SOUTH DAKOTA’S 

 REGIONAL HAZE 

 STATE IMPLEMENTATION PLAN 

RESPONSE TO COMMENTS 

DURING FEDERAL LAND MANAGER 

REVIEW 

South Dakota Department of Environment and Natural Resources

 
1.0 Introduction ........................................................................................................................ 1

2.0 Comments on Executive Summary................................................................................... 2

3.0 Baseline, Natural and Uniform Rate of Improvement.................................................... 3

4.0 IMPROVE Data for Class I Areas.................................................................................... 5

5.0 Source Apportionment....................................................................................................... 7

6.0 Best Available Retrofit Technology (BART) ................................................................. 10

7.0 Reasonable Progress......................................................................................................... 23

8.0 Long Term Strategy ......................................................................................................... 26

9.0 Monitoring Strategy......................................................................................................... 29

10.0 Consultation Requirements............................................................................................. 29

11.0 Proposed ARSD 74:36:21 Rules...................................................................................... 30

12.0 General Comments........................................................................................................... 33

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1.0 Introduction 

In accordance with Title 40 of the Code of Federal Regulations (CFR), § 51.308(i)(2), the state 

must provide the Federal Land Manager with an opportunity for consultation, in person and at 

least 60 days prior to holding any public hearing on an implementation plan (or plan revisions) 

for regional haze. On January 15, 2010, DENR fulfilled this obligation and submitted South 

Dakota’s draft Regional Haze Program to the following Federal Land Managers: 

1. Tim Allen, U.S. Fish & Wildlife Service, Lakewood, Colorado; 

2. Trent Wickman, USDA Forest Service, Great Lakes National Forests – Eastern Region; 

3. John Bunyak, National Park Service, Air Resources Division, Lakewood, Colorado; 

4. John Notar, National Park Service, Air Resources Division, Lakewood, Colorado; 

5. Brian Kenner, National Park Service, Badlands National Park; and 

6. Ken Hyde, National Park Service, Wind Cave National Park. 

In addition, DENR took this opportunity to solicit comments from the following: 

1. Laurel Dygowski, EPA Region VIII; 

2. Amy Platt, EPA Region VIII; 

3. Monica Morales, EPA Region VIII; 

4. Catherine Nueschler and Anne Jackson, State of Minnesota; 

5. Teresa Cooper and Asad Khan, State of Michigan; 

6. Shelley Schneider and Katryna Schaf, State of Nebraska; 

7. Dana Mount and Tom Bachman, State of North Dakota; 

8. Curtis Taipale, State of Colorado; 

9. Dave Klemp, State of Montana; 

10. Tina Anderson, State of Wyoming; 

11. Jim Strain, South Dakota Department of Agriculture; 

12. Gene Nelson, GCC Dacotah, Rapid City, SD; 

13. Tim Rogers, Black Hills Corporation, Rapid City, SD; 

14. Danielle Weibers, Pete Lien and Sons, Rapid City, SD; 

15. Clint Allen, Hills Materials Company, Rapid City, SD; and 

16. Terry Graumann, Otter Tail Power Company, Big Stone I. 

DENR requested comments by March 16, 2010. DENR received comments from the United 

States Department of Agriculture – Forest Service, United States Department of Interior –

National Park Service, Otter Tail Power Company, and the United States Environmental 

Protection Agency (EPA) – Region 8. The comments may be reviewed in Appendix A. 

This document contains DENR’s responses to the comments received during the opportunity for 

consultation from the federal land managers, EPA and Otter Tail Power Company. A summary 

of the comments and DENR’s responses follows. 
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2.0 Comments on Executive Summary 

1. EPA states the BART emission limits, compliance schedule, monitoring, recordkeeping, and 

compliance determining methods for Big Stone I must be specified in the text of the Regional 

Haze State Implementation Plan or in a permit that is incorporated into the State 

Implementation Plan. EPA notes the public notice for the Regional Haze State 

Implementation Plan needs to include notification that an air quality permit to address BART 

requirements is incorporated as part of the State Implementation Plan. 

Response: DENR reviewed 40 CFR §308(1)(e) to determine the BART requirements that 

need to be included in the state implementation plan. In Section 6.1 and 6.2 of the state 

implementation plan, DENR describes the BART review that took place to determine which 

facilities were subject to BART (40 CFR §308(1)(e)(1)(i). Section 6.3 describes the case-bycase BART determination for Otter Tail Power Company’s Big Stone I facility, which is the 

only facility in South Dakota subject to BART. DENR did not establish a technological or 

economic limitation for BART; therefore, 40 CFR §308(1)(e)(1)(iii) is not applicable. 

In accordance with 40 CFR §308(1)(e)(1)(iv), DENR identified Otter Tail Power Company 

must install BART as expeditiously as practicable, but no later than 5 years from EPA’s 

approval of South Dakota’s state implementation plan in Section 6.4. DENR will also add 

this language to ARSD 74:36:21:06. 

In accordance with 40 CFR §308(1)(e)(1)(v), DENR is required to include a requirement that 

each source subject to BART maintain the control equipment and establish procedures to 

ensure the equipment is properly operated and maintained. This requirement is summarized 

in Section 6.4. DENR included these requirements in ARSD 74:36:21:07. However, DENR 

did not identify the minimum requirements for the operation, maintenance, and monitoring 

requirements; therefore, DENR will include the minimum requirements in ARSD 

74:36:21:07. 

DENR did not include a statement that met the requirements of 40 CFR §308(e)(5); 

therefore, DENR added a statement to Section 6.4 which specifies that Otter Tail Power 

Company is subject to the requirements of South Dakota’s state implementation plan in the 

same manner as other sources once they have installed and are meeting the BART 

requirements. 

DENR is not planning on implementing an emission trading program or the Clean Air 

Interstate Rule (CAIR); therefore, 40 CFR §308(e)(2), (3), and (4) are not applicable. Otter 

Tail Power Company has not requested an exemption; therefore 40 CFR §308(e)(6) is not 

applicable. 

DENR did not find in 40 CFR §308(e) where it required the actual BART permit to be 

incorporated in the State Implementation Plan. DENR established the requirements of 40 

CFR §308(e) in the written portion of the state implementation plan and in ARSD 74:36:21, 

which will be adopted in South Dakota’s state implementation plan. In addition, DENR will 
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establish the permit limits for Otter Tail Power Company’s BART eligible unit in ARSD 

74:36:21:10. Therefore, DENR believes it has met the requirements for including the BART 

requirements in the state implementation plan. 

2. EPA requested the timeline for removing the permit requirements related to Big Stone II 

from the existing permit. 

Response: Otter Tail Power Company’s current Title V air quality permit includes 

requirements for Big Stone I and II. Because of the time and expense of revising a Title V 

air quality permit, DENR does not plan on removing the requirements for Big Stone II from 

the Title V air quality permit until either Otter Tail Power Company requests a revision or 

their Title V air quality permit is up for renewal. DENR anticipates revising Otter Tail Power 

Company permit to include the BART requirements once EPA approves DENR state 

implementation plan. If Big Stone II has not been removed by the time the BART 

requirements are incorporated in the Title V air quality permit, DENR will removed Big 

Stone II at that time. 

3. EPA mentioned they did not receive the information in the last sentence of the Executive 

Summary which references Chapter 12.0 of the state implementation plan. Therefore, EPA 

was unable to review and comment on it. 

Response: Chapter 12.0 identifies the documents DENR referenced during the development 

of the state implementation plan. These documents are typically published by EPA and 

readily available to the public. 

3.0 Baseline, Natural and Uniform Rate of Improvement 

4. EPA mentioned it appears Appendix A will contain the IMPROVE data used to determine 

baseline visibility; but the data was not included in the draft document they received. 

Response: DENR did not include the IMPROVE data in the draft but the final document will 

contain the IMPROVE data. 

5. Based on EPA’s review of WRAP’s Visibility Information Exchange Web System (VIEWS) 

and information from the United States Forest Service, EPA indicates there are errors in the 

baseline and natural background figures in Table 3-1, 3-5, and 3-7. EPA mentioned they 

were aware that the United States Forest Service raised concerns with these tables and 

requested the values be revised accordingly. 

Response: Since EPA did not specify what information in the tables was in error, DENR 

reviewed the data in each table. DENR based the baseline and natural background data on 

the IMPROVE data it gathered from the federal land managers IMPROVE website. DENR 

checked the data in Table 3-1 and determined it matches the IMPROVE data that will be 

included in Appendix A. DENR also reviewed the natural background data based on the new 

formula in Table 3-5 and did not find any errors based on the IMPROVE data in Appendix 
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A. DENR agreed to use the default values for natural background which resulted in values in 

Table 3-7 needing to be revised to match the values in Table 3-1 and 3-5. DENR made the 

appropriate changes. 

As far as EPA’s comment on the United States Forest Service raising concerns with DENR 

on the values in the tables. The only concern the United States Forest Service raised in their 

comment letter was on the use of the default natural conditions which will be addressed in 

Comment #6 of this document. 

6. The National Park Service recommended DENR use EPA’s default values for natural 

conditions available on the VIEWS website for this current state implementation plan and 

defer refinements to a later state implementation plan. In addition, the United States Forest 

Service recommended DENR use Western Regional Air Partnership/Technical Support 

System (WRAP/TSS) natural conditions values, which were derived from EPA’s natural 

condition guidance. EPA indicated states must use EPA’s default values for natural 

conditions in the current State Implementation Plan and any refinements deferred to future 

planning periods. 

Response: DENR reviewed 40 CFR § 51.308 and EPA’s Guidance for Estimating Natural 

Visibility Conditions Under the Regional Haze Rule and could not find were it required a 

state to use the default values for natural conditions in the initial state implementation plan 

for regional haze as stated by EPA. EPA’s guidance does state the natural conditions 

estimates developed using the default approach is adequate to satisfy the requirements of the 

regional haze rule for the initial state implementation plan submittals. Therefore, DENR will 

use the default values in EPA’s guidance for the initial state implementation plan and will 

reevaluate natural conditions in future reviews. 

7. EPA stated the footnotes referring to Trijonis estimates for the Eastern United States do not 

need to be included in Table 3-6. 

Response: DENR agrees and made the appropriate change. 

8. EPA stated a column must be added to Table 3-7 to highlight the deciview improvement 

required for both the best and worst days. 

Response: DENR agrees and made the appropriate change. 

9. EPA recommend several changes to the Uniform Rate of Progress which are listed below: 

a. EPA stated Figure 3-11 was omitted in their draft document. 

Response: Figure 3-11 is an equation not a graph and was included in their draft document. 

Since listing an equation as a figure appears to be confusing, DENR will identify equations 

as “Equation” instead of a figure and renumber the figures appropriately. 
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b. EPA stated Table 3-8 needs to include the uniform rate of improvement of the 1st

planning period (2018) for the most and least impaired days, rather than leave it to the 

reader to calculate from the annual numbers provided. 

Response: Instead of listing the uniform rate of improvement for the 1st planning period in 

Table 3-8, DENR provided the uniform rate of improvement for the 1st planning period for 

the most impaired days in Figure 3-5(a) and (b). There is no uniform rate of improvement 

for the least impaired days. DENR is only required to ensure there is no degradation of the 

20% least impaired days. DENR agrees that it should display to the reader how we calculated 

the improvement needed by 2018 and will add a paragraph before Figure 3-5 describing this 

calculation and direct the reader to Figure 3-5 to view the uniform rate of improvement 

needed by 2018 for each Class I area. 

c. EPA was unable to determine the source of the 2018 numbers and thought it should be 

14.89 deciviews for the Badlands and 13.94 deciviews for Wind Cave. 

Response: DENR agrees and added a paragraph prior to Figure 3-5 describing how the 

uniform rate of improvement was calculated. 

4.0 IMPROVE Data for Class I Areas 

10. The National Park Service stated fires are an insignificant contributor to ammonium sulfate 

compared to fossil fuel combustion and recommended DENR delete the reference in Section 

4.1 (fourth paragraph) and the last paragraph of Section 4.2. 

Response: The National Park Service referenced Table 5-1 of the draft document for 

comparison of sulfur dioxide emissions from point versus forest fires. DENR agrees that 

point source emissions of sulfur dioxide are comparably greater than sulfur dioxide emissions 

from fires. However, in both cases mentioned by the National Park Service, DENR is 

identifying sources of ammonia sulfate emissions and not the activity that contributes the 

most. DENR does not recommend any changes. 

11. The National Park Service and United States Forest Service recommended DENR expand its 

analysis of the contribution of wildfire to visibility impairment. The National Park Service 

requested the expansion because wildfires are a major contributor of organic carbon and 

elemental carbon. While the United States Forest Service noted that high organic carbon 

concentrations do not necessarily mean fire impacts, as noted in the draft Regional Haze 

State Implementation Plan. One method of expanding the analysis would be to look at 

aerosol contributions on individual days during the 2000-2004 baseline period to identify 

elevated organic and elemental carbon that could indicate fire impacts. A back trajectory 

analysis could then be conducted to assist in separating impacts from local agricultural, 

prescribed fires, or point sources that might be controllable. Another approach they suggested 

would be to compare the seasonality of prescribed fire with wildfire. For example, South 

Dakota could get prescribed fire activity information from the burners in the states and see if 

it matches measured high organic compound impact days. 
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Response: DENR agrees that wildfire and prescribed fires contribute to visibility impairment 

at both the Badlands and Wind Cave National Parks. This is apparent from the evaluation 

DENR conducted on the IMPROVE data for the base year and WRAPS’ attribution analysis. 

As part of DENR’s long term strategy, DENR will review the IMPROVE data for the base 

year and future years to determine which fires (e.g., size, type of combustibles, distance from 

the Class I area) contribute to visibility impairment in South Dakota’s two Class I areas. 

DENR will use this information and compare to the best management practices that are being 

used across the nation and implement those practices that best fit the needs of South Dakota. 

DENR plans on implementing a Smoke Management Plan in calendar year 2013. 

12. In the seventh paragraph of Section 4.2, the National Park Service disagrees with DENR’s 

conclusion that local sources are not contributing to visibility impairment during the 20% 

least impaired days based on both National Parks having a good comparison of 

concentrations for each aerosol during the 20% least impaired days. The National Park 

Service recommends this statement be rephrased. 

Response: DENR based its conclusion that local sources were not impacting the 20% least 

impaired days because one would expect the concentrations during the 20% least impaired 

days to be different, not similar, because the Badlands National Park is prairie grasses, bare 

rock and sand and the Wind Cave National Park is prairie grasses and ponderosa pine forest. 

Impacts from regional influences would tend to create uniform concentrations throughout the 

area while local sources would impact one but not the other. However, DENR does agree 5-

year averaging would also smooth this out. DENR will need to evaluate this further to 

determine if there are any impacts from local sources hidden by the 5-year average and/or if 

regional influence is the main reason for the elevated concentrations on the 20% least 

impaired days. DENR agrees to rephrase this paragraph in Section 4.2. 

13. In the second paragraph of Section 4.3.3, the National Park Service indicated that visibility 

“impairment” appears to be declining rather than visibility declining. 

Response: DENR agrees and actually included visibility impairment in several other 

appropriate places in this section. 

14. In addition to the visibility trends data presented in Figure 4-7 and 4-8, the National Park 

Service recommended looking at similar time series plots for the individual aerosol 

components to illustrate whether sulfates and nitrates (those components dominated by 

anthropogenic, controllable sources) are declining more than organic carbon mass (an 

indicator of fire). The National Park Service also recommended keeping the y axis scale in 

Figure 4-8 equivalent for a better comparison. 

Response: DENR displays a similar time series plot for the individual aerosols for each 

national park in Figures 4-5 and 4-6 using an extinction comparison. DENR mentions that it 

reviewed this data and could not observe any trends because the aerosol components 

fluctuated. DENR does agree that the y axis scale should be equivalent not only with all the 

charts in Figure 4-8 but also Figure 4-7 and adjusted the scale of the y axis to a maximum of 
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25 deciviews for each graph. After reviewing the revised charts, DENR adjusted its analysis 

for the Wind Cave National Park.

5.0 Source Apportionment 

15. EPA states WRAP’s emission inventory for this planning period is adequate but expects 

future reviews be updated to the most current emission inventory (e.g., include oil and gas 

emission estimates). 

Response: DENR agrees and already mentioned in Section 5.1.5 of the draft that future 

emission inventories should be expanded and improved. 

16. EPA requested DENR elaborate on the “compliance initiative” related to volatile organic 

compound emissions from secondary oil and gas production in northwestern South Dakota. 

In particular, EPA asked what state mechanisms are in place to ensure these four thermal 

oxidizers are operating at a control efficiency of greater than 98%. 

Response: DENR agrees and expanded its discussion by adding the permit mechanism and 

the destruction efficiency requirement in Section 5.1.3. 

17. EPA mentioned there is a large discrepancy between South Dakota’s oil and gas volatile 

organic compound emissions and the WRAP TSS numbers which needs to be explained in 

greater detail. In addition, EPA wanted it explained if these numbers were used for modeling 

and reasonable progress purposes. 

Response: DENR believes the discrepancy between DENR and WRAP on this issue is 

explained sufficiently. WRAP did not use the 33,433 tons of volatile organic compound 

emissions from secondary oil and gas production in northwestern South Dakota in its 2002 

modeling; but the reductions achieved are represented in the modeling for 2018 and 

reasonable progress purposes. DENR will add a paragraph at the end of Section 5.1.1 to 

explain EPA’s second concern. 

18. EPA has questions about the large difference in baseline sulfur dioxide emissions for area 

sources found in Table 5-1 (10,159 tons) and 5-2 (1,071 tons) and requested this be explained 

in further detail. In addition, EPA pointed out a typographical error on the footnotes for 

Table 5-4. The National Park Service also requested that this large difference be explained. 

Response: DENR agrees and added an explanation in the sixth paragraph of Section 5.1.1 

and corrected the typographical error in the footnotes of Table 5-4. 

19. EPA noted that emission inventories from other states that submitted their plans does not 

match what DENR has in Tables 5-6 and 5-7 and requested that we verify their emission 

inventory numbers. 
 8 

Response: As discussed, DENR derived the emission inventory numbers from WRAP’s 

website. It would be safe to state that if North Dakota used WRAP’s emission inventory 

numbers they would not match up with South Dakota’s since we are correcting the emission 

inventory in the state implementation plan just like DENR is assuming North Dakota is doing 

in their state implementation plan. DENR does not propose any changes; but plans on 

updating emission inventories from others states as already stated in Section 5.1.5. 

20. EPA identified a typographical error in the last paragraph on page 54 and second paragraph 

on page 56 and stated the text is not consistent with the figures which show a slight change 

between 2002 and 2018 for both the least and most impaired days. 

Response: DENR agrees there is a typographical error where “most” was used and should 

have been “least” impaired days on both pages. However, the text is correct in stating the 

contributors from 2002 and 2018 for sulfate at each Class I area did not change. Essentially, 

DENR was comparing what areas the sulfate emissions were being generated from (e.g., 

Outside Domain, Canada) and not what type of sources were contributing. DENR corrected 

the typographical errors but made no other changes. 

21. EPA requested the first paragraph, second to last sentence on page 58 should be clarified to 

read that “Natural fire related organic carbon mass generated in Montana contributes 

approximately 34% of the organic carbon mass in Badlands National Park.” 

Response: DENR agrees and will make the appropriate change. 

22. The National Park Service requested DENR separate out Big Stone I emissions in Table 5-2 

to make it easier to compare data from Table 5-2 to Table 5-4, 6-1, and 6-3. The United 

States Forest Service also requested Big Stone I emissions be separated out to show how big 

of a part it is of South Dakota’s point source emission inventory. 

Response: DENR agrees and identified the total emissions from Big Stone I, which are 

included in the “Point” source emissions for comparison purposes. 

23. Based on the sulfur dioxide emissions for the four new point sources in Table 5-4 and all 

other point sources together projected to emit 2,458 tons of sulfur dioxide emissions in 2018 

and area sources projected to emit 1,662 tons by 2018, the National Park Service believes 

these emissions should be assessed in determining if there are reasonable control measures. 

The National Park Service also mentioned the Prevention of Significant Deterioration permit 

application DENR received from Basin Electric for a natural gas fired combined cycle power 

generating facility in Brookings County, South Dakota. 

Response: DENR has already addressed the projected emissions from Big Stone I through a 

BART analysis which will reduce projected sulfur dioxide emissions from 3,425 to 2,212 

tons per year; nitrogen oxide emissions from 15,323 to 2,457 tons per year; and particulate 

matter from 318 to 295 tons per year. On December 1, 2009, Otter Tail Power Company 

relinquished all rights and obligations granted through and by the PSD permit that was issued 

for Big Stone II. Therefore, the Big Stone II emissions in Table 5-4 will be eliminated. 
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The Hyperion Energy Center, which is a proposed combined oil refinery and electric power 

plant, and the Basin Electric’s proposed natural gas fired combined cycle power generating 

facility went through a Prevention of Significant Deterioration permit review to ensure air 

emissions from each of these facilities would not cause or contribute to visibility impairment 

in a Class I area. DENR will include the air emissions from Basin Electric’s proposed 

natural gas fired combined cycle power generating facility in the next 2018 evaluation. 

Basin Electric’s NextGen coal-fired electric power plant will also be required to go through a 

Prevention of Significant Deterioration permit review to ensure its air emissions would not 

cause or contribute to visibility impairment in a Class I area. Currently this permit 

application is on hold. 

DENR’s evaluation on if area sources of sulfur dioxide emissions should be assessed to 

determine if there are reasonable control measures was based on the attribution section of the 

draft Regional Haze State Implementation Plan. According to the attribution analysis, sulfur 

dioxide emissions from all sources in South Dakota are minimal and after Big Stone I installs 

the required controls under BART, sulfur dioxide emissions will be even further reduced. 

24. Otter Tail Power Company requested it be clarified that even though Big Stone II emissions 

may be included in the 2018 emission projections, Big Stone II is no longer proceeding. 

Response: DENR agrees and will make the appropriate changes to the fourth paragraph of 

Section 5.1.3. 

25. The National Park Service requested a clarification on the assumptions used for the WRAP 

regional modeling compared to those used in the Big Stone Unit 1 BART modeling. The 

National Park Service indicated that Table 5-2, 5-4, 6-1, and 6-3 do not appear consistent and 

requested DENR clarify what each table represents. The following summarizes the National 

Park Service’s questions on the emission inventory comparison: 

a. Does Table 6-3 refer to potential emissions? 

Response: Table 6-3 represent the results of WRAP’s modeling analysis of Big Stone Unit 

1’s visibility impact on Class I areas. The emissions represent the 24-hour average actual 

emission rate from the highest emitting day of the meteorological period modeled, not 

including periods of startup, shutdown or malfunctions and was based on WRAP’s modeling 

protocol. The website location for the modeling protocol is included just before Table 6-3. 

To clarify this, DENR will describe how the emissions were determined. 

b. Table 6-3 WRAP BART modeling results based on 88% and 75% of all SD point source 

SO2 and NOx emissions in 2002. Is this correct? 

Response: Table 6-3 would not represent an apple to apple comparison for determining Big 

Stone Unit 1’s sulfur dioxide and nitrogen oxide emissions compared to other sources in 

South Dakota. Table 5-2 would be a good comparison. Based on Table 5-2, Big Stone Unit 
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1’s sulfur dioxide and nitrogen oxide emissions compared to point sources represents 80% 

and 70%, respectively. 

c. Did DENR include assumptions or BART controls for Big Stone Unit 1 in the WRAP 

2018PRP18b regional modeling? 

Response: The emissions from Big Stone Unit 1 in Table 5-4 were used in WRAP’s 

2018PRP18b regional modeling analysis and based on Big Stone II being built and routing 

air emissions from Unit 1 through some of the control equipment associated with Big Stone 

II. The emissions from Unit 1 would pass through the wet scrubber but not the SCR 

associated with Big Stone II. The proposed BART emission limits were not used in WRAP’s 

2018PRP18b regional modeling analysis. 

d. In Table 5-4, Big Stone Unit 1 is projected to emit 3,425 tons SO2 in 2018, 18% of the 

value in Table 6-1 or 28% of the value in Table 6-3. How does this relate to the 90% 

control efficiency listed for dry scrubbing in Table 6-6? 

Response: Again, the emission rates for each Table are not comparable because they are 

based on different assumption. 

e. In Table 5-4, Big Stone Unit 1 NOx emissions in 2018 (15,580 tons) appear to be the 

same as used as the baseline for the BART analysis reported in Table 6-3. Does this mean 

that WRAP regional modeling assumed SO2 controls but not NOx controls for Big Stone 

Unit 1? 

Response: As described earlier, the emissions from Big Stone Unit 1 in Table 5-4 were used 

in WRAP’s 2018PRP18b regional modeling analysis and based on Big Stone II being built 

and routing air emissions from Unit 1 through some of the control equipment associated with 

Big Stone II. The emissions from Unit 1 would pass through the wet scrubber but not the 

SCR associated with Big Stone II. 

6.0 Best Available Retrofit Technology (BART) 

26. EPA identified a typographical error in the second sentence of the first paragraph dealing 

with Pete Lien and Sons’ operations. EPA recommended the wording be “...not in operation 

prior to August 7, 1962...” instead of “in operation”. 

Response: DENR agrees and will make the appropriate change. 

27. EPA agreed it was correct to include Pete Lien and Sons in the WRAP subject-to-BART 

modeling analysis. EPA noted Pete Lien and Sons’ existing Title V air quality permit still 

includes the vertical kiln and there has not been a permit modification to address any such 

dismantling and closure. EPA recommends the permit be modified to reflect this change in 

status of the vertical kiln or the modeling needs to be re-run to correct the input errors and 

accurately determine whether Pete Lien and Sons is subject to BART. 
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Response: DENR disagrees with EPA that Pete Lien and Sons’ Title V air quality permit 

should be revised to reflect the dismantling and closure of the vertical kiln or the modeling 

needs to be re-run. In permit condition 1.1, the footnote for Table 1-1 requires Pete Lien and 

Sons to shutdown and disassemble the vertical kiln before the initial startup of Unit #45, 

which is a newer kiln. Pete Lien and Sons notified DENR on March 13, 2009, that the 

vertical kiln was shutdown and dismantled. DENR does agree to clarify in the discussion in 

Section 6.1.2 that the permit requires them to shutdown and disassemble the vertical kiln and 

that has been completed. This discussion is included in the last paragraph of Section 6.1.2. 

28. EPA stated the modeling inputs and outputs for Otter Tail Power Company’s Big Stone I 

BART assessment need to be incorporated in the State Implementation Plan for 

documentation and public review. 

Response: In Section 6.2, this section states the modeling Otter Tail Power Company 

completed for Big Stone I’s BART assessment will be available in Appendix D – Otter Tail 

Power Company’s Visibility Impact Analysis. DENR did not include this when they sent out 

the review because EPA and the federal land managers had already received copies of the 

modeling analysis. The modeling inputs and outputs were included as part of the modeling 

analysis and will be available to the public in Appendix D. 

29. In Section 6.3.2.4, page 83, footnote 3, EPA requested DENR explain how the 18,000 tons 

per year sulfur dioxide baseline figure was obtained and why it is different from the 19,863 

tons per year identified in Table 6-1. On Table 6-10, page 88, EPA (15) identified a 

typographical error in footnote 3 and should be “nitrogen oxide” instead of “sulfur dioxide”. 

EPA would like a further explanation on how DENR determined 18,000 tons per year of 

nitrogen oxide emissions for baseline instead of 17,179 tons per year from Table 6-1. In 

Section 6.3.4, second paragraph, page 89, EPA (16) requested that the 18,000 tons per year 

of sulfur dioxide and nitrogen oxide emissions for baseline determination should be 

explained further. 

Response: Table 6-1 displays what units at a facility are BART eligible sources and is based 

on the unit’s potential to emit. In 40 CFR Part 51, Appendix Y – Guidelines for BART 

Determination Under the Regional Haze Rule, in the section titled “How should I determine 

visibility impacts in the BART determination” it notes that the model should use the 24-hour 

average actual emission rate from the highest emitting day of the meteorological period 

modeled (for the pre-control scenario). The 19,863 tons of sulfur dioxide per year identified 

in Table 6-1 was based on a heat input rating of 4,560 million Btus per hour, operating 8,760 

hours per year, and the potential sulfur dioxide emission rate of approximately 1 pound per 

million Btus. The 18,000 tons of sulfur dioxide per year identified in the BART analysis is 

based on the highest average 24-hour average emission rate (4,832 pounds per hour) for 

calendar years 2001 through 2003 and operating 85% of the time or 7,746 hours per year. 

The 17,179 tons of nitrogen oxide per year identified in Table 6-1 is the unit’s potential to 

emit and is based on a heat input rating of 4,560 million Btus per hour, operating 8,760 hours 

per year, and a nitrogen oxide emission rate of 0.86 pounds per million Btus. The 18,000 tons 
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of nitrogen oxide per year identified in the BART analysis is based on the highest average 

24-hour average emission rate (4,855 pounds per hour) for calendar years 2001 through 2003 

and operating 85% of the time or 7,746 hours per year. 

Table 6-1 and the annual emission rate used in the BART analysis should not be compared to 

each other. Based on the BART guidelines, the baseline emissions should be the 18,000 tons 

per year for sulfur dioxide and nitrogen oxide. To clarify, DENR added “Potential to Emit” 

as a header to Table 6-1 and will add a paragraph to Section 6.3.2.4 and 6.3.3.4 to explain the 

annual emissions used in the BART analysis. 

DENR agrees with the typographical error and will change it appropriately. 

30. In Section 6.3.3.2, page 85-86, EPA had not completed a thorough review of this section on 

the “Technically Feasible Nitrogen Oxide Control Technologies” and may have additional 

comments during the public comment period. 

Response: Does not require a response. 

31. On Table 6-9, page 87, footnote 5, EPA states the control efficiency of the selective catalytic 

reduction (SCR) and separated over-fire air (SOFA) system should be better than the 90% 

control efficiency of a SCR alone and believes the proposed limit should be lower than the 

proposed 0.1 pounds per million Btu limit. In Section 6.3.3.3, the National Park Service 

requested DENR state the control effectiveness and resulting emission rate that it believes to 

be appropriate for each control technology option. The National Park Service suggests a 30-

day rolling average limit of 0.06 pounds of nitrogen oxide per million Btus. The National 

Park Service based its proposed nitrogen oxide emission limit on an Illinois permit for two 

cyclone boilers firing Powder River Basin subbituminous coal and equipped with over-fire 

air and selective catalytic reductions system at Dominion Energy’s Kincaid Generating 

Station. Illinois required a nitrogen oxide emission limit of 0.07 pounds per million Btus on 

an annual based. In Section 6.3.5.3, the National Park Service believes the Kincaid cyclone 

boilers in Illinois have demonstrated the ability of a SCR to reduce nitrogen oxide emissions 

below the limit proposed by DENR and suggest a 30-day rolling average limit of 0.06 pounds 

per million Btus would be appropriate. 

Response: EPA appears to be basing the BART emission limit on an assumed control 

efficiency and an arbitrary emission rate from Otter Tail Power Company’s Big Stone I 

facility. In considering what emission limit represents BART, one needs to consider the 

operation of the emission unit and the control device. DENR considers it inappropriate to 

take an arbitrary emission rate Otter Tail Power Company has actually emitted and multiply 

it by an arbitrary control efficiency to develop an emission limit. 

The control efficiency is variable as recognized by EPA’s fact sheet (EPA-452/F-03-024) for 

fabric filters controlling particulate matter emissions. The fact sheet notes a fabric filter is a 

constant outlet device and not a constant collection efficiency device. This fact sheet also 

notes the collection efficiency of the fabric filter is constantly changing and average 

collection efficiencies are based on tests with a constant inlet pollutant loading. EPA also 
 13 

recognized the variability in another fact sheet (EPA-452/F-03-032) for selective catalytic 

reduction systems controlling nitrogen oxide emissions. In this fact sheet, EPA states control 

efficiencies greater than 70 percent may be achieved with nitrogen oxide concentrations as 

low as 20 parts per million and that higher nitrogen oxide levels result in increased 

performance. 

EPA acknowledges this concept in rule. In accordance with 40 CFR §60.482-10, a vapor 

recovery system shall be designed and operated to recover the volatile organic compound 

emissions vented to them with an efficiency of 95 percent or greater or to an exit 

concentration of 20 parts per million by volume, whichever is less stringent. 

Depending on the document reviewed, the control efficiency of a selective catalytic reduction 

system varies from 35 to 90 percent. This range is based on EPA’s fact sheet (EPA-452/F-03-

032) for selective catalytic reduction systems and Babcock/Wilcox’s webpage at 

http://www.babcock.com. EPA’s fact sheet notes the efficiency is greater than 70 percent 

with nitrogen oxide concentrations as low as 20 parts per million. Using EPA’s Method 19 

to convert the concentration, 20 parts per million is equivalent to approximately 0.083 

pounds per million Btus at 15% oxygen. This emission rate is at the range of the emission 

limits being discussed. Babcock/Wilcox webpage notes a selective catalytic reduction system 

should obtain a nitrogen oxide control efficiency in the range of 70 to 90 percent. None of the 

documents identify under what operating conditions these control efficiencies will occur 

(e.g., low, mid or high loads); the time period for demonstrating compliance (e.g., hourly or 

30-day average emission rate); and/or the inlet pollutant loading rate. 

To illustrate the problem of just multiplying an emission rate by a control efficiency, DENR 

reviewed Otter Tail Power Company’s hourly nitrogen oxide emissions by obtaining data 

from EPA website - Clean Air Markets – Data and Maps. In calendar year 2006, 2007, and 

2008, and not considering periods of startup and shutdown, the hourly nitrogen oxide 

emission rates ranged from approximately 0.46 to 1.324 pounds per million Btus. Using the 

70 to 90 percent range, the controlled emission rates would range from 0.05 to 0.39 pounds 

per million Btus on an hourly basis. 

DENR also reviewed Otter Tail Power Company’s 30-day rolling average nitrogen oxide 

emission rate from the same data. In calendar year 2006, 2007, and 2008, and not considering 

days that Otter Tail Power Company was not in operation, the 30-day rolling average 

nitrogen oxide emission rate ranged from 0.66 to 0.84 pounds per million Btus. Using the 70 

to 90 percent range, the controlled emission rates would range from 0.07 to 0.25 pounds per 

million Btus. 

DENR reviewed EPA’s Reasonable Achievable Control Technology, Best Available Control 

Technology, and Lowest Achievable Emission Rate Clearinghouse (RBLC) for permits 

issued after calendar year 2000 on the emission limits established for coal fired boilers using 

a selective catalytic reduction system. The RBLC notes that the best available control 

technology emission limits for new coal fired boilers using a selective catalytic reduction 

system were in the range from 0.05 to 0.1 pounds per million Btus. A new boiler is more 

capable of meeting these limits because the system can be designed into the construction of 
 14 

the facility. An existing boiler does not have the advantage of maximizing and optimizing 

the operation of a control device compared to a new unit because the control device must be 

designed and constructed within the constraints of the existing operation and design. 

Therefore, DENR would not expect Otter Tail Power Company installing a new selective 

catalytic on an existing coal fired boiler to meet the lower range of the best available control 

technology emission limit. 

DENR reviewed the operation of the Kincaid Generating Station in Illinois mentioned by the 

National Park Service. The Kincaid Generating Station is an existing coal fired boiler 

burning sub-bituminous coal and using a selective catalytic reduction system. Based on the 

Kincaid Generating Station’s air quality permit, during May through September of each year, 

the facility must meet a nitrogen oxide emission limit of 0.25 pounds per million Btus. 

DENR reviewed Kincaid Generating Station’s hourly nitrogen oxide emissions by obtaining 

data from EPA website - Clean Air Markets – Data and Maps for calendar year 2008. The 

30-day nitrogen oxide rolling average for May through September ranged from 0.06 to 0.10 

pounds per million Btus. For the other months (January, February, March, April, October, 

November, and December), Kincaid Generating Station’s 30-day nitrogen oxide rolling 

average ranged from 0.60 to 0.83 pounds per million Btus. 

Manufacturers will report a control efficiency range in its manuals or brochures; but in 

general and in DENR’s experience, most manufacturers give emission rate guarantees in an 

outlet concentration and not as a control efficiency. Therefore, DENR does not believe citing 

a control efficiency is relevant in determining BART. DENR does not recommend any 

changes. 

The presumptive emission limit established by EPA for a selective catalytic reduction system 

installed on a cyclone coal fired unit is 0.10 pounds per million Btus of fuel heat input 

(Federal Register Volume 70 Number 128 on page 39172). DENR reviewed Otter Tail Power 

Company’s BART analysis and compared their results to other results we identify in the state 

implementation plan and verified the nitrogen oxide emission limit of 0.1 pounds per million 

Btu is BART. DENR does not recommend any changes. 

32. In Section 6.3.3.4, page 87, EPA indicated they do not recommend relying on the CUECost 

model for estimating costs. EPA states the BART Guidelines requires cost estimates to be 

based on the OAQPS Control Cost Manual in order to maintain and improve consistency. 

The National Park Service stated Otter Tail Power Company should have used EPA’s control 

Cost Manual as advised by the BART guidelines and by EPA Region 8 or at least provided 

its CUECost output data. 

Response: DENR reviewed 40 CFR Part 51, Appendix Y – BART Guidelines to determine 

if the guideline actually requires that cost estimates be based on the OAQPS Control Cost 

Manuals as stated by EPA. One of the key words in the title indicates the OAQPS Control 

Cost Manual is not required and that word is “Guideline”. In addition, in several locations in 

the guideline, it states, “In order to maintain and improve consistency, cost estimates should 

be based on the OAQPS Control Cost Manual, where possible.” The words “should be” and 
 15 

“where possible” do not require the use of the OAQPS Control Cost Manual. Therefore, 

DENR is not required to use the OAQPS Control Cost Manual. 

The Sixth Edition of EPA’s Air Pollution Control Cost Manual notes EPA has not developed 

a method for several of the identified controls. For example, cost estimates for controlling 

nitrogen oxide such as fuel switching, low NOx burners, steam/water injection, natural gas 

reburn and non-selective catalytic reduction are not available. The manual lists just two cost 

estimates for selective non-catalytic reduction and selective catalytic reduction to control 

nitrogen oxide emissions. 

Otter Tail Power Company provided Burns and McDonald’s December 7, 2009, letter which 

was in response to DENR’s request for additional information. In this letter Burns and 

McDonald note the selective catalytic reduction and separated over-fire air system cost 

effectiveness using the CUEcost of $825 per ton of nitrogen oxide reduced was similar to the 

OAQPS Control Cost Manual of $900 per ton of nitrogen oxide reduced. Regardless of the 

manual used, DENR considered the submitted cost as a reasonable cost on a $ per ton basis. 

DENR does not propose any changes. 

33. On Table 6-12, page 89, footnote 2, EPA states the rounded modeling values in parentheses 

were used to compare the subject to BART threshold; but actually the unrounded modeled 

value must be used for determining whether a source exceeds the threshold. 

Response: In accordance with 40 CFR Part 51, Appendix Y, a source that has an impact 

equal to or greater than 1.0 deciviews is considered to “cause” a visibility impairment and 

that establishing a threshold for what is considered to “contribute” to a visibility impairment 

should not be any higher than 0.5 deciviews. Appendix Y does not specify the rounding 

method (e.g., conventional, truncate); therefore DENR determined it should be conventional 

rounded to the tenth decimal since both deciview values are to the tenth value. 

Rounding a numerical value means replacing it by another value that is approximately equal 

but as a shorter, simpler, or more explicit representation. Rounding is also done to indicate 

the accuracy of a computed number. In this case, the computer models results are to the 

thousandths and DENR is rounded the results to the nearest tenth for comparison to the 

standards. In addition, the rounding methodology implemented is one of the most common 

methods used. Just because the model gives the results out to three decimal points or to the 

thousandth does not mean that the threshold is required to be to the thousandth. 

As noted in 40 CFR Part 51, Appendix Y, states remain free to use a threshold lower than 0.5 

deciviews if they conclude that a Class I area justifies this approach. South Dakota identified 

it’s contribute threshold as equal to or greater than 0.5 deciviews. This threshold means a 

visibility impact of 0.450 or greater is considered to contribute to visibility impairment. 

Appendix Y does not specify the rounding method (e.g., conventional, truncate); therefore 

DENR determined it should be conventional rounded to the tenth decimal since both 
 16 

)

deciview values are to the tenth value. The rounding convention proposed by South Dakota 

meets the requirements specified in the guideline. DENR does not recommend any changes. 

34. EPA assumed compliance with DENR’s proposed particulate matter BART limit for Big 

Stone I of 0.012 pounds per million Btu is based on a 30-day rolling average basis, as 

required. EPA requested we clarify in the state implementation plan. 

Response: DENR reviewed 40 CFR §51.308 and 40 CFR Part 51, Appendix Y to determine 

if particulate emission limits are required to be based on a 30-day rolling average and found 

no federal requirement. In 40 CFR Part 51, Appendix Y, it states, “...you must establish 

enforceable emission limits that reflect the BART requirements and require compliance with 

a given period of time.” In addition, it states, “Section 302(k) of the CAA requires emission 

limits such as BART to be met on a continuous basis.” Section 302(k) of the CAA defines 

an emission limit as a requirement established by the state or the Administrator which limits 

the quantity, rate, or concentration of emissions of air pollutants on a continuous basis, 

including any requirement relating to the operation or maintenance of a source to assure 

continuous emission reduction, and any design, equipment, work practice or operational 

standard promulgated under this chapter. 40 CFR Part 51, Appendix Y further states, “In 

light of the above, the permit must ... specify a reasonable averaging time consistent with 

established reference methods” and “... For EGUS, specify an averaging time of a 30-day 

rolling average...” 

Otter Tail Power Company proposed to base its pounds per hour limit on a 30-day rolling 

average based on the following equations and methodology. 

( )(

k

HeatInput EmissionRate

DailyRate

k

n

×

=

∑=1

Where: 

• Daily Rate = the average pounds per hour emission rate per day; 

• Heat Input = the hourly heat input recorded from the continuous emission monitor; 

• Emission Rate = the pounds per million Btus emission rate as determined by the most 

recent performance test. The performance test is based on the average of three 1-hour 

runs; and 

• k = the number of hours the boiler operated in the day. 

 

( )

30

30

30

1

∑= = n

DailyRate

Day

 

Where: 

• 30 Day = the 30-day rolling average; and 

• Daily Rate = the average pounds per hour emission rate per day. 
 17 

DENR did not include the 30-day rolling average since theoretically, if the performance test 

demonstrates compliance with the pounds per hour limit and the pounds per million Btu 

limit, it will comply with the same limit on a 30-day rolling average. The pounds per hour 

limit is based on the maximum heat input to the boiler multiplied by the pounds per million 

Btu emission rate. As long as the performance test demonstrates compliance, the only 

theoretical way that the 30-day rolling average would exceed the limit is if Otter Tail Power 

Company operated above is maximum heat input of the boiler. If Otter Tail Power Company 

operates greater than is maximum heat input, Otter Tail Power Company would be in 

violation of its permit. Therefore, DENR did not believe it is worth the manpower to 

calculate a 30-day rolling average when compliance is determined by the performance test 

itself. 

DENR also contends the citation EPA is referencing is for an emission limit where a 

continuous emission monitor is being used to demonstrate compliance such as for sulfur 

dioxide and nitrogen oxide. In the case of the particulate emission limit, compliance on a 

continuous basis will be based on an annual stack test and compliance assurance and periodic 

monitoring as required in the Title V air quality permit program. As noted in 40 CFR Part 51, 

Appendix Y, the particulate emission limit is consistent with the proposed reference method 

(e.g., performance test). 

DENR does not recommend any changes. 

35. EPA assumed compliance with DENR’s proposed sulfur dioxide BART limit for Big Stone I 

of 0.09 pounds per million Btu is based on a 30-day rolling average basis, as required. EPA 

requested that we clarify in the state implementation plan. 

Response: In the last paragraph of Section 6.3.5.2, compliance with the proposed emission 

limit was stated as “should” be based on the continuous emission monitoring system and on a 

30-day rolling average. DENR is clarifying this by stating it “shall” be based on the 

continuous emission monitoring system and on a 30-day rolling average. In this case, since a 

continuous emission monitoring system is being used to demonstrate compliance, the 30-day 

rolling average requirement is applicable. 

36. EPA indicates there is no bright line regarding cost effectiveness and each determination 

must be made taking into account a full five factor BART analysis. EPA states it is 

reasonable to assume that SCR is generally cost-effective on large cyclone units. 

Response: No response required. 

37. EPA requested DENR clarify that DENR’s BART determination is SCR plus SOFA at 0.10 

pounds per million Btus with compliance based on a 30-day rolling average. 

Response: DENR agrees and revised Section 6.3.5.3 appropriately. 

38. EPA is requesting a justification for proposing a separate hourly startup/shutdown limit for 

particulate matter, sulfur dioxide, and nitrogen oxide in the state implementation plan as well 
 18 

as whether the selected value represents BART. EPA asked in their comments if DENR 

evaluated potential impacts of the separate startup/shutdown limit on visibility in the Class I 

areas? EPA states the BART guideline contemplates pounds per million Btu limit that apply 

continuously with a 30-day rolling average period to accommodate potential short term 

fluctuations in the emission rate that may results during startup, shutdown, and other 

conditions. 

Response: DENR explained in Section 6.3.1 and 6.3.5.1 why a baghouse was considered the 

top particulate matter control technology and determined what the particulate matter 

emission limit should be based on our recent Prevention of Significant Deterioration 

evaluation of Big Stone II. DENR explained in the Section 6.3.2 and 6.3.5.2 what the top 

sulfur dioxide control technology is and determined what the sulfur dioxide emission limit 

should be. DENR explained in the Section 6.3.3 and 6.3.5.3 what the top nitrogen oxide 

control technology is and determined what the nitrogen oxide emission limit should be. 

DENR is uncertain what additional information EPA is requesting since EPA did not provide 

any justification on why the selected value did not represent BART. 

DENR disagrees that 40 CFR Part 51, Appendix Y requires compliance with the emission 

limit to be based on a 30-day rolling average if a continuous emission monitoring device is 

not used to demonstrate compliance. Otter Tail Power Company is using continuous 

emissions monitoring devices to demonstrate compliance on a 30-day rolling average for 

sulfur dioxide and nitrogen oxide. For particulate matter, DENR is requiring Otter Tail 

Power Company to demonstrate continuous compliance using annual stack tests and 

compliance assurance monitoring and periodic monitoring requirements in the Title V air 

quality permit. Fluctuations in the emission rate resulting during startup, shutdown, and 

other conditions will not be discovered from an annual stack test. These fluctuations will be 

observed based on the compliance assurance and/or periodic monitoring requirements in the 

Title V air quality permit. 

In regards to how will days be accounted for that include some, but not all, hours of 

startup/shutdown. The calculation would be the same as the calculation used to determine 

the daily rate when the boiler operated some, but not all, hours during the day. The equations 

would look like the following: 

( )

k

EmissionRate

DailyRate

k

n

∑= = 1

Where: 

• Daily Rate = the average pounds per million Btus emission rate per day; 

• Emission Rate = the pounds per million Btus emission rate as determined by the 

continuous emission monitoring; and 

• k = the number of hours the boiler operated in the day, excluding hours that contain 

startup and shutdown. 

 
 19 

( )

30

30

30

1

∑= = n

DailyRate

Day

 

Where: 

• 30 Day = the 30-day rolling average; and 

• Daily Rate = the average pounds per million Btus emission rate per day. 

 

As defined in 40 CFR §51.301, Best Available Retrofit Technology (BART) means an 

emission limitation based on the degree of reduction achievable through the application of 

the best system of continuous emission reduction for each pollutant which is emitted by an 

existing stationary facility. The emission limitation must be established on a case-by-case 

basis taking into consideration the technology available, the costs of compliance, the energy 

and non-air quality environmental impacts of compliance, any pollution control equipment in 

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

improvement in visibility which may reasonably be anticipated to result from the use of such 

technology. As noted in the definition, the units that represent BART are not defined. The 

emission limitation may be in pounds per hour, pounds per ton, pounds per million Btus, etc. 

DENR established a pound per hour emission limit for particulate mater, sulfur dioxide, and 

nitrogen oxide to represent BART, which covers all normal operations including startup and 

shutdown. These hourly limits will be included in the permit because they were used in the 

visibility analysis to demonstrate Otter Tail Power Company was not causing visibility 

impairment in a Class I area. 

When comparing control technology’s and emission limits across or within industrial sectors 

a generalized emission rate is used. The generalized emission rate such as a pound per 

million Btus allows emission rates across boilers of varying sizes to be compared. A pounds 

per hour emission rate is difficult to compare from one boiler to the next if the heat input of 

the boilers are not identical. Whereas, the pound per hour emission rate is a case-by-case 

emission limit and is specific to an emission unit. 

DENR does not recommend any changes. 

39. In Section 6.4, page 99, EPA is concerned that without seeing the permit for a BART source, 

they will not be able to determine if this section of the State Implementation Plan adequately 

addresses requirements for enforceability, including appropriate averaging times, compliance 

verification procedures, recordkeeping and reporting requirements, and proper operation and 

maintenance procedures. 

Response: DENR believes EPA’s concerns are relieved by the fact the state implementation 

plan identifies what the emission limit will be and how they will demonstrate compliance; the 

proposed Administrative Rules of South Dakota (ARSD) section 74:36:21:10 requires the 

BART source to modify its permit to include BART limits and requirements; ARSD section 

74:36:21:07 requires a BART source to establish written procedures to ensure the BART 
 20 

control equipment is properly operated and maintained; ARSD section 74:36:21:08 requires 

the BART sources to conduct periodic monitoring, recordkeeping, and reporting as required 

in ARSD chapter 74:36:13 and section 74:36:05:16.01(9); and ARSD section 74:36:21:12

requires consultation with federal land managers. The periodic monitoring, recordkeeping 

and reporting section specified in these sections are from the Title V air quality program 

which EPA has already approved. All of these requirements will be in a proposed 

construction permit program that will be part of South Dakota’s State Implementation Plan 

and DENR’s approved Title V air quality program. Both of which requires public input and 

in the case of the Title V air quality program, EPA’s concurrence. 

In addition, Otter Tail Power Company is already required to meet the requirements under 

ARSD 74:3616:01 – Acid Rain Program. South Dakota’s continuous emission monitoring 

requirements for the Acid Rain program are the same as EPA’s (40 CFR Part 75). 40 CFR 

Part 75 specifies monitoring provisions, operation and maintenance requirements, missing 

data substitution procedures, recordkeeping and reporting requirements for the monitored 

data. These same requirements will be used to verify compliance with the BART sulfur 

dioxide and nitrogen oxide emission limits. South Dakota performance test requirements 

(ARSD 74:36:11) specifies the performance tests must be conducted in accordance with the 

applicable method specified in 40 CFR Part 60, Appendix A, Part 63, Appendix A and Part 

51, Appendix M. The test methods specify the monitoring provisions to conduct a proper 

test. Therefore, these requirements will be used to verify compliance with the BART 

particulate matter emission limits. 

DENR believes the BART requirements for Otter Tail Power Company are identified in the 

state implementation plan and will be incorporated in a permit issued by DENR that is 

federally enforceable. To ensure the requirements are federally enforceable, DENR added 

ARSD section 74:36:21:10, which specifies the particulate matter, sulfur dioxide, and 

nitrogen oxide BART emission rates for BART-eligible coal-fire power plants. 

40. In Section 6.3.2.3, the National Park Service requested DENR state the control effectiveness 

and resulting emission rate that it believes to be appropriate for each control technology 

option. The National Park Service agreed with DENR’s analysis, but suggests the baseline 

for annual sulfur dioxide emissions should reflect anticipated uncontrolled annual emissions 

which according to EPA’s Clean Air Market database have averaged 0.66 pounds per million 

Btus over the 2000 through 2008 period. 

Response: The National Park Service appears to be requesting DENR specify a control 

effectiveness of 90% for the dry scrubber and calculate an emission limit using that control 

effectiveness on an uncontrolled emission rate of 0.66 pounds per million Btus. In 

considering what emission limit represents BART, one needs to consider the operation of the 

emission unit and the control device. DENR considers it inappropriate to take an arbitrary 

emission rate Otter Tail Power Company has actually emitted and multiply it by an arbitrary 

control efficiency to develop an emission limit. 

The control efficiency is variable as recognized by EPA’s fact sheet (EPA-452/F-03-024) for 

fabric filters controlling particulate matter emissions. The fact sheet notes a fabric filter is a 
 21 

constant outlet device and not a constant collection efficiency device. This fact sheet also 

notes the collection efficiency of the fabric filter is constantly changing and average 

collection efficiencies are based on tests with a constant inlet pollutant loading. EPA also 

recognized the variability in another fact sheet (EPA-452/F-03-034) for flue gas 

desulfurization (wet and dry) controlling sulfur dioxide emissions. In this fact sheet, EPA 

states control efficiencies range from 50 percent to 98 percent. EPA acknowledges this 

concept in rule. In accordance with 40 CFR §60.482-10, a vapor recovery system shall be 

designed and operated to recover the volatile organic compound emissions vented to them 

with an efficiency of 95 percent or greater or to an exit concentration of 20 parts per million 

by volume, whichever is less stringent. 

Depending on the document reviewed, the control efficiency of a selective catalytic reduction 

system varies from 50 to 98 percent. This range is based on EPA’s fact sheet (EPA-452/F-03-

032) for flue gas desulfurization systems. This fact sheet does note that typically a dry 

scrubber has a reduction efficiency less than 80 percent but newer designs are capable of 

higher control efficiencies on the order of 90%. EPA’s document does not identify under 

what operating conditions these control efficiencies will occur (e.g., low, mid or high loads); 

the time period for demonstrating compliance (e.g., hourly or 30-day average emission rate); 

and/or the inlet pollutant loading rate. 

To illustrate the problem of just multiplying an emission rate by a control efficiency, DENR 

reviewed Otter Tail Power Company’s hourly sulfur dioxide emissions by obtaining data 

from EPA website - Clean Air Markets – Data and Maps. In calendar year 2006, 2007, and 

2008, and not considering periods of startup and shutdown, the hourly sulfur dioxide 

emission rates ranged from approximately 0.5 to 1.3 pounds per million Btus. Using an 80 to 

90 percent range, the controlled emission rates would range from 0.05 to 0.26 pounds per 

million Btus on an hourly basis. 

DENR also reviewed Otter Tail Power Company’s 30-day rolling average nitrogen oxide 

emission rate from the same data. In calendar year 2006, 2007, and 2008, and not considering 

days that Otter Tail Power Company was not in operation, the 30-day rolling average 

nitrogen oxide emission rate ranged from 0.59 to 0.89 pounds per million Btus. Using an 80 

to 90 percent range, the controlled emission rates would range from 0.06 to 0.18 pounds per 

million Btus. 

DENR reviewed EPA’s Reasonable Achievable Control Technology, Best Available Control 

Technology, and Lowest Achievable Emission Rate Clearinghouse (RBLC) for permits 

issued after calendar year 2000 on the emission limits established for coal fired boilers using 

a flue gas desulfurization system. The RBLC notes that the best available control technology 

emission limits for new coal fired boilers using a flue gas desulfurization system were in the 

range from 0.04 to 0.17 pounds per million Btus. A new boiler is more capable of meeting 

these limits because the system can be designed into the construction of the facility. An 

existing boiler does not have the advantage of maximizing and optimizing the operation of a 

control device compared to a new unit because the control device must be designed and 

constructed within the constraints of the existing operation and design. Therefore, DENR 

would not expect Otter Tail Power Company installing a flue gas desulfurization on an 
 22 

existing coal fired boiler to meet the lower range of the best available control technology 

emission limit. 

Manufacturers will report a control efficiency range in its manuals or brochures; but in 

general and in DENR’s experience, most manufacturers give emission rate guarantees in an 

outlet concentration and not as a control efficiency. Therefore, DENR does not believe citing 

a control efficiency is relevant in determining BART. DENR does not recommend any 

changes. 

DENR reviewed Otter Tail Power Company’s BART analysis and compared their results to 

other results we identify in the state implementation plan and verified the sulfur dioxide 

emission limit of 0.09 pounds per million Btu is BART. DENR does not recommend any 

changes. 

41. In Section 6.3.2.4, the National Park Service stated Otter Tail Power Company should have 

used EPA’s control Cost Manual as advised by the BART guidelines and by EPA Region 8 

or at least provided its CUECost output data. 

Response: DENR reviewed 40 CFR Part 51, Appendix Y – BART Guidelines to determine 

if the guideline actually requires that cost estimates be based on the OAQPS Control Cost 

Manuals as stated by the National Park Service and EPA. One of the key words in the title 

indicates the OAQPS Control Cost Manual is not required and that word is “Guideline”. In 

addition, in several locations in the guideline, it states, “In order to maintain and improve 

consistency, cost estimates should be based on the OAQPS Control Cost Manual, where 

possible.” The words “should be” and “where possible” do not require the use of the 

OAQPS Control Cost Manual. Therefore, DENR is not required to use the OAQPS Control 

Cost Manual. 

The Sixth Edition of EPA’s Air Pollution Control Cost Manual notes EPA has not developed 

a method for several of the identified controls. For example, cost estimates for controlling 

sulfur dioxide such as wet and dry flue gas desulfurization systems are not available. The 

manual identifies this in the Table of Contents as a Planned Chapter. 

Even though the specific CUECost output file identified by the National Park Service was 

not provided, Otter Tail Power Company provided the CUECost input files and summarized 

the estimated costs from the CUECost output files in its BART analysis. Otter Tail Power 

Company identified the cost per ton as $1,492 per ton. Regardless of the manual used, 

DENR considered the submitted cost as a reasonable cost on a $ per ton basis. 

DENR does not propose any changes. 

42. The National Park Service recommended DENR provide an additional table which illustrates 

the cumulative $/dv for the control options in Table 6-15. 

Response: Instead of adding an additional table, DENR added a row for the cumulative 

$/deciview for each option in Table 6-15. 
 23 

43. Otter Tail Power Company requested the fourth sentence in Section 6.3.1.1 be revised as 

follows: “As such, the filterable particulate may be collected by placing a control device in 

the flue gas stream prior to the stack.” 

Response: DENR agrees and made the appropriate changes. 

44. Otter Tail Power Company requested footnote 4 for Table 6-9 be clarified to represent Best 

Available Control Technology for Basin’s NextGen project is for a new pulverized-fired 

boiler equipped with a low-NOx burner combustion technology which produces lower levels 

of nitrogen oxide emissions entering the selective catalytic reduction than are achievable with 

an existing cyclone-fired boiler. 

Response: DENR agrees to clarify the BACT analysis is for a new pulverized-fired boiler 

equipped with a low-NOx burner combustion technology. 

45. Otter Tail Power Company requested it be clarified that the number of significant digits Otter 

Tail Power Company reported for its deciview impacts included in Table 6-12 and 6-14 are 

consistent with WRAP modeling results presented in Table 6-3 and are also consistent with 

accepted industry practices. 

Response: DENR agrees to state the reporting of the visibility impact to three significant 

digits is consistent with how WRAP reported its modeling results in footnote 2 of Table 6-12 

and the paragraph just before Table 6-14. 

46. Otter Tail Power Company requested the last sentence of the second paragraph in Section 

6.3.5.1 be revised to reference the annual performance test and the number of hours the boiler 

operated that day. 

Response: DENR agrees and will clarify the most recent annual performance test. 

7.0 Reasonable Progress 

47. EPA was unable to determine in Table 7-1 and Section 7.2.1 if 16.50 and 15.28 deciview for 

the Badlands and Wind Cave, respectively were DENR’s reasonable progress goals and 

indicated the numbers do not match those shown in Figure 8-1. EPA requested clarification 

and documentation on how these numbers were derived. EPA also stated in accordance with 

40 CFR §51.308(d)(2)(iv)(A), DENR is required in the state implementation plan to include 

the deciview difference between the baseline and natural conditions for the best and worst 

days for the first planning period (2018). EPA also stated in accordance with 40 CFR 

§51.308(d)(1)(ii), the state implementation plan must provide the number of years necessary 

to reach natural conditions when the reasonable progress goal is less than the uniform rate of 

progress. 
 24 

Response: DENR clarified where the baseline, uniform progress and reasonable progress for 

2018 were derived from by adding footnotes to Table 7-1. The baseline values were derived 

from Table 3-7. The uniform progress goals for 2018 were derived from Figure 3-5. The 

reasonable progress goals for 2018 were derived from WRAP’s modeling. 

DENR realized that Figure 8-1 is actually a table and re-labeled it as Table 8-1. Table 8-1 

was derived from WRAP’s reasonable progress analysis at the Badlands and Wind Cave 

National Parks using what was considered background and natural conditions at the time. 

DENR clarified where the baseline conditions and deciview values for baseline, natural 

conditions and uniform rate of progress were derived in the footnotes. The baseline 

conditions were derived from Table 4.3(b) and 4.4(b) for the Badlands and Wind Cave 

National Parks, respectively. The deciview values were derived from Table 3-7 for the 

baseline and natural conditions and Figure 3-5 for the uniform rate of progress. 

40 CFR §51.308(d)(2)(iv)(A) states the following, “For the first implementation plan 

addressing the requirements of paragraphs (d) and (e) of this section, the number of 

deciviews by which baseline conditions exceed natural visibility conditions for the most 

impaired and least impaired days.” DENR compared the baseline and natural visibility 

condition values but did not display the difference. Therefore, DENR changed Table 3-7 to 

include the difference. 

DENR reviewed 40 CFR §51.308(d)(1)(ii) and agrees with EPA’s interpretation. DENR 

explained its intentions in Section 10.3; but understands the explanation should be in more 

detail and revised this section to explain. 

48. EPA stated the public must be provided a calculation of the number of years required to 

reach natural conditions if the Reasonable Progress Goal provides a slower rate of 

improvement than that needed to attain natural conditions by 2064 per 40 CFR 

§51.308(d)(1)(ii). The State Implementation Plan must include DENR’s best estimate of 

number of years to reach natural condition with the Reasonable Progress Goals. The National 

Park Service stated that because modeled progress in improving visibility by 2018 is less 

than the uniform rate of progress necessary to achieve natural visibility by 2064, DENR 

needs to define when natural conditions are expected to be achieved given the reasonable 

progress goals by 2018. 

Response: DENR reviewed 40 CFR §51.308(d)(1)(ii) and agrees with EPA’s interpretation. 

DENR explained its intentions in Section 10.3; but understands the explanation should be in 

more detail and revised this section to explain. 

49. EPA indicated a four factor analysis must be conducted as part of the Reasonable Progress 

Goals as well as justifying a Reasonable Progress Goal that is less than the Uniform Rate of 

Progress. The National Park Service indicated DENR is missing the required four factor 

analysis of potential emissions controls. The Forest Service believes a four factor analysis is 

required but depending on Big Stone I’s emission contribution, a simple analysis may be 

justified and requested DENR use the information and analysis provided by WRAP. 
 25 

Response: To determine if a four factor analysis is warranted, DENR looked at the air 

pollutants being emitted from point sources that were not meeting the glide path for each 

National Park. Based on Figure 7-1(a), the air pollutant not meeting the glide path at the 

Badlands National Park is ammonia sulfate and organic carbon mass. Based on Figure 7-

1(b), the air pollutant not meeting the glide path at the Wind Cave National Park is ammonia 

sulfate, organic carbon mass, and ammonia nitrate. 

Next, DENR reviewed WRAP’s attribution analysis to determine the major contributors of 

ammonia sulfate, organic carbon mass, and ammonia nitrate in South Dakota’s two Class I 

areas. For the Badlands and Wind Cave National Parks, the major contributors of ammonia 

sulfate are from sources not in South Dakota. South Dakota’s ammonia sulfate contribution 

for 2002 and 2018 is minimal at both national parks at approximately 0.04 micrograms per 

cubic meter. South Dakota’s contribution represents 3% of the ammonia sulfate 

concentrations for 2018 at both national parks. Of the 3%, approximately 1.5% is generated 

from point sources and 1.5% is generated from mobile and other sources. 

The major contributor of organic carbon mass in both National Parks is natural fires with 

point source contributions minimal. Organic carbon mass emissions from natural and 

prescribed fires will be evaluated in a smoke management plan which is part of DENR’s long 

term strategy. 

Ammonia nitrate was only a concern for the Wind Cave National Park since it was on the 

glide path at the Badlands National Park. At the Wind Cave National Park, the major 

contributors to ammonia nitrate are Canada followed by Wyoming, Outside the Domain, and 

South Dakota. South Dakota’s ammonia nitrate contribution for 2002 and 2018 is 

approximately 0.135 and 0.105 micrograms per cubic meter, respectively. South Dakota’s 

contribution represents 10% of the ammonia nitrate concentration for 2018 at the Wind Cave 

National Park. Of the 10%, approximately 4% is generated from point sources and 6% is 

generated from mobile and other sources. 

DENR determined that a four factor analysis is not warranted at this time because of the 

minimal contribution point sources contribute to visibility impairment in South Dakota’s 

Class I areas. DENR will re-evaluate this decision during periodic reviews of the Regional 

Haze State Implementation Plan. This will also give DENR time to determine if the 

implementation of each state’s Regional Haze Program will bring ammonia sulfate, ammonia 

nitrates, and organic carbon mass emissions in line with the Uniform Rate of Progress. 

50. The National Park Service indicated DENR should state explicitly that the reasonable 

progress goals for South Dakota’s Class I areas are the same as the WRAP CMAQ modeling 

results for 2018 and DENR did not include any other emissions reductions beyond those 

modeled by WRAP in setting the reasonable progress goals. 

Response: DENR disagrees since the BART determination for Otter Tail Power Company’s 

Big Stone I facility is not included entirely in WRAP’s modeling analysis of reasonable 

progress goals. In addition, DENR is proposing rules that will require new major sources and 

a modification to an existing major source that are not subject to New Source Review to 
 26 

conduct a visibility impact analysis to ensure the proposal will not contribute to adverse 

impact on visibility in an mandatory Class I area. The later was not mentioned in the draft 

Regional Haze State Implementation Plan and will be included in Section 7.1.

8.0 Long Term Strategy 

51. In accordance with 40 CFR §51.306(c), EPA states DENR must revise its plan to provide for 

a coordinated long term strategy for addressing both reasonably attributable and regional 

haze visibility impairment and future coordinated long term strategies must be submitted 

consistent with the schedule for periodic progress reports set forth in 40 CFR §51.308(g). 

Currently, the requirements in 40 CFR §51.306(c) are under a Federal Implementation Plan. 

EPA has not determined how to coordinate a reasonable attributable long-term strategy under 

a Federal Implementation Plan with a regional haze long-term strategy State Implementation 

Plan. EPA states the simplest approach would be for DENR to adopt a reasonable 

attributable program and asked if DENR was interested in this concept. 

Response: Because EPA has not determined how to coordinate a reasonable attributable 

long-term strategy under a Federal Implementation Plan with a regional haze long-term 

strategy State Implementation Plan does not mean DENR is required to adopt a reasonable 

attributable program. EPA, under the Federal Implementation Plan, must submit their long 

term strategy for addressing reasonably attributable visibility impairment in accordance with 

40 CFR §51.306(c). Currently DENR is not interested in developing a reasonable 

attributable program to replace EPA’s program; but will coordinate with EPA in developing 

a long term strategy that addresses both programs. DENR clarified this commitment in 

Section 11.2. 

52. In Section 8.1, page 105, EPA states DENR must quantify South Dakota’s impact to the 

Class I areas outside the state (similar to that noted in Table 6-4). 

Response: DENR is unsure of what EPA is requesting. In accordance with 40 CFR § 

51.308(d)(3)(i), the long term strategy for each state that causes or contributes to impairment 

in a Class I area is required to demonstrate that it has included in its state implementation 

plan all measures necessary to obtain its share of the emission reductions needed to meet the 

progress goals for the Class I area. DENR determined that Otter Tail Power Company’s Big 

Stone I facility is the only source in South Dakota that is reasonable anticipated to contribute 

to visibility impairment in Class I areas in other states. DENR discusses how the impacts will 

be addressed in Chapter 6.0. Table 6-4, which EPA referenced in their comment, quantifies 

Otter Tail Power Company’s impact. DENR does not believe it needs to be repeated in 

Section 8.1. DENR does not recommend any changes. 

53. In Section 8.3, page 106, EPA recommended DENR add the website addresses and/or 

references to where the technical analyses are located and how they will be maintained going 

forward. In addition, DENR should specify its commitment to continue compilation and 

analysis of the technical requirements for the Regional Haze State Implementation Plan 

regardless of future uncertainness in the WRAP’s role. 
 27 

Response: DENR is confident WRAP will remain a viable resource for states to use in their 

Regional Haze updates in the future. DENR will continue to support the WRAP along with 

the tools developed including the Technical Support System (TSS), Visibility Information 

Exchange Web System (VIEWS), Emissions Data Management System (EDMS), Fire 

Emissions Tracking System (FETS), etc. In the event that the WRAP should cease to exist, 

DENR will continue to monitor and model data for technical analyses to accomplish the 

goals of South Dakota’s Regional Haze State Implementation Plan. DENR will include the 

technical analyses website at: 

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

54. EPA indicated there is currently a Federal Implementation Plan in place for the original 

visibility new source review requirements under 40 CFR §51.307, which incorporated by 

reference the requirements in 40 CFR §51.28 (see 40 CFR §51.2179(b)). EPA asked if 

DENR’s intention was to use the proposed regional haze rules under Administrative Rules of 

South Dakota, Chapter 74:36:21 to replace the nonattainment new source review visibility 

analysis requirements. If so, EPA would provide input on such revision. 

Response: The Administrative Rules of South Dakota, Chapter 74:36:21 is being adopted to 

implement the Regional Haze Program. DENR does not anticipate adopting the original 

visibility program at this time. 

55. In Section 8.5.5, page 109-110, in accordance with 40 CFR §51.308(d)(3)(v)(E), EPA states 

that in establishing DENR’s long term strategy, DENR must consider smoke management 

techniques for agricultural and forestry management purposes including plans as currently 

exist with the state for these purposes. At least some preliminary steps, in coordination with 

the federal land managers, must be included along with citing to existing South Dakota 

burning provisions. The National Park Service would like to see a more complete discussion 

of local options to address emissions of organic carbon mass, elemental carbon, and course 

mass because the source apportionment analyses indicates organic carbon from natural fires 

is a major contributor on the 20% most impaired days. In addition, a more complete 

discussion of options to control smoke from unplanned wildland fires and the relative 

importance of prescribed burns and agricultural burns in the state. In Section 8.5.5, DENR 

states agricultural burning occurs in the eastern part of the state but the National Park Service 

states that does not preclude transport of smoke to the west on some days. The National Park 

Service acknowledges the emissions from prescribed burns in the national parks are 

contributing to visibility impairment and would like to participate in an effective smoke 

management plan. The United States Forest Service offered to assist DENR in developing the 

smoke management plan. 

Response: DENR agrees that in accordance with 40 CFR §51.308(d)(3)(v)(E), smoke 

management techniques for agricultural and forestry management purposes including plans 

as currently exist within the states for these purposes must be considered once DENR 

determines the impacts local burning practices have on the monitoring data being collected at 

the Badlands and Wind Cave National Parks. As noted in Section 8.5.5, we do not believe 
 28 

agricultural burning has much of an impact at our Class I areas because of the distance, the 

size of the burns, and none of 20% most impaired days indicated issues from an eastern 

agricultural burn. But DENR does believe that forestry management including planned 

prescribed burning may have an impact based on the 20% most impaired days indicating a 

large fire impacting one or both Class I areas in South Dakota. DENR committed to 

developing and implementing a smoke management plan in the “Executive Summary” but 

did not make that clear in this section. DENR will clarify that in Section 8.5.5, that DENR 

will develop and implement a smoke management plan. 

Over the past few years DENR has taken the initial steps in developing a smoke management 

plan by contacting those groups that DENR believes would need to be involved, including 

the South Dakota Department of Agriculture, National Park Service and U.S. Forest Service, 

among others. The response from these agencies has been positive and all have offered to 

assist in developing a smoke management plan for South Dakota. More recently, DENR has 

been in contact with the South Dakota Division of Wildland Fire Suppression, which 

maintains a prescribed fire database of fires throughout South Dakota and along our borders 

in neighboring states. DENR will use this database to track fires and compare the fire data 

(e.g., size of fire, material being burned, distance from the Class I areas, dates) to the 

IMPROVE data from our Class I areas to see what the impacts are to the visibility. DENR 

will also research the Best Management Practices for controlling prescribed fires. 

Using this information will be the basis of our smoke management plan and the direction we 

go in development of the smoke management plan will depend on the outcome of the data 

analysis. To start with, the main focus of the smoke management plan will consist of the 

Black Hills region and the areas around the two Class I areas. DENR will work with the 

federal land managers, other state agencies, and local governments during the development 

and implementation of the smoke management plan. 

DENR will discuss this in further detail in Section 8.5.5. 

56. In Section 8.5.6, page 110-111, EPA recognized that DENR plans on establishing the Big 

Stone I BART limits and control measure requirements in either a construction permit or 

Title V permit. EPA states the BART requirements need to be incorporated in the State 

Implementation Plan and does not believe it appropriate for DENR to rely on the 

construction permit since it has not been approved in our State Implementation Plan yet. 

Response: In accordance with 40 CFR §308(1)(e)(1)(v), DENR is required to include a 

requirement that BART-eligible sources maintain the control equipment and establish 

procedures to ensure the equipment is properly operated and maintained. DENR plans on 

adopting these requirements in ARSD Chapter 74:36:21 and submit these rules to EPA to be 

included in the Regional Haze State Implementation Plan. DENR also agreed to establish the 

permit limits for Otter Tail Power Company’s BART eligible unit in ARSD 74:36:21:10, 

which will be included in the State Implementation Plan submitted to EPA. DENR will 

expand on this in Section 8.5.6. 
 29 

57. The National Park Service believes South Dakota should commit in the Regional Haze State 

Implementation Plan to expand regulations requiring public and private construction and 

road projects to limit fugitive dust emissions as part of the long term strategy. 

Response: A majority of the coarse particulate matter emissions are generated from wind 

blown dust (e.g., approximately 54% at the Badlands National Park and 33% at the Wind 

Cave National Park). Based on the coarse particulate matter contributions (see Table 5-7), the 

contribution of coarse particulate matter from fugitive emissions is approximately 8% and 

5% at the Badlands and Wind Cave National Parks, respectively. Public and private road 

construction represents a portion of the fugitive emissions. Therefore, DENR disagrees; but 

will always re-evaluate this request during the periodic reviews. 

9.0 Monitoring Strategy 

58. EPA indicated there is currently a Federal Implementation Plan in place for the original 

visibility monitoring requirements under 40 CFR §51.305, which incorporated by reference 

the requirements in 40 CFR §51.26 (see 40 CFR §51.2179(b)). EPA asked if DENR’s 

intention was to use the monitoring strategy outlined in Chapter 9.0 of South Dakota’s 

Regional Haze Program to replace the current Federal Implementation Plan visibility 

monitoring requirements. If so, they would provide input on such revision. 

Response: The monitoring strategy in Chapter 9.0 of South Dakota’s Regional Haze 

Program is being implemented for South Dakota’s Regional Haze Program. DENR does not 

anticipate adopting the original visibility monitoring program at this time. 

10.0 Consultation Requirements 

59. In Section 10.2, page 118-119, EPA requested that we identify the dates and outcomes of the 

discussions for each consultation. EPA asked if DENR planned to include tribal consultation 

on the public comment version of the State Implementation Plan. 

Response: There is no tribal air quality program approved by EPA within South Dakota. 

Therefore, officially EPA represents South Dakota tribes on air quality matters. However, 

during the public notice phase of adopting the Regional Haze State Implementation Plan, 

tribes and tribal members will have an opportunity to provide input. 

As noted previously, DENR has been a participant in WRAP since its inception and 

considers its involvement as fulfilling part of the requirements for consultation. Within 

WRAP, the Implementation Work Group (IWG) was formed to address states’ issues 

regarding Regional Haze and conducted numerous face-to-face meetings and monthly calls. 

All western states, EPA, Tribes and Federal Land Mangers participated in the WRAP actives 

and were involved throughout the process. Beyond WRAP, South Dakota was involved with 

the Northern Class I Areas workgroup which had monthly conference calls and included 

Minnesota, Michigan, Iowa, along with other Midwestern states. In addition, South Dakota 

consulted with Minnesota directly starting in August of 2007 through emails and phone calls, 
 30 

which continued through December of 2009 when Minnesota submitted its Regional Haze 

State Implementation Plan to EPA. DENR also consulted directly with the State of Nebraska 

over the past few years through email and phone calls, mostly in regards to impacts the 

Gerald Gentleman Power Plant has on visibility impairment in Class I areas in South Dakota 

and their plans to control emissions from the Gerald Gentlemen Power Plant. 

In addition, DENR provided South Dakota’s draft Regional Haze State Implementation Plan 

to all of the neighboring states and Michigan for comments on January 15, 2010. DENR did 

not receive any comments from these states. 

60. In Section 11.2, page 121, EPA recommended that as part of continuing consultation required 

under 40 CFR §51.308(i)(4), we clarify item 7, regarding the monitoring strategy, to note that 

we will consult with EPA and the federal land managers on any revisions deemed necessary. 

Response: Continuing consultation with the federal land managers is addressed in Section 

10.1.2. In this section it specifies DENR is required to consult with the federal land 

managers during the 5-year progress reports. The submittal of the 5-year progress report is to 

EPA which ensures EPA’s involvement. Therefore, DENR believes this is already addressed 

and does not recommend any changes. 

11.0 Proposed ARSD 74:36:21 Rules 

61. In ARSD 74:36:21:02, EPA recommended the following changes to the definitions: 

a. The definition of a “BART-eligible source” must cite to an existing stationary facility as 

defined in ARSD 74:36:21:03. 

Response: DENR identified in ARSD 74:36:21:02 that a “BART-eligible source” is an 

existing stationary facility. In ARSD 74:36:21:03, DENR defined an “existing stationary 

facility”. This is similar to how EPA defined “BART-eligible source” and “existing 

stationary facility”. The only difference, which DENR believes is EPA’s concern, is 

DENR’s definition for “BART-eligible source” does not state at the end of the definition, “as 

defined in this section”. DENR believes this is already required when it states at the 

beginning of this section that “unless otherwise specified, the terms used in this article 

mean.” The style and format of the proposed rule is reviewed by the South Dakota’s 

Legislative Research Council and if they recommend changing it in this matter, DENR will 

oblige. 

b. The definition of “visibility impairment” does not mirror the federal definition in 40 CFR 

§51.301 and must be revised accordingly. 

Response: DENR tried to combined the term “visibility impairment” and “adverse impact 

on visibility” to make it clearer to the public and regulated entities what is visibility 

impairment. Since this is not acceptable by EPA, DENR revised the definition of “visibility 

impairment” to be consistent with 40 CFR §51.301 and added the phrase “adverse impact on 
 31 

visibility” and defined it consistently with 40 CFR §51.301. By doing so, DENR went 

through the proposed rules and replaced “visibility impairment” with “adverse impact on 

visibility”. 

c. The definition of “contribute to visibility impairment” is not appropriate in the regional 

haze context and must be removed since there is no threshold for such a contribution. 

Response: DENR revised the term “contribute to visibility impairment” to “contribute to 

adverse impact on visibility” based on EPA’s earlier concern with the term “visibility 

impairment”. “Contribute to adverse impact on visibility” is used in both the Prevention of 

Significant Deterioration and in the New Source Review programs to determine the visibility 

impacts on mandatory Class I federal areas. The five-tenths deciview threshold is identified 

in EPA’s draft New Source Review Manual, the federal land managers draft FLAG 

document (page 34), and in EPA’s BART guidelines. DENR believes it is appropriate as part 

of its long term strategy to ensure new sources and modifications to existing sources, not 

covered already by the Prevention of Significant Deterioration or New Source Review, 

should demonstrate they will not contribute to adverse impact on visibility. DENR reviewed 

40 CFR §51.308 and did not see where this was prohibited. DENR does not recommend any 

changes. 

d. The definition of “major source” must site to 40 CFR §51.166 and DENR must include 

the definition of “major modification” from 40 CFR §51.166 since the definition of major 

stationary source under the regional haze regulations includes major modifications. 

Response: EPA is referencing a “major source” and “major modification” covered under the 

New Source Review Program, which is already addressed in ARSD 74:36:09 – Prevention of 

Significant Deterioration and 74:36:10 – New Source Review. Both of these programs are 

part of South Dakota’s State Implementation Plan. The major sources addressed under 

ARSD 74:36:21 – Regional Haze Program are defined in ARSD 74:36:21:02(6), which 

identifies a major source as a source that meets the definition of a major source under the 

Title V air quality permit program for criteria pollutants. The definition does not include a 

major source under the New Source Review Program. The term “modification” is already 

defined in ARSD 74:36:01:10 – Modification Defined, and was not reiterated in ARSD 

74:36:21. DENR does not recommend any changes. 

62. In ARSD 74:36:21:04, EPA states this section must be revised to clarify the existing 

provisions of 74:36:09 are not replaced by this new section. EPA also asked what DENR’s 

intention with this new provision. 

Response: DENR believes it would be appropriate to clarify that Chapter 74:36:21 does not 

apply to major sources and major modifications under the New Source Review Program. To 

accomplish this, DENR added a sentence to ARSD 74:36:21:01 that states this chapter does 

not apply to a source applicable to the Prevention of Significant Deterioration Program or 

New Source Review Program. 
 32 

63. In ARSD 74:36:21:07, EPA recommends to improve clarity, this section should include more 

detail, such as specifying the minimum criteria for an acceptable operation and maintenance 

plan and when the source specific operation and maintenance to meet such criteria shall be 

submitted for permitting authority approval. 

Response: DENR believes it would be appropriate to identify the minimum requirements 

for the operation and maintenance of controls and added the minimum requirements to 

ARSD 74:36:21:07. DENR disagrees the written plan needs to be submitted to DENR for 

approval since a BART source is required to be inspected at least once per year and submits 

periodic reports to DENR to ensure compliance with the permit requirements. 

64. In ARSD 74:36:21:08, EPA is concerned this provision is not clear whether all of the sulfur 

dioxide and nitrogen dioxide emissions from the BART-eligible source will be routed to the 

main stack. The term “main stack” implies the presence of other stack(s) which is/are not 

equipped with continuing emission monitoring system(s) as is the “main stack”. EPA 

recommended alternative language. 

Response: DENR agrees and will make the appropriate changes. 

65. In ARSD 74:36:21:11, EPA stated that as required in the regional haze rule, federal land 

managers must be provided a 60-day consultation period prior to any public hearing on the 

regional haze state implementation plan. EPA argues that since a BART permit is an integral 

part of the regional haze state implementation plan, this 60-day consultation period must 

extend to the federal land managers BART permit review as well. EPA also argues that since 

any BART permit must be incorporated into the regional haze state implementation plan, the 

30-day public notice for the state implementation plan needs to identify the inclusion of any 

BART permits. 

Response: South Dakota’s draft Regional Haze State Implementation Plan was submitted to 

the federal land managers on January 15, 2010 and DENR plans on holding the public 

hearing in September 2010. Therefore, DENR provided the federal land managers more than 

60-day consultation prior to the public hearing on the Regional Haze State Implementation 

Plan. In accordance with 40 CFR § 51.308(e)(1)(i), the draft Regional Haze State 

Implementation Plan contains a list of BART-eligible sources in Section 6.1. In accordance 

with 40 CFR § 51.308(e)(1)(ii), the draft Regional Haze State Implementation Plan contains 

the BART determination for each BART-eligible source in Section 6.2 and 6.3 and Appendix 

C, D, and E. In accordance with 40 CFR § 51.308(e)(1)(iv), each source subject to BART is 

required to install and operate BART no later than 5 years after approval of the Regional 

Haze State Implementation Plan as required in ARSD 74:36:21:06. In accordance with 40 

CFR § 51.308(e)(1)(v), each source subject to BART must install the control equipment 

required by the BART determination and establish procedures to ensure such equipment is 

operated and maintained as discussed in Section 6.3 and 6.4 of the Regional Haze State 

Implementation Plan and in accordance with ARSD 74:36:21:07. In addition, DENR has 

already agreed to include the BART emission limits for Big Stone I in ARSD 74:36:21:10. 
 33 

DENR believes the BART requirements are specified in South Dakota’s draft Regional Haze 

State Implementation Plan and DENR provided the federal land managers more than a 60-

day consultation period before the public hearing. DENR was unable to determine what 

federal regulation EPA is using to state the BART permit must be included in the state 

implementation plan. However, this is a mute point since DENR added the BART emissions 

limits for Big Stone I in ARSD 74:36:21:10. 

12.0 General Comments 

66. In Chapter 1.0, EPA requested DENR clarify the 1977 Clean Air Act Amendments and 

EPA’s 1980 reasonable attributable visibility impairment regulations addressed visibility 

impairment caused or contributed to by one or a small group of sources. 

Response: DENR reviewed Section 169A of the Clean Air Act and agree major sources built 

and operated during a certain timeframe that “...may reasonably be anticipated to cause or 

contribute to visibility impairment...” are required to install Best Available Retrofit 

Technology. Therefore, DENR changed the language in the fourth paragraph of the 

“Introduction” to reflect the change. 

DENR reviewed 40 CFR Part 51, Subpart P which discusses EPA’s 1980 rules on visibility 

protection and the language is similar to how DENR represented it. DENR does not 

recommend any changes. 

67. EPA requested DENR revise the date of delegation of the Prevention of Significant 

Deterioration program from September 15, 1994 to July 6, 1994. 

Response: September 15, 1994 is the date of the federal register notice for the final rule and 

the effective date is July 6, 1994. DENR agrees and will make the appropriate change in the 

third paragraph of the “Introduction”. 

68. EPA indicated the “Date of Reconstruction” definition in Section 6.1 did not quite match the 

federal definition. 

Response: DENR reviewed the definition and agrees. Instead of stating, “...must occur 

between August 7, 1962 and August 7, 1977...” the definition will be revised to state 

“...must occur during the August 7, 1962 to August 7, 1977 time period...” 

69. EPA indicated the last sentence of the definition for “Potential to Emit” in Section 6.1 

contains a typographical error and should be “26” instead of “28”. 

Response: DENR reviewed the definition and agrees. DENR will make the appropriate 

change. 

70. EPA requested it be clarified in Sections 7.1 and 8.5.1 that although some of the cited 

Administrative Rules of South Dakota control emissions of pollutants that ultimately 
 34 

contribute to visibility impairment, the rules were not written specifically to address visibility 

impairment. 

Response: Section 7.1 identifies state and federal rules in place and those planned for the 

future that will help South Dakota achieve reasonable progress in protecting and improving 

visibility in our Class I areas. Section 8.5.1 references 40 CFR § 51.308(d)(3)(v)(A), which 

requires an assessment of emission reductions due to ongoing air pollution control programs. 

DENR provided an assessment of which existing state rules assist in reducing air emissions 

and help achieve reasonable progress. Since the EPA reviewer(s) did not reference a federal 

regulation which specifically requires EPA’s requests, DENR believes these comments are a 

preference and not a requirement. DENR does not propose any changes. 

71. In Section 8.5, page 107, EPA believes there is a typographical error and it should state 

“emissions reductions” instead of “emissions” in the last paragraph. 

Response: DENR agrees that it should be “emission reductions” and made the appropriate 

changes.

72. The National Park Service requested DENR add footnotes to the tables and graphs 

throughout the document to define the abbreviations used, especially for organic carbon 

mass, particulate organic aerosol, elemental carbon, and fine mass elemental carbon. The 

terms vary depending on the data source used and can be confusing to the reader. 

Response: DENR agrees and made the appropriate changes.
Appendix A 

Comment Letters on South Dakota’s 

Draft Regional Haze Program
United States 

USDA Department of 

Agriculture 

Rick Boddicker 

Forest 

Service 

Senior Environmental Scientist 

SDDENR 

523 East Capitol 

Pierre, SD 57501 

Dear Mr. Boddicker: 

Superior 

National 

Forest 

8901 Grand Ave. Place 

Duluth, MN 55808·1122 

Phone: (218) 626·4300 

Fax: (218) 626·4398 

File Code: 2580-2 

Date: February 24, 2010 

RECEIVED 

FEB 26 2010 

AIR QUALITY 

PROGRAM 

On January 15,2010, the State of South Dakota submitted a draft implementation plan 

describing your proposal to improve air quality regional haze impacts at mandatory Class I areas 

across your region. We appreciate the opportunity to work closely with the State through the 

initial evaluation, development, and, now, subsequent review of this plan. Cooperative efforts 

such as these ensure that together we will continue to make progress toward the Clean Air Act's 

goal of natural visibility conditions at our Class I wilderness areas and parks. 

This letter acknowledges that the U.S. Department of Agriculture Forest Service has received 

and conducted a substantive review of your proposed Regional Haze Rule implementation plan. 

Please note, however, that only the U.S. Environmental Protection Agency (EPA) can make a 

final determination about the document's completeness, and therefore, only the EPA has the 

ability to approve the document. Participation by the Forest Service in the State of South 

Dakota's administrative process does not waive any legal defenses or sovereignty rights it may 

have under the laws of the United States, including the Clean Air Act and its implementing 

regulations. 

As outlined in a letter to South Dakota dated November 1, 2006, our review focused on eight 

basic content areas. The content areas reflect priorities for the Federal Land Manager agencies, 

and we have attached comments to this letter associated with these priorities. We look forward 

to your response required by 40 CFR 51.308(i)(3). For further information, please contact 

Eastern Region Air Resource Specialist Trent Wickman at (218) 626-4372 or Rocky Mountain 

Region Air Resource Specialist Jeff Sorkin at (406) 329-3672. 

Again, we appreciate the opportunity to work closely with the State of South Dakota. The Forest 

Service compliments you on your hard work and dedication to significant improvement in our 

nation's air quality values and visibility. 

Sincerely, i /t:;:f£~ Forest Supervisor 

cc: Charles E Sams, Jeff A Sorkin, Terry Svalberg, Amy Platt, Don Shepherd, Tim Allen 

Caring for the Land and Serving People Printed on Recycled Paper 
Technical Comments 

1) In regards to your approach to estimating natural conditions, for consistency, we would 

prefer that South Dakota (SD) use the standard Western Regional Air Partnership/ 

Technical Support System (WRAP/TSS) natural conditions values unless there is a 

justification for your alternate values. 

2) We want to be involved in the development of your smoke management plan (SMP). We 

will give a local Forest Service contact when requested. 

3) We note that high organic carbon (OC) concentrations don't necessarily mean fire 

impacts, as noted in the draft SIP. Please provide more analysis on individual high OC 

days (for example use back trajectories) to see where the OC came from. Another 

approach that could be used would compare the seasonality of prescribed fire with 

wildfire. Using calendar quarters are not a fine enough temporal resolution for this task. 

For example SD could get prescribed fire activity info from the burners in the state and 

see if it matches measured high OC impact days. 

4) We commend SD for selecting selective catalytic reduction as BART for Big Stone. 

5) Please show how big a part of the state's point source emission inventory Big Stone is. 

6) It is our view that the regional haze regulations require a four factor analysis. Depending 

on the answer to question 5) above, a simple analysis may be justified. Please make use 

of information and analyses provided by WRAP. 
United States Department of the Interior 

NATIONAL PARK SERVICE 

Air Resources Division 

P.O. Box 25287 

IN REPLY REFER TO: Denver, CO 80225 

February 25, 2010 

N3615 (2350) 

Mr. Brian Gustafson 

Administrator, Air Quality Program 

South Dakota Department of Environment and Natural Resources 

523 E Capitol 

Pierre, SD 57501 

Dear Mr. Gustafson: 

TAKE PRIDE" II~A.MERICA 

RECEIVED 

MAR 0 1 2010 

AIR QUALITY 

PROGRAM 

On January 15, 2010, we received South Dakota's draft regional haze implementation 

plan for review. We appreciate the opportunity to work closely with the State through the 

development and review of this plan. Cooperative efforts such as these ensure that, 

together, we will continue to make progress toward achieving natural visibility conditions 

at our National Parks and Wilderness Areas. 

This letter acknowledges that the U.S. Department of the Interior, National Park Service 

(NPS), in consultation with the U.S. Fish and Wildlife Service, has received and 

conducted a substantive review of the South Dakota draft Regional Haze Rule 

implementation plan in fulfillment of your requirements under the federal regulations 40 

CFR 51.308(i)(2). Please note, however, that only the U.S. Environmental Protection 

Agency (EPA) can make a final determination regarding the document's completeness 

and, therefore, ability to receive federal approval from EPA. 

As outlined in a letter to each State dated August 1, 2006, our review focused on eight 

basic content areas. The content areas reflect priorities for the Federal Land Manager 

agencies, and we have enclosed comments associated with these priorities. Overall the 

draft implementation plan was well organized and addressed most of the key elements 

outlined in our letter. We are very pleased to see South Dakota's commitment to semidry flue gas desulfurization for sulfur dioxide (S02) controls and selective catalytic 

reduction for nitrogen oxide controls as best available retrofit technology for the Otter 

Tail Big Stone Unit 1 coal-fired power plant. However, we have two primary concerns 

with the draft plan: 1) the reasonable progress analyses should include a four factor 

analysis of potential controls on S02 emissions from point and areas sources, and 2) the 

long-term strategy should provide more discussion of activities to reduce smoke impacts 

from fires and to reduce fugitive dust from construction and road projects. 
· . -. 2 

We look forward to your response, as per section 40 CFR 51.308(i)(3). For further 

information regarding our comments, please contact Pat Brewer of my staff, at (303) 969-

2153. 

Again, we appreciate the opportunity to work closely with the State of South Dakota and 

compliment you on your hard work and dedication to significant improvement in 

visibility in our Class I national parks and wilderness areas. 

Sincerely, 

~!:2f Chief, Air Resources Division 

Enclosure 

Cc: Gail Fallon 

Air Quality Planning Unit (8P-AR) 

US EPA Region 8 

1595 Wynkoop Street 

Denver, CO 80202-1129 
". "" 

National Park Service Comments 

South Dakota Draft State Implementation Plan for Regional Haze 

February 25,2010 

General Comments 

South Dakota's draft State Implementation Plan (SIP) is well organized and addresses most of 

the key elements of a regional haze SIP as outlined in our August 2006 letter to the states. South 

Dakota has defined current and natural visibility conditions and has applied technical analyses 

provided by the Western Regional Air Partnership (WRAP) to describe emissions inventories, 

state and source sector contributions to haze at Class I areas, and visibility response to expected 

emissions controls by 2018. SD has proposed controls for the Otter Tail Big Stone electric 

generating plant under Best Available Retrofit Technology (BART). We are pleased to see these 

substantive reductions of sulfur dioxide (S02) and nitrogen oxide (NOx) emissions. SD has 

defined reasonable progress goals and addressed a long-term strategy to improve visibility in SD 

Class I areas. We would like to see a more developed four factor analysis of emissions control 

options, but overall SD has demonstrated a commitment to protecting visibility in our national 

parks and wilderness areas. 

Specific Comments 

Please add footnotes to the tables and graphs throughout the document to define the 

abbreviations used, especially for organic carbon mass, particulate organic aerosol, elemental 

carbon, and fine mass elemental carbon. The terms vary depending on the data source used and 

can be confusing to the reader. 

Chapter 3 Baseline, Natural and Uniform Rate ofImprovement 

As stated on page 12, EPA's guidance on determining natural conditions provides default 

assumptions for natural background visibility and allows states to refine estimates. For Class I 

areas in and near SD, the greatest uncertainty is related to the contributions of organic carbon 

and elemental carbon from natural wildland fires. SD's revisions to fine soil and coarse matter 

assumptions are based on 2000-2004 IMPROVE monitoring and effectively suggest that natural 

background should be lower than the default assumption. This revision would require even 

greater reductions in current anthropogenic sources of fine soil and coarse matter to achieve the 

revised natural background conditions. Given the large uncertainties, we recommend that SD 

retain EPA's default assumptions using natural background values avaihible on the VIEWS 

website for this current SIP and defer refinements to a later SIP. 

Chapter 4 IMPROVE Data for Class I Areas 

Chapter 4 describes the IMPROVE data used as the current baseline visibility. Contributions of 

aerosol components to the 20% least and the 20% most impaired days are informative for 

developing priorities for emissions reductions. Page 21, second paragraph, and page 26, second 

paragraph, refer to combustion of organic mass in forest fires and grasslands as a source of 
· . . ... 

ammonium sulfate. Fires are actually an insignificant contribution to ammonium sulfate 

compared to fossil fuel combustion (see Table 5-1 S02 emissions by source sector), and we 

recommend that you delete the references to fires as a source of ammonium sulfate. 

Wildland fires are major contributors to organic carbon and elemental carbon, and we 

recommend that you expand the analysis of the contribution of wildfire to visibility impairment 

at the SD Class I areas. Tables 4.1 and 4.2 indicate that for both Badlands and Wind Cave 

National Parks (NPs), on the 20% worst days, organic carbon mass (OCM) is greater than 

ammonium sulfate mass. In addition to the averages of the 20% least and 20% most impaired 

days and quarterly averages, if you look at the aerosol contributions on individual days during 

the 2000-2004 baseline period, you could identify frequency of elevated organic and elemental 

carbon that could indicate fire impacts. It is likely that OCM from fires dominates aerosol 

concentrations on some 20% worst days. Back trajectory analyses could assist in defining source 

areas for exceptional fire events such as referenced for July 2, 2008, and October 25, 2005, and 

could assist separating impacts from local agricultural or prescribed fires that might be 

controllable from major wildland fires. Considering aerosol composition on individual days will 

also assist in assessing the relative contributions from other sources (fossil fuel combustion, 

biogenic, etc). 

On page 25, SD concludes, based on the similarity in aerosol composition between Badlands and 

Wind Cave NPs, that it is reasonable to assume that the contribution to visibility impairment on 

the 20% best days is not being impacted by local sources. It is likely that the neighboring parks 

are influenced by similar sources, but the data do not support the conclusion that local sources 

are not contributing. Please rephrase this statement. 

On page 33, second paragraph should indicate that visibility impairment appears to be declining 

(rather than visibility declining). 

The visibility trends data presented in Figures 4-7 and 4-8 are helpful. Looking at similar time 

series plots for the individual aerosol components would illustrate whether sulfate and nitrate, 

those components dominated by anthropogenic, controllable, sources, are declining more than 

OCM, an indicator of fire. Figure 4-8-a uses a narrow scale for the y axis (14 to 17 dv), different 

from the other plots in the series (0-25 dv). This compressed scale gives the impression of a 

much larger change in dv than if the full scale were presented. By looking at individual aerosol 

components, SD could better understand the contributions to this trend in total aerosol extinction. 

Section 5.0 Source Apportionment 

Section 5.1 discusses SD's emissions inventory, which relies on well documented WRAP 

analyses. In Tables 5-1 and 5-2, 2002 S02 emissions from SD area sources drop from 10,159 

tons/yr to 1,071 tons/yr. WRAP documentation of differences between the WRAP 2002 Base 

2002b and 2002d inventories includes revisions to SD area source categories. Please clarify the 

basis for the revised area source estimate. Were some SD area source categories reclassified as 

point sources? 

2 
.... .. .... 

It would be helpful to understand the contribution from Big Stone Unit 1 to 2002 total point 

source S02 and NOx emissions. In Table 5-2, 2002d South Dakota Emissions Inventory, please 

list the S02 and NOx emissions from Big Stone 1 separately from the other point sources. This 

will make it easier to compare data in Table 5-2 to Table 5-4, 2018 SD Emissions, Table 6.1, 

Emissions from BART-eligible sources, and Table 6-3 WRAP Modeling Results for Big Stone 

Unit 1. 

The 2018 point source emissions in Table 5-4 include emissions from planned new facilities; two 

of these (Big Stone II and Basin Electric's NextGen) are now on hold. These two facilities 

represent 45% of total S02 point source emissions and 15% of total NOx point source emissions 

in 2018. These facilities may become operational by 2018 so it is appropriate that WRAP 

modeling results accounted for new generation by 2018. Separate from this regional haze SIP, 

we received notice of a Draft Environmental Impact Statement for a proposed new 300 megawatt 

natural gas-fired, combined-cycle electric generating facility in eastern South Dakota. The 

emissions from this proposed new facility were not included in this SIP emissions discussion nor 

in the WRAP 2018 emissions projections. 

In addition to the four electric generating units listed in Table 5-4, all other point sources 

together are projected to emit 2458 tons S02/year in 2018. Area sources are projected to 

contribute another 1662 tons/yr. In Section 7 under the reasonable progress analysis, these 

emissions should be assessed to determine if there are reasonable control measures. 

Tables 5-6 and 5-7 are helpful in illustrating SD's emissions relative to neighboring states. 

Section 5.2 discusses Source Apportionment Analyses. WRAP PSAT analyses (Figure 5-1) 

project that point sources dominate contributions to sulfate at the SD Class I areas. Neighboring 

states of WYand ND have a greater contribution to sulfate at the SDClass I areas on the 20% 

worst days than SD point sources. SD area sources are as important as SD point sources, 

suggesting that emissions controls for area sources could have measureable benefits at the Class I 

areas. WRAP Weighted Emissions Potential (WEP) analyses indicate that SD is the largest 

contributor to organic carbon, elemental carbon, and coarse mass at the SD Class I areas. 

Natural fires in SD dominate the organic carbon contributions. WRAP PSAT analyses indicate 

that SD's contribution to nitrate is intermediate between that for sulfate and organic carbon. 

These analyses support SD's focus on reducing anthropogenic S02 and NOx emissions and also 

encourage managing fire, agriculture, and construction activities to minimize emissions. 

Section 6: Best Available Retrofit Technology (BART) 

The SD BART analysis is one of the best that we have reviewed to date; the discussion is 

thorough and informative. The National Park Service (NPS) is very pleased and commends SD 

for concluding that for Otter Tail Big Stone 1 power plant, the best available retrofit technologies 

are semi-dry flue gas desulfurization for S02 and selective catalytic reduction (SCR) for NOx. 

There are still a few areas where we offer additional suggestions: 

3 
6.3.2.3 Sulfur Dioxide Control Effectiveness 

SD evaluated the control effectiveness by comparing the effectiveness in Table 6.6. 

NPS: SD should state the control effectiveness and resulting emission rate that it believes to 

be appropriate for each control technology option. For example, it appears that SD has 

concluded that a semi-dry scrubber can achieve 90% S02 control. We agree with SD's 

analysis, but suggest that the baseline for annual S02 emissions should reflect anticipated 

uncontrolled annual emissions which, according to EPA's Clean Air Market Database, have 

averaged 0.66 Ib/mmBtu (range 0.63 - 0.70) over the 2000 - 2008 period. 

6.3.2.4 Sulfur Dioxide Control Technology Impacts 

SD: Otter Tail Power Company identified cost estimates for each of the control options. In 

addition, Otter Tail Power Company identified cost estimated for two different operating 

scenarios for each of the two control alternatives. Table 6-7 summarizes Otter Tail Power 

Company's estimated costs. 

Otter Tail: Cost estimates for the wet and semi-dry (including SDA and fabric filter) S02 

control technologies were completed utilizing the Coal Utility Environmental Cost 

(CUECost) computer model (Version 1.0). The model was run with 2008 designated as the 

cost basis year because equipment cost estimating in the model is based on the Chemical 

Engineering Cost Index and the composite 2008 index is the latest version available. 

Following completion of the estimating on a 2008 cost basis year, all costs were escalated to 

a 2009 basis year utilizing the inflation rates designated in Table 1.2-3. 

NPS: Otter Tail should have used the EPA Control Cost Manual as advised by the BART 

Guidelines and by EPA Region 8. Otter Tail should at least have provided its CUECost 

output data. 

6.3.3.3 Nitrogen Oxide Control Effectiveness 

SD: Step 3 requires the evaluation of control effectiveness for each control technology. SD 

evaluated the control effectiveness by comparing the effectiveness in Table 6.9. 

NPS: SD should state the control effectiveness and resulting emission rate that it believes to 

be appropriate for each control technology option. For example, it appears that SD has 

concluded that SOFA+SCR can achieve 88% NOx control. However, if SOFA can reduce 

NOx emissions to 0.50 Ib/mmBtu, then it is reasonable to expect that addition of SCR would 

reduce NOx emissions by another 90% or down to 0.05 Ib/mmBtu on an annual average. For 

example, the Illinois EPA has proposed that the two cyclone boilers firing PRB coal at 

Dominion Energy's Kincaid Generating Station should achieve 0.07 Ib/mmBtu on an annual 

basis with over-fire air (OFA) and SCR. (Please see 02116/2010 email from Don Shepherd to 

Kyrik Rombough for Excel spreadsheet of NOx performance at Kincaid.) To meet that limit, 

the Kincaid SCRs would reduce inlet NOx emission by slightly over 89%. It should be 

feasible for Big Stone #1 to achieve a lower limit because of the superior initial NOx 

reductions that can be achieved with SOFA versus the OFA at Kincaid. We suggest that, to 

allow for some operational flexibility, a 30-day rolling average limit ofO.06lb/mmBtu would 

be appropriate for Big Stone #1 if equipped with current-technology SOFA+SCR. 

4 
6.3.3.4 Nitrogen Oxide Control Technology Impacts 

SD: Otter Tail Power Company identified cost estimates forfive control options. Table 6-10 

summarizes Otter Tail Power Company's estimated costs. 

NPS: Otter Tail has applied a generalized "unit cost factor" of $ 172lkW to estimate a Total 

Capital Investment (TCI) of$81.8 million for SOFA+SCR. Applying the recommended EPA 

Control Cost Manual results in a TCI of $44.3 million. Otter Tail has estimated O&M costs 

at $4.1 million versus our $2.4 million estimate from application of the Cost Manual 

methods. Otter Tail has estimated a Total Annual Cost of $13.2 million to achieve 0.10 

lblmmBtu with a cost-effectiveness of$825/ton. Our Cost manual approach estimates a Total 

Annual Cost of $6.8 million to achieve 0.05 lblmmBtu on an annual basis with a costeffectiveness of $493/ton. 

6.3.5.2 Sulfur Dioxide BART Recommendation 

SD: As noted in Table 6-16, "approximately 40 percent of the modeling, the top ranked 

control option generated a higher visibility impact than the second ranked control option. 

Whereas, approximately 60 percent of the modeling, the second ranked control option 

generated a higher visibility impact than the top ranked control option. Therefore, based on 

the visibility modeling there is no discemable difference between these two control options. 

As such, SD considers that the semi-dry flue gas desulfurization system is considered 

BART .... SD considers the emission limit representing BART should be 505 pounds per 

hour, which would include periods of startup and shutdown and 0.09 pounds per million 

Btus, which would not include startup and shutdown. Compliance with these emission limits 

should be based on the continuous emission monitoring system and on a 30-day rolling 

average." 

NPS: Based upon the data presented by Otter Tail and summarized by SD, we agree that the 

difference between wet and dry scrubbing is not sufficient to justify the additional costs and 

impacts of wet scrubbing. 

6.3.5.3 Nitrogen Oxide BART Recommendation 

SD proposes a BART emission limit for NOx of 561 pounds per hour, "which would include 

periods of startup and shutdown and 0.10 pounds per million Btus, which would not include 

startup and shutdown periods. Compliance with the emission limits would be based on the 

continuous emission monitoring system and on a 30-day rolling average." 

NPS: We believe that the Kincaid cyclone boilers in Illinois (described above) have 

demonstrated the ability of SCR to reduce NOx emissions below the limit proposed by SD. 

We suggest that, to allow for some operational flexibility, a 30-day rolling average limit of 

0.06 lblmmBtu would be appropriate for Big Stone #1 if equipped with current-technology 

SOFA+SCR. 

Please clarify emissions assumptions used for the WRAP regional modeling compared to those 

used in the Big Stone Unit 1 BART modeling. Emissions used in Tables 5-2, 5-4, 6-1, and 6-3 

do not appear to be consistent, likely because they are based on different assumptions. Does 

Table 6-1 refer to potential emissions, not annual emissions? If so, please clarify. Table 6.1 lists 

Big Stone Unit 1 S02 emissions as 19,363 tons and NOx emissions as 17,179 tons. Table 5-2 

5 
whether a few large sources dominate the S02 inventory and whether controls are cost effective 

for these sources. For example, switching to a fuel oil with lower sulfur content might reduce 

S02 emissions from point or areas sources at relatively low cost. SD should also discuss options 

to reduce anthropogenic emissions of organic carbon (including reference to later discussion of 

smoke management practices). 

Section 8: Long-term strategy 

SD has addressed the major elements of a long-term strategy. We would like to see more 

complete discussion of local options to address emissions of organic carbon mass, elemental 

carbon, and course mass. Because WRAP source apportionment analyses indicate that organic 

carbon from natural fires is a major contributor to impairment on the 20% most impaired days, 

SD needs to provide a more complete discussion of options to control smoke from unplanned 

wildland fires and the relative importance of prescribed burns and agricultural burning in the 

state. SD stated on page 110 that agricultural burning occurs in the eastern part of the state but 

that does not preclude transport of smoke to the west on some days. SD is encouraged to 

develop a smoke management plans for prescribed burns options. We appreciate. that emissions 

from prescribed bums in the national parks are contributing to visibility impairment. Weare 

available to assist the parks and SD in developing effective smoke management plans. 

SD references an existing regulation that limits fugitive emissions from state facilities in Rapid 

City. As part of the long-term strategy SD should consider expanding regulations that require 

public and private construction and road projects to limit fugitive dust emissions. 

SD could commit in this SIP to pursuing these activities as part of the long-term strategy. 

Section 9: Monitoring Strategy 

We commend SD for maintaining S02, NOx, Ozone, PM2.5, PM 10, and meteorological 

measurements next to the IMPROVE sites at Badlands and Wind Cave NPs. These data will 

assist SD in evaluating source contributions to air quality and visibility in these Class I areas. 

Section 10: Consultation Requirements " 

The Federal Land Managers appreciate this opportunity to consult with SD. WRAP has 

facilitated coordination and consultation among the WRAP states. We encourage SD to discuss 

directly with the neighboring states the planned controls and the contributions from neighboring 

states to SD Class I areas. 

We look forward to continuing to work with SD to protect visibility in our Class I areas. 

7 
." 

215 South Cascade Street 

PO Box 496 

Fergus Falls, Minnesota 56538-0496 

218 739-8200 

www.otpco.com 

February 25,2010 

Mr. Rick Boddicker 

Senior Environmental Scientist 

South Dakota Department of Environment 

and Natural Resources 

Joe Foss Building 

523 East Capitol 

Pierre, SD 57501-3181 

Dear Mr. Boddicker: 

Subject: Comments Draft Proposed Regional Haze SIP 

RECEIVED 

MAR 0 1 2010 

AIR QUALITY 

PROGRAM 

c5) 

OrT£R~~fIIJ=L= POWER COMPANY 

The following comments are offered by Otter Tail Power Company as operating agent for Big Stone 

Plant. Big Stone Plant is co-owned by NorthWestern Corporation d/b/a NorthWestern Energy, 

Montana-Dakota Utilities Co. A Division ofMDU Resources Group, Inc., and OtterTail Power 

Company a wholly owned subsidiary of Otter Tail Corporation. 

Otter Tail Power Company generally concurs with the DENR draft proposed Regional Haze State 

Implementation Plan as distributed on January 15, 2010. Otter Tail supports the DENR's selection of 

the existing baghouse for particulate matter control and the semi-dry spray dryer for S02 control as 

BART. 

While we are disappointed with the proposed designation of an SCR as BART for NOx control, we 

do not have any criticism of the accuracy of the DENR's evaluation methodology. Nevertheless, Big 

Stone Plant co-owner's customers will incur approximately $13.2 million of levelized annual costs 

for the SCR capital cost and ongoing SCR operation and maintenance costs as compared to SOFA 

levelized annual costs of $0.65 million. Furthermore, the SCR installation under Control Option 8 

will result in a projected visibility improvement at Boundary Waters of only 0.354 deciview as 

compared to SOFA installation under Control Option 5. 

We support the DENR's selection of the proposed emission rates for inclusion in the construction 

permit and ultimately in the Title V Operating Permit. The emission rates reflect an appropriate 

balance between the need for plant operational flexibility during short-term periods of plant startup 

and shutdown, and the emission rates during extended periods of normal plant operation. 

We note that the proposed ARSD 74:36:21:06 requires "The owner or operator of a BART -eligible 

source required to install BART must install, operate and demonstrate compliance with BART as 

expeditiously as practicable but no later than five years from EPA's approval of the state 

implementation plan for regional haze." Ifthe proposal is adopted, Otter Tail will work withDENR 

to meet their installation timing requirement. 

An Equal Opportunity Employer AN. OTTERTAIL COMPANY 
Mr. Rick Boddicker 

February 25,2010 

Page 2 

However, Otter Tail must balance the future cost impacts on its customers in meeting this 

requirement. We must be allowed adequate time for thoughtful project design and selection of 

control technology vendors. This will also be a major construction project that is expected to take 

approximately three years of actual on-site construction to complete at a cost that is expected to be 

more than double the cost of the original plant. The construction must be tailored to minimize plant 

outages. Finally, technology preoperational check-out and system tuning will also need to be 

completed prior to a demonstration of compliance with the requirements. 

Otter Tail offers the following specific comments on DENR's proposed SIP. 

Page 43 - Last sentence of first paragraph. Please clarify that even though Big Stone II emissions 

may be included in the 2018 emissions projections, Big Stone II is no longer proceeding. 

Page 79 - Section 6.3.1.1 - Please correct the following sentence as noted. As such, the filterable 

particulate may be collected by placing a control device in the flue gas stream prior to the stack. 

Page 87 - Please clarify that the NOx emission rates for the Basin NextGen project listed in Table 6-9 

represent BACT for a new pulverized-fired boiler equipped with a 10w-NOx burner combustion 

technology which produces lower levels of NOx entering the SCR than are achievable with an 

existing cyclone-fired boiler. As noted on page 85, 10w-NOx burners are not a technically feasible 

option for a cyclone-fired boiler. 

Page 89, 91, and 92 - Please clarify that the number of significant digits that Otter Tail reported for 

its deciview impacts that are included in Tables 6-12 and 6-14 are consistent with WRAP modeling 

results presented in Table 6-3 and are also consistent with accepted industry practice. 

Page 95 - Section 6.3.5.1 - Please revise the last sentence of the second paragraph to read as follows: 

Each day, Otter Tail Power Company will multiply the emission rate, in pounds per million Btus as 

determined by a the annual performance test, by the heat input to the boiler, as determined by a 

continuous emission monitoring system, and dividing by the number of hours #iey the boiler operated 

that day . 

. Sfl~~ ~umann Manager, Environmental Services 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 8 

Ref: 8P-AR 

Brian Gustafson, Administrator 

Air Quality Program 

1595 Wynkoop Street 

DENVER, CO 80202-1129 

Phone 800-227-8917 

http://www.epa.govlregion08 

KAR 12 2010 

South Dakota Department of Environment and Natural Resources 

523 East Capitol Avenue 

Pierre, SD 57501-3182 

RECEIVED 

MARt? 20tO 

AIR QUALITY 

PROGRAM 

RE: EPA Region 8 Comments on January 15,2010 

Draft Regional Haze SIP (FLM Consultation 

Version) 

Dear Brian: 

EPA has completed a preliminary review of South Dakota's January 15,2010 draft 

Regional Haze State Implementation Plan (SIP), as received via email through your Federal Land 

Manager (FLM) consultation process. Our comments and questions are detailed in the Enclosure 

to this letter. 

We understand that you intend to consider all comments received on this FLM 

consultation version of the Regional Haze SIP prior to preparing the documents for your public 

notice and comment process. The final draft of the SIP, which will include a summary of the 

FLMs' comments and your responses, will then undergo a broader public hearing process prior to 

adoption and submission to EPA. We emphasize that we will only reach a final conclusion 

regarding the adequacy of South Dakota's Regional Haze SIP when we act on the South Dakota 

Regional Haze SIP revision through our own public notice and comment rulemaking. 

We want to acknowledge your efforts in developing this SIP and working with us to 

resolve concerns related to subject-to-BART modeling for Big Stone 1. This effort has helped to 

narrow the issues significantly; however, important issues remain. Our comments are intended to 

assist you in revising the draft SIP before you begin your public hearing process. Please note that 

our most serious concerns are summarized at the beginning of the Enclosure. 

As you are aware, South Dakota received a finding of failure to submit its Regional Haze 

SIP by the required deadline. As a result, a 2-year clock was initiated for EPA to fully approve a 

SIP or promulgate a Federal Implementation Plan by January 15,2011. In order to meet this 

deadline, we continue to advise you to submit the South Dakota Regional Haze SIP in a timely 

manner. Please do not hesitate to contact me with any concerns related to this timeline. 
ENCLOSURE 

EPA Region 8 Preliminary Comments on the January 15, 2010 Draft Regional Haze SIP 

(FLM Consultation Version) 

Summary of Major Concerns - (see detailed comments for more information): 

• No justification for separate startup/shutdown limits for PM, S02, and NOx. See 

comments #18-20 below. 

• No details on how the BART emission limits will be made enforceable as a practical 

matter. See comments #1 and #21 below. 

• No identification of the number of years to reach natural conditions as required when the 

Reasonable Progress Goal is less than the Uniform Rate of Progress. See comment #23 

below. 

• No 4-factor Reasonable Progress analysis. See comment #24 below. 

• No smoke management plan even though fire is identified as a major contributor. See 

comment #31 below. 

Detailed Comments: 

1. Executive Summary, pp. viii-ix: 

(A) The BART emission limits, compliance schedules, monitoring, recordkeeping, and 

compliance determining methods for Big Stone I must be specified in the text of the Regional 

Haze SIP or in a permit that is incorporated into the SIP. You note that you intend to 

establish the appropriate averaging times, compliance verification procedures, and 

recordkeeping and reporting requirements in an air quality construction permit. Since this 

document is not included in this draft SIP, we would like to work with you to ensure that 

these requirements are adequately addressed in the SIP. Note that the public notice for the 

Regional Haze SIP needs to include notification that an air quality permit to address BART 

requirements is incorporated as part of the SIP. Additionally, with MDU Resources Group's 

November 2, 2009 announcement that Big Stone II will not be built, does SD DENR planto 

amend and/or revoke the existing permit provisions in order to reflect the Company's 

announcement and the forthcoming BART determination, and what is the timeline for doing 

so? 

(B) The last sentence references a Chapter 12 that was not included in this draft FLM 

consultation version of the SIP; therefore, we were unable to review and comment on it. 

2. Chapter 1, Introduction, p. 1: 

(A) Please clarify that the 1977 Clean Air Act Amendments and EPA's 1980 reasonable 

attributable visibility impairment regulations addressed visibility impairment that was caused 

or contributed to by one or a small group of sources. 

(B) Please revise the date for delegation of the Prevention of Significant Deterioration (PSD) 

- 1 -
program to July 6,1994. The September 15,1994 date is simply when EPA provided notice 

that the delegation had been granted as of July 6, 1994. 

3. Sections 3.1, Baseline Visibility Conditions, and 3.2, Natural Visibility Conditions, 

pp.11-16: 

(A) It appears that Appendix A will contain the IMPROVE data used to determine baseline 

visibility; however, Appendix A was not included with this draftFLM consultation version of 

the SIP. 

(B) Based on our review of WRAP's Visibility Information Exchange Web System (VIEWS) 

and information from the USFS, it appears that there are some errors in the baseline and 

natural background figures provided in Tables 3-1, 3-5, and 3-7. We understand that the 

USFS has raised these concerns with you and requested the opportunity to discuss; therefore, 

we will look for these figures to be revised accordingly. Please note that EPA's default 

values for natural conditions must be used in the current SIP and any refinements deferred to 

future planning periods. 

(C) Table 3-6 addresses the western natural conditions, but the footnotes refer to Trijonis 

estimates for both East and West. The Trijonis estimates for the East do not need to be 

included. 

(D) A column must be added to Table 3-7 to highlight the deciview improvement required 

for both best and worst days. 

4. Figure 3-11, Uniform Rate of Progress, p. 17: This figure has been omitted. Perhaps with its 

inclusion, our following comment would be addressed. 

5. Table 3-8, Annual Uniform Rate ofImprovement, p. 18: This table needs to include the 

uniform rate of improvement for the 1 sl planning period (2004-2018) for the most and the 

least impaired days, rather than leaving it to the reader to calculate from the annual numbers 

provided. 

6. Figure 3-12, Uniform Rate ofImprovement, pp. 18-19: For both Class I areas, we could not 

determine the source of the 2018 numbers. For Badlands, it appears that the 2018 uniform 

rate of progress should be 14.89 dV (based on the 14 year lSI planning period) instead of 

15.04 dV, and for Wind Cave, 13.94 dV instead of 14.01 dV. In addition, once the baseline 

and natural background values are revised per our comment #3 above, these values will need 

to be recalculated. 

7. Section 5.0, Source Apportionment, pp. 37-58: 

(A) Section 5.1, Air Emission Inventory, pp. 37-38: In general, the WRAP inventories 

utilized are adequate for this planning period. However, there are some known shortcomings 

with the WRAP inventories, including the oil and gas emissions estimates. Please note that 

we would expect future reviews of the South Dakota Regional Haze SIP to rely on the most 

current, updated emissions inventory. 

-2-
(B) Pages 39 & 43: Please elaborate on the "compliance initiative" related to VOC emissions 

from secondary oil and gas production in northwestern South Dakota. The draft document 

indicates that the initiative identified emissions that needed to be addressed, and it appears 

emission control devices were installed. What state mechanisms are in place to ensure these 

four thermal oxidizers are operating at greater than 98% control? 

(C) Tables 5-1,5-2, and 5-4, pp. 40-44: In Tables 5-1 and 5-2, the baseline vOC emissions 

from oil and gas are identified as 33,721 tons, while the 2018 projected VOC emissions from 

oil and gas are shown as 562 tons in Table 5-4. According to the WRAP Technical Support 

System (TSS), the corresponding baseline and projected VOC emissions from oil and gas are 

288 tons and 562 tons, respectively. This large discrepancy between South Dakota's reported 

numbers and the WRAP TSS must be explained in greater detail in the SIP. In addition, 

please explain whether these emissions from secondary oil and gas production were used for 

modeling and reasonable progress purposes. We also note that Table 5-1 provides the 

baseline S02 emissions from area sources as 10,159 tons, while Table 5-2 lists 1,071 tons 

from the same source. This very substantial difference is consistent with values reported on 

the WRAP TSS; however, no explanation is provided. The SIP text must provide 

clarification. Finally, there appears to be a typographical error in the footnotes to Table 5-4-

two footnotes labeled "3." 

(D) Tables 5-6 and 5-7, p. 46: We note some discrepancies compared with what was 

included in other state plans. In order to ensure consistency with other states' assumptions it 

would be prudent to verify their emission inventory numbers. For example, the North Dakota 

draft plan lists North Dakota NOx emissions for 2018 at 171,566 tons, but the South Dakota 

draft plan lists North Dakota NOx emissions at 187,032 tons for 2018. 

(E) Last paragraph, p. 54, and second paragraph, p. 56: There may be typographical errors,. 

but in any case the text is not consistent with the figures which show a slight change between 

2002 and 2018 for both the least and most impaired days. Please clarify. 

(F) First paragraph, 2

nd to last sentence, p. 58: The text regarding Montana's organic carbon 

mass contribution must be clarified to read that, "Natural fire related organic carbon mass 

generated in Montana contributes approximately 34% of the organic carbon mass in Badlands 

National Park." 

8. Section 6.1, BART-Eligible Sources, pp. 70-71: 

(A) The definition of "Date of Reconstruction" does not quite match the Federal definition 

and must be revised. The Federal definition is for the date of operation, construction, or 

reconstruction and applies to sources that were not in operation before August 7, 1962 and in 

existence as of August 7, 1977 with any reconstruction occurring during the August 7, 1962 

to August 7, 1977 time period. 

(B) The last sentence of the definition for "Potential to Emit" contains a typographical errorshould be 26 categories. 

-3-
9. Section 6.1.2, Pete Lien, pp. 72-73: . 

(A) There appears to be Ii typographical error in the 2

nd sentence of the first paragraphshould be worded as "not in operation prior to August 7, 1962 ... " 

(B) Because there is a rotary kiln (Unit 4a) producing lime within the Pete Lien facility, Pete 

Lien is classified as a lime plant according to the definition in 40 CFR Part 60, Supart HH. 

The fact that the unit in question under BART is a vertical kiln does not exclude Pete Lien 

from the lime plant category, since it does have a rotary kiln producing lime within the plant. 

Therefore, it was the appropriate decision to include Pete Lien in the WRAP 

subject-to-BART modeling analysis. We were unaware that you had determined there were 

errors in the modeling inputs and a need for are-run. You note that the vertical kiln was 

shutdown and dismantled in 2009 prior to completion of a modeling re-run. However, the 

November 12,2008 Title V permit for Pete Lien still includes the vertical kiln, and there has 

not been a permit modification to address any such dismantling and closure. Either the 

permit needs to be modified to reflect this change in status of the vertical kiln, or the 

modeling needs to be re-run to correct the input errors and accurately determine whether Pete 

Lien is subject to BART. 

10. Section 6.2, Otter Tail Power Company's Modeling Results, pp. 75-77: We note that the 

specific version of CAL PUFF, coordinate grid points, wind field options, terrain, dispersion 

options, receptor coordinates, plume characteristics and other model parameters approved by 

the DENR were used for modeling. The DENR approved protocol (i. e .. the August 31, 2009 

Revised Modeling Protocol for a BART Assessment of the Big Stone I Coal-Fired Power 

Plant) is acceptable to EPA; however, the modeling input and output files need to be 

ihcorporated into the SIP for documentation and public review. 

11. Section 6.3.2.4, Sulfur Dioxide Control Technology Impacts, p. 83: Footnote number 3 

indicates a baseline level of 18,000 tons of S02/year; however, according to Table 6-1 on 

p. 71, the baseline was 19,863 tons/year. This larger baseline figure results in an 81 % 

emission reduction for the 3rd option, as opposed to 90% with the 18,000 tons/year figure. 

Please explain how the 18,000 tons/year S02 baseline figure was obtained. 

12. Section 6.3.3.2, Technically Feasible Nitrogen Oxide Control Technologies, pp. 85-86: At 

this time, we have not completed a thorough review of your comments regarding commercial 

availability and technical feasibility of the various NOt control technologies listed. 

Therefore, we may have additional comments on this section during the public comment 

period. 

13. Table 6-9, p. 87: Footnote 5 references a 1999 EPA Technical Bulletin on NOx controls as 

justification for the 35%-90% control efficiency range for the top three options. The large 

range in EPA's bulletin is due to inclusion of SCR, selective non-catalytic reduction (SNCR), 

and fuel reburning for wet-bottom boilers. It is well documented that SCR achieves the high 

end of the range. The EPA bulletin also lists a 30%-70% control efficiency for a group of 

temperature-reducing controls, including over-fire air. Therefore, the proposed BART 

-4-
determination ofSCR plus separated over-fire air (SOFA) should be better than the 90% 

control efficiency of SCR alone. It is not clear from the SIP text how the proposed emission 

limit was calculated; however, according to EPA's Acid Rain Database, Big Stone I NOx 

emissions have averaged O.77lbIMMBtu over the last five years. Assuming a control 

efficiency greater than 90% should result in a limit lower than the proposed 0.1 IbIMMBtu. 

14. Section 6.3.3.4, Nitrogen Oxide Control Technology Impacts, p. 87: We assume you are 

relying on Otter Tail's analysis of estimated costs, which relied on the CUECost model. 

While we are satisfied with the control technology conclusions of your NOx BART 

determination (i.e., SCR plus SOFA), in general we do not recommend relying on the 

CUECost model. According to the BART Guidelines, in order to maintain and improve 

consistency, cost estimates must be based on the OAQPS Control Cost Manual. 

15. Table 6-10, p. 88: Footnote 3 contains typographical errors - should be nitrogen oxides. In 

addition, similar to comment #11 above, it is unclear how the baseline level of 

18,000 tons/year was obtained. According to Table 6-1, p. 71, baseline NOx emissions were 

17,179 tons/year. The larger baseline figure results in an 89% emission reduction for the 1 st 

option, as opposed to 93% with the 17,179 tons/year figure. As stated above in comment 

# 13, a control efficiency greater than 90% is appropriate for the proposed SCR plus SOFA 

controls. Please explain how the 18,000 tons/year NOx baseline figure was obtained; 

16. Section 6.3.4, Visibility Impact Evaluations, 2

nd paragraph, p. 89: Again, the text refers to 

Big Stone I baseline emissions of 18,000 tons S02 and 18,000 tons NOx• Please explain how 

these numbers were obtained. 

17. Table 6-12, p. 89: According to Footnote 2 of Table 6-12, the rounded modeling values 

shown in the parentheses were used to compare with the subject-to-BART threshold, but 

actually, the unrounded modeled value must be used for determining whether a source 

exceeds the threshold. 

18. Section 6.3.5.1, Particulate Matter BART Recommendation, p. 95: 

(A) We assume DENR's proposed particulate matter BART limit ofO.OI2Ib/MMBtu is on a 

30-day rolling average basis, as required. Please clarify in the SIP. 

(B) While we agree that a baghouse is the top particulate control technology, what is the 

justification for proposing a separate hourly startup/shutdown limit? The SIP must document 

the need for such a separate limit, as well as whether the selected value represents BART. 

Has DENR evaluated potential impacts of the separate startup/shutdown limit on visibility? 

The BART Guidelines contemplate pounds per million Btu limits that apply continuously, 

with a 30-day rolling average period to accommodate, among other things, potential shortterm fluctuations in the emissions rate that may result during startup, shutdown, and other 

conditions. Presumably, your proposed 3D-day rolling average limit already includes some 

margin of safety for operational variation. If you are able to justify the separate limits, we 

would work closely with you as you draft appropriate permit language to help ensure SIP 

approvability related to determining compliance with the normal 30-day rolling average limit 

-5-
and the hourly startup/shutdown limit. For example, in calculating 30-day averages, how will 

days be accounted for that include some, but not all, hours of startup/shutdown? 

19. Section 6.3.5.2, Sulfur DioxideBART Recommendation, pp. 96-97: 

(A) We assume DENR's proposed S02 BART limit ofO.09Ib/MMBtu is on a 30-day rolling 

average basis, as required. Please clarify in the SIP. 

(B) As noted in comment #18 above, justification for proposing a separate Ib/hour limit for 

periods of startup and shutdown must be provided. The SIP must document the need for such 

a separate limit, as well as whether the selected value represents BART. Has DENR 

evaluated potential impacts of the separate startup/shutdown limit on visibility? The BART 

Guidelines contemplate pounds per million Btu limits that apply continuously, with a 30-day 

rolling average period to accommodate, among other things, potential short-term fluctuations 

in the emissions rate that may ~esult during startup, shutdown, and other conditions. 

Presumably, your proposed 30-day rolling average limit already includes some margin of 

safety for operational variation. If you are able to justify the separate limits, we would work 

closely with you as you draft appropriate permit language to help ensure SIP approvability 

related to determining compliance with the normal30-day rolling average limit and the 

hourly startup/shutdown limit. For example, in calculating 30-day averages, how will days 

be accounted for that include some, but not all, hours of startup/shutdown? 

20. Section 6.3.5.3, Nitrogen Oxide BART Recommendation, pp. 97-98: 

(A) Regarding the term "threshold" in reference to $1500/ton for NOx removal, EPA's 

position is that the NOx presumptive limits were established based on the relatively low cost 

ofless than $1500/ton for the majority oflarge EGUs. There is no bright line regarding cost 

effectiveness and each determination must be made taking into account a full five factor 

BART analysis. In addition, although Big Stone I has a capacity less than 750 MW, it is 

greater than 200 MW and operating without post-combustion controls. Per the BART 

Guidelines, it is reasonable to assume that SCR is generally cost-effective on large cyclone 

units. See 70 FR 39171, July 6, 2005. 

(B) Please clarify that DENR's NOx BART determination is SCR plus SOFA at 

0.10 Ib/MMBtu on a 30-day rolling average. 

(C) As noted in comments # 18-19 above, justification for proposing a separate lb/hour limit 

for periods of startup and shutdown must be provided. The SIP must document the need for 

such a separate limit, as well as whether the selected value represents BART. Has DENR 

evaluated potential impacts of the separate startup/shutdown limit on visibility? The BART 

Guidelines contemplate pounds per million Btu limits that apply continuously, with a 30-day 

rolling average period to accommodate, among other things, potential short-term fluctuations 

in the emissions rate that may result during startup, shutdown, and other conditions. 

Presumably, your proposed 30-day rolling average limit already includes some margin of 

safety for operational variation. If you are able to justify the separate limits, we would work 

closely with you as you draft appropriate permit language to help ensure SIP approvability 

related to determining compliance with the normal30-day rolling average limit and the 

-6-
hourly startup/shutdown limit. For example, in calculating 30-day averages, how will days 

be accounted for that include some, but not all, hours of startup/shutdown? 

21. Section 6.4, BART Requirements, p. 99: According to your proposed revisions to the 

South Dakota Administrative Rules, Chapter 74:36:21 :10, a permit modification will be 

required for your BART determination on Otter Tail's Big Stone 1. Without seeing the 

details of such permit, it is difficult to determine whether this section of the SIP adequately 

addresses requirements for enforceability, including appropriate averaging times, compliance 

verification procedures, and recordkeeping and reporting requirements, and proper operation 

and maintenance procedures. As noted in comment # 1 above, these requirements must be 

specified either in the text ofthe Regional Haze SIP or in a permit that is incorporated into 

the SIP. 

22. Section 7.1, State and Federal Rules, pp. 100-101: Please clarify that although some of the 

cited Administrative Rules of South Dakota (ARD) control emissions of pollutants that 

ultimately contribute to visibility impairment, they were not written specifically to address 

visibility impairment. 

23. Table 7-1 and Section 7.2.1, Breakdown ofCMAQ Modeling Results, pp. 102-103: We were 

unable to determine if 16.50 dv for Badlands and 15.28 dv for Wind Cave are your 

Reasonable Progress Goals (RPG). These numbers don't quite match with those shown in 

Figure 8-1. Please clarify and document how the numbers were obtained. Also, the SIP must 

include the dv difference between the baseline and natural conditions for the best and worst 

days for the 1 st planning period per 40 CFR 51.308( d)(2)(iv)(A). Finally, the SIP must 

provide the number of years necessary to reach natural conditions, as required by 

40 CFR 51.308(d)(1)(ii) when the RPG is less than the uniform rate of progress (URP). 

24. Section 7.2.2, Four Factor Analysis, p. 104: DENR's determination that a four-factor 

analysis is not warranted at this time is not acceptable. A four-factor analysis must be 

completed in establishing the RPGs for Class I areas impacted by South Dakota emissions, as 

well as in justifying a RPG that is less than URP. While we realize that the emissions 

reductions proposed under BART for Big Stone I will provide significant emissions 

reductions in South Dakota, remaining sources must be considered under Reasonable 

Progress. For example, are there any further reductions that could be obtained from 

GCC Dacotah, Ben French, or Pete Lien? What about potential impacts from the close 

proximity of Rapid City to Badlands? A simple Q/d analysis can provide a starting point. It 

may be reasonable for DENR to conclude, upon completion of an adequate four-factor 

analysis, that additional controls under Reasonable Progress are not warranted in this 

planning period. However, such a determination cannot be made without the analysis. 

Perhaps information from the WRAP's May 19, 2009 draft Supplementary Information for 

Four-Factor Analysesfor Selected Individual Facilities in South Dakota, and WRAP's 

May 4, 2009 draft Supplementary Informationfor Four Factor Analyses by WRAP States, can 

be utilized to address some of the Reasonable Progress analysis requirements. If so, our 

August 12,2009 comments on the draft WRAP reports must be taken into account. 

-7-
25. Section 8.0, Long Term Strategy, pp. 104-105: According to 40 CFR 51.306(c), the State 

must revise its plan to provide for a coordinated long-term strategy for addressing both 

reasonably attributable and regional haze visibility impairment, and future coordinated 

long-term strategies must be submitted consistent with the schedule for periodic progress 

. reports set forth in 40 CFR 51.308(g), i. e., every 5 years. South Dakota never adopted a plan 

to address the requirements of 40 CFR 51.306 for a reasonably attributable visibility 

impairment long-term strategy; therefore, a Federal Implementation Plan (FIP) was 

promulgated to incorporate by reference the reasonably attributable visibility impairment 

long-term strategy requirements described in 40 CFR 52.29. See the federally-approved 

South Dakota Identification of Plan section at 40 CFR 52.2l79( c). At this time, it is not clear 

from a national perspective how to coordinate a reasonably attributable long-term strategy 

FIP with a regional haze long-term strategy SIP. The simplest approach would be for you to 

develop your own reasonably attributable long-term strategy to replace the FIP. Is this 

approach something you would consider? We would be happy to work with you to develop 

appropriate language and believe it would not take too much additional work given the effort 

you have already put into the draft regional haze SIP. 

26. Section 8.1, Class I Areas in Other States Impacted by South Dakota, p. 105: This section 

must quantify South Dakota's impact to the Class I areas outside the State (similar to that 

noted in Table 6-4). 

27. Section 8.3, Technical Basis for Modeling, Monitoring and Emissions Information, p. 106: 

To assist the reader, please include website addresses and/or references to where these 

technical analyses are housed and how they will be maintained going forward. In addition, 

the text must address DENR's commitment to continued compilation and analysis of the 

technical requirements for the Regional Haze SIP, regardless of future uncertainty in the 

Western Regional Air Partnership's (WRAP's) role. 

28. Section 8.5, Factors in Developing Long Term Strategy, p. 107: There appear to be 

typographical errors in the last paragraph - should be "emissions reductions." 

29. Section 8.5.1, Emission Reductions from Ongoing Air Pollution Control Programs, 

pp.107-108: As noted in comment #22 above, please clarify that although some of the cited 

Administrative Rules of South Dakota were not written specifically to address visibility . 

impairment, they do control emissions of pollutants that may ultimately contribute to 

visibility impairment. 

30. Section 8.5.2, Measures to Mitigate Impacts of Construction Activities, pp. 108-109: 

South Dakota never adopted a plan to address the original Visibility New Source Review 

(NSR) requirements of 40 CFR 51.307; therefore, a Federal Implementation Plan (FIP) was 

promulgated to incorporate by reference the Visibility NSR requirements described in 

40 CFR 52.28. See the federally-approved South Dakota Identification of Plan section at 

40 CFR 52.2179(b). Is it your intention to replace the nonattainment NSR visibility analysis 

requirements of 40 CFR 52.21 79(b) with your proposed revisions to ARSD 74:36:21? Ifso, 

we would provide input for such a revision if requested. 

-8-
31. Section 8.5.5, Smoke Management, pp. 109-110: Given that your source apportionment 

analysis identified organic carbon mass as one of the largest contributors on the most 

impaired days, it is difficult to understand why DENR has deferred consideration of smoke 

management techniques until 2013. In establishing its long-term strategy, the State must 

consider smoke management techniques for agricultural and forestry management purposes 

including plans as currently exist within the State for these purposes 

See 40 CFR 51.308( d)(3)(v)(E). At least some preliminary steps, in coordination with the 

FLMs, must be included, along with citing to any existing South Dakota burning provisions. 

32. Section 8.5.6, Enforceable Emission Limits and Control Measures, pp. 110-111: We note 

your intention to establish the Big Stone I BART limits and control measure requirements in 

either a construction permit or the Title V permit. Note that any air quality permit used to 

address BART requirements will need to be incorporated into the SIP. The South Dakota 

draft construction permit program regulations are currently under review by our office. Until 

this has been approved into the SIP, it will not be appropriate to rely upon the program for 

your BART permits. 

33. Section 9.0, Monitoring Strategy, p. 113-116: South Dakota never adopted a plan to address 

the original Visibility Monitoring requirements of 40 CFR 51.305; therefore, a FIP was 

promulgated to incorporate by reference the Visibility Monitoring requirements described in 

40 CFR 52.26. See the federally-approved South Dakota Identification of Plan section at 

40 CFR 52.2l79(b). Is it your intention to replace the South Dakota Visibility Monitoring 

FIP requirements of 40 CFR 52.2179(b) with the DENR Monitoring Strategy as outlined in 

Section 9.0 of the Regional Haze SIP? If so, we would provide input for such a revision if 

requested. 

34. Section 10.2, Consultation with Other States, pp. 118-119: For clarity, it would be helpful if 

in each instance of consultation, the text identified the dates and outcomes of the discussions. 

In addition, other than their involvement in WRAP, does DENR have a plan to include tribal 

consultation on the public comment version of the SIP? 

35. Section 10.3, Public Input, p. 119: As noted in comment #23 above, the SIP must provide 

the public with a calculation of the number of years required to reach natural conditions if the 

RPG provides a slower rate of improvement than that needed to attain natural conditions by 

2064 per 40 CFR 51.308(d)(I)(ii). We understand your concerns regarding assumptions for 

other states included in the WRAP analysis; however, this SIP must include your best 

estimate of number of years to reach natural conditions with the proposed RPGs. 

36. Section 11.2, Report Every 5 Years, p. 121: As part of continuing consultation required 

under 40 CFR 51.308(i)(4), please clarify item 7, regarding the monitoring strategy, to note 

that you will consult with EPA and the FLMs on any revisions deemed necessary. 

37. Appendices: We are unable to comment on any of the appendices since they were not 

included. Information in these appendices may have been necessary for a more thorough 

-9-
review by EPA. If you are able to share the draft appendices prior to the official public 

comment period, it would be very helpful. 

38. ARSD Chapter 74:36:21, Regional Haze Program: 

(A) 74:36:21:02, Definitions: The definition of "BART-eligible source" must cite to an 

existing stationary facility as defined in 74:36:21 :03. The definition of "visibility 

impairment" does not mirror the federal definition contained in 40 CFR 51.301 and must be 

revised accordingly. The definition of "contribute to visibility impairment" is not appropriate 

in the regional haze context and must be removed since there is no threshold for such a 

contribution. Finally, the definition of "major source" must cite to 40 CFR 51.166, and you 

must include the definition of "major modification" from 40 CFR 51.166, since the definition 

of major stationary source under the regional haze regulations includes major modifications. 

(B) 74:36:21 :04, Visibility Impact Analysis: This section must be revised to clarify that the 

existing provisions of 74:36:09, Prevention of Significant Deterioration, are not replaced by 

this new section 74:36:21 :04. Given that you do have existing regulations, what is your 

intent with this new provision? 

(C) 74:36:21 :07, Operation and Maintenance of Controls: To improve clarity, this section 

should include more detail, such as specifying the minimum criteria for an acceptable 

operation and maintenance plan and when the source specific operation and maintenance plan 

to meet such criteria shall be submitted for permitting authority approval. 

(D) 74:36:21 :08, Monitoring, Recordkeeping and Reporting: As this provision is drafted, the 

term "main stack" is a concern because it is not clear whether all of the sulfur dioxide and 

nitrogen dioxide emissions from the BART-eligible source will be routed to the main stack. 

The term "main stack" implies the presence of other stack(s) which is/are not equipped with 

continuous emission monitoring system(s) as is the "main stack." The language in 

74:36:21 :08 (page 8, second sentence) should be revised to read, "All sulfur dioxide and 

nitrogen dioxide emissions from the BART eligible source shall be routed to the main stack 

of the BART-eligible source. Monitoring of sulfur dioxide and nitrogen dioxide emissions 

from the main stack shall be conducted using a continuous emission monitoring system 

which complies with continuous emission monitoring system requirements in 74:36: 13." 

(E) 74:36:21 :11, Federal Land Manager Notification and Review: As required by the 

Regional Haze Rule, the Federal Land Managers must be provided a 60-day consultation 

period prior to any public hearing on the Regional Haze SIP. Since a BART permit is an 

integral part of the Regional Haze SIP, this 60-day consultation period must extend to FLM 

BART permit review as well. In addition, since any BART permit must be incorporated into 

the Regional Haze SIP, the 30-day public notice for the SIP needs to identify the inclusion of 

any BART permits. 

-10-
February 23, 2010 

SOUTH DAKOTA DEPARTMENT OF AGRICULTURE 

DIVISION OF WILDLAND FIRE SUPPRESSION 

4250 Fire Station Rd., Ste 2 

Rapid City, SD 57703-8722 

Phone: 605-393-8011 

FAX: 605-393-8044 

Web Address - www.state.sd.us/doa 

South Dakota Department of Environment and Natural Resources 

ATTN: Rick Boddicker, Senior Environmental Scientist 

523 East Capitol 

Pierre SD 57501 

Dear Mr. Boddicker: 

Thank you for the opportlmity for the Division of Wildland Fire Suppression to comment on the 

proposed SIP and ARSD rules. 

As you are well aware, the use of open fire to dispose of logging slash and biomass residues in 

the Black Hills Forest Fire Protection District by broadcast or pile burning is a very important 

management tool for this agency. In addition, this tool is very important for private landowners 

and the Black Hills National Forest in the management of forest health in a fire dependent 

ponderosa pine ecosystem. The use of broadcast burning for prescribed fire, as the SIP plan 

pointed out, is an important management tool for the National Park Service for ecosystem 

management of Wind Cave and the Badlands National Parks. 

This division manages the wildfire activity in Custer State Park as mandated by South Dakota 

state law. One challenge facing this division and the Department of Game Fish and Parks is the 

fuel loading of hazardous fuels within Custer State Park, which is just north of Wind Cave 

National Park. An important tool in mitigating the risk of hazardous fuel loading in Custer State 

Park is that of slash pile burning. In addition, Custer State Park has identified a goal in their 

current resource management plan of treating 1324 acres per year by prescribed fire. Also this 

division issues approximately one thousand burning permits annually in the Custer County 

portion of the Black Hills Forest Fire Protection District. Some of these pem1its are adjacent to 

Wind Cave National Park. 

SD DENR Draft SIP and ARSD Comments 

February 2010 

Page 1 of 2 

Agriculture - Struth Dakota's #1 Industry 
Therefore, the Department of Agriculture strongly feels that the use of fire in a ponderosa pine 

ecosystem to maintain forest health is part and parcel a continuation of a natural process that 

existed in this area long before any anthropogenic influences on air quality were measured. 

We also feel very strongly as an agency, that management practices by federal land managers to 

promote prairie dog habitat in and around the Conata Basin at the Badlands National Park and 

also at Wind Cave National Park leave bare soil that produces blowing dust in the areas of 

concern. Therefore, if smoke produced from wildfire and fire use activities are to be measured as 

background haze on days of poor visibility, then measurement techniques should be in place to 

quantifY the amount of dust being produced from these prairie dog towns as a factor for poor 

visibility during the same measuring period. 

This division looks forward to future collaboration with your agency in finding ways to meet air 

quality objectives that are needed for the nation's national parks, while at the same time, 

allowing land management agencies, private landowners, and this division, to use fire as an 

effective and proven tool in maintaining healthy forest and rangeland within our state. 

Sincerely; 

rr-~ Joe Lowe 

Division Director/State Wildland Fire Coordinator 

cc: Bill Even; Secretary of Agriculture 

Jon Farris, Deputy Secretary 

Raymond Sowers, State Forestry 

SD DENR Draft SIP and ARSD Comments 

February 2010 

Page 2 of 2