Comments Received in Response to the November 18, 2003 Public Hearing 

The Division responded to comments following each public comment period with responses that were relevant during that time period. No attempt was made to revise responses from earlier time periods. 

As information changed over time, the Division’s responses changed accordingly.

Commenter Comment # Section Comment DEQ Response

The Center 

for Energy 

and 

Economic 

Development

A1 General

It is premature for Wyoming to take any administrative action on 

the RHR by choosing § 308 or § 309 as an option because of 

uncertainty created by American Corn Growers Assoc. v EPA, 

291 F.3d 1 (D.C.Cir 2002) decision which invalidated RHR 

especially BART provisions.

EPA’s approval of the Annex on June 5, 2003 addressed the impact of the May 24, 2002 

American Corn Growers Decision (Federal Register, Vol.68, No. 108, pages 33766-33767). The 

approval notice states, “The American Corn Growers court decision did not address the 

provisions in the regional haze rule allowing States to adopt a trading program or other 

alternative measures in place of source specific measures for BART sources.” The State of 

Wyoming has developed a SIP under Section 309 of the Regional Haze Rule based on years of 

work with the Grand Canyon Visibility Transport Commission (GCVTC) and the Western 

Regional Air Partnership (WRAP) that identified the best approach to address regional haze on 

the Colorado Plateau. The approach is flexible, and addresses all of the significant sources of 

haze in the west. The 309 approach also includes provisions allowing States to address other 

Class I areas beyond those on the Colorado Plateau. The American Corn Growers decision does 

not change these underlying reasons for implementing the regional approach allowed under 

Section 309 of the Regional Haze Rule.

The Center 

for Energy 

and 

Economic 

Development

A2 General

Wyoming should not commit to a specific regional haze 

implementation approach until after EPA has responded to the 

court’s remand of the RHR because § 309 is one of the BART 

provisions affected by Corn Growers decision.

Although CEED has filed a challenge to the Annex - it is valid law until overturned/remanded. 

Pursuant to § 307(d)(7)(B) of the CAA [42 USC 7607(d)(7)(B)], “reconsideration of a rule shall 

not postpone the effectiveness of the rule. The effectiveness of the rule may be stayed by 

court order for up to 3 months.” There is no stay order in effect for these rules.

Arch Coal A3 General Dual SIPs

The respondent alleges that because Wyoming’s Class I areas are not on the Colorado Plateau 

and that Section 308 of the Regional Haze Rule addresses all Class I areas that Wyoming will be 

required to submit a SIP under both Section 308 and 309 of the Regional Haze Rule. 40 CFR 

51.309(g) allows a state electing to submit a SIP pursuant to Section 309 to make a declaration 

that it will address other Class I areas than those on the Colorado Plateau pursuant to the 

requirements of Sections 309(g)(2) and 309(g)(3) rather than pursuant to Section 308. 

Wyoming has elected to do so.
2

Arch Coal A4 General Adjacent 308 States

The SO2 strategies are satisfied for Wyoming sources under the provisions of Section 309(g). 

Regardless of timing issues and the success of Senator Imhofe’s efforts, the states represented 

in the WRAP are committed to a coordinated effort to address NOx & PM strategies. Wyoming 

and all of its neighboring states are participants in the WRAP.

B. Analysis of 309(g) Comments received from the Forest Service letter dated October 19, 2006

Commenter Comment # Section Comment DEQ Response

Forest 

Service B1 Natural 

Conditions

It is important to provide a detailed description of the methods 

used to develop natural conditions. We encourage states to use 

calculations that are based on recommendations from the 

IMPROVE steering committee and the EPA.

The State was not involved in the development of the natural visibility conditions. The WRAP 

states utilized the conditions developed by EPA. The EPA relied heavily on the National Acid 

Precipitation Program (NAPAP) developed in 1990 to establish natural visibility conditions for 

the Regional Haze SIP. The following website provides a detailed description of the NAPAP 

program: http://www.epa.gov/airmarkets/resource/docs/NAPAP.pdf.

Forest 

Service B2 Emission 

Inventories

It would be helpful if the State could spend a considerable effort 

describing how the inventories were developed.

An entire chapter has been dedicated to describing the emissions inventory. Please see 

Chapter 4 of the SIP. Additional inventory information can also be found on the TSS site: 

http://vista.cira.colostate.edu/TSS/Results/Emissions.aspx

Forest 

Service B3 BART BART source identification, elimination, and level determination 

will be of particular interest for review. Chapter 6 of the SIP provides a detailed description of analyses performed on BART sources.

Forest 

Service B4 Area of 

Influence

We suggest that each state clearly identify and apportion by 

State, or other geographical means, the significant levels of 

pollutants contributed to each Class I area by source. 

Developing this information together with neighboring States 

and Tribes will facilitate consistency.

Wyoming worked closely with other states and tribes to develop the significance levels of 

pollutants in each Class I area. The significance level of each pollutant was developed by 

WRAP, which ensured consistency among the states. All of this information is compiled on the 

TSS website: http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx. The consultation 

process between Wyoming and surrounding states and tribes can be found in Chapter 11 of 

the SIP.

Forest 

Service B5 Reasonable 

Progress

For Class I areas where the reasonable progress goal is more 

impaired than the uniform rate of progress, consider presenting 

information on a component basis.

The State has presented the information on a component basis throughout the SIP. Figures 

7.6-1 to 7.6-3 present the time series by pollutant for the 20% worst days, when the uniform 

reasonable progress goal was not met. Section 7.6 provides a demonstration that the 

reasonable progress goals set are reasonable. In this section there is component-specific 

discussion.
3

Forest 

Service B6 Wildland Fire

If anthropogenic fire contributes to the index used to track longterm reasonable progress in Class I areas, the visibility SIP should 

identify how it will be addressed.

The SIP contains a section that addressed anthropogenic fire. Section 8.2.5 outlines the State’s 

agricultural and forestry smoke management techniques. The DEQ has ensured that this 

smoke management program meets all of the requirements set forth by the Regional Haze 

Rule.

Forest 

Service B7 Regional 

Consistency

The FS hopes that the states will work towards consistent 

descriptions of apportionment and emission control goals, thus 

resulting in development of similar progress goals, regardless of 

release dates.

The inventories, monitoring and modeling was performed by WRAP to maintain consistency 

within the Western states. Wyoming has consulted with other states continuously throughout 

the SIP development process. Chapter 11 summarizes the consultation process.

Forest 

Service B8

Verification 

and 

Contingencies

Given the uncertain future of any individual monitoring site, we 

suggest that the SIP address the representativeness of both 

primary and alternative data sites for each Class I area.

The State has identified IMPROVE sites as the representative monitoring sites. It is believed 

that these sites appropriately capture emissions in all of the Class I areas. Since these are EPArecognized monitoring sites that have been sited under the guidance of a steering committee, 

the Division does not find it necessary to consider alternative data sites.

C. Analysis of 309(g) Comments Received in Response to EPA Comment Letter Dated May 29, 2008

Commenter Comment # Section Comment DEQ Response

EPA C1 BART WRAP needs to justify using 0.5 deciviews as a threshold for 

determining whether sources are subject to BART.

EPA’s BART guidelines state that “As a general matter, any threshold that you use for 

determining whether a source ‘contributes’ to visibility impairment should not be higher than 

0.5 deciviews.” The guidelines give states the discretion to establish a lower threshold “if they 

conclude that the location of a large number of BART-eligible sources within the State and in 

proximity to a Class I area justify this approach. When developing the modeling protocols for 

the visibility analysis, the four participating states established the threshold at 0.5 deciviews 

because it is consistent with EPA guidelines, and is consistent with long-standing visibility 

modeling practices. Significant BART-eligible sources that are in proximity to Class I areas in 

the West have been addressed through the reasonably attributable visibility impairment 

process, and there is not a large concentration of BART-eligible sources that are in proximity to 

a Class I area. In addition, the backstop trading program will include all sources with emissions 

over 100 tons/year and will therefore still include sources that may not be subject to BART. 

The guidelines do not require states to establish a lower threshold, and the four participating 

states do not believe that a lower threshold is needed or justified.

Language has been added to the Better Than BART demonstration to explain that the 0.5 

deciview threshold is consistent with EPA’s BART guidelines.
4

EPA C2 BART

When estimating BART emission reductions WRAP excluded 

some non-utility sources that it characterizes as potentially 

subject to BART and this is not consistent with regulatory 

requirements.

The analysis excluded a small number of non-utility sources that in aggregate represent 1% of 

the regional milestone. EPA has not established a presumptive control level for these sources 

and there is little benefit to doing a case-by-case analysis because the results would have a 

negligible impact on the regional milestone. These sources will still be included in the 

Backstop Trading Program.

D. Analysis of 309(g) Comments Received in Response to the October 27, 2009 Public Hearing

Commenter Comment # Section Comment DEQ Response

Judith Hamm D1 General

Concerned that particulate matter caused by quarries and 

road construction were not addressed as a contributing factor 

of haze. There also does not appear to be any monitoring 

responsibilities applied to the quarry or construction 

operations.

The emissions inventory developed by WRAP identifies construction emissions, as well as 

industrial activities, including mining and quarrying as particulate matter source categories. 

The entire list of source categories can be found in Table 2 of the dust emissions document in 

WRAP’s technical support document 

(http://vista.cira.colostate.edu/TSS/Results/Emissions.aspx “Emissions Methods”).

Wyoming’s Air Quality Standards and Regulations (WAQSR) Chapter 3, Section 2, contains 

Emissions Standards for Particulate Matter. Both construction activities and quarry operations 

fall under this chapter. Test method requirements for determining particulate matter 

emissions are found in Chapter 3, Section 2(h)(iii).

The SIP addresses road construction in Section 8.2: Required Factors for the Long-Term 

Strategy. It is a requirement under Section 51.308(d)(3)(v) of the Regional Haze Rule for the 

SIP to consider measures to mitigate impacts of construction activities. Chapter 3, Section 2(f) 

of WAQSR addresses this requirement.

Please note that the day-to-day impacts of such facilities are not analyzed by the regional haze 

program. The regional haze program focuses on long-term overall impacts of all sources 

combined at a regional level. The day-to-day responsibilities of the quarry are better 

addressed through the compliance program.
5

Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

D2 General WOC believes that DEQ should plan for a visibility 

improvement of greater than 45% in this planning period.

The WRAP states have stressed that the Uniform Rate of Progress (URP) is not achieved in any 

of the western states because there are too many uncontrollable sources of emissions 

impacting visibility in the West, overwhelming the controllable sources. As identified in the 

SIP, organic carbon from wildfires is the single biggest contributor to visibility impairment. 

Section 51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must 

provide for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over the 

same period”. Therefore, the only days that are required to be analyzed for visibility are the

worst and best days. Since there is no degradation in visibility for the 20% best days, this 

portion of the Rule is satisfied. During the 20% worst days, wildfires are a major contributing 

factor. Therefore, without the ability to control wildfires, it is difficult to demonstrate a greater 

than 45% improvement of visibility.

Please note that not all reductions were included in the WRAP modeling. The results do not 

include the BART and long-term strategy reductions proposed in this SIP or any other WRAP

SIPs. The WRAP could only include enforceable reductions that were on the books at the time 

of the last model run.

Wyoming 

Outdoor 

Council

D3 General

Since improvements of less than 1.0 dv are not apparent to 

most people, Wyoming Outdoor Council recommends that 

DEQ revise its SIP to achieve recognizable visibility 

improvements of 1.2 dv on the most impaired days.

With the exception of Yellowstone National Park and Grand Teton National Park and 

Wilderness Area, improvements of 1.2 dv would exceed the URP goal. For Yellowstone and 

Grand Teton, a 1.2 dv decrease would result in projected visibility of 0.1 dv over the URP goal. 

It is explained in Chapter 7 of the SIP that Wyoming was not able to achieve its URP for the first 

planning period. Therefore, to improve visibility at a level greater than URP is also not viable in 

this planning period.
6

Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

D4 General

WOC recommends that DEQ focus greater attention on 

correcting haze during the winter months when fire is not 

likely a significant contributing factor, specifically in the 

Bridger and Fitzpatrick Wilderness areas.

Section 51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must 

provide for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over the 

same period”. Therefore, it is only required to analyze the monitored best and worst days. In 

the case of the best days, modeling demonstrates no further degradation of visibility. Since 

the worst days occurred in the summer months, focusing on correcting the winter months will 

have no impact on the results of the worst days modeling.

However, BART-eligible sources identified in the SIP are required to control emissions year 

round, and the Division is confident that the implementation of BART will have significant 

visibility impairment improvements in both the summer and winter months.

Wyoming 

Outdoor 

Council

D5 Chapter 6: 

BART

EPA has not approved Section 309, and therefore it cannot be 

relied on as BART.

Under the Regional Haze Rule, the State is required to implement a plan that will reduce 

visibility impairment. This is occurring in two parts; Section 309 and Section 309(g). Under this 

rule, EPA allows the State to take credit for any SO2 reduction achieved in section 309, as 

stated in 51.309(g)(i): “In developing long term strategies pursuant to 51.308(d)(3), the state 

may build upon the strategies implemented under paragraph 9(d) of this section, and take full 

credit for the visibility improvement achieved through these strategies.” There is no 

requirement in this rule that the State must have an EPA-approved 309 program before it is 

relieved of its BART responsibility.

 

The original vision of the EPA Regional Haze Rule developed in 1999 was to complete Section 

309 before 309(g), which enabled Section 309(g) to take credit for the SO2 reductions. The 

original deadline for the 309 submittal was 2003, while 309(g) wasn’t due until 2008. Since this 

time, the State has submitted two SIPs to EPA and will submit its third revision in early 2011. 

EPA has also changed the Rule several times, and pushed back the 309 submittal until 2007. 

Due to delays, the process has been taking longer than expected and the 309 and 309(g) 

processes are now overlapping, and SIP submittal for both programs are occurring in parallel.

Wyoming 

Outdoor 

Council

D6 General

WOC suggests that companies are submitting BART with SO2

controls that would achieve better reduction than Section 309, 

and therefore these proposals should be adopted because 

they are achieving greater reasonable progress than the 309 

program.

The 309 program has undergone analysis to demonstrate that the program is achieving 

reasonable progress that is better than BART. Please refer to the Demonstration that the SO2

Milestones Provide Greater Reasonable Progress than BART in Appendix E. In this 

demonstration, the State not only verifies that the program meets or exceeds presumptive SO2 

BART levels, but also provides other benefits of implementing the milestone program. One of 

these benefits includes limiting new source growth for SO2 emissions in the participating 
7

Commenter Comment # Section Comment DEQ Response

states. In addition, the program includes every source that emits 100 tons per year or greater 

of SO2, and therefore targets a greater number of sources than what would be identified in the 

BART program. Also, The 309 program does not only focus on stationary sources, but also 

includes strategies to address mobile sources, prescribed fire, pollution prevention, and Clean 

Air Corridors.

Wyoming 

Outdoor 

Council

D7 General

Since “the largest point source of NOx emissions is coal-fired 

power plants”, WOC believes that controls on the Bridger and 

Naughton power plants should be a focus of DEQ.

The DEQ has included these power plants as BART-eligible sources, and has performed the 

appropriate BART analysis for both plants. The Naughton power plant has been required to 

install and operate low NOx burners with overfire air on two of its units, and install and operate 

low NOx burners with overfire air and install selective catalytic reduction on the third unit. The 

overall NOx reduction from baseline achieved by these units is 10,525 TPY. These control 

systems will be installed within 5 years of the SIP approval. The Bridger power plant is required 

to install and operate low NOx burners with overfire air on all four units. The overall reduction 

from baseline achieved by these four units is 13,749 TPY. These systems have already been 

installed and performance tested for units 2-4, and will be installed within 5 years of SIP 

approval for Unit 1. In addition to these BART requirements, the State will require the Jim 

Bridger units to install selective catalytic reduction as part of the long-term strategy.

Wyoming 

Outdoor 

Council

D8 Oil and Gas 

Sources

Since oil and gas sources are the second largest category of 

stationary sources, WOC believes that DEQ needs to pursue 

regulation of this industry, such as adoption of BACT 

requirements, codifying its offsets policy, and regulating drill 

rigs.

DEQ agrees that it is important to recognize and regulate oil and gas emissions. As outlined in 

the long-term strategy portion of the SIP, DEQ cannot complete the evaluation of oil and gas 

impacts on visibility until Phase III of the WRAP study has been completed. In terms of 

adoption of BACT requirements, WAQSR Chapter 6, Section 2, already contains the permitting 

BACT requirements for oil and gas production facilities. DEQ also agrees that policies and 

regulations for oil and gas sources need to be codified, and are in the process of doing so as 

ozone is addressed.

Wyoming 

Outdoor 

Council

D9 Chapter 2: 

Monitoring

WOC states that it is widely recognized (especially by the 

Forest Service) that the Bridger IMPROVE site is not 

appropriately located to monitor the contribution of oil and 

gas emissions in the field. WOC suggests that there is a need 

for visibility monitoring that reflects the oil and gas field.

The Forest Service has added an additional IMPROVE monitor at a location that is believed to 

capture oil and gas impacts on the Bridger Wilderness area. The new monitor is located at 

Boulder Lake, and the Forest Service has been collecting data from the monitor since August 

2009.
8

Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

D10 General

WOC’s statement: “DEQ claims that air quality is good in 

Wyoming, much better than in the east. The implication is we 

should be happy with what we’ve got and not worry about 

Wyoming making as much progress as URP calls for”.

DEQ is not in any way trying to imply that “we should be happy with what we’ve got and not 

worry about Wyoming making as much progress as URP calls for”. DEQ is simply trying to 

demonstrate that it is not as easy to show progress when there are fewer initial visibility 

impacts. It is much easier to show increased original progress when there are greater impacts. 

In addition, there is a large difference in vegetation and meteorological conditions between the 

East and the West. For example, in comparison to the East, the Class I areas in Wyoming are 

located in more heavily forested areas, and therefore more natural fires occur within the Class 

I area proximity. The low humidity in the West also allows for a more noticeable difference in 

the visibility when such an event occurs. The DEQ is not making excuses for not achieving URP 

goals and the Division does take the goal very seriously. The DEQ simply wanted to explain in 

the SIP why other states such as those in the East may be able to meet the URP in the initial 

phase, while Wyoming and other Western states were not.

Wyoming 

Outdoor 

Council

D11

Chapter 6: 

BART

Coal-Fired 

Power Plants

Wyoming Outdoor Council believes that coal-fired power 

plants should use Selective Catalytic Reduction (SCR) NOx

Control technology to meet EPA presumptive BART limit 

(which is not believed to be met with current BART that the 

State is proposing). WOC believes this is particularly important 

for the plants that do not have additional NOx controllers as 

part of its long-term strategy (Dave Johnston, Wyodak and 

Naughton).

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on 

BART. Permit applications and the DEQ analysis for each BART source can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp. 

Wyoming 

Outdoor 

Council

D12

Chapter 6: 

BART

Coal-Fired 

Power Plants

DEQ is proposing BART limits that are lower than the NSPS of 

0.11 lb/MMBTU established by EPA.

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on 

BART. Permit applications and the DEQ analysis for each BART source can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp.

Wyoming 

Outdoor 

Council

D13

Chapter 6: 

BART

Coal-Fired 

Power Plants

WOC pointed out a number of ways in which particulate 

matter control could be achieved, specifically through the 

installation of full scale baghouse technology or polishing 

baghouses.

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on 

BART. Permit applications and the DEQ analysis for each BART source can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp.
9

Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

D14

Chapter 6: 

BART

Trona Plants

WOC believes that the lack of BART for the Granger facility is 

shortsighted and illegal. It is believed that the facility should 

be analyzed as a small group of facilities with the other two 

Trona plants in the area. Although the Regional Haze Rule 

does not require this, WAQSR Chapter 9 does require BART if 

all facilities are grouped together. 

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. The public hearing for the Granger facility occurred on 

September 11, 2008, in Rock Springs, WY. All comments and responses can be found in the 

TSD, under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses 

on BART. Permit applications and the DEQ analysis for each BART source can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp.

EPA D15 Chapter 5: 

Modeling

The modeling performed by WRAP was not representative of 

all of the controls implemented under the regional haze 

program. EPA suggests the State consider remodeling as part 

of the five-year review.

The State of Wyoming has not planned to do any additional modeling. All modeling was 

performed by WRAP on a regional level. WRAP currently does not have the budget to do any 

additional modeling, but has made a request to EPA for more funding.

EPA D16

Chapter 4: 

Statewide 

Emissions 

Inventory

Although overall state SO2 and NOx projected emissions 

decrease, Tables 4.2.1 and 4.3-1 show increase in area SO2

emissions and in area and oil and gas emissions by 2018. 

Chapter 5 modeling also shows increase in impacts in all 3 

Wyoming Class I areas for SO2 on the 20% best and worst days. 

Modeling also shows increase in impacts for NOx on the 20% 

worst days in Yellowstone National Park and Bridger 

Wilderness area. The State needs to address the impacts in 

Class I areas from area and oil and gas sources, including 

enforceable emission limitations, compliance schedules and 

other measures as necessary.

The State of Wyoming appreciates the level of detail that EPA used when reviewing the SIP. 

When the State investigated the cause of the SO2 area source increase, it was found that the 

increase was due to growth factors applied by WRAP in the inventory. Of the 6,300-ton 

increase, 4,800 tons of it came from residual oil burners, and 900 tons from industrial distillate 

oil. Wyoming does not have any of these sources, so the growth factor does not apply and 

these emissions were removed from the calculations. The additional 600-ton increase came 

from commercial coal, industrial processes, and drill rig growth. Wyoming does have these 

sources, so the 600-ton increase will remain in the calculations. The appropriate tables have 

been updated to reflect these changes.

In terms of the NOx increase, the State is in a difficult position since the Division is hoping to 

combine efforts for ozone and regional haze as a more efficient strategy and ozone is the 

driving force in this process. 

In terms of the oil and gas increase, DEQ agrees that it is important to recognize and regulate 

oil and gas emissions. As outlined in the long-term strategy portion of the SIP, DEQ cannot 

complete the evaluation of oil and gas on visibility until Phase III of the WRAP study has been 

completed.
10

Commenter Comment # Section Comment DEQ Response

EPA D17 Chapter 6: 

BART

EPA previously commented on Wyoming’s BART 

determination. See attached letters.

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on 

BART. Permit applications and the DEQ analysis for each BART source can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp.

EPA D18 Chapter 6: 

BART

The State is relying on two documents for BART 

determination: the BART application submitted by source, and 

the analysis of the BART application performed by the State. 

These documents need to be submitted with the SIP.

Both of these documents will be included in the SIP for each BART determination. The analysis 

of the BART determinations and applications for each eligible source can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp.

EPA D19

Chapter 7: 

Reasonable 

Progress 

Goals

EPA has pointed out that SO2 controls need to be evaluated in 

non-Plateau Class I areas as part of the long-term strategy and 

reasonable progress goals. The State must provide a 

demonstration of how Section 309 strategies, including the 

Backstop Trading Program are meeting visibility goals, and an 

analysis of whether other SO2 controls are needed to meet 

reasonable progress. EPA also notes that since the reasonable 

progress goals are less than URP goals, stationary sources that 

are not required to implement SO2 BART controls, and other 

source categories of SO2 still have to be considered and 

addressed for the purpose of reasonable progress.

The State has modeled visibility in the additional non-plateau Class I area monitor locations. 

Wyoming Class I areas and Class I areas in surrounding states were included in the modeling. 

Table 6.2-2, demonstrates visibility broken down by sulfate extinction only. It can be seen in 

this table that all Class I areas show visibility improvement for the worst days, and no 

degradation in visibility for the best days, thereby meeting the requirements outlined in the 

Regional Haze Rule. In addition, Table 6.2-1 outlines the Regional SO2 Emissions and Milestone 

Report summary. This table demonstrates that the 309 states have had significant SO2

reduction and have more than exceeded the goals set by the program.

The Regional Haze Rule requires that the above demonstration is necessary, as well as a 

demonstration that the milestone provides greater reasonable progress than BART. This 

demonstration can be found in Appendix E, Demonstration that the SO2 Milestones Provide 

Greater Reasonable Progress than BART. As long as this demonstration is performed, under 

the Regional Haze Rule, EPA allows the State to take credit for any SO2 reduction achieved in 

section 309, as stated in 51.309(g)(i): “In developing long term strategies pursuant to 

51.308(d)(3), the state may build upon the strategies implemented under paragraph 9(d) of this 

section, and take full credit for the visibility improvement achieved through these strategies.” 

However, if the URP goal is not met, the Rule does not require SO2 sources to undergo further 

reduction in order to meet this goal. If the URP goal cannot be met for a given planning period, 

it is the requirement that the State demonstrate why this goal cannot be met, which the State 

believes it has done throughout the SIP.
11

Commenter Comment # Section Comment DEQ Response

Therefore, the State believes that all requirements of the Regional Haze Rule as it relates to the 

309 strategies for meeting visibility goals have been met and the SO2 sources do not require 

further analysis.

EPA D20

Chapter 7: 

Reasonable 

Progress 

Goals

For Q/d calculations, FLM’s proposed FLAG guidance 

amendments specify inclusion of direct PM and H2SO4 (in 

addition to SO2 and NOX) and use of a consistent baseline 

across all sources.

The EPA Regional Haze Rule did not provide guidance on source selection for the four-factor 

analysis. Therefore, the State looked at the best way to perform an estimate that would 

capture the emissions in the WRAP inventory. DEQ did not include H2SO4 because it is not a 

pollutant that was included in the WRAP inventory. PM was not used for source selection 

because the WRAP inventory is incomplete for this pollutant. Since SO2 was addressed in the 

309 portion, DEQ believed that the evaluation of NOx was a reasonable first step in 

determining sources that should undergo the four-factor analysis. Although PM was not used 

to determine source selection, it was addressed when determining the potential control 

strategies.

EPA D21

Chapter 7: 

Reasonable 

Progress 

Goals

For Q/d Calculations, EPA does not believe it is appropriate to 

separate individual units for emission calculations at the EGUs.

DEQ believed that it was appropriate to separate individual units for two reasons, the first 

being that the BART analysis addressed individual units, so this process was done the same in 

order to maintain consistency. Secondly, not all EGUs are controlled the same, so DEQ 

believed it was appropriate to look at each unit separately. Using this strategy, all EGUs in 

Wyoming were either captured by BART or by the four-factor analysis.

EPA D22

Chapter 7: 

Reasonable 

Progress 

Goals

Wyoming needs to provide additional justification for the 

selection of Q/d>10 as a screening threshold, such as a 

reasonable analysis of relative emissions/impacts of sources 

captured by different levels of Q/d versus sources not 

captured.

Wyoming selected Q/d>10 as a screening threshold based on the Federal Land Manager’s 

recommendations. When the State used this threshold it was found that all BART sources 

were captured along with other sources, and therefore DEQ determined that this threshold 

was a good place to start. DEQ agrees that there needs to be a better screening process as it 

goes forward to address regional haze in future SIP reviews.

EPA D23

Chapters 7 

and 8: 

Reasonable 

Progress 

Goals & Long 

Term Strategy

In SIP section 8.3.4, DEQ states “The Division will be 

developing a state rule to obtain authority to further evaluate 

non-BART sources identified in the four-factor analysis for 

retrofits. The rulemaking will require an estimate of the 

expected visibility benefit associated with east retrofit. The 

Division will complete this rulemaking by the next scheduled 

plan update in 2013”. EPA indicates that the Regional Haze 

Rule does not allow for commitments to implement strategies 

at some later date that are identified under reasonable 

progress or for the State to make such commitments. In 

This language has been removed and replaced with the following: The Air Quality Administrator 

cannot, per Wyoming Statute 35-11-202, establish emission control requirements except 

through state rule or regulation. Furthermore, the Wyoming statute requires the Administrator 

to consider the character and degree of injury of the emissions involved. In this case, visibility 

modeling would be required to assess the degree of injury caused by the emissions. Modeling is 

not available at this time to determine impacts from emission reduction. The state believes it 

has taken a strong and reasonable first step in identifying potential contributors to visibility 

impairment, and that the next step of creating an appropriate rule or regulation will be 

accomplished in the next SIP revision. The visibility progress was designed as a long-term 

program going out to 2064.
12

Commenter Comment # Section Comment DEQ Response

addition, the control measures identified in the four-factor 

analysis need to be included and made enforceable as part of 

the long-term strategy.

EPA D24

Chapter 8: 

Long-Term 

Strategy

In the SIP DEQ states in section 8.2.6 “Wyoming has ensured 

that all existing emission limitations and control measures, for 

which the state of Wyoming is responsible, used to meet 

reasonable progress goals are enforceable either through the 

WAQSR or SIP measures approved by the EPA”. EPA indicated 

that the State cannot take credit for limitations or control 

measures that are only enforceable at the State level and that 

are not federally enforceable.

This language has been removed from the SIP and replaced with the following: Wyoming has 

ensured that all existing emission limitations and control measures, for which the State of 

Wyoming is responsible, used to meet reasonable progress goals are enforceable at the State 

level through the Wyoming Air Quality Standards and Regulations (WAQSR) or State-issued 

permits. Once EPA approves this SIP, these measures will be federally enforceable. (This 

language was further revised at a later date.)

EPA D25

Chapter 8: 

Long-Term 

Strategy

The controls for Laramie River Station and Jim Bridger need to 

be implemented under BART in this SIP and the 

implementation of controls cannot be postponed until some 

later date under reasonable progress.

This issue has been appealed through the Environmental Quality Council (EQC) and will be 

resolved at the State level through the EQC. The State is still negotiating the details.

PacifiCorp D26 Chapter 6: 

BART

PacifiCorp does not believe it is appropriate for the Division to 

propose the Regional Haze SIP until BART determinations are 

final.

The State has a deadline with EPA for when the SIP must be completed, and therefore the 

BART determinations and the SIP must be done on a parallel path. It was initially expected that 

BART would be finalized first, but the determinations took much longer than expected, 

especially with appeals underway for a number of the BART permits.

PacifiCorp D27

Chapter 8: 

Long-Term 

Strategy

PacifiCorp believes that the Division should exercise more 

flexibility in setting long-term strategy requirements than what 

is currently reflected in specific dates of NOX reductions 

assigned to the four Jim Bridger power plant units. The 

emission rates and timing should be determined by the four or 

five factor tests, which will be undertaken at the time of the 

permit submittal.

This issue has been appealed through the Environmental Quality Council (EQC) and will be 

resolved at the State level through the EQC. The State is still negotiating the details.
13

Commenter Comment # Section Comment DEQ Response

PacifiCorp D28

Chapter 8: 

Long-Term 

Strategy

PacifiCorp believes the term “lowest viable” is not believed to 

be the proper standard to determine NOX reductions, and is 

subject to the varying interpretations in the SIP.

This language has been removed from the SIP.

PacifiCorp D29 Chapter 6: 

BART

Once BART determinations are final, state and federal rules 

require BART controls to be implemented “as expeditiously as 

practicable, but no later than 5 years after approval”. By 

contrast, rules governing the Regional Haze SIP require that a 

long-term strategy include “enforceable emissions limitations, 

compliance schedules and other measures as necessary to 

achieve reasonable progress goals....”. The emission limits and 

timing provisions for the Jim Bridger power plant go beyond 

both of these requirements.

The SIP has been revised to remove the set dates of BART control implementation and 

replaced with “as expeditiously as practicable, but no later than 5 years after approval”.

PacifiCorp D30 Chapter 6: 

BART

PacifiCorp does not believe that tuning existing LNB and OFA 

and installing SCR with an emission limit of 0.07 lb/MMBtu for 

the Naughton Power Plant is BART. PacifiCorp has 

demonstrated that tuning the existing LNB with OFA and an

emission rate of 0.035 lb/MMBtu is BART.

DEQ does not agree. When determining the appropriate BART for each source, the Division 

followed Chapter 6, Section 9 from the Wyoming Air Quality Standards and Regulations 

(WAQSR), as well as EPA’s Subpart Y Guidance. Each source underwent permitting and went 

out for public comment. DEQ responded to each comment. The public hearing for this permit 

occurred on August 4, 2009, in Kemmerer, WY. All comments and responses can be found in 

the TSD, under Chapter 11, Summary of FLM (and Other) Comments on BART and State 

Responses on BART. The permit application and State analysis can be found in Attachment A of 

the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp.

PacifiCorp D31 Chapter 6: 

BART

PacifiCorp disagrees with the conclusion that a NOx removal 

cost of $2,830 per ton is reasonable for the Naughton power 

plant. Appendix Y contemplates a removal cost of $100-$1000 

per ton of NOx removal is reasonable.

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. The public hearing for this permit occurred on August 4, 

2009 in Kemmerer, WY. All comments and responses can be found in the TSD, under Chapter 

11, Summary of FLM (and Other) Comments on BART and State Responses on BART. The 

permit application and State analysis can be found in Attachment A of the SIP at: 

http://deq.state.wy.us/aqd/regionalhaze.asp.
14

Commenter Comment # Section Comment DEQ Response

National Park 

and Fish and 

Wildlife 

Services 

D32 General

Overall, DOI stated that the draft implementation plan was 

well organized, recognizing that Wyoming is committed to 

significant point source emission reductions. DOI was pleased 

with these reductions and recommend the State highlight total 

expected reductions in a summary table.

The State appreciates the fact that DOI recognizes the significance of the reductions made in 

this first SIP. The National Park Service and US Fish and Wildlife have been involved in the 

WRAP process from the beginning and have a good sense of the progress achieved. They also 

understand that not all emission reductions will occur in the first planning period, and that the 

Regional Haze Rules allow for emission reductions out to 2064. 

National Park 

and Fish and 

Wildlife 

Services

D33 General

DOI is concerned that Wyoming relied on the 309 SIP to 

address impacts from sulfur dioxide, pointing out that the 309 

SIP focuses on Class I areas on the Colorado Plateau. 

Wyoming did rely heavily on the 309 SIP to address impacts from sulfur dioxide. The Rule 

allows the State to take credit for SO2 reductions from the 309 program to show progress in 

Wyoming’s Class I areas. The State of Wyoming would not have participated in the 309 

program in the first place if meaningful reductions were not anticipated at the monitors in 

Wyoming Class I areas. Wyoming Class I areas all show improvement with respect to sulfate 

extinction as a result of the 309 program. This improvement has been documented in the 

309(g) SIP (see Table 6.2-2). The Regional Haze Rule allows the State to take credit for the 309 

improvements when addressing 309(g) requirements. 

National Park 

and Fish and 

Wildlife 

Services

D34 Oil and Gas

DOI is concerned about projected increases in NOx emissions 

by 2018 from oil and gas activities. 

The State is also concerned about projected increases in NOx from oil and gas activities. The 

State has been working continuously to develop better estimates of emissions from this sector. 

The WRAP has also been working on a Phase III estimate with the oil and gas industry to better 

characterize the emissions from all of the western gas fields. This information has not been 

completed, but it will be used in future SIP efforts. 

National Park 

and Fish and 

Wildlife 

Services

D35 Chapter 6: 

BART

DOI references previous comments regarding BART 

determinations. 

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on 

BART. The permit application and State analysis can be found in Attachment A of the SIP at: 

http://deq.state.wy.us/aqd/regionalhaze.asp.
15

Commenter Comment # Section Comment DEQ Response

National Park 

and Fish and 

Wildlife 

Services

D36

Chapter 3: 

Pollutants 

Causing 

Visibility 

Impairment

DOI would like the State to include in Chapter 3 a brief 

description of how light extinction and deciviews are 

calculated from IMPROVE measurements instead of putting it 

in Chapter 13 which includes explanatory information on 

IMPROVE monitoring. 

The State will include some additional explanatory information on IMPROVE in Chapter 3 and a 

cross reference for more detail in Chapter 13.

National Park 

and Fish and 

Wildlife 

Services

D37

Chapter 4: 

Statewide 

Emissions 

Inventory

DOI would like the State to clarify in Chapter 4 which 

inventories were used for various modeling exercises, rather 

than sending the reader to the Technical Support Document. 

The DOI is also pointing out that the 2018PRP inventory has 

some uncertainties, especially relating to the oil and gas 

industry, and that perhaps the 2018PRP inventory 

underestimates oil and gas projections. 

The State will include clarifying language in Chapter 4 on which inventories were used for the 

various modeling runs and an explanation for readers who were not involved in the WRAP 

process for why there are multiple inventories and multiple model runs.

The State agrees that there are uncertainties associated with the 2018PRPb inventory, but it 

was the best inventory available at the time of the last model run the WRAP was able to do. 

Furthermore, while it is not perfect, it is a huge improvement over the regional scale emission 

inventories generated at the beginning of the regional haze process. All emission inventories 

have uncertainties, and this very large regional scale inventory is no exception. Oil and gas 

projections for the West are just one area that needs refinement. The western states are 

currently participating in a Phase III oil and gas inventory update and that information was not 

available at the time the last model run required for the SIP (2018PRPb) was completed. Since 

that study has not been completed, the State cannot say at this time whether the Phase III 

estimates will increase or decrease emissions.

National Park 

and Fish and 

Wildlife 

Services

D38

Chapter 5: 

Source 

Apportionment 

and Regional 

Haze Modeling

DOI is simply making comments about differences in results 

between CAMx-PSAT and CMAQ and WEP modeling tools used 

by the WRAP. There is a request for a discussion on how 

relative response factors are calculated. The DOI points out 

that in spite of decreases in sulfates and nitrates, Wyoming 

Class I areas will not achieve the uniform rate of progress. The 

DOI recommends that the State explain that the WRAP model 

results used by all 13 WRAP states do not include final BART 

determinations for most of the states, including Wyoming. 

The State will include in Chapter 5 an explanation for how relative response factors were 

calculated by the WRAP. DOI’s comment on the fact that decreases in nitrate and sulfate 

extinction does not result in achieving the uniform rate of progress is an important one. The 

WRAP states have stressed the fact that the uniform rate of progress is not achieved in any of 

the western states because there are too many uncontrollable sources of emissions impacting 

visibility in the West, overwhelming the controllable sources. The State has pointed out in 

numerous places in this SIP that organic carbon from wildfires is the single biggest contributor 

to visibility impairment. 

The State will include more discussion in Chapter 5 for those that were not involved in the 

WRAP process, pointing out that the modeling results and all of the graphics associated with 
16

Commenter Comment # Section Comment DEQ Response

the modeling results do not include the BART and Long-Term Strategy reductions proposed in

this SIP or any other WRAP SIPs. The WRAP could only include enforceable reductions that 

were on the books at the time of the last model run.

National Park 

and Fish and 

Wildlife 

Services

D39 Chapter 6: 

BART

DOI previously submitted comments on BART during the BART 

permitting process. DOI would like to see the cumulative NOx

reductions from BART at the end of Chapter 6. The question 

was also asked if actual emissions or milestone commitments 

were used in the SO2 2018 inventory, since actuals are lower 

than milestone numbers.

All comments on BART determinations are being addressed through a parallel permitting 

process for BART. All comments and responses can be found in the TSD, under Chapter 11, 

Summary of FLM (and Other) Comments on BART and State Responses on BART.

Cumulative NOx reductions from BART are already included at the end of Chapter 8 showing 

the relative reduction from BART and Long-Term Strategy. A figure showing just BART 

reductions will be included at the end of Chapter 6 as requested.

Since the WRAP does not have “actual emissions” for 2018 since it is in the future, the WRAP 

had to use milestone commitments in the 2018 emission inventories. An explanation will be 

added to the footnotes in Table 6.2-2.

National Park 

and Fish and 

Wildlife 

Services

D40

Chapter 7: 

Reasonable 

Progress 

Goals

DOI again requests explanation in the text in Chapter 7 that 

reasonable progress goals are based on the only modeling 

available and that actual reductions may be greater than those 

modeled.

DOI believes that because Wyoming’s Class I areas do not 

achieve the uniform rate of progress that the reasonable 

progress analysis needs to consider SO2 controls for facilities 

not already addressed in Wyoming’s 309 SIP. That 

participating in the 309 program does not exempt Wyoming 

from considering how emission reductions from 309 and 

potentially additional reductions could protect Class I areas 

not on the Colorado Plateau. DOI wants more information 

from the 309 SIP included in this SIP explaining emission 

reductions expected. Also, DOI would like to see a reference 

to Table 7.2-1.

A sentence has been added to Section 7.5 explaining that results of RPGs listed in Table 7.5-1 

do not include any additional controls beyond WRAP 2018b modeling.

Wyoming’s Class I areas do not achieve the uniform rate of progress, nor do any of the Class I 

areas in the West, but it is not because of SO2 impacts. The regional analysis of impacts on 

Wyoming’s Class I areas show that smoke from wildfires on federal lands is the most important 

factor in the State not achieving the uniform rate of progress. Until we are able to do 

something to control smoke from wildfires, we are not going to be able to achieve the uniform 

rate of progress. The uniform rate of progress is not a very useful tool in assessing success in 

the West in dealing with regional haze.

With respect to considering how emissions reductions from 309 impact Class I areas off the 

Colorado Plateau, Wyoming has been very interested throughout the process. The State of 

Wyoming would not have participated in the 309 program in the first place if meaningful 

reductions were not anticipated at the monitors in Wyoming Class I areas. Wyoming Class I 

areas all show improvement with respect to sulfate extinction as a result of the 309 program. 

This improvement has been documented in the 309(g) SIP (see Table 6.2-2). The Regional Haze 
17

Commenter Comment # Section Comment DEQ Response

Rule allows the State to take credit for the 309 improvements when addressing 309(g) 

requirements. There is nothing in the Regional Haze Rule that says if the uniform rate of 

progress has not been met, that those credits cannot be taken. There is nothing in the 

Regional Haze Rule that says that the State has to meet the uniform rate of progress; it says 

that if the State cannot achieve that rate, it must explain why, and that has been done in 

Chapter 5, Section 5.3.

Answers to all of the questions posed about reductions in SO2 from the 309 program can be 

found in the 309 submittal package to EPA. 

National Park 

and Fish and 

Wildlife 

Services

D41

Chapter 7: 

Reasonable 

Progress 

Goals

DOI describes the process the State used in analyzing sources 

for reasonable progress. They would like to see a reference in 

Chapter 7, Section 7 to where the outcome of the reasonable 

progress analysis is provided. 

Several references to Section 8.3.4 have been added to Chapter 7, Section 7.

National Park 

and Fish and 

Wildlife 

Services

D42

Chapter 8: 

Long-Term 

Strategy

DOI discusses how Wyoming has addressed impacts to Class I 

areas outside of Wyoming and how Wyoming addressed 

impacts from outside the state to the Wyoming Class I areas, 

including emissions from other countries and the shipping 

industry which are the responsibility of EPA. Again, DOI states 

that Wyoming needs to consider what additional controls not 

considered in the 309 SIP are feasible. 

Wyoming’s Class I areas do not achieve the uniform rate of progress, nor do any of the Class I 

areas in the West, but it is not because of SO2 impacts. The regional analysis of impacts on 

Wyoming’s Class I areas show that smoke from wildfires on federal lands is the most important 

factor in the State not achieving the uniform rate of progress. Until we are able to do 

something to control smoke from wildfires, we are not going to be able to achieve the uniform 

rate of progress. The uniform rate of progress is not a very useful tool in assessing success in 

the West in dealing with regional haze.

With respect to considering how emissions reductions from 309 impact Class I areas off the 

Colorado Plateau, Wyoming has been very interested throughout the process. The State of 

Wyoming would not have participated in the 309 program in the first place if meaningful 

reductions were not anticipated at the monitors in Wyoming Class I areas. Wyoming Class I 

areas all show improvement with respect to sulfate extinction as a result of the 309 program. 

This improvement has been documented in the 309(g) SIP (see Table 6.2-2). The Regional Haze 

Rule allows the State to take credit for the 309 improvements when addressing 309(g) 

requirements. There is nothing in the Regional Haze Rule that says if the uniform rate of 

progress has not been met, that those credits cannot be taken. There is nothing in the 
18

Commenter Comment # Section Comment DEQ Response

Regional Haze Rule that says that the State has to meet the uniform rate of progress; it says 

that if the State cannot achieve that rate, it must explain why, and that has been done in 

Chapter 5, Section 5.3.

Answers to all of the questions posed about reductions in SO2 from the 309 program can be 

found in the 309 submittal package to EPA.

National Park 

and Fish and 

Wildlife 

Services

D43

Chapter 8: 

Long-Term 

Strategy

DOI says the oil and gas development and production are 

important sources of NOx. Wyoming should work closely with 

the oil and gas industry to develop better estimates of 

emissions growth. Furthermore, DOI speculates that WRAP 

phase II inventory underestimates NOx emissions for 2018. 

Wyoming is well aware that oil and gas development and production are important sources of 

NOx . The State has been working continuously to develop better estimates of emissions from 

this sector. The WRAP has also been working on a Phase III estimate with the oil and gas 

industry to better characterize the emissions from all of the western gas fields. This 

information has not been completed, but it will be used in future SIP efforts. 

National Park 

and Fish and 

Wildlife 

Services

D44

Chapter 8: 

Long-Term 

Strategy

DOI seems to understand that the State is currently working 

on reductions from the oil and gas industry in response to 

ozone nonattainment issues. They ask that the State ask 

industry to offset emissions prior to regulatory requirements. 

DOI further understands that Wyoming lacks regulatory 

authority to impose additional controls on non-BART sources, 

underscoring that it is important to revisit the control options 

in 2013. 

Wyoming is already implementing an interim policy on emission offsets. As far as we are 

aware, it is the only place in the country where minor sources of oil and gas are being offset. 

National Park 

and Fish and 

Wildlife 

Services

D45

Chapter 8: 

Long-Term 

Strategy

DOI has requested a table to support Figure 8.3.6-7 to help 

understand the magnitude of expected emissions reductions 

from BART implementation and long-term strategy.

Table 8.3.6-7 will be inserted to support Figure 8.3.6-7. (The Division decided at a later date 

not to add this table.)
19

Commenter Comment # Section Comment DEQ Response

US Forest 

Service D46 General

The RH SIP does not appear to address visibility impacts at the 

Savage Run Wilderness Area. Although this Wilderness area is 

not one of the 156 Federal Class I areas, the State of Wyoming 

has determined that it should be managed as a Class I area.

The Regional Haze Rule only requires the State to address impacts at the mandatory Federal 

Class I areas, as stated in 51.308(d): “The State must address regional haze in each mandatory 

Class I Federal area located within the State and in each mandatory Class I Federal area located 

outside the State which may be affected by the emissions from within the State”. Since the 

Savage Run Wilderness area is not one of the 156 mandatory Class I Federal area, it will not be 

evaluated in this SIP.

US Forest 

Service D47 General

Multiple air quality modeling exercises (PRB Coal, Pinedale 

Anticline, and others) identify potential ongoing visibility 

impacts in Class I areas within Wyoming and in adjacent states. 

The FS believes that the results of this modeling could benefit 

Wyoming in designing Reasonable Progress strategies.

Wyoming relied on the modeling performed by WRAP for the development of the Regional 

Haze SIP. It was more logical for the State to use WRAP’s complete air quality model rather 

than piecing together other multiple modeling exercises. The WRAP model allows Western 

States to compare results obtained using identical modeling methodologies. Wyoming does 

not plan on utilizing results obtained from the National Environmental Policy Act (NEPA) 

Environmental Impact Statements (EISs). These documents are to be used as a decision 

making tool, and not an implementation planning and regulation development tool. All 

information contained in EISs is pre-decisional until a draft has been released to the public and 

is not approved until a record of decision is released.

US Forest 

Service D48 Chapters 4 & 

5

Tables 4.2-1 and 4.3-1 show projected decreases in overall 

state SOx and NOx emissions. However, the same tables show 

increases in SOx emissions from area sources and NOx

emissions from area sources and oil and gas sources by 2018. 

The subsequent model results (Figures 5.2.1-1, etc.) show 

increases in SOx impacts from Wyoming on the best and worst 

20% days in all three Wyoming Class I areas. The FS believes 

that increasing Wyoming’s impacts at Class I areas cannot be 

understood to be reducing Wyoming’s “share of the emission 

reductions”.

When the State investigated the cause of the SO2 area source increase, it was found that the 

increase was due to growth factors applied by WRAP in the inventory. Of the 6,300-ton 

increase, 4,800 tons of it came from residual oil burners, and 900 tons from industrial distillate 

oil. Wyoming does not have any of these sources, so the growth factor does not apply and 

these emissions were removed from the calculations. The additional 600-ton increase came 

from commercial coal, industrial processes, and drill rig growth. Wyoming does contain these 

sources, so the 600-ton increase will remain in the calculations. The appropriate tables have 

been updated to reflect these changes.

In terms of the NOx increase, the State is in a difficult position since the Division is hoping to 

combine efforts for ozone and regional haze as a more efficient strategy and ozone is the 

driving force in this process. 

In terms of the oil and gas increase, DEQ agrees that it is important to recognize and regulate 

oil and gas emissions. As outlined in the long-term strategy portion of the SIP, DEQ cannot 
20

Commenter Comment # Section Comment DEQ Response

complete the evaluation of oil and gas on visibility until Phase III of the WRAP study has been 

completed.

US Forest 

Service D49 Figure 5.2.8-3

How can “natural fire” be such a dominant fraction on the 20% 

best days at the BRID monitoring site? The cleanest days at 

Bridger principally occur in the winter when “natural fire” is 

rare compared to residential wood burning for example? 

Figure 5.2.8-3 represents weighted emissions. This means that both emissions totals and the 

probability of it spending time in the given area were modeled. This figure represents that 

Wyoming is the biggest contributor to elemental carbon in the Bridger and Fitzpatrick 

Wilderness area, and that the greatest percentage of elemental carbon is attributed to 

wildfires. The Division is not trying to suggest that elemental carbon is the cause of 

impairment on the 20% best days.

It can be seen from the monitoring graphs: 

http://vista.cira.colostate.edu/TSS/Results/HazePlanning.aspx that while many of the best days 

occur in the winter months, some occur in the summer, which can be seen particularly in 1998. 

On those days, elemental carbon is not one of the largest contributors.

US Forest 

Service D50 Chapter 7

Wyoming’s 309 status does not absolve Wyoming of its 

requirement to perform a reasonable progress analysis for SO2

at Class I areas that are not part of the 16 Colorado Plateau 

Class I areas.

Reasonable progress has been analyzed for Class I areas in Wyoming and surrounding states 

that are not included in the Colorado Plateau boundaries. Table 6.2-2 summarizes the 

modeling results by sulfate extinction. Section 51.308(d) of the Regional Haze Rule states that 

“the reasonable progress goals must provide for an improvement in visibility for the most 

impaired days over the period of the implementation plan and ensure no degradation in 

visibility for the least impaired days over the same period”. It can be seen on the Table that 

visibility in the Class I areas improved on the worst days, and did not have any degradation on 

the best days. In fact, many of the Class I areas showed improvement on the best days, 

thereby exceeding the expectations. The DEQ believes that this demonstration is an adequate 

reasonable progress analysis for SO2 emissions in the Class I areas outside of the Colorado 

Plateau.

US Forest 

Service D51 Chapter 7

Has Wyoming demonstrated that its plan represents greater 

visibility improvements than is expected to result from 

implementation of other requirements of the CAA (40CFR 

51.308(d)(1)(iv))? For example, Table 4.3-1 lists roughly 

24,000 tons per year (TPY) of NOx increase from area and oil 

When the State investigated the cause of the SO2 area source increase, it was found that the 

increase was due to growth factors applied by WRAP in the inventory. Of the 6,300-ton 

increase, 4,800 tons of it came from residual oil burners, and 900 tons from industrial distillate 

oil. Wyoming does not have any of these sources, so the growth factor does not apply and 

these emissions were removed from the calculations. The additional 600-ton increase came 
21

Commenter Comment # Section Comment DEQ Response

and gas sources, 7,000 TPY NOx reductions from BART sources, 

and 50,000 TPY from mobile sources rules which can be 

counted as “other requirements of the CAA”. Excluding 

mobile source emissions, Wyoming has chosen a reasonable 

progress goal that is a net addition of NOx, which represents 

“less visibility improvement...”.

from commercial coal, industrial processes, and drill rig growth. Wyoming does contain these 

sources, so the 600-ton increase will remain in the calculations. The appropriate tables have 

been updated to reflect these changes.

In terms of the NOx increase, the State is in a difficult position since the Division is hoping to 

combine efforts for ozone and regional haze as a more efficient strategy and ozone is the 

driving force in this process. 

In terms of the oil and gas increase, DEQ agrees that it is important to recognize and regulate 

oil and gas emissions. As outlined in the long-term strategy portion of the SIP, DEQ cannot 

complete the evaluation of oil and gas on visibility until Phase III of the WRAP study has been 

completed.

US Forest 

Service D52 Chapter 7

The use of a Q/d screening tool for evaluating reasonable 

progress controls seems reasonable for large stationary 

sources. Is Q/d on unit emissions or facility/project emissions? 

Is it Wyoming’s intent to decrease the Q/d threshold for future 

planning periods, hence allowing more facilities to be 

considered? Does Wyoming DEQ have a list of all considered 

sources (not just Q/d=10) and the corresponding Q/d? If so, 

that list should be included in the SIP. How many additional 

sources would be included if Wyoming applied a Q/d of 9 for 

example?

Wyoming selected Q/d>10 as a screening threshold based on the Federal Land Manager’s 

recommendations. When the State used this threshold it was found that all BART sources 

were captured, and therefore DEQ determined that this was a good place to start. The process 

is performed on unit emissions. The State has not decided that the same screening threshold 

will be used in subsequent planning periods.

The Division performed calculations to determine what percentage of the total NOx emissions 

in the State were captured using a threshold of Q/d equal to 10. This threshold captures nearly 

90% of the total emissions in Wyoming. Reducing the threshold to 5 only captures another 5% 

of the total emissions. Therefore, a Q/d of ten was considered appropriate by the State.

US Forest 

Service D53 Chapter 7

The Q/d analysis does not practically address area sources. 

How will area sources be addressed under reasonable 

progress?

The Q/d analysis addresses all inventoried sources, not just point sources. The analysis uses 

WRAP’s emissions inventory to identify all sources that have a Q/d greater than ten. In 

general, area sources did not meet this criterion which is why they were not identified in the 

analysis. It is important to note that this criterion was used as a starting point for the first 

planning period. The Division will likely look at using a more refined method in future SIP 

revisions, which will in turn capture more sources.
22

Commenter Comment # Section Comment DEQ Response

US Forest 

Service D54 Chapter 7

From the 309(g) Technical Support Document on the Wyoming 

DEQ website, this table lists sources with Q/d>10. Please add 

to this table the identification of which sources were 

controlled, by what technologies, and whether under BART or 

Reasonable Progress.

The table identified by the FS does indicate whether or not the plant is subject to BART (in 

parenthesis under the plant name). If the source is subject to BART, then controls were 

applied. A list of the BART controls for each source can be found in Table 6.4-1 of the SIP. The 

remaining sources were identified under reasonable progress for sources that could be 

controlled as part of the SIP’s long-term strategies. 

US Forest 

Service D55 Section 7.3.3

When citing cost effectiveness value, such as in regard to lowNOx burners with or without overfire air, please reiterate that 

lower values are considered more favorable.

The DEQ believes that the following sentences in Section 7.3.3 imply that lower values are 

more favorable: “While SCR is expected to be far more efficient in controlling NOx emissions 

than LNB or LNB w/OFA, the estimated capital and annual costs are far higher than the costs 

associated with LNB or LNB w/OFA. As shown in Table 7.3.3-1, NOx reductions using LN or LNB 

w/OFA technology are far more cost effective than the SNCR and SCR technologies.”

US Forest 

Service D56 Section 7.3.5 When will the phase II report be available?

WRAP’s Phase II report is already available through the following website: 

http://www.wrapair.org/forums/ogwg/Phases_I_and_II_Inventories.html

According to WRAP’s project schedule: 

http://www.wrapair.org/forums/ogwg/documents/Phase_III_Project_Overview.pdf

The final report for Phase III was scheduled to be released June 2009. The WRAP ran out of 

funding and Wyoming has recently contributed additional dollars to this effort to complete the 

task. The DEQ is hopeful that the report will be finalized in the near future.

US Forest 

Service D57 Section 7.3.5

Table 7.3.5-1 lists 16-36 $/ton for SNCR with 90-99% efficiency 

for compressor engines. Why not require this on all units?

Oil and gas sources were not addressed in this SIP. The DEQ is waiting for the WRAP Phase III 

report before it will begin the rulemaking process to control oil and gas sources. However, 

many compressor engine facilities have already installed control equipment. For lean burn 

engines, oxidation catalysts are commonly installed while SNCR catalysts with AFRC are

commonly installed for rich burn engines.
23

Commenter Comment # Section Comment DEQ Response

US Forest 

Service D58 Section 7.6

Neff, et al. 2008 suggests that roughly 75% of windblown dust 

is attributed to human activity. As such, is it not appropriate 

to use windblown dust as a reason for failure to achieve the 

URP?

Although windblown dust is an uncontrollable activity, the DEQ does not find it appropriate to 

include windblown dust as a reason why the Division’s Reasonable Progress Goals (RPG) are 

lower than the Uniform Rate of Progress (URP). It can be seen on the regional haze 

composition page 

(http://vista.cira.colostate.edu/dev/web/AnnualSummaryDev/Composition.aspx) that the 

Wyoming Class I areas are dominated by organic carbon and sulfate. Fine soil, including 

windblown dust, only makes up between 3-7% of the total composition on the 20% worst days. 

In all monitor locations the fine soil either meets the URP goal or falls just short of achieving it 

(0.1 Mm-1 below).

US Forest 

Service D59 Section 7.6

While it is true that Western Class I areas are cleaner than 

their Eastern counterparts that can make it less difficult to 

show improvements. That is, cleaner air is more sensitive to 

changes in pollution. This is why it is important to consider 

visibility impacts (e.g. $/dv) when determining control 

strategies.

It is true that cleaner air is more sensitive to changes in pollution, and wildfires within the 

Western states have caused Western states to be unable to meet the URP goals. 

EPA’s Appendix Y BART guidance does mention that “dollars per deciview” ($/dv) is a metric 

that could be used to evaluate the cost of BART compliance, but by no means identifies $/dv as 

an essential or required metric. The Division considered capital cost, annual cost, cost 

effectiveness, and incremental cost effectiveness in the cost evaluation of each proposed BART

control option. The Division chose not to use a hybrid metric such as $/dv primarily because of 

the lack of historical precedent regarding reasonable/acceptable levels for such a metric. 

Additionally, the use of a hybrid cost metric such as $/deciview can introduce uncertainty as to 

how the value was calculated. The value of “/deciview” could be based on the highest 

modeled value in a given area or the 98th percentile modeled value. It could be based on the 

98th percentile value for any one modeled year or it could be an average for multiple years. It 

could even be based on an average modeled value across an entire Class I area or the sum of 

deciview changes across multiple areas. The Division has found that $/dv values are often 

presented without explanation of the basis for the calculation. To avoid these confounding 

factors, the Division chose to evaluate and present the cost analyses and visibility analyses

separately.

US Forest 

Service D60 Section 7.6

Section 7.6 lists many reasons why Wyoming considers its RP 

goals to be reasonable, however none appear to be related to 

the four factors in 40 CFR 51.308(d)(1)(i)(A), which are 

The State has provided a four-factor analysis for all qualifying sources. The Division believes 

that it has adequately identified the State’s inability to install the control technology within the 

first planning period under the Time Necessary for Compliance sections. 40 CFR 
24

Commenter Comment # Section Comment DEQ Response

required to be considered in making the determination of RP 

goals below the URP. In absence of the four-factor 

demonstration referred to above, the FS concludes that 

Wyoming’s proposed RP goals are not sufficiently justified.

51.308(d)(1)(i)(A) indicates that the State must “include a demonstration showing how these 

factors were taken into consideration in selecting the goal”. Although the four-factor analysis 

was not outlined as a reason why URP goals could not be achieved, Section 7.5 outlines how 

the results were used to develop the RPGs, satisfying 51.308(d)(1)(i)(A).

US Forest 

Service D61 Chapter 8

While Tables 8.1.2.1-1 and 8.1.2.1-2 do an adequate job of 

demonstrating impacts from Wyoming emissions on 

surrounding States’ Class I areas, documentation of the 

projected impacts from Wyoming emissions on surrounding 

States’ Class I areas in the future is left in the 309(g) Technical 

Support Document. All discussions belong in the SIP as part of 

the RP demonstration.

The DEQ believes that the SIP does an adequate job of demonstrating impacts from Wyoming 

emissions on surrounding states. As participating members of the WRAP, the State has 

ongoing discussions with other states regarding Wyoming’s contributions to out of state Class I 

areas. The Division believes it is appropriate to list these discussions in the Technical Support 

Document.

US Forest 

Service D62 Chapter 8

The comment that impacts from Wyoming emissions are “a 

small portion of out-of-state visibility degradation” is 

subjective and perhaps misleading. The impacts are averaged 

over many days, and the maximum daily contributions could 

be much higher. Projections of future increases in Wyoming 

NOx impacts could significantly increase Wyoming’s share of 

impacts even as surrounding States try to meet their 

reasonable progress goals. Page 130: “By 2018, NOx emissions 

from Wyoming are projected by the WRAP to decrease by 

39,861 tons, which will help reduce Wyoming’s impact to out 

of state Class I areas”. While these emissions should decrease 

impacts on average, localized emissions increases could clearly 

cause some Class I area impacts to increase.

DEQ believes it is appropriate to average impacts over many days, rather than look at each day 

individually. While it is true that episodes may increase the impacts from Wyoming on some 

days, it is also true that on other days the impacts will be much lower. For this reason, an 

average is used to account for the highs and lows. The State’s overall goal is to decrease haze 

causing emissions to a level that allows the achievement of natural visibility conditions by 

2064. A decrease of 39,861 tons of NOx by 2018 will help achieve this goal. Although the 

overall impacts on Class I areas outside of Wyoming should decrease due to this NOx reduction, 

there may be some areas that do not experience as strong of an impact reduction. Growth 

factors have been applied to the WRAP emissions inventory to account for industrial growth. 

Depending on the proximity of out of state Class I areas to areas of growth, there are some 

areas that will experience an increase in NOx emissions. The State has and will comply in the 

future with 40 CFR 51.308(d)((3)(ii): “If the State has participated in a regional planning 

process, the State must ensure it has included all measures needed to achieve its 

apportionment of emission reduction obligations agreed upon through that process”. 

Wyoming’s contribution to other states’ visibility impairment has been addressed with the 

appropriate states. The consultation process can be found in Chapter 11 of the SIP and also 

Chapter 11 of the Technical Support Document (TSD).
25

Commenter Comment # Section Comment DEQ Response

US Forest 

Service D63 Chapter 8

What is the final proposal for RP controls at Laramie Cement 

Plant? What are the actual NOx emissions at Laramie Cement 

Plant? Are they 524 TPY 9 Table 4.1 EC/R report) or 2080 TPY 

(Table 7-1 EC/R general report)?

The four-factor analysis was performed on the Laramie Cement Plant to identify potential 

control devices. Since the State does not have the authority to regulate this source for 

purposes of meeting regional haze goals, a final control device has not yet been proposed. It is 

unfortunate that the EC/R reports are not consistent. However, this report has been finalized 

by EC/R Incorporated. If there is an opportunity for the State to comment at a later date, this 

comment will be included. 

US Forest 

Service D64 Chapter 8

The FS supports the decisions for SCR at the Laramie River and 

Jim Bridger Power Plants.

The DEQ appreciates FS support for the decisions made in the long-term strategy. However,

the Laramie River Station does not require SCR. The facility appealed the BART permit before 

the Environmental Quality Council (EQC), and a settlement was reached. The resulting 

requirement is that the Laramie River Station shall further reduce the NOx emissions from Units 

1, 2, and 3 to a plant-wide emission limit of 12,773 tons of NOx per year by December 31, 2017 

and continuing thereafter, unless this changes pursuant to new regulatory or permit 

requirements. The new Laramie River conditions allow for greater reductions to occur within 

the first regional haze planning period. All reductions for the units will occur by 2017, rather 

than 2023.

US Forest 

Service D65 Section 

8.2.1.6

Manufacturers are supposed to begin producing 

tier/transitional heavy-duty engines in the period 2011-2014 

and tier 4/final engines beginning in 2015. Since these 

changes will occur in the planning period, they should be 

acknowledged in the SIP.

It is true that manufacturers will begin producing tier IV engines and making them available to 

sources. However, there is not a federal or State standard or rule in place that will require 

sources to use these engines. The Regional Haze SIP can only contain enforceable measures, 

and at this time, the use of tier IV engines is not enforceable. Although there are not any 

standards or rules in place that require sources to use tier IV engines, the New Source Review 

(NSR) program requires facilities to analyze the Best Available Control Technology. Therefore, 

if tier IV engines are the best available control technology at the time of permitting, they will 

be captured through the NSR program.

US Forest 

Service D66 Section 

8.2.1.7.2

As of 2007, EPA’s natural events policy of 1996 has been 

superseded by an exceptional events rule under 40 CFR 50.13. 

The rule covers all areas in Wyoming, not just the PRB.

The Division recognizes that EPA’s Natural Events Policy has been superseded by the 

Exceptional Events Rule. Since rule revision is currently being considered by EPA, the State has 

decided to revise this section in the next planning period.
26

Commenter Comment # Section Comment DEQ Response

US Forest 

Service D67 Section 8.3.4

Wyoming states that RP rulemaking will be completed by 

2013. The FS believes that Wyoming has not demonstrated 

that it is meeting its share of emissions reductions for Class I 

areas inside and possibly outside of Wyoming. The WRAP 

commissioned reports with supplementary information for 

“four factor analyses” for a variety of source categories. Many 

of these analyses suggest low cost controls for source 

categories with significant emissions. Why is this information 

not mentioned or incorporated in the current SIP draft (other 

than as addendums in the TSD)?

Section 8.3.4 has been revised, and the commitment to complete rulemaking by 2013 has been 

removed. The WRAP supplementary reports were considered in the SIP. There were two fourfactor analyses documents referenced in the SIP that were prepared by WRAP; one for all 

participating WRAP states and one for only Wyoming. The first document contains all of the 

sources in the participating states that were identified through the four-factor analysis. The 

Wyoming -specific report summarizes the four-factor analyses that were performed on sources 

within Wyoming. There were only two Wyoming sources that were identified under the fourfactor analysis: PacifiCorp Dave Johnston Electric Generating Station, and Mountain Cement 

Company Laramie Plant. The four-factor analysis was included in the SIP in Sections 7.3.3 and 

7.3.4.

US Forest 

Service D68 Chapter 9

FS notes that Wyoming operates IMPROVE protocol samplers 

at Thunder Basin National Grasslands and Cloud Peak 

Wilderness. FS finds this information useful and wishes to 

acknowledge Wyoming’s efforts. The FS also acknowledges 

the support we receive from Wyoming in providing a site 

operator at the North Absaroka IMPROVE site. Wyoming’s 

cooperation in visibility monitoring is greatly appreciated.

DEQ appreciates the acknowledgement of the Division’s visibility monitoring efforts.

US Forest 

Service D69 Section 5.2.9 Should “fine PM” be “fine soil”?

Fine PM was used to include all fine PM sources such as those from industrial sources, not just 

fine soil.

US Forest 

Service D70 Table 7.3.4-1

Are the cost effectiveness values for selective non-catalytic 

reduction with urea and ammonia correct?

This table was developed by EC/R Incorporated. The report includes references for all of the 

values used in the tables: http://deq.state.wy.us/aqd/308%20SIP/ECR%20Four%20Factor%20Analysis%20WY_final050609_Chap.%207.pdf.

US Forest 

Service D71 Table 7.3.4-2 

Column 3

Potential Emission Reduction (1000 tons/yr) should be TPY. TPY is an abbreviation of tons/yr, and carries the same meaning.
27

Commenter Comment # Section Comment DEQ Response

US Forest 

Service D72 Page 167

“In spite of the large number of growing uncontrollable 

sources in the WRAP region, however, Wyoming does not see 

a net visibility improvement at the Wyoming Class I areas 

through 2018.” Should read “uncontrollable sources 

impacting the WRAP region...”

The DEQ cannot find this reference in the revised SIP. Please provide a section number where 

this error can be found.

US Forest 

Service D73 Section 7.3.5

Please correct the typo on the acronym for air-fuel ratio 

controls (AFRC).

This has been corrected in the SIP.

US Forest 

Service D74 Chapter 8

In the last sentence under the Bridger-Fitzpatrick nitrate 

section, please revise the phrase “of at least 39861 tons” to 

“by at least 39,861 tons”.

This wording has been changed in the SIP.

US Forest 

Service

D75 Dispersion 

Modeling

The FS is concerned that visibility impacts may be 

underestimated in the refined modeling, as caused by an 

under-representation of the ozone concentrations. The ozone 

data used in the BART modeling is not believed to be spatially 

or temporally representative of the ozone concentration of 

the plume/puff traveling from any of the BART-eligible 

emission sources near Green River toward the Fitzpatrick and 

Bridger Wilderness areas. The ozone data used in the 

modeling is from 2001 through 2003. The emissions must pass 

through the atmosphere near the Jonah and Wamsutter fields, 

and by 2006 the producing wells increased dramatically, and 

the first ever winter ozone exceedance was experienced. 

Similarly, the spatial distribution of the ozone monitoring sites 

used in the BART modeling analysis is suspect. To remedy this 

issue, the FS is requesting that Wyoming DEQ re-evaluate the 

more recent hourly ozone data to ensure an appropriately 

representative value is used, and rerun the BART dispersion 

modeling analysis.

The AQD believes the background ozone concentrations used in the BART modeling were both 

temporally and spatially representative. The commenter provides two examples relative to 

their claim that the background ozone data are not temporally representative. For one, they 

cite the increase in oil and gas wells producing in Wyoming from the time period used in the 

modeling (2001-03) to 2006. Secondly, they cite the wintertime exceedances of the ozone 

standard that were first measured in Sublette County in 2006. Regarding the first example, the 

Division has calculated annual average ozone concentrations for recent years (2007-2008, and 

part of 2009) from many of the ozone monitoring stations within the modeling domain, 

including Thunder Basin, Jonah, Rocky Mountain National Park, Centennial, and Pinedale. 

Annual average values for these stations ranged from 35 ppb to 49 ppb. The data from the 

seven ozone monitoring stations used in the 2001-03 BART modeling showed a range of annual 

averages of 38 ppb to 55 ppb, which suggests the data used in the modeling is temporally 

representative. Regarding the exceedances of the ozone standard in Sublette County, it is 

important to note that this phenomenon occurs over a very limited geographical area under a 

specific set of meteorological conditions. These ideal conditions occur temporarily during a 

limited number of weeks in the late winter and early spring, if at all during a given year. 

The AQD also believes that the ozone data used for the BART modeling were spatially 

representative. Data from seven ozone monitoring stations located throughout the modeling 
28

Commenter Comment # Section Comment DEQ Response

domain were input to the model (CALPUFF), and the model accounts for background ozone for 

each grid cell on the domain by using data from the nearest monitor.

US Forest 

Service

D76 Natural 

Background 

Concentrations

The DEQ states that “Species concentrations corresponding to 

the 20 percent best days were calculated for each Class I area

by scaling back the annual average concentrations given in 

Table 2-1 of the EPA document Guidance for Estimating 

Natural Visibility Conditions Under the Regional Haze Rule.” 

Additional information is needed to understand and evaluate 

the use of scaling factors as applied to the annual average 

concentrations for calculating background concentrations for 

the 20 percent best days.

Individual species concentrations corresponding to the 20% best days natural background were 

calculated for each Class I area by scaling back the annual average natural background 

concentrations given in Table 2-1 of the EPA document Guidance for Estimating Natural 

Visibility Conditions Under the Regional Haze Rule. The EPA guidance document provides 

annual average values of natural background for individual species, and total deciview values 

for the 20% best days for particular areas, but does not provide values for individual species for 

the 20% best days. Therefore, the Division developed separate scaling factors for each Class I 

area such that, when multiplied by the guidance table annual concentrations for each species, 

the 20% best days concentrations for each species for that particular Class I area could be 

calculated.

The scaling procedure is illustrated here for Bridger WA. From Appendix B in the EPA natural 

visibility guidance document, the total deciview value for the 20% best days at Bridger WA is 

1.96 dv. To obtain the speciated background concentrations representative of the 20% best 

days, the deciview value (1.96 dv) was first converted to light extinction. The relationship 

between deciviews and light extinction is expressed as follows:

dv = 10 ln (bext/10) or bext = 10 exp (dv/10)

where: bext = light extinction expressed in inverse megameters (Mm-1)

Using this relationship with the known deciview value of 1.96, one obtains an equivalent light 

extinction value of 12.17 Mm-1. Next, the annual average natural visibility concentrations 

were set equal to a total extinction value of 12.17 Mm-1. The relationship between total light 

extinction and the individual components of the light extinction is as follows:

bext = (3)f(RH)[ammonium sulfate] + (3)f(RH)[ammonium nitrate] + (0.6)[coarse mass] + 

(4)[organic carbon] + (1)[soil] + (10)[elemental carbon] + bray

where:
29

Commenter Comment # Section Comment DEQ Response

• bracketed quantities represent background concentrations in μg/m3

• values in parenthesis represent scattering efficiencies

• f(RH) is the relative humidity adjustment factor (applied to hygroscopic species 

only)

• bray is light extinction due to Rayleigh scattering (10 Mm-1 used for all Class I 

areas)

Substituting the total light extinction for the 20% best days, the annual average natural 

background concentrations, the average f(RH) for Bridger WA, and including a coefficient for 

scaling, one obtains:

12.17 = (3)(2.1)[0.12]X + (3)(2.1)[0.1]X + (0.6)[3.0]X + (4)[0.47]X + (1)[0.5]X + (10)[0.02]X + 10

In the equation above, X represents a scaling factor needed to convert the annual average 

natural background concentrations to values representative of the 20% best days natural 

background. Solving for X provides a value of 0.376. 

Because of the geographical proximity and similar annual background visibility for the Bridger 

WA and Fitzpatrick WA, the scaled aerosol concentrations for the two areas were averaged. 

US Forest 

Service

D77 FMC Granger 

BART

The FS understands that two BART-eligible units were 

evaluated and deemed exempt from BART based on refined 

dispersion modeling at the FMC Granger plant; two coal-fired 

boilers each equipped with FGD scrubber and EPS controls. 

Given the modeling concerns expressed, the FS cannot concur 

that these units are not subject to BART at this time.

As indicated in the above comments, the DEQ is confident in the modeling approach taken to 

evaluate the FMC Granger BART sources. The State used a 0.5 dv threshold level to exempt a 

source from BART or to deem the modeled impacts as insignificant. The Division is 

comfortable with this threshold level. EPA’s Regional Haze Regulations and Guidelines for Best 

Available Retrofit Technology (BART) Determinations (Appendix Y to 40 CFR part 51), suggest 

that 0.5 dv can represent the level at which a source “contributes” to visibility impairment. 

This is also consistent with the rules which are being applied by most states in the WRAP 

region, including the State of Wyoming (Chapter 6, Section 9), WAQSR. Further, the Division 

believes that the 0.5 deciview threshold is a conservative value given that language in the 

Regional Haze Rule suggests that 1.0 dv is an appropriate perceptibility threshold and recent 

literature suggests that the perceptibility threshold is greater than 1.0 dv (from page 39120 of 

Appendix Y to 40 CFR part 51). 
30

Commenter Comment # Section Comment DEQ Response

US Forest 

Service

D78 FMC 

Westvaco

The FS acknowledges the approach taken by the DEQ for the 

BART determination for the Westvaco facility. However, 

recognizing that BART is one of three components of the 

Regional Haze Rule that the State will use to achieve our 

natural visibility goals, we encourage the DEQ to consider the 

cumulative impacts of several BART-eligible sources in the 

Green River area. The general comments regarding the 

dispersion modeling apply to this facility, and if the impacts 

are underestimated, it would warrant further emission 

reductions. The costs for implementing controls beyond the 

minimum proposed by the DEQ are reasonable. Additional 

controls implemented at this time will help the DEQ move 

closer toward its reasonable progress goals.

As stated in the above responses, the DEQ is confident in the modeling approach taken to 

estimate impacts from BART sources, and does not believe the impacts to be underestimated. 

The DEQ does not agree that facilities identified by the FS should be grouped together, and 

cumulative impacts considered. Summing the 98th percentile modeled visibility impacts for 

separate facilities is not an accurate portrayal of combined impacts because the individual 

impacts may occur at different locations (receptors) and during different 24-hour time periods. 

Moreover, the visibility impacts from BART-eligible sources are to be determined separately. 

As stated in the EPA’s Appendix Y to part 40 CFR 51 - Guidelines for BART Determinations 

Under the Regional Haze Rule, relative to the use of the CALPUFF model for BART 

determinations, “We believe that CALPUFF is an appropriate application for States to use for 

the particular purposes of this rule, to determine if an individual source is reasonably 

anticipated to cause or contribute to impairment of visibility in Class I areas, and to predict the 

degree of visibility improvement which could reasonably be anticipated to result from the use 

of retrofit technology at an individual source. We encourage States to use it for these 

purposes.”

US Forest 

Service

D79

FMC

Westvaco: 

SO2 Controls

The SO2 controls identified for the two coal-fired boilers are 

limited to two options for increasing the amount of gas-routed 

exhaust through the wet scrubber. The EPA BART rule 

identifies several other wet scrubber upgrade options such as: 

installation of liquid distribution rings, installation of 

perforated trays, use of organic acid additives, improve or 

upgrade scrubber auxiliary system equipment, and redesign 

spray header of nozzle configuration. Each of these options 

should be considered in the BART analysis. 

Wyoming is a §309 state and will participate in the Western Backstop Sulfur Dioxide Trading 

Program, should it be triggered. §308(e)(2) provides States with the option to implement or 

require participation in an emissions trading program or other alternative measure rather than 

requiring sources subject to BART to install, operate, and maintain additional control 

technology to meet an established emission limit. In their BART application, FMC presented 

information relative to several preferred options for SO2 control. Consideration of an 

exhaustive list of SO2 control methods would be immaterial given Wyoming’s status as a §309

state.
31

Commenter Comment # Section Comment DEQ Response

US Forest 

Service

D80

FMC

Westvaco: 

Visibility 

Modeling

It would be helpful if the modeling results were presented for 

a combination of LNB/OFA/SNCR (NOx) and scrubber upgrades, 

both with and without a new bypass (SO2).

Visibility modeling was conducted for six control options, including LNB/OFA/SNCR with 

baseline SO2, and baseline NOx with scrubber upgrades/new bypass. The 98th percentile 

results for all of the control scenarios for each of the two FMC Westvaco boilers were less than 

the 0.5 dv threshold used to deem modeled impacts as insignificant, and provided the AQD 

adequate information to determine BART relative to the fifth statutory factor (visibility 

improvement).

US Forest 

Service

D81 FMC Westvaco: 

BART 

Determination

The BART determination is based upon considerations of the 

model-predicted change in deciviews compared to baseline 

conditions. EPA states in the preamble of its BART Guideline 

that “Even though visibility improvements from an individual 

source may not be perceptible, it should still be considered in 

setting BART because the contribution to haze may be 

significant relative to other source contribution in the Class I 

areas.” Given the proximity of the two boilers, the combined 

effect of requiring more stringent controls, such as LNB/OFA 

with SNCR, will likely allow the State to reach its reasonable 

progress goals.

The AQD determined the visibility impacts from BART-eligible sources separately. As stated in 

the EPA’s Appendix Y to part 40 CFR 51 - Guidelines for BART Determinations Under the 

Regional Haze Rule, relative to the use of the CALPUFF model for BART determinations, “We 

believe that CALPUFF is an appropriate application for States to use for the particular purposes 

of this rule, to determine if an individual source is reasonably anticipated to cause or 

contribute to impairment of visibility in Class I areas, and to predict the degree of visibility 

improvement which could reasonably be anticipated to result from the use of retrofit 

technology at an individual source. We encourage States to use it for these purposes.”

US Forest 

Service

D82

General 

Chemical 

Green River 

Works: 

Effectiveness 

of Control 

Technologies: 

NOx

In its preamble to its BART Guidelines, EPA states “ Many 

control techniques....can perform at a wide range of levels...It 

is important however, that in analyzing the technology, you 

take into account the most stringent emission control level 

that the technology is capable of achieving”. The FS states 

what DEQ identified as achievable NOx control limits, and what 

can be achieved by other facilities with the same controls. The 

FS believes that the DEQ should analyze more stringent 

control levels. The use of lower than best available control 

technologies results in lower model-predicted reductions in 

haze, and therefore potentially affects the determinations of 

BART.

The initial BART determination for the two boilers at the Green River Works called for LNB with 

existing OFA systems and a NOx emission limit of 0.32 lb/MMBtu. Based on new engineering

information that indicated the emission limit of 0.32 lb/MMBtu would not be achievable using 

LNB with existing OFA systems, General Chemical has applied for a revised BART permit that 

would include LNB with new separated overfire air (SOFA) and NOx emission limits of 0.28 

lb/MMBtu. The NOx emission limit of 0.28 lb/MMBtu would represent emissions reductions of 

more than 40% as compared to baseline.

The control efficiencies and emissions used by the AQD for the BART modeling resulted in 

predicted visibility impacts below 0.5 Δdv for all of the control options. The use of even lower 

emission rates would not have changed the AQD’s BART determination relative to the modeled 

visibility impacts. 
32

Commenter Comment # Section Comment DEQ Response

US Forest 

Service

D83

General 

Chemical 

Green River 

Works: Costs

The costs for applying each control technology in the Green 

River Works plant are higher than typical cost ranges.

Costs presented by the BART applicant, as described in the BART application document, were 

developed using budgetary quotes from equipment vendors and methods from the EPA’s 

Control Cost Manual. All costs were scrutinized by AQD permit engineers as part of the permit 

application review process, and the AQD believes the presented costs were reasonable.

US Forest 

Service

D84

General 

Chemical 

Green River 

Works: 

Western 

Backstop 

Sulfur Dioxide 

Trading 

Program

The DEQ has stated that “General Chemical will not be 

required to meet either proposed emission limit under BART. 

Instead, General Chemical will be required to participate in the 

emissions trading program under Chapter 14 of the WAQSR 

should the program be triggered”. The FS requests additional 

information to support that greater reasonable progress will 

be in the Fitzpatrick and Bridger Wilderness Areas through the 

milestones program.

The Division has demonstrated the superiority of the 309 program in the Demonstration that 

the SO2 Milestones Provide Greater Reasonable Progress than BART document in Appendix E. 

In this demonstration, the State not only verifies that the program meets or exceeds 

presumptive SO2 BART levels, but also provides other benefits of implementing the milestone 

program. One of these benefits includes limiting new source growth for SO2 emissions in the 

participating states. In addition, the program includes every source that emits 100 tons per 

year or greater of SO2, and therefore targets a greater number of sources than what would be 

identified in the BART program. Table 6.2.2 of the SIP demonstrates visibility improvement on 

the worst days and no degradation of visibility, and in many cases improvement, on the best 

days for all Wyoming Class I areas and Class I areas in surrounding states. The DEQ believes 

that the better than BART determination is adequate and the BART-eligible sources are not 

required to achieve the limits established under BART.

US Forest 

Service

D85 General

Upon review of the five statutory factors, the FS believes that 

selective catalytic reduction (SCR) should be BART for nitrogen 

oxides (NOx) for all units in both the Jim Bridger and Naughton 

power plants. The FS applauds the State of Wyoming for 

proposing to install SCR at the four units at the Jim Bridger 

EGU, but believes the installation timeframe should be within 

2015-2016 timeframe for all four units at the facility.

The Division determined BART for NOx control at the Jim Bridger and Naughton power plants 

based on consideration of all five statutory BART factors, as required by EPA’s Appendix Y BART 

guidance. No single factor was weighted as being more important than another, because the 

Division looked at all five statutory factors in their entirety. The BART determination for NOx

control on all four units at Jim Bridger included low NOx burners (LNB) with overfire air (OFA). 

The BART determinations for NOx control at Naughton included LNB/OFA on Units 1 and 2 and 

SCR on Unit 3. The Division’s BART analyses provide the basis for the BART determination for 

both plants.

Regarding the installation of additional control equipment at the Jim Bridger plant, PacifiCorp is 

required by the BART permit to install SCR on Jim Bridger Unit 3 in 2015 and Jim Bridger Unit 4 

in 2016 as well as add-on NOx control on Units 1 and 2 no later than 2023. The schedule for 

installation is based on the incorporation of SCR add-on control on these units under the longterm strategy component of Wyoming’s SIP for regional haze as well as PacifiCorp’s 
33

Commenter Comment # Section Comment DEQ Response

construction plan for pollution control projects. The schedule for the installation of SCR 

controls at other plants is uncertain at this point due to the demands on PacifiCorp for 

compliance with BART and other regulatory programs. PacifiCorp operates 19 coal-fired units, 

14 of which are BART-eligible. Additional BART-eligible units are owned or partly owned in 

Arizona, Colorado, and Montana. 

The BART permits for the Jim Bridger plant are currently under appeal with the Environmental 

Quality Council.

US Forest 

Service

D86

BART: Jim 

Bridger and 

Naughton

The FS commends PacifiCorp and Wyoming DEQ for the strong 

NOx controls proposed for BART and reasonable progress. The 

FS believes the proposed controls will significantly improve air 

quality in the many Class I areas surrounding the facilities. 

While the FS does not agree with every conclusion, the BART 

documents are thorough and well written.

DEQ appreciates the FS recognition of the air quality improvements that will occur due to the 

BART controls.

US Forest 

Service

D87

BART: Jim 

Bridger and 

Naughton

The FS believes that the cost of each BART alternative should 

be divided by the sum of the deciviews improvement at all 

impacted Class I areas to determine the cost per deciviews. 

This may results in acceptance of previously discarded control 

alternatives due to the showing of reasonable cost of visibility 

improvement.

EPA’s Appendix Y BART guidance does mention that “dollars per deciview” ($/dv) is a metric 

that could be used to evaluate the cost of BART compliance, but by no means identifies $/dv as 

an essential or required metric. The Division considered capital cost, annual cost, cost 

effectiveness, and incremental cost effectiveness in the cost evaluation of each proposed BART 

control option. The Division chose not to use a hybrid metric such as $/dv primarily because of 

the lack of historical precedent regarding reasonable/acceptable levels for such a metric. 

Additionally, the use of a hybrid cost metric such as $/deciview can introduce uncertainty as to 

how the value was calculated. The value of “/deciview” could be based on the highest 

modeled value in a given area or the 98th percentile modeled value. It could be based on the 

98th percentile value for any one modeled year or it could be an average for multiple years. It 

could even be based on an average modeled value across an entire Class I area or the sum of 

deciview changes across multiple areas. The Division has found that $/dv values are often 

presented without explanation of the basis for the calculation. To avoid these confounding 

factors, the Division chose to evaluate and present the cost analyses and visibility analyses

separately.
34

Commenter Comment # Section Comment DEQ Response

US Forest 

Service

D88

BART: Jim 

Bridger and 

Naughton

The FS would like to see visibility modeling for all Class I areas 

within 300 km. If any modeling already exists that shows 

visibility improvement benefits greater than 0.5 dv beyond 

300 km, the FS requests that information be included as well.

Only those Class I areas most likely to be impacted by sources subject to BART at a given facility 

were modeled, as determined by source/Class I area locations, distances to each Class I area, 

and professional judgment considering meteorological and terrain factors. The Division 

recognizes that more distant Class I areas may yield modeled impacts of some magnitude, but 

the Division is also satisfied that Class I areas at a greater distance and in directions of less 

frequent plume transport would not yield modeled impacts greater than those yielded by the 

Class I areas chosen for BART modeling. The modeling results for the Class I areas chosen for 

analysis allowed the Division to make an informed decision on the effect on visibility from the 

various BART control options. Additionally, EPA’s Appendix Y BART guidance does not include 

any requirements for modeling distance.

US Forest 

Service

D89

BART: Jim 

Bridger and 

Naughton

The State of Wyoming has determined that the Savage Run 

Wilderness Area will be managed as a Class I airshed. 

Therefore, the FS would like Savage Run Wilderness Area to be 

treated as such in all Regional Haze planning including this 

BART review.

EPA’s Regional Haze Rule affects sources that may cause or contribute to visibility impairment 

at any mandatory, federal Class I area. Because Savage Run is a State-designated Class I area, 

the Division was not required to include it in the BART modeling. Additionally, the Division did 

not include Savage Run in any of its analyses for the State’s Regional Haze Visibility SIP. For 

BART, the Division did model the impacts at several mandatory Class I areas that are located in 

the same general plume transport direction downwind of Savage Run, including Mt. Zirkel 

Wilderness, Rawah Wilderness, and Rocky Mountain National Park. Based on the modeling 

results for these Class I areas in the proximity of Savage Run, the Division anticipates similar 

improvements in visibility from the analyzed emission reductions.

US Forest 

Service

D90

BART: Jim 

Bridger and 

Naughton

Pages E2-5 and 5-10 of the PacifiCorp BART analysis discuss 

“Just-noticeable difference in atmospheric haze” indicating 

that minimal, if any observable visibility improvements at the 

Class I areas would be expected under any of the control 

scenarios. It is incorrect to dismiss a control strategy on the 

basis that the resulting improvement is not perceptible or 

significant.

The Division used 0.5 dv as the threshold level to exempt a source from BART or to deem 

modeled impacts as insignificant. EPA’s Regional Haze Regulations and Guidelines for Best 

Available Retrofit Technology (BART) Determinations (Appendix Y to 40 CFR part 51), suggest 

that 0.5 dv can represent the level at which a source “contributes” to visibility impairment. 

This is also consistent with the rules which are being applied by most states in the Western 

Regional Air Partnership (WRAP) region.

US Forest 

Service

D91

BART: Jim 

Bridger and 

Naughton

EPA’s view of presumptive limits for SO2 and NOx for EGUs are 

that they are “highly cost effective”. So although the 

presumptive requirements are “extremely likely to be 

Although the BART emission limits for NOx for Naughton Units 1 and 2 exceed the presumptive 

BART limit for tangential-fired boilers burning subbituminous coal, PacifiCorp’s analysis of coal 

composition was not a factor in the Division’s determination. The Division established NOx
35

Commenter Comment # Section Comment DEQ Response

appropriate” the State can demonstrate otherwise based on 

the five statutory factors. The FS believes that the analysis of 

coal composition is not only flawed in its conclusions, more 

principally, it does not meet the requirement for a 

demonstration of why presumptive limits cannot be reached.

emission limits for BART at the Naughton plant based on consideration of all five statutory 

factors, as required by EPA’s Appendix Y BART guidance. The Division interpreted the 

presumptive emission levels for NOx and SO2 as recommended control levels proposed by EPA 

after reviewing technical data related to BART. Requiring sources to meet presumptive 

emission levels was not required as one of the five statutory factors. Conversely, the Division 

did not automatically determine emission levels below presumptive levels to be BART, but 

considered all five statutory factors before making a BART determination.

US Forest 

Service

D92

BART: Jim 

Bridger and 

Naughton

The FS believes that SCR is BART for all units at Jim Bridger and 

Naughton power plants.

The Division determined BART for NOx control at the Jim Bridger and Naughton power plants 

based on consideration of all five statutory BART factors, as required by EPA’s Appendix Y BART 

guidance. No single factor was weighted as being more important than another, because the 

Division looked at all five statutory factors in their entirety. The BART determination for NOx

control on all four units at Jim Bridger included low NOx burners (LNB) with overfire air (OFA). 

The BART determinations for NOx control at Naughton included LNB/OFA on Units 1 and 2 and 

SCR on Unit 3. The Division’s BART analyses provide the basis for the BART determination for 

both plants.

Regarding the installation of additional control equipment at the Jim Bridger plant, PacifiCorp is 

required by the BART permit to install SCR on Jim Bridger Unit 3 in 2015 and Jim Bridger Unit 4 

in 2016 as well as add-on NOx control on Units 1 and 2 no later than 2023. The schedule for 

installation is based on the incorporation of SCR add-on control on these units under the longterm strategy component of Wyoming’s SIP for regional haze as well as PacifiCorp’s 

construction plan for pollution control projects. The schedule for the installation of SCR 

controls at other plants is uncertain at this point due to the demands on PacifiCorp for 

compliance with BART and other regulatory programs. PacifiCorp operates 19 coal-fired units, 

14 of which are BART-eligible. Additional BART-eligible units are owned or partly owned in 

Arizona, Colorado, and Montana. 

The BART permits for the Jim Bridger plant are currently under appeal with the Environmental 

Quality Council.
36

Commenter Comment # Section Comment DEQ Response

US Forest 

Service

D93

BART: Jim 

Bridger and 

Naughton

Greater SCR efficiencies that can be achieved by modern NOx 

control systems should be factored into the cost and visibility 

analyses.

The Division conducted a search of the EPA RACT/BACT/LAER Clearinghouse (RBLC) to find NOx

emission limits as BACT associated with SCR control in recently issued permits. Two plants 

have limits of 0.05 lb/MMBtu NOx with a 12-month rolling average, which is significantly longer 

than a 30-day averaging period. Because the 0.05 lb/MMBtu limits are based on a 12-month 

averaging period, they are not comparable to the 30-day limits established by the Division. The 

two plants with 30-day averaging periods will be subjected to either a 0.08 lb/MMBtu or 0.07 

lb/MMBtu limit, and the limits established by the Division meet these lower limits. A 

spreadsheet compiled by the National Park Service with a summary of nationwide BART 

determinations shows that both units outside of Wyoming for which SCR is proposed as BART 

will be subject to a NOx emission limit of 0.07 lb/MMBtu, and both will be based on a 30-day 

averaging period.

The RBLC search showed two plants that will be subject to 24-hour NOx limits of less than 0.07 

lb/MMBtu (0.067 lb/MMBtu), but these limits are for newly constructed plants which have 

been engineered to meet these levels. BART will require the retrofit of significant controls at 

plants that were not designed to meet these lower levels. Based on the Division’s evaluation, 

the Division is satisfied that the NOx emission limit of 0.07 lb/MMBtu (30-day rolling average) 

that was evaluated for SCR control under BART is the most stringent control level likely to be 

achieved in a retrofit.

US Forest 

Service

D94

BART: Jim 

Bridger and 

Naughton

The FS requests clarification as to why units 1 & 2 at the 

Naughton Power plant are not required to install SCR as part 

of reasonable progress like the other five units.

Based on the cost of compliance and visibility improvement presented by PacifiCorp in the 

BART applications for Naughton Units 1 and 2 and taking into consideration the logistical 

challenge of managing multiple pollution control installations within the regulatory time 

allotted for installation of BART by the Regional Haze Rule, the Division did not require 

additional controls under the Long-Term Strategy for this SIP. These two units are the smallest 

of PacifiCorp’s units, and since the Division had to prioritize target emission reduction sources, 

these two units were left to the next planning period. The State is committed to analyzing 

additional controls for Naughton Units 1 and 2 in the next planning period.

US Forest 

Service

D95

BART: Jim 

Bridger and 

Naughton

The FS believes that the already-permitted installation of wet 

FGD equipment of the Jim Bridger Power Plant units 1-4 

should be considered BART. Similarly, the FS believes that the 

WFGD upgrades have already been (or are scheduled to be) installed on all units at the Jim 

Bridger plant. For the Naughton plant, WFGD is scheduled to be installed on Units 1 and 2 and 

WFGD is scheduled to be upgraded for Unit 3. BART limits for SO2 will not be set because 
37

Commenter Comment # Section Comment DEQ Response

installation of wet FGD equipment for the Naughton Power 

Plant units 1-3 should be considered BART.

Wyoming is a §309 state participating in the Regional SO2 Milestone and Backstop Trading 

Program. §308(e)(2) provides states within the Transport Region addressed by the Grand 

Canyon Visibility Transport Commission with the option to implement or require participation 

in an emissions trading program or other alternative measure rather than to require sources 

subject to BART to install, operate, and maintain additional control technology to meet an 

established emission limit on a continuous basis.

US Forest 

Service

D96

BART: Jim 

Bridger and 

Naughton

There appears to be an error in the analysis for unit 3 at 

Naughton. The performance of the wet FGD was stated to be 

0.10 lb/MMBtu (Table 18) but the cost effectiveness analysis is 

based on 0.15 lb/MMBtu (Table 24).

The application of wet FGD on Unit 3 is anticipated to lower SO2 emissions to 0.10 lb/MMBtu,

based on an average coal sulfur content of 0.58% by weight, and to 0.15 lb/MMBtu, based on 

an average coal sulfur content of 1.02% by weight. Because both low sulfur and high sulfur 

coals are used to fuel the boilers at Naughton, 0.15 lb/MMBtu was used as the basis for cost 

effectiveness. The cost effectiveness is not relevant because BART limits for SO2 will not be set. 

Wyoming is a §309 state participating in the Regional SO2 Milestone and Backstop Trading 

Program. §308(e)(2) provides states with the option to implement or require participation in 

an emissions trading program or other alternative measure rather than to require sources 

subject to BART to install, operate, and maintain additional control technology to meet an 

established emission limit on a continuous basis.

US Forest 

Service

D97

BART: Jim 

Bridger and 

Naughton

The FS would like to know if the controls in place at the 

Naughton and Jim Bridger Power Plants are at least equivalent 

to the control scenario used in the demonstration report.

The State of Wyoming submitted a 309 SIP as is allowed by the Regional Haze Rule. The 

demonstration is regional, and a unit-by-unit analysis is not required. It is not required by the 

Regional Haze Rule that the State perform source-specific BART analyses to determine that the 

309 program has achieved better than BART reductions. EPA clearly explains the intent for the 

Rule in the Federal Register, Volume 71, No. 198, Dated October 13, 2006 / Rules and 

Regulations, in the second paragraph on page 60615: “As discussed in more detail below, 

today’s rule also makes clear that where a trading program or other similar alternative 

program has been designed primarily to meet a Federal or State requirement other than BART, 

the State can use a more simplified approach to demonstrating that the alternative program 

will make greater reasonable progress than BART.” The following statement is also made in 

the same Federal Register on page 60618, middle column, second paragraph: “The regulations 

finalized today therefore provide that where an emissions trading program has been designed 
38

Commenter Comment # Section Comment DEQ Response

to meet a requirement other than BART, including the reasonable progress requirement, the 

State may establish a BART benchmark based on an analysis that includes simplifying 

assumptions about BART control levels for sources within a source category.” 

US Forest 

Service

D98

BART: Jim 

Bridger and 

Naughton

The FS notes that the 309 program sunsets in 2018, and that 

additional SO2 controls may be appropriate for reasonable 

progress at that time.

The Division is aware that the 309 program only establishes milestones through 2018, and that 

following 2018 another strategy may be necessary to reduce visibility-impairing pollutants. 

Additional strategies will be addressed in future SIP revisions.

US Forest 

Service

D99

BART: Jim 

Bridger and 

Naughton

US EPA BART guidelines state that 0.5 dv “contributes” to 

impairment, and 1.0 dv “causes” impairment. The discussion 

from Ronald Henry is irreverent and used in an improper 

context.

The Division did not attempt to endorse a particular threshold for human eye “perceptibility” 

since the level of perceptibility has long been disputed. Instead, the Division has relied on 

EPA’s Appendix Y BART guidance, which suggests a value of 0.5 dv as the level that a source 

“contributes” to visibility impairment. One of the metrics used by the Division to evaluate the 

relative benefit of a given BART control option was the number of days yielding a modeled 

impact of 0.5 dv or more.

E. Analysis of 309(g) Comments Received in Response to the December 8, 2010 Public Hearing

Commenter Comment # Section Comment DEQ Response

Powder River 

Basin 

Resource 

Council

E1

Better than 

BART 

Demonstration

DEQ continues to fail to adequately demonstrate that the 

backstop trading program is “better than BART”. DEQ cannot 

rely upon the high level WRAP analysis in place of a unit-by-unit 

specific BART analysis. DEQ’s reliance on the WRAP “Better than 

BART” determination is undercut by actions in states across the 

region that are implementing BART limits that are stronger than 

the SO2 limits at power plants in Wyoming. While BACT may not 

necessarily equate to BART, the limits imposed at these new 

plants demonstrate that a thorough BART analysis is needed in 

light of improved technology efficiencies and costs.

The Regional Haze rule does not require that the State perform a unit-by-unit specific BART 

analysis to demonstrate that the Backstop Trading Program is “Better than BART”. EPA clearly 

explains the intent for the Rule in the Federal Register, Volume 71, No. 198, Dated October 13,

2006 / Rules and Regulations, in the second paragraph on page 60615: “As discussed in more 

detail below, today’s rule also makes clear that where a trading program or other similar 

alternative program has been designed primarily to meet a Federal or State requirement other 

than BART, the State can use a more simplified approach to demonstrating that the alternative 

program will make greater reasonable progress than BART.” The following statement is also 

made in the same Federal Register on page 60618, middle column, second paragraph: “The 

regulations finalized today therefore provide that where an emissions trading program has 

been designed to meet a requirement other than BART, including the reasonable progress 
39

Commenter Comment # Section Comment DEQ Response

requirement, the State may establish a BART benchmark based on an analysis that includes 

simplifying assumptions about BART control levels for sources within a source category.”

Therefore, DEQ believes that the State’s “Better than BART” determination is adequate. As 

demonstrated, EPA does not require the analysis to be performed on a unit-by-unit basis. 

Since the procedure for making the “Better than BART” determination meets EPA’s 

requirements, DEQ does not believe that a thorough BART analysis needs to be performed in 

light of improved technology efficiencies and costs.

Powder River 

Basin 

Resource 

Council

E2 General

All of Wyoming’s Class I areas (and Class I areas in South Dakota 

that are impacted by Wyoming sources) are off of the Colorado 

Plateau. Therefore, these are additional Class I areas that must 

be addressed through the 309(g) plan. DEQ must fully discuss 

these Class I areas and establish enforceable goals.

The Division believes that the additional Class I areas that are located outside the Colorado 

Plateau are appropriately addressed in the 309 SIP. The State has modeled visibility in the 

additional non-plateau Class I area monitor locations. Table 6.2-2, demonstrates visibility in 

Wyoming and surrounding states broken down by sulfate extinction only. It can be seen in this 

table that all Class I areas show visibility improvement for the worst days, and no degradation 

in visibility for the best days, thereby meeting the requirements outlined in the Regional Haze 

Rule. In addition, Table 6.2-1 outlines the Regional SO2 Emissions and Milestone Report 

summary. This table demonstrates that the 309 states have had significant SO2 reduction and 

have more than exceeded the goals set by the program.

The Regional Haze Rule requires that the above demonstration is necessary, as well as a 

demonstration that the milestones provide greater reasonable progress than BART. This 

demonstration can be found in Appendix E, Demonstration that the SO2 Milestones Provide 

Greater Reasonable Progress than BART. As long as this demonstration is performed, under 

the Regional Haze Rule, EPA allows the State to take credit for any SO2 reduction achieved in 

Section 309, as stated in 51.309(g)(i): “In developing long term strategies pursuant to 

51.308(d)(3), the state may build upon the strategies implemented under paragraph 9(d) of this 

section, and take full credit for the visibility improvement achieved through these strategies.” 

However, if the URP goal is not met, the Rule does not require SO2 sources to undergo further 

reduction in order to meet this goal. If the URP goal cannot be met for a given planning 

period, it is the requirement that the State demonstrate why this goal cannot be met, which 

the State believes it has done throughout the SIP.

Therefore, the State believes that the additional Class I areas are appropriately addressed in 

the 309 SIP, and it is not necessary to further discuss SO2 enforceable goals in the 309(g) SIP.
40

Commenter Comment # Section Comment DEQ Response

Powder River 

Basin 

Resource 

Council

E3

Modeling, 

Monitoring 

and Emission 

Inventories

DEQ must fully document the technical basis for the SIP, 

including monitoring data, modeling, and emission information, 

including the baseline inventory upon which its strategies are 

based. Additionally, the SIP should consider “major and minor 

stationary sources, mobile sources and area sources”. 

Wyoming’s SIP is deficient because it does not properly account 

for all relevant emission sources or use available monitoring and 

modeling information.

The regional haze emissions inventory for all Western states was compiled by WRAP. The 

inventory data used for this SIP was pulled from WRAP’s Emissions Data Management System 

(EDMS) warehouse. This warehouse facilitates regional emission data collection using a 

consistent and comparable approach between states. The emissions source categories 

contained in this warehouse are point/stationary, area non-point, on road mobile, off road 

mobile, fires, windblown dust, and biogenic. The following website contains a description of 

EDMS, as well as an inventory description, including the inventory compiled for this SIP: 

http://www.wrapedms.org/. Emission inventory summaries can be found in Tables 4.2-1 

through 4.9-1. 

The modeling that was used for Wyoming’s SIP as well as all other Western states, was 

performed by WRAP. This is a complete model that allows Western states to compare results 

that were obtained using identical methodologies. The Division believes that it is appropriate 

to use only these modeling results.

Monitoring results were obtained from the IMPROVE sites identified in Chapter 2. These are 

EPA-approved monitors that are recognized by all state and federal authorities.

The compiled emissions inventories, as well as modeling and monitoring data can be found in 

the Technical Support Document, as well as on the following website (which is referenced 

heavily in the Technical Support Document): 

http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx.

Powder River 

Basin 

Resource 

Council

E4 Oil and Gas 

Emissions

The draft SIP explains that DEQ cannot include a full inventory of 

oil and gas related emissions because the modeling and 

monitoring has not been completed. DEQ ignores a wealth of 

information about oil and gas related emissions that can easily 

be integrated into the regional haze plan. DEQ has obtained 

substantial funding through Abandoned Mine Lands funding o 

undertake modeling and monitoring efforts of air quality in 

energy impacted areas. There is also significant information 

available from the BLM Environmental Impact Statements for oil 

and gas development. Finally, DEQ should have a wealth of 

information on facilities that are operated under Title V permits.

DEQ is aware that there is an abundance of oil and gas related information. However, there is 

not a clean inventory available that contains information compiled using a systematic method. 

WRAP is working on such an inventory right now in Phase III of its project. DEQ is awaiting this 

inventory, not modeling and monitoring results.

Oil and gas inventories are complicated to quantify. It is true that the DEQ has access to Title V 

emissions data, but this is a very small fraction of the total emissions. To compile a complete 

inventory, every source must be looked at right down to the wellhead level. This includes the 

emissions associated with drilling and completing each well, which in itself is very complex. To 

name a few, the drilling and completion process alone has emissions associated with trucking 
41

Commenter Comment # Section Comment DEQ Response

trips for various fluids and pieces of equipment, drill rigs, completion rigs, wirelines, and 

fraccing equipment. Each well has different emissions associated with each activity. After the 

well is drilled and completed, the production process begins and there will be emissions 

associated with various pieces of production equipment such as tanks, flares, dehy units, 

compressor stations, fluid trucking, and pipeline losses. To account for all of these emissions, 

some of the things that must be known are how many pieces of production equipment are in 

the state, what types of controls each unit has, and how much oil and gas is being produced 

from each facility. These are only some examples of the complexity of an inventory 

development for oil and gas sources. A complete inventory will have to look at many more 

aspects than what was just outlined.

The BLM Environmental Impact Statements are to be used by the BLM as a decision making 

tool, not an implementation planning and regulation development tool. In addition, all 

information is pre-decisional until a draft document has been released to the public and is not 

approved until a Record of Decision is released.

The State of Wyoming is making great strides for identifying and quantifying sources and 

emissions from new fields. However, it is much more difficult to quantify emissions associated 

with older fields in the state. The Division has started collecting inventories for oil and gas 

sources. The WRAP study will assist the State in understanding all of the sources that need to 

be evaluated.

Powder River 

Basin 

Resource 

Council

E5 Coal Mines

Coal Mines in Wyoming, particularly large surface mines in the 

Powder River Basin, are significant area sources of haze-causing 

pollution including NOx and particulate matter. Coal mine 

related emissions data is easily available to DEQ through BLM 

Environmental Impact Statements, to which DEQ is a 

cooperating agency. DEQ should prioritize coal mine emissions 

as part of its regional haze plan.

NOx and PM emissions from coal mines were taken into account in the development of the 

emissions inventory. The Dust Emissions document (under the following link: 

http://vista.cira.colostate.edu/TSS/Results/Emissions.aspx) summarizes all sources used to 

develop the PM portion of the inventory. Mining operations are included in this list. It is 

difficult for DEQ to prioritize the coal mine emissions since most of the NOx is generated by

trucks and railroads, which is regulated by EPA. The State does not have the authority to 

regulate mobile sources. However, there are some area source NOx emissions included in the 

inventory. WRAP-developed pivot tables summarize the PM and NOx emissions that result

from mining operations: http://www.wrapair.org/forums/ssjf/pivot.html. As explained in the 

above comment response, Environmental Impact Statements are to be used by the BLM as a 
42

Commenter Comment # Section Comment DEQ Response

decision making tool, not an implementation planning and regulation development tool. In 

addition, all information is pre-decisional until a draft document has been released to the 

public and is not approved until a Record of Decision is released.

Powder River 

Basin 

Resource 

Council

E6 Visibility

DEQ should explain visibility conditions and progress goals for all 

Class I areas within 300 km. This includes not just Class I areas in 

Wyoming, but all Class I areas that are impacted by Wyoming 

pollution. We especially encourage DEQ to explain conditions 

and progress goals for Badlands and Wind Cave National Parks, 

which are impacted by current sources of pollution and are 

greatly threatened by future sources and increasing industrial 

development in the Powder River Basin.

DEQ cannot set progress goals for Class I areas outside of Wyoming. The Division only has the 

ability to set goals within the State’s jurisdiction. However, DEQ has not ignored Wyoming’s 

contribution to visibility impairment in the surrounding states. Tables 8.1.2.1-1 and 8.1.2.1-2 

summarize Wyoming’s sulfate and nitrate contribution to regional haze in the closest Class I 

areas for all surrounding states. Badlands and Wind Cave National Parks are included in these 

tables. There is no requirement in the rule that the State look at all Class I areas within 300 

km, and instead chose the approach of analyzing the Class I areas closest to the state and 

fanning out further if any significant contributions were observed.

Powder River 

Basin 

Resource 

Council

E7 Visibility on 

Reservation

There is a need to refer briefly to the Class I area of the Northern 

Cheyenne Indian Reservation (NCIR). While the NCIR Class I area 

in not a “mandatory” Class I area under the Regional Haze Rule, 

it is a significant Class I area with ecological and cultural 

importance that is impacted by industrial pollution from 

Wyoming.

The DEQ recognizes that the Northern Cheyenne Indian Reservation is an area with ecological 

and cultural importance. Since this Class I area is not a mandatory area under the Regional 

Haze Rule, it is not necessary to include a projection of the improvement in visibility. However, 

the State has worked closely with the Tribe. Tribal consultation descriptions can be found in 

Section 11.3 of the SIP and Chapter 11 of the TSD.

Powder River 

Basin 

Resource 

Council

E8

Reasonable 

Progress 

Goals

DEQ’s new plan does not include enforceable emissions 

limitations, especially for minor and area sources. DEQ assumes 

that emissions will be greatly reduced from area and minor 

sources without explaining how and when these reductions will 

take place. Industrial development in Wyoming is increasing –

not decreasing – and therefore emissions will only increase in 

the years to come.

Wyoming’s SIP includes a number of enforceable emission reduction actions, with compliance 

schedules to ensure the reasonable progress goals are achieved. There are three categories of 

steps being taken to achieve the reasonable progress goal. This first includes a variety of 

emission reductions due to programs already in place. The State has implemented a number 

of enforceable permit programs with the goal of reducing emissions. These programs include 

New Source Review (NSR), Prevention of Significant Deterioration (PSD), Minor Source Best 

Available Control Technology (BACT), and Title V permitting. The State has also adopted New 

Source Performance Standards (NSPS), the Phase I Visibility Rule, and National Emission 

Standards for Hazardous Air Pollutants (NESHAPs) from EPA into Wyoming’s Air Quality 

Standards and Regulations (WAQSR). Additional ongoing programs include implementation of 

federal mobile source regulations, implementation of programs to meet PM10 National 

Ambient Air Quality Standards (NAAQS), development of a Nonattainment SIP for PM10 for the 
43

Commenter Comment # Section Comment DEQ Response

City of Sheridan, preparation of a natural events action plan, establishment of Chapter 3 in 

WAQSR to mitigate impacts of construction activities, source retirement and replacement 

schedules, and agricultural and forestry smoke management techniques. All programs listed 

are enforceable at the State level through the WAQSR or permits. Each program is described 

in more detail in Section 8.2 of the SIP.

The second category of emission reduction techniques is BART determination and installment. 

Table 6.4-1 summarizes all of the BART determinations made for Wyoming sources. All BART 

sources are enforceable through BART permits and contain compliance schedules.

The last category of emission reduction techniques are the additional requirements that the 

State is placing on Laramie River Station and Jim Bridger Power Plant. A description of these 

strategies can be found in Section 8.3.3. The requirements are enforceable through permits 

and contain compliance schedules.

DEQ does not assume that area source emissions will decrease in the future. The State takes 

into account growth factors for industrial development. Tables 4.2-1 and 4.3-1 demonstrate 

an increase in NOx area sources due to industrial growth.

Powder River 

Basin 

Resource 

Council

E9 Oil and Gas

The draft SIP explains that new regulations would be needed in 

order to reduce oil and gas emissions. DEQ does not address 

any efforts to undertake the needed regulations. DEQ does not 

even fully explain what emissions reductions would be possible 

under new regulations.

DEQ cannot complete the evaluation of oil and gas impacts on visibility until Phase III of the 

WRAP study has been completed. Until the evaluation has been finalized and emissions from 

oil and gas sources are better understood, it is difficult to determine what new regulations will 

be necessary or what reductions can be achieved by the regulations. The development of new 

rules and regulations will also occur in parallel as the State addresses ozone.

Powder River 

Basin 

Resource 

Council

E10 Coal Mines There is no discussion in the SIP about enforceable reasonable 

progress goals for coal mines.

Reasonable Progress Goals are not set for individual source categories. The goals are set for 

each Class I area and incorporate all sources in that area, including coal mines.
44

Commenter Comment # Section Comment DEQ Response

Powder River 

Basin 

Resource 

Council

E11 Plan 

Evaluation

DEQ fails to discuss evaluation of the plan and what additional 

actions will be taken if visibility improvement goals are not being 

met.

Under the Regional Haze Rule, the State is required to submit an evaluation of the plan every 5 

years following the initial submittal of the SIP. The State has committed to submitting a report 

on reasonable progress every 5 years. The requirement of the evaluation report can be found 

in Chapter 10 of the SIP.

Powder River 

Basin 

Resource 

Council

E12 BART

The SIP must include updated information regarding the BART 

process. The settlement agreements for coal fired power plants 

are available on the EQC website, but not on DEQ’s. Thus, any 

interested parties would essentially be unaware of these 

settlement agreements and could not comment on them as part 

of the draft SIP. As the BART process is perhaps the most 

important component of the regional haze SIP, it is important 

that this portion of the plan be finalized prior to public notice 

and comment. Since the portion of the plan related to BART is 

not finalized in this draft, DEQ should re-release the plan for 

public comment.

The public comment process on the draft RH SIP provided adequate notice and an opportunity 

for meaningful participation. Section 6.5.8 of the draft RH SIP for 309(g) stated that "BART 

permit for Basin Electric Power Cooperative - Laramie River Station is under appeal before the 

Wyoming Environmental Quality Council, docketed as Case No 10-2802, and is subject to 

change”. Section 8.3.3 included similar language and also stated that "BART permit for 

PacifiCorp-Jim Bridger Power Plant is under appeal before the Wyoming Environmental Quality 

Council, docketed as Case No. 10-2801, and is subject to change." These statements appear to 

have adequately informed commenter’s that they should file comments on these subjects 

during the public comment period because changes to these sections were possible. 

Powder River 

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Resource 

Council

E13 BART

DEQ must fully demonstrate through a plant by plant analysis 

that the SO2 backstop trading program is better than BART. 

Additionally, the Section 309 backstop trading program may only 

excuse the DEQ from establishing SO2 BART emission limits if 

that program has been approved by the EPA. DEQ’s 309 

program has not been approved by EPA, as evidenced by it being 

out currently for public comment. Without an approved Section 

309 SIP, DEQ must establish BART for SO2 emissions.

The State believes that the Better than BART determination was done appropriately. The 

Regional Haze Rule does not require that the State perform a unit-by-unit specific BART 

analysis to demonstrate that the Backstop Trading Program is “Better than BART”. EPA clearly 

explains the intent for the Rule in the Federal Register, Volume 71, No. 198, Dated October 13, 

2006 / Rules and Regulations, in the second paragraph on page 60615: “As discussed in more 

detail below, today’s rule also makes clear that where a trading program or other similar 

alternative program has been designed primarily to meet a Federal or State requirement other 

than BART, the State can use a more simplified approach to demonstrating that the alternative 

program will make greater reasonable progress than BART.” The following statement is also 

made in the same Federal Register on page 60618, middle column, second paragraph: “The 

regulations finalized today therefore provide that where an emissions trading program has 

been designed to meet a requirement other than BART, including the reasonable progress 

requirement, the State may establish a BART benchmark based on an analysis that includes 

simplifying assumptions about BART control levels for sources within a source category.”

The original vision of the EPA Regional Haze Rule developed in 1999 was to complete Section 
45

Commenter Comment # Section Comment DEQ Response

309 before 309(g), which enabled Section 309(g) to take credit for the SO2 reductions. The 

original deadline for the 309 submittal was 2003, while 309(g) wasn’t due until 2008. Since 

this time, the State has submitted two SIPs to EPA and will submit its third revision in early 

2011. EPA has also changed the Rule several times, and pushed back the 309 submittal until 

2007. Due to delays, the process has been taking longer than expected and the 309 and 309(g) 

processes are now overlapping, and SIP submittal for both programs are occurring in parallel.

Powder River 

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Council

E14 BART

PacifiCorp proposed to meet a BART limit of 0.015 lb/MMBtu for 

its Wyoming power plants. It remains unclear why DEQ rejected 

this analysis and instead proposed higher limits at some of the 

plants.

Recent Prevention of Significant Deterioration (PSD) permits issued by the Division did include

PM/PM10 limits of 0.012 lb/MMBtu for fabric filter controls, but those limits (and PM/PM10

limits established for the Desert Rock Project in New Mexico) were determined through Best 

Available Control Technology (BACT) analyses for new sources. The BART process deals with 

retrofit controls on existing units, and therefore is not directly comparable to BACT 

determinations. Additionally, visibility modeling described in the Division’s BART analysis for 

the Jim Bridger plant showed that the addition of a fabric filter to replace an Electrostatic 

Precipitator (ESP) provided very little in the way of visibility improvement, with predicted 

cumulative improvements across three Class I areas of only 0.03 to 0.1 Δdv for Units 1-4. 

These results indicate that requiring more stringent control levels for a fabric filter would not 

provide significant visibility improvement.

Powder River 

Basin 

Resource 

Council

E15 BART

It was stated that the DEQ should fully consider the comments 

of the federal land management agencies and other information 

that is widely available for demonstrating the cost-effectiveness 

of achieving lower BART limits.

The DEQ fully considers the comments received from the Federal Land Managers and all other 

interested parties. Each BART permit went out for public comment, and were responded to by 

DEQ. BART comment responses can be found in the TSD under Chapter 11, Summary of FLM 

(and Other) Comments on BART and State Responses on BART. Permit applications and State 

analyses can be found in Attachment A of the SIP at: 

http://deq.state.wy.us/aqd/regionalhaze.asp.

Powder River 

Basin 

Resource 

Council

E16 BART 

The PRBRC commented that the DEQ’s preliminary BART 

determination for the Laramie River Station (LRS) was SCR on all 

three units, but due to Basin Electric’s claims that funding would 

be difficult to obtain to allow installation of SCR within the BART 

timeframe, the DEQ did not require SCR as BART. The PRBRC 

believes that SCR should be required for all three LRS units as 

BART, should be installed within the 5-year BART timeframe, and 

that these requirements should be implemented as part of the 

Regional Haze SIP. At the very least, the PRBRC believes that 

In determining BART for the three units at LRS, DEQ-AQD considered all five BART statutory 

factors. During the cost of compliance evaluation, the AQD recognized that a time limitation to 

install BART-determined controls was imposed by the Regional Haze Rule, but timing of control 

installation was not explicitly considered in the BART statutory factors. Based on the control 

costs and visibility modeling presented by Basin Electric in the BART applications for the LRS, 

and taking into consideration the logistical challenge of managing multiple pollution control 

installations within the 5-year regulatory timeframe allotted for BART, the AQD required 

installation of SCR (or equivalent) on two LRS units under the Long-Term Strategy of the 

Wyoming Regional Haze State Implementation Plan (SIP). A legal appeal of that Long-Term 

Strategy requirement by Basin Electric and subsequent negotiations between Basin Electric 

and the AQD led to a settlement agreement that will require the LRS to install NOx controls that 
46

Commenter Comment # Section Comment DEQ Response

presumptive BART limits should be considered. DEQ should also 

consider the current NSPS limits for NOx for new coal-fired 

plants.

will achieve emissions that are lower than the EPA’s presumptive BART levels on all three LRS 

units. These controls must be installed within the BART timeframe. Further reductions will be 

required by the end of 2017 that are the equivalent of the addition of SCR control on one of 

the LRS units.

Consideration of NSPS limits that are intended for new coal-fired plants is not relevant for the 

determination of BART, because BART pertains to existing sources that may not be configured 

to accommodate the emissions limits that can be achieved by newly constructed sources. 

Powder River 

Basin 

Resource 

Council

E17 Long-Term 

Strategy

DEQ’s long-term strategy proposal regarding NOx emissions (i.e., 

settlement agreement) at the LRS is problematic because 

required levels are based on the total emissions for all three 

units combined. The PRBRC believes that the DEQ should 

analyze unit by unit limits.

The AQD established a plant-wide NOx limit for the LRS under Condition 7d of the settlement 

agreement to allow Basin Electric the flexibility to achieve the emissions reductions by applying 

additional controls on any or all of the LRS units. The plant-wide emission limit will be the 

equivalent of the EPA’s presumptive BART level on two of the LRS units and SCR control on one 

of the LRS units.

Powder River 

Basin 

Resource 

Council

E18 Long-Term 

Strategy

The SIP must provide a long-term strategy for achieving 

reasonable progress towards meeting natural visibility 

conditions by 2064. DEQ is implementing modest goals with 

minor improvements in visibility when significant reduction are 

possible to greatly improve visibility in Class I areas sooner than 

later.

DEQ believes that the State is achieving reasonable progress for this planning period. Section 

51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must provide 

for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over 

the same period”. Even though the Uniform Rate of Progress (URP) was not achieved in this 

planning period, the requirements for the reasonable progress goals set under the Regional 

Haze Rule have been achieved. According to 51.308(d)(1)(i)(B) “For the period of the 

implementation plan, if the State establishes a reasonable progress goal that provides for 

slower rate of improvement in the visibility than the rate that would be needed to attain 

natural conditions by 2064, the State must demonstrate, based on the factors in 

paragraph(d)(1)(i)(A) of this section, that the rate of progress for the implementation plan to 

attain natural conditions by 2064 is not reasonable; and that the progress goal adopted by the 

State is reasonable.” DEQ believes that an adequate demonstration has been made as to why 

the goals set by the State are reasonable. This can be found in Section 7.6. Overall, a 

combination of natural and international emissions which the DEQ has no control over is the 

primary cause of the Division’s inability to achieve the URP.

Powder River 

Basin 

Resource 

Council

E19 Long-Term 

Strategy

SCR should not be part of the long term strategy and instead 

should be required as BART.

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. All BART sources underwent DEQ’s permitting process, and went out for 

public comment. DEQ responded to each comment. All comments and responses can be 

found in the TSD, under Chapter 11, Summary of FLM (and Other) Comments on BART and 

State Responses on BART. Refer to Attachment A of the SIP for BART analyses, applications, 
47

Commenter Comment # Section Comment DEQ Response

and additional information for the applicable sources at: 

http://deq.state.wy.us/aqd/regionalhaze.asp.

Powder River 

Basin 

Resource 

Council

E20 Long-Term 

Strategy

DEQ should consider closure of coal-fired plant units as a long 

term strategy option.

DEQ cannot consider the closing of coal-fired power plants unless it is proposed by the 

companies that own them. The Division has had discussions with the unit operators, and all 

operators are looking at reducing emissions rather than shutting down the facilities. If a 

company were to propose the shut-down of a facility in the future, it would be evaluated in 

future SIPs.

Peabody 

Energy E21

Reasonable 

Progress 

Goals

Peabody fully supports the Air Quality Division’s RPG analysis 

and believes that the RPGs proposed represent an attainable 

standard. The Regional Haze Rule sets no presumptive target for 

making determinations of RPGs, and does not mandate specific 

rates of progress. Although the 2018 RPGs are less than the 

2018 URP, they nevertheless represent a realistic and attainable 

improvement over baseline conditions.

DEQ agrees that the Division has properly justified why the URPs could not be attained. DEQ 

appreciates Peabody’s recognition of the State’s RPGs.

Peabody 

Energy E22 Long-Term 

Strategy

Peabody commends the Air Quality Division’s plan, outlined in 

the Long-Term Strategy section of its SIP, to apply the terms of 

its Natural Events Action Plan to moderate the impact of 

uncontrollable natural events on visibility in the state.

DEQ appreciates Peabody’s recognition of the Long-Term Strategy to moderate uncontrollable 

natural events visibility in the state.

Peabody 

Energy E23 General

Peabody notes that Wyoming has taken steps to ensure 

meaningful visibility improvements through the requirement of 

significant reductions in controllable, anthropogenic emissions 

of sulfur dioxides (SO2) and nitrogen oxides (Nox) emissions via 

the implementation of BART requirements and other control 

measures. While the reduction falls short of the URP goal, 

Peabody believes that the Air Quality Division has presented 

ample evidence that natural and international emissions are the 

cause of this shortfall, and that it has required all emission 

reductions from in-state sources that it reasonably can.

DEQ appreciates Peabody’s recognition of the reasonable steps that the Division has taken to 

reduce emissions.

Peabody 

Energy E24 BART In general, Peabody supports the Air Quality Division’s BART 

analysis – using a “top-down” framework is consistent with EPA DEQ appreciates Peabody’s support for the Division’s BART analysis approach.
48

Commenter Comment # Section Comment DEQ Response

guidance and provides a rational and deliberate means for 

analyzing potential control alternatives.

Peabody 

Energy E25 BART

Peabody Energy commented that some of the AQD BART 

determinations appear to be driven by the fact that the facility 

was already planning to install certain control equipment, and 

the SIP should explain if controls are required under other 

authority or a negotiated settlement. Peabody notes that costs 

cited for SCR and fabric filters appear low. Peabody also noted 

that the AQD deemed the costs of fabric filters to be 

unreasonable, but accepted fabric filters as BART. Other BART 

determinations developed under similar circumstances should 

be fully explained in the SIP. Peabody suggests alternatives for 

the AQD in order to avoid setting an inappropriate precedent for 

BART determinations. Peabody suggested that the SIP could 

consider controls that facilities already plan to install to be the 

baseline condition for evaluating other control options, or that 

the cost-effectiveness calculation could be eliminated if the 

source does not seek to rule out the most effective control on 

the basis of cost-effectiveness. 

Several of the facilities that were subject to BART committed to pollution control projects prior 

to submittal of BART applications to the AQD. The Division thoroughly evaluated all control 

alternatives, including those already installed or proposed to be installed, and determined 

BART based on consideration of all five statutory BART factors as required by EPA’s Appendix Y 

BART guidance. Fabric filters were selected as BART for PM control for several sources that 

intended to install the fabric filters as part of pollution control projects. Estimated costs for 

the fabric filters are deemed by the AQD to be reasonable when considering all factors relating 

to the existing PM controls in addition to those considered for the BART analysis (AQD and 

PacifiCorp BART Appeal Settlement Agreement, Wyoming Environmental Quality Council, 

November 9, 2010). 

Costs presented by BART applicants were developed using sources such as the EPA OAQPS 

Control Cost Manual, vendor-obtained price quotes, and engineering databases. All costs were 

scrutinized by AQD permit engineers as part of the permit application review process. The 

commenter did not provide specific examples of control equipment costs that they believed to 

be underestimated, and therefore the AQD cannot provide specific responses.

The alternative proposed by the commenter that would include consideration of controls 

already to be installed as baseline would not be acceptable to the AQD. 40 CFR 51.309(b)(7) 

provides guidance for the selection of the baseline year for BART, and the baseline year chosen 

using this guidance was 2003. All control alternatives that represented additional control 

beyond the baseline condition were individually evaluated by the AQD as possible BART 

alternatives without regard to the source’s intention to install particular sets of controls. The 

suggestion that the AQD eliminate the cost-effectiveness evaluation altogether in cases where 

a source intends to install controls regardless of costs is not acceptable to the AQD. The 

Division determined BART based on consideration of all five statutory BART factors, including 

the costs of compliance, and would continue to present complete information for each 

evaluation factor.
49

Commenter Comment # Section Comment DEQ Response

Peabody 

Energy E26 BART

As an alternative to the EPA guidance recommended “dollar-perton” cost-effectiveness calculation, Peabody submits that a 

“dollar-per-deciview” approach may represent a more 

appropriate means.

EPA’s Appendix Y BART guidance does mention that “dollars per deciview” ($/dv) is a metric 

that could be used to evaluate the cost of BART compliance, but by no means identifies $/dv as 

an essential or required metric. The Division considered capital cost, annual cost, cost 

effectiveness, and incremental cost effectiveness in the cost evaluation of each proposed BART 

control option. The Division chose not to use a hybrid metric such as $/dv primarily because of 

the lack of historical precedent regarding reasonable/acceptable levels for such a metric. 

Additionally, the use of a hybrid cost metric such as $/deciview can introduce uncertainty as to 

how the value was calculated. The value of “/deciview” could be based on the highest 

modeled value in a given area or the 98th percentile modeled value. It could be based on the 

98th percentile value for any one modeled year or it could be an average for multiple years. It 

could even be based on an average modeled value across an entire Class I area or the sum of 

deciview changes across multiple areas. The Division has found that $/dv values are often 

presented without explanation of the basis for the calculation. To avoid these confounding 

factors, the Division chose to evaluate and present the cost analyses and visibility analyses

separately.

Peabody 

Energy E27 BART

Peabody Energy commented that it is meaningless to rely upon 

cumulative visibility modeling results because of the manner in 

which visibility impacts are modeled. Peabody recommends that 

the AQD revise the Regional Haze SIP to remove all references to 

cumulative visibility improvements.

The AQD agrees that reporting cumulative visibility modeling (CALPUFF) results can at times 

lack clear meaning. For determining the visibility impacts for units that were subject to BART, 

the AQD modeled each unit separately as recommended in EPA’s Appendix Y guidance. 

Results of the modeling were reported for individual units in terms of the 98th percentile deltadeciview (dv) impact at particular Class I areas or in terms of the number of days with greater 

than a 0.5 dv impact at a particular Class I area. Any mention in the SIP of “cumulative” results 

for BART determinations pertains to the sum of the 98th percentile results for a particular unit 

for the (two or three) closest Class I areas. The AQD believes that the consideration of the 

summed results, along with a strong consideration of the results at individual Class I areas, was 

an appropriate approach for the BART determinations.

Peabody 

Energy E28 BART

Peabody Energy disagrees with the AQD’s consideration of other 

environmental factors in making BART determinations. For 

example, a statement on page 109 of the SIP describes that 

“enhanced mercury removal co-benefits” were part of the 

justification for a fabric filter on Naughton Unit 3 as BART. 

As described in Section 6.5.6 of the SIP, the AQD concluded that the costs for a fabric filter for 

Naughton Unit 3 are reasonable, based on consideration of all the factors above and beyond 

the benefits associated with regional haze. This approach to assessing the costs associated 

with the fabric filter was prompted by a settlement agreement between the AQD and 

PacifiCorp. (AQD and PacifiCorp BART Appeal Settlement Agreement, Wyoming Environmental 

Quality Council, November 9, 2010).
50

Commenter Comment # Section Comment DEQ Response

Peabody contends that such additional considerations are 

beyond the scope of the EPA’s BART regulations. 

Peabody 

Energy E29 Long-Term 

Strategy

Peabody supports the Air Quality Division’s proposed Long Term 

Strategy in that it takes steps towards collecting and analyzing 

additional information that will help the state determine 

whether additional controls may be imposed on non-BART 

eligible sources.

DEQ appreciates Peabody’s recognition of the efforts the State is making to determine 

additional controls that can be imposed on non-BART sources.

Basin Electric 

Power 

Cooperative

E30 General

Basin Electric summarized the BART settlement, and the 

company’s opinions on the settlement.

DEQ has received Basin Electric’s summary of the BART settlement. There were no specific 

requests made that the Division needs to address. The DEQ will adhere to its portion of the 

settlement agreement.

Forest Service E31 Oil and Gas

In Section 8.3.5, Wyoming indicates that the DEQ can’t complete 

evaluation of oil and gas contributions without the WRAP Phase 

III report. The FS understands that the Phase III work is in 

progress for the Wind River, Upper Green River, and Powder 

River Basins. We look forward to Wyoming addressing this 

important emission category when the Phase III report is 

completed; however these reports apparently will not address 

oil and gas development in the entire state.

The WRAP Phase III report contains the basins identified by the Forest Service, as well as Big 

Horn and Denver Basin. It also includes the entire Green River Basin, not just the Upper Green 

River. The project scope includes “all Rocky Mountain states’ basins with significant oil and gas 

development activity”. The Project Scope document identifies the boundaries for Wyoming 

basins:

http://www.wrapair.org/forums/ogwg/documents/Phase_III_Oil&Gas_EI_project_Scope_of_

Work_Final_110507.pdf

The map on page 4 of this document prepared by ENVIRON illustrates that all areas in 

Wyoming that have significant oil and gas development are covered in the WRAP Phase III 

Report.

Forest Service E32 BART

Figure 8.3.6-7 does not appear to reflect the changes in BART 

compliance dates. This figure has been changed in the SIP.

Earthjustice E33 General

AQD inexplicably relies on Wyoming’s relative clean air as a 

justification for failing to meet more stringent visibility 

milestones.

It is not DEQ’s intention to rely on its “relative clean air” as a justification for not meeting more 

stringent visibility milestones. The Division wanted to outline the difficulty of the task 

expected, but in no way is the DEQ using the “relative clean air” as an excuse for not achieving 

the URP goal. DEQ is trying to demonstrate that it is not as easy to show progress when there 

are fewer initial visibility impacts. DEQ explains in the SIP that the URP goal is difficult to 

achieve due to forest fire impacts in the state. Therefore, the lack of URP goal achievement is 
51

Commenter Comment # Section Comment DEQ Response

not an issue of motivation by the State, but rather an issue of environmental impacts beyond 

the Division’s control.

Earthjustice E34

Greater 

Reasonable 

Progress than 

BART

The alternative 309 program does not appear to be an 

improvement over BART for Colorado Plateau Class I areas. AQD 

must either demonstrate the superiority of the alternative 

program based on complete and accurate information, or 

require installation and operation of BART for SO2 emissions at 

Wyoming sources subject to BART.

The Division has demonstrated the superiority of the 309 program in the Demonstration that 

the SO2 Milestones Provide Greater Reasonable Progress than BART document in Appendix E. 

In this demonstration, the State not only verifies that the program meets or exceeds 

presumptive SO2 BART levels, but also provides other benefits of implementing the milestone 

program. One of these benefits includes limiting new source growth for SO2 emissions in the 

participating states. In addition, the program includes every source that emits 100 tons per 

year or greater of SO2, and therefore targets a greater number of sources than what would be 

identified in the BART program. DEQ believes that this conclusion is based on complete and 

accurate information.

Earthjustice E35

Greater 

Reasonable 

Progress than 

BART

In most cases this “Better-than-BART” determination must be 

based on an analysis of BART technology and corresponding 

emission reductions achievable for each source that is subject to 

BART within the state. By relying on an inflated presumptive SO2 

emission rate for power plants, rather than a lower emission 

rate achievable through BART, WRAP has improperly discounted 

the visibility improvement that may be achieved through 

implementation of BART on eligible sources.

It is not required by the Regional Haze Rule that the State perform source-specific BART 

analyses to determine that the 309 program has achieved better than BART reductions. EPA 

clearly explains the intent for the Rule in the Federal Register, Volume 71, No. 198, Dated 

October 13, 2006 / Rules and Regulations, in the second paragraph on page 60615: “As 

discussed in more detail below, today’s rule also makes clear that where a trading program or 

other similar alternative program has been designed primarily to meet a Federal or State 

requirement other than BART, the State can use a more simplified approach to demonstrating 

that the alternative program will make greater reasonable progress than BART.” The following 

statement is also made in the same Federal Register on page 60618, middle column, second 

paragraph: “The regulations finalized today therefore provide that where an emissions trading 

program has been designed to meet a requirement other than BART, including the reasonable 

progress requirement, the State may establish a BART benchmark based on an analysis that 

includes simplifying assumptions about BART control levels for sources within a source 

category.”

Since EPA allows the State to use a simplified approach to analyze BART-eligible sources, it is 

appropriate to use 40 CFR part 51 Appendix Y to determine presumptive levels, rather than 

look at each source separately.

Therefore, the State believes that the “Better than BART” determination has been conducted 

appropriately, and no further analysis is required.
52

Commenter Comment # Section Comment DEQ Response

Earthjustice E36

Greater 

Reasonable 

Progress than 

BART

AQD apparently intends to rely on WRAP’s “better-than-BART” 

determination. However, WRAP’s analysis does not support its 

“better-than-BART” finding. Even if WRAP’s reliance on EPA’s 

presumptive SO2 emissions limit for power plants was 

appropriate, it has failed to establish that the 309 alternative 

program achieves “greater reasonable progress” than BART. 

WRAP concedes that the alternative program will, at best, result 

in the same SO2 reductions achievable through the application of 

BART. WRAP justified the determination in part through its 

claim that emission reductions will happen sooner under the 

alternative program than under BART.

WRAP’s Demonstration that the SO2 Milestones Provide Greater Reasonable Progress than 

BART report (provided in Appendix E) does support the State’s better than BART finding. On 

Page 12 of the report it states, “The Regional SO2 milestone of 141,849 equals the BART 

benchmark, but provides greater reasonable progress than BART for the reasons outlined 

below.....” The report continues to explain the additional advantages of the 309 program such 

as early reductions, the addition of sources that would not be included in BART, a cap in new 

source growth, the inclusion of strategies to address mobile sources, prescribed fire, pollution 

prevention and clean air corridors, tribal set asides, and an improvement in Class I areas off of 

the Colorado Plateau. The report does not state that “emission reductions will happen sooner 

under the alternative program than they would under BART”, but rather that the program will 

“contain specific provisions to encourage and reward early emissions reduction...”. This 

program has achieved a 60% SO2 reduction from 1990 to 2008, verifying that this program has 

been successful in achieving early reduction. DEQ believes that WRAP has adequately 

demonstrated that the 309 program has achieved better than BART progress.

Earthjustice E37 General

The draft 309(g) SIP fails to justify Wyoming’s adoption of an 

emissions-reduction strategy that would not achieve the 

“uniform rate of progress” necessary to restore natural visibility 

conditions by 2064. AQD’s attempt to demonstrate the 

reasonableness of its “reasonable progress goals” is illogical and 

does not pass legal muster.

DEQ believes that the State has adequately justified why the URP was unachievable in this 

planning period. According to 51.308(d)(1)(i)(B) of the Regional Haze Rule “For the period of 

the implementation plan, if the State establishes a reasonable progress goal that provides for 

slower rate of improvement in the visibility than the rate that would be needed to attain 

natural conditions by 2064, the State must demonstrate, based on the factors in 

paragraph(d)(1)(i)(A) of this section, that the rate of progress for the implementation plan to 

attain natural conditions by 2064 is not reasonable; and that the progress goal adopted by the 

State is reasonable.” Section 7.6 of the SIP outlines nine reasons as to why the State believes 

that the progress goals set are reasonable.

Earthjustice E38 General

AQD states that it is “more difficult to show improvement in 

visibility over time in Wyoming than it is in the Eastern states

because the state it starting out so clean”. It does not follow 

from AQD’s premise, however, that it should take far longer to 

achieve natural visibility in Wyoming than other states that face 

the challenge of greater pollution levels.

When comparing Wyoming air to air in the Eastern states, DEQ was trying to demonstrate that 

it is not as easy to show progress when there are fewer initial visibility impacts. The initial URP 

does not dictate the total time that it will take to achieve natural visibility, and it is therefore 

inappropriate to estimate the total time that it will take Wyoming to achieve natural 

conditions based on the URP for the first planning period. The uniform rate of progress 

assumes that identical emission reductions will occur each year in order to achieve natural 

visibility conditions by 2064, and serves as a guideline to keep states on track. In reality, 

emission reductions will not occur at a uniform rate for each planning period. Therefore, DEQ 

is trying to express that in states with higher visibility impacts should be able to achieve the 

initial URP goal, but may experience the same problem as Wyoming and other Western states 

when trying to achieve URP in the later stages of the plan when their air becomes “cleaner”.
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Commenter Comment # Section Comment DEQ Response

Earthjustice E39 General

AQD also attempts to justify its laggardly progress toward 

natural visibility by pointing to “[m]ajor reductions in SO2

emissions” due to the 309 alternative program.

DEQ is not attempting to justify its laggardly progress toward natural visibility conditions by 

pointing out the progress made by the 309 program. The state is permitted to take full credit 

for SO2 emissions achieved in the 309 program according to 51.309(g)(20(i): “...the State may 

build upon the strategies implemented under paragraph (d) of this section, and take full credit 

for the visibility improvement achieved through these strategies”. The State is taking full 

advantage of the 309 program and taking credit for SO2 reductions achieved by the program. 

The State has made great strides for reducing SO2 emissions from the 309 program and found 

it appropriate to mention in the SIP. As explained in Section 7.6 of the 309(g) SIP, the biggest 

impediment to reaching natural visibility goals is wildland fires.

Earthjustice E40 BART

AQD’s claim that significant NOx emissions reductions will be 

achieved through BART is unsatisfactory justification for slow 

visibility improvement, when AQD has failed to require timely 

implementation of SCR on coal-fired power plants and failed to 

require installation of cost-effective control technologies on oil 

and gas development activities.

The BART determination process has taken longer than expected to complete. It was originally 

envisioned that BART determination would occur before the 309(g) was released. However, 

since this did not occur as expeditiously as expected, the BART and 309(g) processes are 

occurring in parallel. Therefore, the DEQ was not able to take credit for or model BART 

reductions during this planning period. DEQ believes that it is appropriate to include this 

argument in the demonstration that the progress goals are reasonable.

Specific control strategies for oil and gas sources have not been incorporated into this SIP. The 

State is waiting for the WRAP Phase III report to be released, so that the Division can get a 

better understanding of how the emissions are distributed and what sources the State should 

look at controlling.

Earthjustice E41

Reasonable 

Progress 

Goals

At Wyoming’s proposed rate of progress, natural visibility 

conditions will not be reached for more than 100 years in any 

Wyoming Class I area. Under any definition, this goal is not 

“reasonable”, particularly given the multiple additional 

strategies available.

Wyoming is not in a unique position. Most of the Western states are expressing difficulty 

achieving the URP goal due to the presence of uncontrollable fires in the West. Section 

51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must provide 

for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over 

the same period”. Since there is no degradation in visibility for the 20% best days, this portion

of the Rule is satisfied. During the 20% worst days, wildfires are a major contributing factor. 

Until there is a decrease in wildfires, it will continue to be difficult to achieve URP goals.

Please note that not all reductions were included in the WRAP modeling. The results do not 
54

Commenter Comment # Section Comment DEQ Response

include the BART and long-term strategy reductions proposed in this SIP or any other WRAP 

SIPs. The WRAP could only include enforceable reductions that were on the books at the time 

of the last model run.

Earthjustice E42 Better than 

BART

AQD’s 309(g) SIP is insufficient with respect to SO2 because it 

fails to include a demonstration that the WRAP alternative 

program “will achieve greater reasonable progress than would 

have resulted from the installation and operation of BART at all 

sources subject to BART in the state”. This demonstration is 

required for all Class I areas with visibility impacts from 

Wyoming sources, not just Colorado Plateau Class I areas 

covered by the WRAP alternative program. Neither WRAP nor 

AQD have demonstrated that the improvements under the 

WRAP alternative program are better than BART for Class I areas 

outside of the Colorado Plateau.

The demonstration that the 309 program will achieve greater reasonable progress than BART is 

required at the State level. Emission reductions were calculated on a state-wide basis, not at 

each Class I area. This can be seen in the Demonstration that the SO2 Milestones Provide 

Greater Reasonable Progress than BART provided in Appendix E. Visibility was modeled at all 

Wyoming Class I areas, and Class I areas in surrounding states. It can be seen in Table 6.2-2 of 

the SIP, and more extensively in Table 4 of the Demonstration document, that visibility in all 

surrounding Class I areas improves on the 20% worst days and improves or remains flat on the 

20% best days.

Earthjustice E43 Better than 

BART

According to section 51.308(e)(3) when the “distribution of 

emissions is not substantially different than under BART, and the 

alternative measure results in greater emissions reductions...”, 

WRAP cannot lawfully comply with the “greater reasonable 

progress” requirement using the alternative method.

The Demonstration that the SO2 Milestones Provide Greater Reasonable Progress than BART 

report found in Appendix E does not take into account new source growth. For sources that 

have the potential to emit greater than 100 TPY of SO2, the 309 program places a cap on all 

new source growth. There is no such cap placed on the growth of BART sources, which can 

continue to grow as long as the source meets the permitting requirements. Thus, there will be 

greater reasonable progress long-term with the 309 program, but emission reductions are 

difficult to quantify. 

Earthjustice E44

Reasonable 

Progress 

Goals

Since Wyoming’s 2018 reasonable progress goals are less than 

the 2018 uniform rate of progress, Wyoming must evaluate any 

additional controls to achieve greater progress, including 

whether additional SO2 emissions reductions are feasible.

If the State’s reasonable progress goals are less than the uniform rate of progress, the Regional 

Haze Rule requires that the State demonstrate why the goals set are reasonable. It is not a 

requirement that the State evaluate additional controls. According to 51.308(d)(1)(i)(B) of the 

Regional Haze Rule, “For the period of the implementation plan, if the State establishes a 

reasonable progress goal that provides for slower rate of improvement in the visibility than the 

rate that would be needed to attain natural conditions by 2064, the State must demonstrate, 

based on the factors in paragraph(d)(1)(i)(A) of this section, that the rate of progress for the 

implementation plan to attain natural conditions by 2064 is not reasonable; and that the 
55

Commenter Comment # Section Comment DEQ Response

progress goal adopted by the State is reasonable.” Section 7.6 of the SIP outlines nine reasons 

as to why the State believes that the progress goals set are reasonable.

Earthjustice E45 BART

AQD’s BART determinations for Nox emissions are inadequate, 

because they do not require timely installation of selective 

catalytic reduction (“SCR”) at Wyoming power plants. As EPA 

and NPS have noted, SCR is BART for coal-fired power plants.

When determining the appropriate BART for each source, the Division followed Chapter 6 

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

subpart Y Guidance. Each source underwent permitting and went out for public commenting. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11 State Responses to BART. Permit applications and analysis can be found in 

Attachment A of the SIP.

Earthjustice E46 BART

AQD improperly relies on installation and operation of BART as 

part of its long term strategy, rather than requiring immediate 

BART compliance. Since AQD has determined that SCR is BART 

for these PacifiCorp units, AQD lacks the discretion to extend 

BART compliance beyond the regulatory deadline.

DEQ did not determine that SCR is BART for any of the PacifiCorp units. When determining the 

appropriate BART for each source, the Division followed Chapter 6, Section 9 from the WAQSR, 

as well as EPA’s Subpart Y Guidance. The permit application and DEQ analyses can be found in 

Attachment A of the SIP at: http://deq.state.wy.us/aqd/regionalhaze.asp. The summary of 

BART determination for each source can be found on Table 6.4-1 of the SIP. According to SIP 

Section 6.4, all BART is to be installed “as expeditiously as practicable, but no later than five 

years after EPA approval of the state implementation plan revision”.

Earthjustice E47 Oil and Gas

The 309(g) SIP does not satisfy regulatory requirements because 

it includes no measures for even maintaining, let alone reducing, 

current emissions levels from Wyoming’s oil and gas industry. 

Wyoming has already evaluated potential control technology 

and has identified cost effective technologies that could readily 

be installed on oil and gas exploration and production 

equipment.

DEQ cannot complete the evaluation of oil and gas impacts on visibility until Phase III of the 

WRAP study has been completed. Until the evaluation has been finalized and emissions from 

oil and gas sources are better understood, it is difficult to determine what sources should be 

controlled. If Wyoming has evaluated any control technology for oil and gas exploration, there 

is currently no regulation that requires companies to install these control technologies. The 

SIP can only include enforceable actions, and until oil and gas operations are better 

understood, rules and regulations cannot be developed. Therefore, it is necessary for Phase III 

of the WRAP study to be completed before the DEQ can begin regulating oil and gas sources.

Earthjustice E48 Oil and Gas

Wyoming states that it does not yet have regulatory authority to 

require oil and gas operations to install control technology, and 

contemplates that such a rulemaking could take up to two years. 

While we appreciate that rulemakings of this nature take time, it 

is inexcusable that Wyoming has delayed this process even while 

it has known of its obligations under the regional haze rule for 

Before the State can begin rulemaking, the Division must understand what types of oil and gas 

sources should be regulated. The WRAP Phase III report will contain emissions broken down 

by source, which will allow the DEQ to determine which sources should be the focus of 

emission reductions. The Division does encourage oil and gas operators to offset emissions 

prior to regulatory requirements. Significant reductions are being made in the Upper Green 

River Basin partially as a result of voluntary reductions. The State currently has interim policies 
56

Commenter Comment # Section Comment DEQ Response

more than a decade. In any event, while AQD lacks regulatory

authority to limit emissions from oil and gas activities, the 

agency should evaluate the potential for voluntary reductions 

through incentives programs or, as the National Park Service 

recommended in its October 21, 2009 309(g) SIP comments, 

encourage industry to offset emissions prior to regulatory 

requirements.

for emissions offsets.

Earthjustice E49 Oil and Gas

The AQD is a cooperating agency in numerous environmental 

review documents that address the visibility impact of oil and 

gas development in Wyoming Class I areas. Various 

Environmental Impact Statements have been prepared that 

include an evaluation of potential mitigation measures.

The DEQ is a cooperating agency in the National Environmental Policy Act (NEPA) analysis. 

However, Environmental Impact Statements are to be used as a decision making tool, not an 

implementation planning and regulation development tool. In addition, all information is predecisional until a draft document has been released to the public and is not approved until a 

Record of Decision is released.

Earthjustice E50 Oil and gas

At minimum, AQD’s long term strategy must include timelines 

for completing the oil and gas emissions inventory and finalizing 

of oil and gas development activities.

The DEQ is not able to provide a timeline for completing the oil and gas emissions inventory. 

The Division can only provide timelines that DEQ can enforce. The estimated deadline for the 

report that WRAP has proposed is not enforceable.

PacifiCorp E51 General

PacifiCorp supports the emission reduction requirements and 

time schedule contained in Wyoming’s Regional Haze SIP as 

those relate to PacifiCorp’s facilities in Wyoming.

The State appreciates PacifiCorp’s recognition of the emission control strategies taken by the 

Division.

PacifiCorp E52 BART

PacifiCorp believes that the emission reduction projects and 

their timing-including those described in the Wyoming Regional 

Haze SIP-appropriately balance the need for emission reductions 

over time with the cost and other concerns of our customers, 

our state utility regulatory commissions, and other stakeholders. 

PacifiCorp believes this plan is complementary and consistent 

with the Wyoming BART and regional haze planning 

The State of Wyoming appreciates PacifiCorp’s recognition that the State has fulfilled the 

requirements set forth by the Regional Haze Rule and has also followed Chapter 6, Section 9 of 

the WAQSR and EPA’s Subpart Y Guidance for permitting BART sources.
57

Commenter Comment # Section Comment DEQ Response

requirements, and that it is a reasonable approach to achieving 

emission reductions in Wyoming and other states.

PacifiCorp E53 BART

When considering PacifiCorp’s entire fleet of coal-fired 

generating units, it is unrealistic to expect the installation of any 

additional controls on a time schedule any faster than is already 

contemplated by the proposed Regional Haze SIP.

When determining the appropriate BART for each source, the Division followed Chapter 6,

Section 9 from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s 

Subpart Y Guidance. Each source underwent permitting and went out for public comment. 

DEQ responded to each comment. All comments and responses can be found in the TSD, 

under Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on 

BART. The State believes that the BART analysis has been conducted appropriately and all of 

the requirements stated on the permits, and the appeal decision documents will be DEQ’s 

enforceable requirements for each source.

PacifiCorp E54 BART

Arguments that the cost effectiveness criteria utilized under the 

BART determinations, in the range of $3,500 to $4,300 per ton of 

NOx removed at the PacifiCorp facilities to improve visibility are 

disproportionate with the health-based criteria established 

under many other EPA rulemakings and regulatory programs.

The EPA’s Appendix Y guidance describes the EPA’s selection of presumptive NOx limits for 

coal-fired EGUs, and provides approximate cost levels for meeting the presumptive limits with 

current combustion controls, and a somewhat higher cost level for a subset of units that would 

require advanced combustion controls such as rotating opposed fire air (ROFA). The EPA 

guidance does not attempt to establish cost thresholds that would be considered 

unreasonable for a given control technology, nor does it present the approximate costs 

associated with the presumptive levels as absolute limits above which cost should be deemed 

unreasonable. The Division established NOx emission limits for BART based on consideration of 

all five statutory factors in their entirety, as required by the Appendix Y guidance.

PacifiCorp E55 Averaging 

Period

PacifiCorp recommends that a standard method be utilized at its 

four power plants owned and operating in Wyoming to 

demonstrate compliance with any pound per hour or pound per 

million Btu emission limits based on a 30-day rolling average. 

PacifiCorp recommends that the Dave Johnston, Wyodak, Jim 

Bridger and Naughton plants demonstrate compliance with 

these 30-day rolling averages based on all valid 1-hour average 

emissions contained in the previous 30 calendar days. The 

following equation describes the recommended method to be 

used to calculate the pound per hour and pound per million Btu

emission rates on a 30-day rolling average basis:

The DEQ has included PacifiCorp’s recommendation in the SIP. Section 6.5 V has been changed 

accordingly.
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Commenter Comment # Section Comment DEQ Response

PacifiCorp E56 BART

PacifiCorp requests that the description regarding the baghouses 

for the Dave Johnston (pages 106-107) and Wyodak (pages 111-

112) facilities be amended, consistent with the language set 

forth in the amended language for the Naughton facility (page 

109).

This language has been changed in the SIP.

PacifiCorp E57 BART

Section 6.5 (page 99): change this provision to note that the 

BART determinations have now been finalized.

This language has been changed in the SIP.

PacifiCorp E58 BART

Section 6.5.4 (page 104): remove the provision which states that 

the Bridger plant BART permit is under appeal.

This language has been changed in the SIP.

PacifiCorp E59 BART

Section 6.5.6 (page 108): remove the provision which states that 

the Naughton plant BART permit is under appeal.

This language has been changed in the SIP.

PacifiCorp E60 BART

Section 8.3.3 (page 172-173): remove the provision which states 

that the Bridger plant BART permit is under appeal.

This language has been changed in the SIP.

Wyoming 

Outdoor 

Council

E61 General

We believe that the current massive amount of technical 

language that is found in these SIPs is language that very few can 

really understand, and thus defeats this important underlying 

purpose and policy. Consequently we ask the AQD to correct 

The DEQ has strived to present a highly technical subject in a manner that is understandable by 

the general public. Unfortunately, due to the technical nature of the topic, and the rules set 

forth by the Regional Haze Rule, it is not possible to completely remove all technical language. 

The Division has posted additional background information for the public on the DEQ website: 
59

Commenter Comment # Section Comment DEQ Response

this problem, and make this important public policy statement 

regarding regional haze and the protection of iconic Class I areas 

fully understandable to the public-at-large, not just a few 

specialists.

http://deq.state.wy.us/aqd/regionalhaze.asp. The additional information is aimed at helping 

the public understand regional haze and what is required by the Rule and Implementation 

Plan. The SIP contains a Regional Haze Glossary of Visibility Acronyms, Abbreviations, and 

Terms in the Technical Support Document to assist in technical language understanding.

Wyoming 

Outdoor 

Council

E62 General

We ask the AQD to fully consider prior comments that we have 

submitted to it regarding the regional haze rule and 

implementation of it.

All prior comments that were signed and dated and submitted to the DEQ within the assigned 

commenting periods were responded to by the Division and can be found in the Technical 

Support Document. The Division takes every comment seriously and has responded to each 

one individually. This process can often take a prolonged period of time since the answers 

must be consistent with all stakeholders and presented in one unified document.

Wyoming 

Outdoor 

Council

E63 General

Three sets of comments were submitted by the Wyoming 

Outdoor Council to the AQD on September 10, 2008 regarding 

the Green River Works, Westvaco, and Granger trona plant BART 

permits. Supplemental comments regarding the trona plant 

BART permits were submitted to the AQD on October 17, 2008. 

Comments regarding the power plant BART permits were 

submitted to the AQD on August 4, 2009. In our view, the 

current draft SIPs do not make it clear that these prior 

comments have been fully considered.

The New Source Review (NSR) programs respond to all BART related comments. When 

determining the appropriate BART for each source, the Division followed Chapter 6, Section 9 

from the Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s Subpart Y 

Guidance. Each source underwent permitting and went out for public comment. DEQ 

responded to each comment. All comments and responses can be found in the TSD, under 

Chapter 11, Summary of FLM (and Other) Comments on BART and State Responses on BART. 

Permit applications and DEQ’s analysis of each permit can be found in Attachment A of the SIP

at: http://deq.state.wy.us/aqd/regionalhaze.asp.

All prior comments that were signed and dated and submitted to the DEQ within the assigned 

commenting periods were responded to by the Division and can be found in the Technical 

Support Document. The DEQ takes every comment seriously and has prepared an appropriate 

response for each comment received. 

Wyoming 

Outdoor 

Council

E64 General

Comments regarding the first draft 309(g) SIP were submitted to 

the AQD on October 26-27 2009. Comments were also 

submitted to the AQD on October 19, 2009. In our view, the 

current draft SIPs do not make it clear that these prior 

comments have been fully considered.

All of these noted comments were received in the appropriate commenting period, and have 

been addressed by the DEQ in this SIP revision. The DEQ has taken each comment seriously 

and have prepared a response to each comment. All responses can be found in the Technical 

Support Document. The comments that are 309-related take a little longer to answer since 

they must be reviewed by all of the 309 states, and consistent conclusions must be developed 

between all stakeholders. However, all responses to 309 comments are also included in the 

Technical Support Document.
60

Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

E65 General

Forest fires are not new. They have been occurring since time 

immemorial. While it is generally recognized that we have 

recently been in a period of heightened forest fire activity (and 

perhaps intensity) due to drought and past forest management 

practices, this current upsurge probably will not last forever. 

Thus, claims that forest fires will prevent us from achieving 

natural visibility conditions could be overstated, at least in the 

medium-to-long-term. The AQD should recognize this long-term 

eventuality and put in place a long-term strategy that recognizes 

the possible future diminishment of forest fire activity. We ask 

the AQD to consult closely with the Forest Service on this issuethe Forest Service is a Federal Land Manager and thus should be 

intimately involved in the development of this SIP-so as to 

ensure that its clams regarding forest fires are supported by the 

best available science.

The DEQ recognizes that forest fire activity changes through time and is not implying that 

achievement of natural visibility conditions is not possible in the lifetime of the SIP. The State 

attributes the inability to meet this planning period’s URP goals primarily to forest fires. 

Reasonable progress goals will be re-evaluated in subsequent reporting periods, and if a 

decrease in forest fire activity is seen, then it may be possible to meet the URP goals for the 

given period. Section 51.308(d)(3) states “The long term strategy must include enforceable 

emissions limitation, compliance schedules, and other measures as necessary to achieve the 

reasonable progress goals established...”. According to this section of the Rule, the State can 

only set long-term strategies that are enforceable. A decrease in forest fires is not enforceable 

or quantifiable, but rather a guess that activity may decrease in the future. Therefore, possible 

diminishment of forest fires cannot be included in the long-term strategy. The State has 

consulted closely with the Forest Service, recognizing the agency as a Federal Land Manager, 

and will continue to do so in future SIPs.

Wyoming 

Outdoor 

Council

E66 Forest Fires

If the claims in the 309(g) SIP that natural visibility conditions are 

approximately 6.0 dv on the worst visibility days are incorrect 

and that the current conditions on the worst visibility days 

(approximately 11.5) are more in line with what is possible given 

forest fires (this is the implication of AQD’s claims forest fires 

prevent achievement of natural conditions), the SIP should be 

revised to reflect this changed understanding.

The EPA has estimated the natural conditions based on factors such as mass components, 

IMPROVE methodology, relative humidity data (used to develop relative humidity 

adjustments), and error factors. The EPA developed a detailed document on how natural 

conditions were established: 

http://www.epa.gov/ttn/oarpg/t1/memoranda/rh_envcurhr_gd.pdf. Natural condition 

development as it relates to fire can be found in Section 1.14. Natural emissions from fires 

were taken into account through estimates based on compilations of natural versus man-made 

levels, ambient measurements in remote areas, regression studies and applied uncertainties. 

The EPA relied heavily on the National Acid Precipitation Program (NAPAP) developed in 1990 

to establish natural visibility conditions for the Regional Haze SIP. The following website 

provides a detailed description of the NAPAP program: 

http://www.epa.gov/airmarkets/resource/docs/NAPAP.pdf.

Natural visibility conditions are an estimate, and are difficult to determine. It is expected that 
61

Commenter Comment # Section Comment DEQ Response

EPA will revise the natural conditions estimate in future SIP revisions when there is a better

understanding of natural visibility conditions, and estimation methodologies.

Wyoming 

Outdoor 

Council

E67 General

As noted in the October 2009 comment, no matter what the 

impact of forest fires is on visibility, they only occur for about six 

months of the year, often more like four months per year, so in 

much of the year forest fires are of little issue relative to visibility 

impacts. Thus, the 309(g) SIP should be constructed from this 

perspective.

Section 51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must 

provide for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over 

the same period”. In the case of the best days, modeling demonstrates no further degradation 

of visibility. The worst days occurred in the summer months. Therefore, focusing on

correcting the winter months will have no impact on the results of the worst days modeling. 

The worst days can be seen in the modeling section: 

http://vista.cira.colostate.edu/TSS/Results/HazePlanning.aspx

BART-eligible sources identified in the SIP are required to control emissions year round, and 

the Division is confident that BART implementation will have significant visibility impairment 

improvements in both the summer and winter months.

Wyoming 

Outdoor 

Council

E68 Oil and Gas 

Development

The 309(g) SIP does not specifically plan to take any additional 

actions to control emissions from the oil and gas industry. We 

believe there is already in place more than enough information 

that dictates the need to take further action under the SIP.

DEQ is aware that there is an abundance of oil and gas related information. However, there is 

not a clean inventory available that contains information compiled using a systematic method. 

WRAP is working on such an inventory right now in Phase III of its project.

Oil and gas inventories are complicated to quantify. It is true that the DEQ has access to 

information for various small pieces of the process. However, to compile a complete 

inventory, every source must be looked at right down to the wellhead level. This includes the 

emissions associated with drilling and completing each well, which in itself is very complex. To 

name a few, the drilling and completion process alone has emissions associated with trucking 

trips for various fluids and pieces of equipment, drill rigs, completion rigs, wirelines, and 

fraccing equipment. Each well has different emissions associated with each activity. After the 

well is drilled and completed, the production process begins and there will be emissions 

associated with various pieces of production equipment such as tanks, flares, dehy units, 

compressor stations, fluid trucking, and pipeline losses. To account for all of these emissions, 

some of the things that must be known are how many pieces of production equipment are in 

the state, what types of controls each unit has, and how much oil and gas is being produced 
62

Commenter Comment # Section Comment DEQ Response

from each facility. These are only some examples of the complexity of an inventory 

development for oil and gas sources. A complete inventory will have to look at many more 

aspects than what was just outlined.

The State of Wyoming is making great strides for identifying and quantifying sources and 

emissions from new fields. However, it is much more difficult to quantify emissions associated 

with older fields in the state. In addition, the Division has started collecting inventories for oil 

and gas sources. The WRAP study will assist the State in understanding all of the sources that 

need to be evaluated.

Wyoming 

Outdoor 

Council

E69 Oil and Gas

The Bureau of Land Management (BLM) has prepared a number 

of Environmental Impact Statements (EIS) in recent years that 

address the visibility impacts of oil and gas development in 

Wyoming Class I areas. The AQD was designated as a 

“cooperating agency” in the preparation of the EIS, meaning that 

the AQD was a full party to these analyses, and the records of 

decision (ROD) that were put in place to implement them. The 

AQD should adopt provisions from the RODs. For example, 

operators are to comply with AQD Best Available Control 

Technology (BACT) standards.

The BLM Environmental Impact Statements are to be used by the BLM as a decision making 

tool, not an implementation planning and regulation development tool. Although the AQD is a 

cooperating agency, all of the information is pre-decisional until a draft document has been 

released to the public and is not approved until a Record of Decision (ROD) is released. The 

ROD can only be applied to the Federal land within the project boundaries. Therefore, 

agreements made in the ROD cannot be applied state wide. All operators must comply with 

DEQ’s Best Available Control Technology (BACT), not only the ones identified in the Pinedale 

ROD. Chapter 6, Section 2 of the WAQSR contains a permitting guidance, including BACT 

requirements for sources statewide.

Wyoming 

Outdoor 

Council

E70 Oil and Gas

Another area where reduction of the already well documented 

impacts of the oil and gas industry on visibility in Class I areas 

might be achieved is through the EPA’s upcoming revision of the 

New Source Performance Standards and National Emissions 

Standards for Hazardous Air Pollutants in the oil and gas 

industry. The AQD should commit to assisting the EPA in 

revising these regulations, and the 309(g) SIP should make 

enforcement of them a component of the SIP.

The WAQSR contains chapters that include New Source Performance Standards (NSPS) and 

National Emission Standards for Hazardous Air Pollutants (NESHAPs). The State of Wyoming 

adopts portions of each EPA standard. However, if the standard is not adopted, then the EPA 

regulates the sources contained in the category. Thus, each regulation is enforceable at the 

State or Federal level. There are a number of oil and gas related NSPSs that Wyoming has 

adopted such as standards of performance for petroleum refineries, storage vessels for 

petroleum liquids, VOC equipment leaks in petroleum refineries and natural gas processing 

plants, and onshore natural gas processing SO2 emissions. A full list of the adopted NSPS 

standards can be found in Section 8.2.1.3 of the SIP, and the full standards and regulations 

adopted by Wyoming can be found in Chapter 5, Section 2 of the WAQSR. There are also a 
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Commenter Comment # Section Comment DEQ Response

number of oil and gas sources regulated under the Wyoming NESHAP program such as

petroleum refineries, oil and natural gas production facilities and gasoline distribution 

facilities. A full list of the adopted NESHAP standards can be found in Section 8.2.1.4 of the 

SIP, and the full standards and regulations can be found in WAQSR Chapter 5, Section 3, and 

Chapter 6, Section 5.

The State and Federal rulemaking processes are performed separately. Other than 

commenting during the appropriate commenting periods, the DEQ cannot assist the EPA in the 

Federal rulemaking process. The State does undergo periodic revisions to the NSPS and 

NESHAP sections of the Wyoming rules, and will incorporate by reference at that time any new 

EPA standards and regulations that the Division determines to be appropriate for State 

regulation.

Wyoming 

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E71 BART

There are at least five point sources of air pollution that 

significantly affect visibility in the Bridger and Fitzpatrick 

Wilderness Areas, and the AQD has full authority to regulate 

them: the Naughton and Jim Bridger power plants and the 

Granger, Westvaco, and Green River Works trona plants. Thus, 

the SIP should focus special attention on dealing with haze 

causing pollution generated by these sources of pollution 

because it could lead to direct and meaningful improvement of 

visibility in these discrete, well defined Class I areas. In 

particular, the AQD should require Selective Catalytic Reduction 

(SCR) as a nitrogen oxides pollution control measure at these 

plants. 

All of the listed point sources have been analyzed by the BART process. When determining the 

appropriate BART for each source, the Division followed Chapter 6, Section 9 from the 

Wyoming Air Quality Standards and Regulations (WAQSR), as well as EPA’s Subpart Y Guidance. 

Each source underwent permitting and went out for public comment. DEQ responded to each 

comment. The public hearings for Granger, Westvaco, and Green River Works were all held in 

Rock Springs, WY on September 11, 2008. The public hearing for Jim Bridger was held on 

August 4, 2009 in Rock Springs, WY. Finally, Naughton’s public hearing was held on August 4, 

2009 in Kemmerer, WY. All comments and responses can be found in the TSD, under Chapter 

11, Summary of FLM (and Other) Comments on BART and State Responses on BART. Permit 

applications and analyses can be found in Attachment A of the SIP at: 

http://deq.state.wy.us/aqd/regionalhaze.asp.

Wyoming 

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E72 BART

Relying solely on the milestones and backstop trading program is 

only appropriate when it “will result in greater reasonable 

progress than source-specific BART in all Class I areas, including 

Bridger and Fitzpatrick, not just the sixteen (16) on the Colorado 

Plateau”. Thus, BART relative to sulfur dioxide pollution should 

be required for these five large sources of air pollution, in 

The State has modeled visibility in the additional non-Colorado Plateau Class I area monitor 

locations in Wyoming and surrounding states. Table 6.2-2 demonstrates visibility broken down 

by sulfate extinction only. It can be seen in this table that all Class I areas show visibility 

improvement for the worst days, and no degradation in visibility for the best days, thereby 

meeting the requirements outlined in the Regional Haze Rule. In addition, Table 6.2-1 outlines 

the Regional SO2 Emissions and Milestone Report summary. This table demonstrates that the 

309 states have experienced significant SO2 reductions and have more than exceeded the goals 
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Commenter Comment # Section Comment DEQ Response

addition to compliance with the milestone program, so as to 

achieve greater reasonable progress toward the natural visibility

goal at the Bridger and Fitzpatrick Wilderness Areas.

set by the program.

The Regional Haze Rule requires the above demonstration, as well as a demonstration that the 

milestones provide greater reasonable progress than BART. This demonstration can be found 

in Appendix E, Demonstration that the SO2 Milestones Provide Greater Reasonable Progress 

than BART. As long as this demonstration is performed, under the Regional Haze Rule, EPA 

allows the State to take credit for any SO2 reduction achieved in Section 309, as stated in 

51.309(g)(i): “In developing long term strategies pursuant to 51.308(d)(3), the state may build 

upon the strategies implemented under paragraph 9(d) of this section, and take full credit for 

the visibility improvement achieved through these strategies.” The rule does not require that 

SO2 sources undergo further reduction to achieve greater reasonable progress toward natural 

visibility.

Therefore, the State believes that all requirements of the Regional Haze Rule as it relates to 

the 309 strategies for meeting visibility goals have been met and the SO2 sources do not 

require further analysis.

Wyoming 

Outdoor 

Council

E73 General

Current visibility on the worst days is 11.1 dv, the needed 

improvement to be the “glide slope” would be 10.0 dv, yet the 

AQD is only planning to achieve visibility quality of 10.6 dv by 

2018. But it seems apparent that considerably more 

improvement in visibility in these Class I areas should be 

achieved if the AQD focused greater pollution control efforts on 

the five sources of nitrates and sulfates located in Wyoming that 

contribute very significantly to this visibility degradation.

The WRAP states have stressed that the uniform rate of progress is not achieved in any of the 

Western states because there are too many uncontrollable sources of emissions impacting 

visibility in the West, overwhelming the controllable sources. Organic carbon from wildfires is 

the single biggest contributor to visibility impairment in the West.

Section 51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must 

provide for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over 

the same period”. Since there is no degradation in visibility for the 20% best days, this portion 

of the Rule is satisfied. During the 20% worst days, wildfires are a major contributing factor. 

Therefore, without the ability to control wildfires, it is difficult to demonstrate enough 

reasonable progress to reach the URP goal.

The State believes that the appropriate BART analysis has been conducted on the five BARTspecific sources addressed by these comments. When determining the appropriate BART for 

each source, the Division followed Chapter 6, Section 9 from the Wyoming Air Quality 

Standards and Regulations (WAQSR), as well as EPA’s Subpart Y Guidance. Each source 
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Commenter Comment # Section Comment DEQ Response

underwent permitting and went out for public comment. DEQ responded to each comment. 

The public hearings for Granger, Westvaco, and Green River Works were all held in Rock 

Springs, WY on September 11, 2008. The public hearing for Jim Bridger was held on August 4, 

2009 in Rock Springs, WY. Finally, Naughton’s public hearing was held on August 4, 2009 in 

Kemmerer, WY. All comments and responses can be found in the TSD, under Chapter 11, 

Summary of FLM (and Other) Comments on BART and State Responses on BART. Permit 

applications and analysis can be found in Attachment A of the SIP at: 

http://deq.state.wy.us/aqd/regionalhaze.asp.

Also note that not all reductions were included in the WRAP modeling. The results do not 

include the BART and long-term strategy reductions proposed in this SIP or any other WRAP 

SIPs. The WRAP could only include enforceable reductions that were on the books at the time 

of the last model run. These regional model runs take many months to set up and run.

Wyoming 

Outdoor 

Council

E74 URP Goals

Table 7.2-1 in the 309(g) SIP shows that natural visibility 

conditions will not be reached until many years after the goal of 

reaching natural conditions by 2064. This raised significant 

questions regarding whether the State of Wyoming is pursuing 

reasonable progress towards natural visibility conditions.

Wyoming is not in a unique position. Most of the Western states are expressing difficulty 

achieving the URP goal due to the presence of uncontrollable fires in the West. Section 

51.308(d) of the Regional Haze Rule states that “The reasonable progress goals must provide 

for an improvement in visibility for the most impaired days over the period of the 

implementation plan and ensure no degradation in visibility for the least impaired days over 

the same period”. Since there is no degradation in visibility for the 20% best days, this portion 

of the Rule is satisfied. During the 20% worst days, wildfires are a major contributing factor. 

Until there is a decrease in wildfires, it will continue to be difficult to achieve URP goals.

It is important to note that not all reductions were included in the WRAP modeling. The results 

do not include the BART and long-term strategy reductions proposed in this SIP or any other 

WRAP SIPs. The WRAP could only include enforceable reductions that were on the books at 

the time of the last model run.
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Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

E75

Reasonable 

Progress 

Goals

The AQD states that tremendous progress has been made in the 

past controlling sulfur dioxide emissions. While this may be 

true, and we appreciate the AQD’s efforts in this regard, this 

does not change the fact that if visibility is still impaired-which it 

is-then additional reductions must be made.

The DEQ is trying to express that even though the State experiences the obstacle of visibility 

impairment due to forest fires, there has been significant progress made in the areas that are 

within the Division’s control. The State has addressed how further reductions can be made in 

the Long-Term Strategy section of the SIP.

Wyoming 

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E76

Reasonable 

Progress 

Goals

The AQD says that since “the state is starting out so clean” it 

essentially is reasonable to not expect more; compared to the 

East Wyoming is pretty good, so let’s not ask for more. We find 

this statement offensive and ask that it be removed from the 

SIP.

DEQ is not in any way trying to imply that the State “should not expect more”. DEQ is simply 

trying to demonstrate that it is not as easy to show progress when there are fewer initial 

visibility impacts. It is much easier to show increased original progress when there are greater

impacts. In addition, there is a large difference in vegetation and meteorological conditions 

between the East and the West. For example, in comparison to the East, the Class I areas in 

Wyoming are located in more heavily forested areas, and therefore more natural fires occur 

within the Class I area proximity. The low humidity in the West also allows for a more 

noticeable difference in the visibility when such an event occurs. The DEQ is not making 

excuses for not achieving URP goals and the Division does take the goal very seriously. The 

DEQ simply wanted to explain in the SIP why other states such as those in the East may be able 

to meet the URP in the initial phase, while Wyoming and other Western states were not.

Wyoming 

Outdoor 

Council

E77 Long-Term 

Strategy

The AQD evaluated non-BART sources of emissions for potential 

controls so as to comply with the regional haze rule, and to meet 

its goal. We believe that delaying pollution controls for these 

sources for nearly ten years is not reasonable and should be 

revisited by the AQD. The AQD could initiate any needed 

rulemaking now, or in the near future, and not wait nearly ten 

years to do this.

The DEQ does not claim to wait until the next revision to begin the rulemaking process. 

Rather, the Division is stating that the State currently does not have the authority to regulate 

these sources at this time, and that rules need to be developed in order to do so. The next SIP 

revision will be the first opportunity to control these sources through rules that may be in 

place by the next revision. Oil and gas rulemaking will not begin until the WRAP Phase III 

report has been complete, and the Division has a better understanding of what source types 

need to be controlled. 
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Commenter Comment # Section Comment DEQ Response

Wyoming 

Outdoor 

Council

E78 BART

The AQD claims that it is appropriate to essentially give 

PacifiCorp a break on pollution control requirements because it 

owns several large pollution sources in several states, and it 

could be difficult for the company to manage regional haze rule 

compliance on all of these plants at the same time.

The DEQ is not giving PacifiCorp a “break on pollution control requirements”. The State 

initially staggered the implementation deadline of the BART requirements in order to provide 

PacifiCorp with the appropriate time limit that would allow the installation of the equipment at 

all of the 19 sites. However, the SIP has undergone revisions, and the permit has undergone 

an appeal process. The SIP now states that PacifiCorp shall install and operate the required 

BART “in accordance with the Division’s BART determination, and conduct the required initial 

performance tests to demonstrate compliance as expeditiously as practicable, but no later than 

five years after EPA approval of the state implementation plan revision”.

Wyoming 

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Council

E79 Long-Term 

Strategy

Unlike many pollutants where the AQD is projecting reductions 

in emissions, dust is projected to increase fairly dramatically. 

Yet as best as we can determine the AQD is not planning to take 

any steps to control this increase in haze causing dust. Most of 

this dust will likely be created from dirt roads and construction 

activities. At a minimum the AQD should commit to 

investigating and if needed, putting in place requirements for 

the use of best managements practices to control this dust.

The State of Wyoming has implemented a number of programs to reduce PM emissions. The 

first is a nonattainment SIP for the City of Sheridan which addresses four PM10 control 

measures. The second is a Natural Events Action Plan which is aimed to protect public health 

in the Powder River Basin where wind-generated dust results in 24-hour NAAQS exceedances. 

Descriptions of these two programs can be found in Sections 8.2.1.7.1 and 8.2.1.7.2,

respectively.

Wyoming’s Air Quality Standards and Regulations (WAQSR) Chapter 3, Section 2, contains 

Emissions Standards for Particulate Matter. Specifically, Chapter 3, Section 2(f), prescribes 

measures to ensure the control of fugitive dust emissions during construction or demolition 

activities, handling, storage, and transporting of materials and agricultural practices. Further 

discussion on measures taken to mitigate construction dust can be found in Section 8.2.2 of 

the SIP.

Wyoming 

Outdoor 

Council

E80 BART

The AQD has certified that the Granger trona plant is one of a 

small group of sources that is causing visibility impairment (1.73 

dv) at the Bridger Wilderness Area. Thus, under the RAVI rule 

the AQD must initiate BART permitting for this trona plant, and 

such permitting should include sulfur dioxide controls as well as 

nitrogen oxides and particulate matter controls.

The DEQ does not believe that the trona plant should be grouped with other surrounding 

sources. Summing the 98th percentile modeled visibility impacts for separate facilities is not an 

accurate portrayal of combined impacts because the individual impacts may occur at different 

locations (receptors) and during different 24-hour time periods. Moreover, the visibility 

impacts from BART-eligible sources are to be determined separately. As stated in the EPA’s 

Appendix Y to part 40 CFR 51 - Guidelines for BART Determinations Under the Regional Haze 

Rule, relative to the use of the CALPUFF model for BART determinations, “We believe that 

CALPUFF is an appropriate application for States to use for the particular purposes of this rule, 

to determine if an individual source is reasonably anticipated to cause or contribute to 
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Commenter Comment # Section Comment DEQ Response

impairment of visibility in Class I areas, and to predict the degree of visibility improvement 

which could reasonably be anticipated to result from the use of retrofit technology at an 

individual source. We encourage States to use it for these purposes.”

EPA E81 BART

The BART determinations relied on two documents that need to 

be submitted as part of the SIP: 1) the BART application 

submitted by the BART sources; and 2) the analysis of the BART 

application performed by the State.

These documents have been included as Attachment A in the SIP.

EPA E82 Long-Term 

Strategy

The control measures identified in the four factor analysis need 

to be included and made enforceable as part of the long-term 

strategy, and the State needs to provide a justification as to why 

those control measures are not reasonable in the context of the 

four factors.

The State has provided an evaluation of the Control Strategies for the four-factor analysis as 

part of the long- term strategy in Section 8.3.4. DEQ explains, “the Air Quality Administrator 

cannot, per Wyoming Statute 35-11-202, establish emission control requirements except 

through State rule or regulation. Furthermore, the Wyoming statute requires the Administrator 

to consider the character and degree of injury of the emissions involved. In this case, visibility 

modeling would be required to assess the degree of injury caused by the emissions. Modeling is 

not available at this time to determine impacts from emission reduction. The State believes it 

has taken a strong and reasonable first step in identifying potential contributors to visibility 

impairment, and that the next step of creating an appropriate rule or regulation will be 

accomplished in the next SIP revision. The visibility progress was designed as a long-term 

program going out to 2064”.

EPA E83 Long-Term 

Strategy

Any emission limitations or control measures that the State is 

taking credit for under reasonable progress need to be federally 

enforceable. In draft SIP section 8.2.6, it states “Wyoming has 

ensured that all existing emission limitations and control 

measures, for which the State of Wyoming is responsible, used 

to meet reasonable progress goals, are enforceable at the State 

level through the Wyoming Air Quality Standards and 

Regulations (WAQSR) or State issued permits. Once EPA 

approves this SIP, these measures will be federally enforceable”. 

It is not clear what measures the State is referring to. The State 

needs to specify the particular regulations that are not currently 

The portions of the SIP that are currently not federally enforceable, but will be after the SIP 

approval are the BART determinations, summarized in Table 6.4-1 and the long-term strategy 

commitments for the Laramie River Station and Jim Bridger Power Plant BART facilities, found 

in Section 8.3.3.

Section 8.2.6 has been revised to read the following: “Wyoming has ensured that all existing 

emission limitations and control measures, for which the State of Wyoming is responsible, used 

to meet reasonable progress goals are enforceable at the State level through the Wyoming Air 

Quality Standards and Regulations (WAQSR) or State-issued permits. Many of the actions 

included in the SIP are already federally enforceable. However, BART permit conditions and 

long-term strategy commitments for the Laramie River Station and the Jim Bridger Power Plant 
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Commenter Comment # Section Comment DEQ Response

federally enforceable that will become federally enforceable. 

These regulations would have to be proposed as part of the SIP, 

submitted to EPA, and be approved as part of the SIP.

are currently only enforceable at the State level. Once EPA approves this SIP, these measures 

will be federally enforceable. The BART determinations are summarized in Table 6.4-1 and the 

long-term strategy commitments can be found in Section 8.3.3.”

EPA E84 Reasonable 

Progress

The U.S. EPA commented that the DEQ has included NOx controls 

for the LRS in the Regional Haze SIP that will be implemented 

under reasonable progress and not under BART. The EPA is 

concerned about this proposed approach, and will communicate 

any concerns to the State when the EPA’s evaluation is 

complete.

The AQD acknowledges the comment.

EPA E85 Long-Term 

Strategy

EPA’s regional haze rule does not allow for commitments such as 

those under Section 8.3.4 to implement strategies at some later 

date that are identified under reasonable progress or for the 

state to take credit for such commitments. Lacks of authority or 

information are not valid reasons to delay implementation of 

controls under reasonable progress.

As mentioned in the SIP, the DEQ does not currently have the regulatory authority to 

implement the controls identified in the four-factor analysis. However, the State commits to 

making changes going forward. The first planning period has identified sources that require 

further regulations, and the State is committed to reductions in the next SIP revision.