Final Report 

BART Analysis for 

Wyodak 

Prepared For: 

PacifiCorp 

1407 West North Temple 

Salt Lake City, Utah 84116 

December 2007 

Prepared By: 

215 South State Street, Suite 1000 

Salt Lake City, Utah 84111 
Final Report 

BART Analysis for 

Wyodak 

Submitted to 

PacifiCorp 

December 2007 
JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC ES-1

Executive Summary 

In response to the Regional Haze Rule and Best Available Retrofit Technology (BART) 

regulations and guidelines, CH2M HILL was requested to perform a BART analysis for 

PacifiCorp’s Wyodak plant (hereafter referred to as Wyodak). A BART analysis has been 

conducted for the following criteria pollutants: nitrogen oxides (NOx), sulfur dioxide (SO2), 

and particulate matter less than 10 micrometers in aerodynamic diameter (PM10). The Wyodak 

station consists of one unit with a total generating capacity of 335 megawatts (MW). 

Therefore, the presumptive BART limits do not apply to Wyodak. However, they are being 

referenced in this analysis, based on the United States Environmental Protection Agency’s 

(EPA) guidelines for units greater than 200 MW. BART emissions limits must be achieved 

within 5 years after the State Implementation Plan (SIP) is approved by the EPA, and a 

compliance date of 2014 was assumed for this analysis. 

In completing the BART analysis, technology alternatives were investigated and potential 

reductions in NOx, SO2, and PM10 emissions rates were identified. The following technology 

alternatives were investigated, listed below by pollutant: 

• NOx emission controls: 

− Low-NOx burners (LNBs) with over-fire air (OFA) 

− Rotating opposed fire air (ROFA) 

− LNBs with selective non-catalytic reduction system (SNCR) 

− LNBs with selective catalytic reduction (SCR) system 

• SO2 emission controls: 

− Upgrade existing dry lime flue gas desulfurization (FGD) system 

− Upgrade existing dry FGD system and replace existing electrostatic precipitator 

(ESP) with a new fabric filter 

− New wet FGD system with ESP 

• PM10 emission controls: 

− Sulfur trioxide (SO3) injection flue gas conditioning system followed by the existing 

ESP 

− New polishing fabric filter 

− New baghouse fabric filter 
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC ES-2

BART Engineering Analysis 

The specific steps in a BART engineering analysis are identified in the Code of Federal 

Regulations (CFR) at 40 CFR 51, Appendix Y, Section IV. The evaluation must include: 

• The identification of available, technically feasible, retrofit control options 

• Consideration of any pollution control equipment in use at the source (which affects the 

availability of options and their impacts) 

• The costs of compliance with the control options 

• The remaining useful life of the facility 

• The energy and non-air quality environmental impacts of compliance 

• The degree of visibility improvement that is anticipated from the use of BART 

The following steps are incorporated into the BART analysis: 

• Step 1 – Identify All Available Retrofit Control Technologies 

• Step 2 – Eliminate Technically Infeasible Options 

− The identification of available, technically feasible, retrofit control options 

− Consideration of any pollution control equipment in use at the source (which affects 

the applicability of options and their impacts) 

• Step 3 – Evaluate Control Effectiveness of Remaining Control Technologies 

• Step 4 – Evaluate Impacts and Document the Results 

− The costs of compliance with the control options 

− The remaining useful life of the facility 

− The energy and non-air quality environmental impacts of compliance 

• Step 5 – Evaluate Visibility Impacts 

− The degree of visibility improvement that may reasonably be anticipated from the use 

of BART 

Separate analyses have been conducted for NOx, SO2, and PM10 emissions. All costs included 

in the BART analyses are in 2006 dollars, and costs have not been escalated to the assumed 

2014 BART implementation date. 

Recommendations 

CH2M HILL recommends installing the following control devices, which include LNBs with 

OFA, dry FGD system, and the existing ESP. This combination of control devices is 

identified as Scenario 1 throughout this report. 

NOx Emission Control 

The Wyodak plant burns only Powder River Basin (PRB) coal, a sub-bituminous coal. 

CH2M HILL recommends new LNBs with over-fire air (LNB with OFA) as BART for 
BART ANALYSIS FOR WYODAK 

Wyodak, based on the projected significant reduction in NOx emissions, reasonable control 

costs, and the advantages of no additional power requirements or non-air quality 

environmental impacts. This technology is expected to achieve an emission rate of 

0.23 pound (lb) per million British thermal units (MMBtu). 

SO2 Emission Control 

CH2M HILL recommends upgrading the existing lime spray drying FGD system with the 

existing ESP as BART for Wyodak, based on the significant reduction in SO2 emissions, 

reasonable control costs, and the advantages of minimal additional power requirements and 

minimal non-air quality environmental impacts. This upgrade approach is projected to have 

an emission rate of 0.32 lb per MMBtu. 

PM10 Emission Control 

CH2M HILL recommends maintaining the performance of the existing ESP as BART for 

Wyodak, based on the PM10 emissions associated with the current equipment configuration, 

reasonable control costs, and the advantages of no additional power requirements and no 

non-air quality environmental impacts. 

BART Modeling Analysis 

CH2M HILL used the CALPUFF modeling system to assess the visibility impacts of 

emissions from Wyodak at Class I areas. The Class I areas potentially affected are located 

more than 50 kilometers (km), but less than 300 km, from the Wyodak Plant. 

The Class I areas include the following national parks (NPs): 

• Wind Cave NP 

• Badlands NP 

Because Wyodak will simultaneously control NOx, SO2, and PM10 emissions, four 

post-control atmospheric dispersion modeling scenarios were developed to cover the range of 

effectiveness for combining the individual NOx, SO2, and PM10 control technologies under 

evaluation. These modeling scenarios, and the controls assumed, are as follows: 

• Scenario 1: New LNBs with OFA modifications, upgrading the dry FGD system, and 

maintaining performance of the existing ESP. As indicated previously, this scenario 

represents CH2M HILL’s BART recommendation. 

• Scenario 2: New LNBs with OFA modifications, upgrading the dry FGD system, and 

installing a new fabric filter to replace the existing ESP. 

• Scenario 3: New LNBs with OFA modifications and SCR, upgrading the dry FGD 

system, and installing a new fabric filter to replace the existing ESP. 

• Scenario 4: New LNBs with OFA modifications and SCR, installing a new wet FGD 

system, and utilizing the existing ESP. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC ES-3
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC ES-4

 

Visibility improvements for all emission control scenarios were analyzed, and the results 

were compared utilizing a least-cost envelope, as outlined in the New Source Review 

Workshop Manual.1

Least-cost Envelope Analysis 

EPA has adopted the Least-cost Envelope Analysis Methodology as an accepted 

methodology for selecting the most reasonable, cost-effective controls. Incremental 

cost-effectiveness comparisons focus on annualized cost and emission reduction differences 

between dominant alternatives. The dominant set of control alternatives is determined by 

generating what is called the envelope of least-cost alternatives. This is a graphical plot of 

total annualized costs for total emissions reductions for all control alternatives identified in 

the BART analysis. 

To evaluate the impacts of the modeled control scenarios on the two Class I areas, the total 

annualized cost, cost per deciview (dV) reduction, and cost per reduction in number of days 

above 0.5 dV were analyzed. This report provides a comparison of the average incremental 

costs between relevant scenarios for the two Class I areas; the total annualized cost versus 

number of days above 0.5 dV, and the total annualized cost versus 98th percentile ΔdV 

reduction. 

Results of the least-cost envelope analysis validate the selection of Scenario 1, based on 

incremental cost and visibility improvements. Scenario 2 (LNB with OFA, upgrade dry FGD, 

and fabric filter) is eliminated, because it is to the left of the curve formed by the “dominant” 

control alternative scenario, which indicates a scenario with lower improvement and/or 

higher costs. Scenario 3 (LNB with OFA and SCR, upgrade dry FGD, and replacement of the 

fabric filter in lieu of the ESP) is not selected due to very high incremental costs, on the basis 

of both a cost per day of improvement, and cost per dV reduction. While Scenario 4 (LNB 

with OFA and SCR, wet FGD, and ESP) provides some potential visibility advantage over 

Scenario 1, the projected improvement is less than 0.5 dV, and the projected costs are 

excessive. Therefore, Scenario 1 represents BART for Wyodak. 

Just-Noticeable Differences in Atmospheric Haze 

Studies have been conducted that demonstrate only dV differences of approximately 1.5 to 

2.0 dV or more are perceptible by the human eye. Deciview changes of less than 1.5 cannot 

be distinguished by the average person. Therefore, the modeling analysis results indicate that 

only minimal, if any, observable visibility improvements at the Class I areas studied would 

be expected under any of the control scenarios. Thus, the results indicate that even though 

PacifiCorp will be spending many millions of dollars at this single unit—and over a billion 

dollars when considering its entire coal fleet—only minimal discernable visibility 

improvements may result.

1 EPA, 1990. New Source Review Workshop Manual. Draft. Environmental Protection Agency. October. 
Contents 

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

2.0 Present Unit Operation...................................................................................... 2-1

3.0 BART Engineering Analysis ............................................................................. 3-1

3.1 Applicability ............................................................................................ 3-1 

3.2 BART Process.......................................................................................... 3-1 

3.2.1 BART NOx Analysis.................................................................... 3-2 

3.2.2 BART SO2 Analysis .................................................................. 3-10 

3.2.3 BART PM10 Analysis ................................................................ 3-15 

4.0 BART Modeling Analysis.................................................................................. 4-1

4.1 Model Selection ....................................................................................... 4-1 

4.2 CALMET Methodology........................................................................... 4-1 

4.2.1 Dimensions of the Modeling Domain.......................................... 4-1 

4.2.2 CALMET Input Data ................................................................... 4-3 

4.2.3 Validation of CALMET Wind Field............................................ 4-6 

4.3 CALPUFF Modeling Approach............................................................... 4-6 

4.3.1 Background Ozone and Ammonia............................................... 4-6 

4.3.2 Stack Parameters.......................................................................... 4-6 

4.3.3 Emission Rates............................................................................. 4-7 

4.3.4 Post-control Scenarios ................................................................. 4-7 

4.3.5 Modeling Process......................................................................... 4-9 

4.3.6 Receptor Grids ............................................................................. 4-9 

4.4 CALPOST................................................................................................ 4-9 

4.5 Presentation of Modeling Results .......................................................... 4-10 

4.5.1 Visibility Changes for Baseline vs. Preferred Scenario............. 4-10 

5.0 Preliminary Assessment and Recommendations ............................................ 5-1

5.1 Least-cost Envelope Analysis.................................................................. 5-1 

5.1.1 Analysis Methodology................................................................. 5-1 

5.1.2 Analysis of Results ...................................................................... 5-6 

5.2 Recommendations.................................................................................... 5-6 

5.2.1 NOx Emission Control ................................................................. 5-6 

5.2.2 SO2 Emission Control.................................................................. 5-6 

5.2.3 PM10 Emission Control................................................................ 5-7 

5.3 Just-Noticeable Differences in Atmospheric Haze.................................. 5-7 

6.0 References........................................................................................................... 6-1

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC iii
CONTENTS (CONTINUED) 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC iv

Tables 

2-1 Present Unit Operation 

3-1 NOx Control Technology Emission Rate Ranking 

3-2 NOx Control Cost Comparison 

3-3 SO2 Control Technology Emission Rate Ranking 

3-4 SO2 Control Cost Comparison 

3-5 PM10 Control Cost Comparison 

4-1 User-specified CALMET Options 

4-2 BART Model Input Data 

4-3 Average Natural Levels of Aerosol Components 

4-4 Costs and Visibility Modeling Results for Baseline vs. Post-control Scenarios at 

Class I Areas 

5-1 Badlands Class I Agent Control Data 

5-2 Wind Caves Class I Area Control Data 

5-3 Badlands Class I Area Incremental Data 

5-4 Wind Caves Class I Agent Incremental Data 

Figures 

3-1 First Year Control Cost for NOx Air Pollution Control Options 

3-2 First Year Control Cost for SO2 Air Pollution Control Options 

4-1 Wyodak Source–specific Class I Areas to be Addressed 

4-2 Surface and Upper Air Stations Used in the Wyodak BART Analysis 

5-1 Least-cost Envelope Badlands Class I Area Reduction 

5-2 Least-cost Envelope Badlands Class I Area 98th Percentile 

5-3 Least-cost Envelope Wind Caves Class I Area Reduction 

5-4 Least-cost Envelope Wind Caves Class I Area 98th Percentile 

Appendices 

A Economic Analysis 

B 2006 Wyoming BART Protocol 
Acronyms and Abbreviations 

oF Degree Fahrenheit 

BACT Best Available Control Technology 

BART Best Available Retrofit Technology 

CALDESK Program to Display Data and Results 

CALMET Meteorological Data Preprocessing Program for CALPUFF 

CALPOST Post-processing Program for Calculating Visibility Impacts 

CALPUFF Gaussian Puff Dispersion Model 

CFR Code of Federal Regulations 

CO Carbon Monoxide 

COHPAC Compact Hybrid Particulate Collector 

dV Deciview 

ΔdV Delta Deciview, Change in Deciview 

ESP Electrostatic Precipitator 

EPA United States Environmental Protection Agency 

FGC Flue Gas Conditioning 

FGD Flue Gas Desulfurization 

H2SO4 Sulfuric Acid 

kW Kilowatt 

kWh Kilowatt-hour 

LAER Lowest Achievable Emission Rate 

lb Pound 

LNB Low-NOx Burner 

MMBtu Million British Thermal Units 

MM5 Mesoscale Meteorological Model, Version 5 

MW Megawatt 

NH4 Ammonium 

(NH4)HSO4 Ammonium Bisulfate 

(NH4)2SO4 Ammonium Sulfate 

NOx Nitrogen Oxide 

NP National Park 

NSR Manual New Source Review Workshop Manual (EPA, 1990) 

OFA Over-fire Air 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC v
ACRONYMS AND ABBREVIATIONS (CONTINUED) 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC vi

PM Particulate Matter 

PM2.5 Particulate Matter less than 2.5 Micrometers in Aerodynamic Diameter 

PM10 Particulate Matter less than 10 Micrometers in Aerodynamic Diameter 

PRB Powder River Basin 

ROFA Rotating Opposed Fire Air 

S&L Sargent & Lundy 

S&L Study Multi-Pollutant Control Report dated October, 2002 

SCR Selective Catalytic Reduction 

SIP State Implementation Plan 

SNCR Selective Non-catalytic Reduction 

SO2 Sulfur Dioxide 

SO3 Sulfur Trioxide 

tpy Tons per Year 

TRC TRC Companies, Inc. 

USGS U.S. Geological Survey 

WDEQ Wyoming Department of Environmental Quality 

WDEQ-AQD Wyoming Department of Environmental Quality – Air Quality Division 
1.0 Introduction 

Best Available Retrofit Technology (BART) guidelines were established as a result of United 

States Environmental Protection Agency (EPA) regulations intended to reduce the 

occurrence of regional haze in national parks (NPs) and other Class I protected air quality 

areas in the United States. These guidelines provide guidance for states when determining 

which facilities must install additional controls, and the type of controls that must be used. 

Facilities eligible for BART installation were built between 1962 and 1977, and have the 

potential to emit more than 250 tons per year of visibility-impairing pollutants. 

The Wyoming Department of Environmental Quality (WDEQ) BART regulations state that 

each source subject to BART must submit a BART application for a construction permit by 

December 15, 2006. PacifiCorp received an extension from the WDEQ to submit the BART 

report for Wyodak on February 2, 2007. The BART report that was submitted to WDEQ in 

February 2007 included a BART analysis, and a proposal and justification for BART at the 

source. This revised report—submitted in October 2007—incorporates editorial revisions 

since the February 2007 version. 

The State of Wyoming has identified those eligible, in-state facilities that are required to 

reduce emissions under BART, and will set BART emissions limits for those facilities. This 

information will be included in the State of Wyoming State Implementation Plan (SIP), 

which the State has estimated will be formally submitted to the EPA by early 2008. The EPA 

BART guidelines also state that the BART emission limits must be fully implemented within 

5 years of EPA’s approval of the SIP. 

Five elements related to BART address the issue of emissions for the identified facilities: 

• Any existing pollution control technology in use at the source 

• The cost of the controls 

• The remaining useful life of the source 

• The energy and non-air quality environmental impacts of compliance 

• The degree of improvement in visibility that is anticipated from using such technology 

This report documents the BART analysis that was performed on Wyodak by CH2M HILL 

for PacifiCorp. The analysis was performed for nitrogen oxides (NOx), sulfur dioxide (SO2), 

and particulate matter less than 10 micrometers in aerodynamic diameter (PM10) because 

they are the primary criteria pollutants that affect visibility. 

Section 2 of this report provides a description of the present unit operation, including a 

discussion of coal sources and characteristics. The BART Engineering Analysis is provided 

in Section 3 by pollutant type. Section 4 provides the methodology and results of the BART 

Modeling Analysis, followed by recommendations in Section 5 and references are provided 

in Section 6. Appendices provide more detail on the economic analysis and the 2006 

Wyoming BART Protocol.

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 1-1
2.0 Present Unit Operation 

The Wyodak plant consists of one nominal 335-megawatt (MW) unit located near Gillette, 

Wyoming. Wyodak is equipped with a wall-fired boiler manufactured by Babcock & Wilcox. 

A Babcock & Wilcox Rothemuhle weighted wire electrostatic precipitator (ESP) is used for 

particulate control (PM) and a Joy Niro, three-tower, lime-based spray dryer was added for 

flue gas desulfurization (FGD) in 1986. An Emerson Ovation distributed control system was 

installed in 2006. Table 2-1 lists additional unit information and the basis of design 

assumptions. 

Coal currently being burned at Wyodak is from the Clovis Point mine, operated by Black 

Hills Power, and is located near the plant site. The coal is ranked sub-bituminous. 

Wyodak was placed in service in 1978. Its current economic depreciation life is through 

2042; however, this analysis is based on a 20-year life for BART control technologies—and 

for purposes of this analysis—will continue operation until 2033. Assuming a BART 

implementation date of 2014, this will result in an approximate remaining useful life for 

Wyodak of 20 years from the installation date of any new or modified BART-related 

equipment. This report does not attempt to quantify any additional life extension costs 

needed to allow Wyodak to operate until 2042. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 2-1
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 2-2

TABLE 2-1 

Present Unit Operation 

Wyodak 

General Plant Data 

Site Elevation (feet above mean sea level) 4420 

Stack Height (feet) 400 

Stack Exit Internal Diameter (feet) /Exit Area (square feet) 20.0 / 314.2 

Stack Exit Temperature (degrees Fahrenheit) 185 

Stack Exit Velocity (feet per second) 77 

Stack Flow (actual cubic feet per minute) 1,451,604 

Latitude (degree: minute: second) 44:17:16.36 

Longitude (degree: minute: second) 105:23:2.47 

Annual Unit Capacity Factor (percentage) 90 

Net Unit Output (megawatts) 335 

Net Unit Heat Rate (British thermal unit [Btu]/kilowatt hour )(100% 

load) 

12,087 (as measured by fuel 

throughput) 

Boiler Heat Input (million British thermal units [MMBtu]/Hr)(100% 

load) 

4,700 (as measured by continuous 

emissions monitoring) 

Type of Boiler Wall fired 

Boiler Fuel Coal 

Coal Sources Clovis Point Mine 

Coal Heating Value (Btu per pound)a 8,050 

Coal Sulfur Content (percentage by weight)a 0.65 

Coal Ash Content (wt. %)a 7.46 

Coal Moisture Content (wt. %)a 30.79 

Coal Nitrogen Content (wt. %) 0.57 

Current Nitrogen Oxide (NOx) Controls Good Combustion Practices 

Pre-project NOx Emission Rate (lb per MMBtu)(b) 0.31 

Current Sulfur Dioxide (SO2) Controls Lime Based Spray Dryer 

Pre-project SO2 Emission Rate (lb per MMBtu) 0.50 

Current Particulate Matter less than 10 micrometers (PM10) 

Controls Electrostatic Precipitator 

Pre-project PM10 Emission Rate (lb per MMBtu)(c) 0.030 

NOTE: 

a

Coal characteristics vary between sources 

b

Emission rates stated on annual average basis 

c

Emission rate stated from test results 
3.0 BART Engineering Analysis 

This section presents the required BART engineering analysis. 

3.1 Applicability 

In compliance with regional haze requirements, the State of Wyoming must prepare and 

submit visibility SIPs to the EPA for Class I areas. The State has estimated that the formal 

submittal of the SIPs will occur by early 2008. The first phase of the regional haze program 

is the implementation of BART emission controls on all BART-eligible units, within 5 years 

after EPA approval of the SIP. 

3.2 BART Process 

The specific steps in a BART engineering analysis are identified in the Code of Federal 

Regulations (CFR) at 40 CFR 51, Appendix Y, Section IV. The evaluation must include: 

• The identification of available, technically feasible, retrofit control options 

• Consideration of any pollution control equipment in use at the source (which affects the 

availability of options and their impacts) 

• The costs of compliance with the control options 

• The remaining useful life of the facility 

• The energy and non-air quality environmental impacts of compliance 

• The degree of visibility improvement is anticipated from using BART 

The following steps are incorporated into the BART analysis: 

• Step 1 – Identify All Available Retrofit Control Technologies 

• Step 2 – Eliminate Technically Infeasible Options 

− The identification of available, technically feasible, retrofit control options 

− Consideration of any pollution control equipment in use at the source (which affects 

the applicability of options and their impacts) 

• Step 3 – Evaluate Control Effectiveness of Remaining Control Technologies 

• Step 4 – Evaluate Impacts and Document the Results 

− The costs of compliance with the control options 

− The remaining useful life of the facility 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-1
BART ANALYSIS FOR WYODAK 

− The energy and non-air quality environmental impacts of compliance 

• Step 5 – Evaluate Visibility Impacts 

− The degree of visibility improvement that is anticipated from using BART 

To minimize costs in the BART analysis, consideration was made of any pollution control 

equipment in use at the source, the costs of compliance associated with the control options, 

and the energy and non-air quality environmental impacts of compliance using these existing 

control devices. In some cases, enhancing the performance of the existing control equipment 

was considered. Other scenarios with new control equipment were also developed. 

Separate cost analyses have been conducted for NOx, SO2, and PM10 emissions. All costs 

included in the BART analysis are in 2006 dollars, and costs have not been escalated to the 

assumed 2014 BART implementation date. 

3.2.1 BART NOx Analysis 

Nitrogen oxide formation in coal-fired boilers is a complex process that is dependent on a 

number of variables, including operating conditions, equipment design, and coal characteristics. 

Formation of NOx

During coal combustion, NOx is formed in three different ways. The dominant source of NOx

formation is the oxidation of fuel-bound nitrogen (also referred to as fuel NOx). During 

combustion, part of the fuel-bound nitrogen is released from the coal with the volatile matter, 

and part is retained in the solid portion (char). The nitrogen chemically bound in the coal is 

partially oxidized to nitrogen oxides (nitric oxide and nitrogen dioxide) and partially reduced 

to molecular nitrogen. A smaller part of NOx formation is due to high temperature fixation of 

atmospheric nitrogen in the combustion air. A very small amount of NOx is called prompt 

NOx. Prompt NOx results from an interaction of hydrocarbon radicals, nitrogen, and oxygen. 

In a conventional pulverized coal burner, air is introduced with turbulence to promote good 

mixing of fuel and air to provide stable combustion. However, not all of the oxygen in the air 

is used for combustion. Some of the oxygen combines with the fuel nitrogen to form NOx. 

Coal characteristics directly and significantly impact NOx emissions from coal combustion. 

Coal ranking is a means of classifying coals according to their degree of metamorphism in 

the natural series, from lignite to sub-bituminous to bituminous and on to anthracite. Lower 

rank coals, such as the sub-bituminous coals from the Powder River Basin (PRB), produce 

lower NOx emissions than higher rank bituminous coals, due to their higher reactivity and 

lower nitrogen content. The fixed carbon to volatile matter ratio (fuel ratio), coal oxygen 

content, and rank are good relative indices of the reactivity of a coal. Lower rank coals 

release more organically bound nitrogen earlier in the combustion process than do higher 

rank bituminous coals. When used with low-NOx burners (LNBs), sub-bituminous coals 

create a longer time for the kinetics to promote more stable molecular nitrogen, and hence 

result in lower NOx emissions. 

Coals from the PRB are classified as sub-bituminous C and demonstrate the high reactivity 

and low NOx production characteristics described previously. Based on data from the Energy 

Information Administration, PRB coals currently represent 88 percent of total U.S. 

sub-bituminous production and 73 percent of western coal production (Energy Information 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-2
BART ANALYSIS FOR WYODAK 

Administration, 2006). Most references to western coal and sub-bituminous coal infer PRB 

origin and characteristics. Emissions standards differentiating between bituminous and 

sub-bituminous coals are presumed to use PRB coal as the basis for the sub-bituminous 

standards, due to its dominant market presence and unique characteristics. 

Wyodak burns sub-bituminous coal from the PRB. The BART presumptive NOx limit for 

sub-bituminous coal combusted in a wall-fired boiler is 0.23 pound (lb) per million British 

thermal units (MMBtu). The current NOx emission rate at Wyodak is 0.31 lb per MMBtu. 

The BART analysis for NOx emissions from Wyodak is described in this section. 

Step 1: Identify All Available Retrofit Control Technologies 

The first step of the BART process is to evaluate NOx control technologies with practical 

potential for application to Wyodak, including those control technologies identified as Best 

Available Control Technology (BACT) or lowest achievable emission rate (LAER) by 

permitting agencies across the United States. A broad range of information sources have been 

reviewed in an effort to identify potentially applicable emission control technologies. 

Wyodak NOx emissions are currently controlled through the use of good combustion 

practices. 

The following potential NOx control technology options were considered: 

• New/modified LNBs with advanced over-fire air (OFA) 

• Mobotec rotating opposed fire air (ROFA) 

• Conventional selective non-catalytic reduction (SNCR) system 

• Selective catalytic reduction (SCR) system 

Step 2: Eliminate Technically Infeasible Options 

For Wyodak, a wall-fired configuration burning sub-bituminous coal, technical feasibility will 

primarily be determined by physical constraints and boiler configuration. Wyodak’s current 

NOx emission rate is 0.31 lb per MMBtu. 

For this BART analysis, information pertaining to LNBs, OFA, SNCR, and SCR were based 

on the Multi-Pollutant Control Report (Sargent & Lundy, 2002, hereafter referred to as the 

S&L Study). The cost estimates for SCR and SNCR were updated by Sargent & Lundy 

(S&L) in October 2006. PacifiCorp provided additional emissions data and costs developed 

by boiler vendors for LNBs and OFA. Also, CH2M HILL solicited a proposal from Mobotec 

for their ROFA technology. 

With SNCR, an amine-based reagent such as ammonia, or more commonly urea, is injected 

into the furnace within a temperature range of 1,600 degrees Fahrenheit (°F) to 2,100°F, 

where it reduces NOx to nitrogen and water. Nitrogen oxide reductions of up to 60 percent 

have been achieved, although 20 to 40 percent is more realistic for most applications. 

Selective non-catalytic reduction is typically applied on smaller units. Adequate reagent 

distribution in the furnaces of large units can be problematic. 

Table 3-1 summarizes the control technology options evaluated in this BART analysis, along 

with projected NOx emission rates. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-3
BART ANALYSIS FOR WYODAK 

TABLE 3-1 

NOx Control Technology Emission Rate Ranking 

Wyodak 

Technology Projected Emission Rate (pounds 

per million British thermal units ) 

Presumptive Best Available 

Retrofit Technology (BART) 

Limit (for reference only) 

0.23 

Low-NOx Burners (LNBs) with 

Over-fire Air (OFA) 0.23 

Rotating Opposed Fire Air 0.20 

LNBs with OFA and Selective 

Non-catalytic Reduction 

(SNCR) 

0.18 

LNBs with OFA and SCR 0.07 

Step 3: Evaluate Control Effectiveness of Remaining Control Technologies 

Preliminary vendor proposals, such as those used to support portions of this BART analysis, 

may be technically feasible and provide expected or guaranteed emission rates; however, the 

proposals include inherent uncertainties. These proposals are usually prepared in a limited 

time frame, may be based on incomplete information, may contain overly optimistic 

conclusions, and are non-binding. Therefore, emission rate values obtained in such 

preliminary proposals must be qualified, and it must be recognized that contractual 

guarantees are established only after more detailed analysis has been completed. The 

following subsections describe the control technologies and the control effectiveness 

evaluated in this BART analysis. 

New LNBs with OFA System. The mechanism used to lower NOx with LNBs is to stage the 

combustion process and provide a fuel-rich condition initially; this is so oxygen needed for 

combustion is not diverted to combine with nitrogen and form NOx. Fuel-rich conditions 

favor the conversion of fuel nitrogen to N2 instead of NOx. Additional air (or OFA) is then 

introduced downstream in a lower temperature zone to burn out the char. 

Information provided to CH2M HILL by PacifiCorp—based on the S&L Study and data 

from boiler vendors—indicates that new LNB and OFA retrofit at Wyodak would result in an 

expected NOx emission rate of 0.23 lb per MMBtu. PacifiCorp has indicated that this rate 

corresponds to a vendor guarantee plus an added operating margin, not a vendor prediction, 

and they believe that this emission rate can be sustained as an average between overhauls. 

This emission rate represents a significant reduction from the NOx emission rate of 0.31 lb 

per MMBtu and meets the presumptive NOx emission rate of 0.23 lb per MMBtu. 

ROFA. Mobotec markets ROFA as an improved second generation OFA system. Mobotec 

states that: “the flue gas volume of the furnace is set in rotation by asymmetrically placed air 

nozzles. Rotation is reported to prevent laminar flow, so that the entire volume of the furnace 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-4
BART ANALYSIS FOR WYODAK 

can be used more effectively for the combustion process. In addition, the swirling action 

reduces the maximum temperature of the flames and increases heat absorption. The 

combustion air is also mixed more effectively.” A typical ROFA installation will have a 

booster fan(s) to supply the high-velocity air to the ROFA boxes, and Mobotec would 

propose one 7,000 horsepower fan for Wyodak. 

Mobotec expects to achieve a NOx emission rate of 0.18 lb per MMBtu using ROFA 

technology. An operating margin of 0.02 lb per MMBtu was added to the expected rate due 

to Mobotec’s limited ROFA experience with western sub-bituminous coals. Under the 

Mobotec proposal, primarily based on ROFA equipment, the operation of existing LNB and 

OFA ports will be analyzed. While a typical installation does not require modification to the 

existing LNB system, and the existing OFA ports are not used, results of computational fluid 

dynamics modeling will determine the quantity and location of new ROFA ports. The 

Mobotec proposal includes bent tube assemblies for OFA port installation. Mobotec does not 

provide installation services because they believe that the Owner can more cost-effectively 

contract for these services. However, they do provide one onsite construction supervisor 

during installation and startup. 

Because of the expected marginal emission rate improvement, the burden of significant 

ongoing parasitic costs, the operating difficulties, and the lack of vendor experience with 

sub-bituminous coals, ROFA was not considered in the post-control modeling scenarios. 

SNCR. Selective non-catalytic reduction is generally utilized to achieve modest NOx

reductions on smaller units. With SNCR, an amine-based reagent such as ammonia—or more 

commonly urea—is injected into the furnace within a temperature range of 1,600°F to 

2,100°F, where it reduces NOx to nitrogen and water. NOx reductions of up to 60 percent 

have been achieved, although 20 to 40 percent is more realistic for most applications. 

Reagent utilization, which is a measure of the efficiency with which the reagent reduces NOx, 

can range from 20 to 60 percent, depending on the amount of reduction, unit size, operating 

conditions, and allowable ammonia slip. With low-reagent utilization, low temperatures, or 

inadequate mixing, ammonia slip occurs, allowing unreacted ammonia to create problems 

downstream. The ammonia may render fly ash unsaleable, react with sulfur to foul heat 

exchange surfaces, and/or create a visible stack plume. Reagent utilization can have a 

significant impact on economics, with higher levels of NOx reduction generally resulting in 

lower reagent utilization and higher operating cost. 

Reductions from higher baseline concentrations (inlet NOx) are lower in cost per ton, but 

result in higher operating costs, due to greater reagent consumption. To reduce reagent costs, 

S&L has assumed that combustion modifications including LNBs and advanced OFA, 

capable of achieving a projected NOx emission rate of 0.23 lb per MMBtu. At a further 

reduction of 20 percent in NOx emission rates for SNCR would result in a projected emission 

rate of 0.18 lb per MMBtu. 

Because of the expected marginal emission rate improvement, the burden of significant 

ongoing parasitic costs, the operating difficulties and the potential ammonia slip emission 

problems; SNCR was not considered in the post-control modeling scenarios. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-5
BART ANALYSIS FOR WYODAK 

SCR. SCR works on the same principle as SNCR, but a catalyst is used to promote the 

reaction. Ammonia is injected into the flue-gas stream, where it reduces NOx to nitrogen and 

water. Unlike the high temperatures required for SNCR, the reaction takes place on the 

surface of a vanadium/titanium-based catalyst at a temperature range between 580°F to 

750°F. Due to the catalyst, the SCR process is more efficient than SNCR. The most common 

type of SCR is the high-dust configuration, where the catalyst is located upstream of the air 

heater and downstream from the economizer. The high-dust configuration is assumed for 

Wyodak. In a full-scale SCR, the flue ducts are routed to a separate large reactor containing 

the catalyst. With in-duct SCR, the catalyst is located in the existing gas duct, which may be 

expanded in the area of the catalyst to increase flue gas residence time. Due to the higher 

removal rate, a full-scale SCR was used as the basis for analysis at Wyodak. 

S&L prepared the design conditions and cost estimates for SCR at Wyodak. As with SNCR, 

it is generally more cost effective to reduce NOx emission levels as much as possible through 

combustion modifications, in order to minimize the catalyst surface area and ammonia 

requirements of the SCR. To reduce reagent costs, S&L has assumed that combustion 

modifications, including LNBs and OFA, providing a NOx emission rate of 0.23 lb per 

MMBtu, would be installed in conjunction with the SCR. The S&L design basis results in a 

projected NOx emission rate of 0.07 lb per MMBtu. Additional catalyst surface was included 

in the SCR design to accommodate the characteristics of the coal used at Wyodak. 

Level of Confidence for Vendor Post-control Emissions Estimates. In order to determine the 

level of NOx emissions needed to achieve compliance consistently with an established goal, a 

review of typical NOx emissions from coal-fired generating units was completed. As a result 

of this review, it was noted that NOx emissions can vary significantly around an average 

emissions level. Variations may result for many reasons, including changing coal 

characteristics, unit load, boiler operation including excess air, boiler slagging, burner 

equipment condition, coal mill fineness, and so forth. 

The steps utilized for determining a level of confidence for the vendor expected value are as 

follows: 

• Establish expected NOx emissions value from vendor. 

• Evaluate vendor experience and historical basis for meeting expected values. 

• Review and evaluate unit physical and operational characteristics and restrictions. The 

fewer variations there are in operations, coal supply, etc., the more predictable and less 

variant the NOx emissions are. 

• For each technology expected value, there is a corresponding potential for actual NOx

emissions to vary from this expected value. From the vendor information presented, 

along with anticipated unit operational data, an adjustment to the expected value can be 

made. 

Step 4: Evaluate Impacts and Document the Results 

This step involves the consideration of energy, environmental, and economic impacts 

associated with each control technology. The remaining useful life of the plant is also 

considered during the evaluation. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-6
BART ANALYSIS FOR WYODAK 

Energy Impacts. Installation of LNBs with OFA is not expected to impact the boiler 

efficiency or forced draft fan power usage significantly. Therefore, these technologies will 

not have energy impacts. 

The Mobotec ROFA system requires installation and operation of one 7,000 horsepower 

ROFA fan. 

Selective catalytic reduction retrofit impacts the existing flue gas fan systems, due to the 

additional pressure drop associated with the catalyst, which is typically a 6- to 8-inch water 

gauge increase. Total additional power requirements for SCR installation at Wyodak are 

estimated at approximately 2,420 kilowatts (kW), based on the S&L Study. 

Environmental Impacts. Installation of LNBs with OFA may increase carbon monoxide (CO) 

emissions and loss on ignition which may result in higher unburned carbon in the ash. 

Mobotec has predicted that CO emissions and unburned carbon in the ash, commonly 

referred to as loss on ignition, would be the same or lower than prior levels for the ROFA 

system. 

The installation of SNCR and SCR systems could impact the saleability and disposal of fly 

ash due to ammonia levels, and could potentially create a visible stack plume, which may 

negate other visibility improvements. Other environmental impacts involve the storage of 

ammonia, especially if anhydrous ammonia is used, and the transportation of the ammonia to 

the power plant site. 

Economic Impacts. Costs and schedules for the LNBs and OFA, SNCR, and SCR were 

furnished to CH2M HILL by PacifiCorp, developed using S&L’s internal proprietary 

database, and supplemented (as needed) by vendor-obtained price quotes. The relative 

accuracy of these cost estimates is stated by S&L to be in the range of plus or minus 

20 percent. Cost for the ROFA system was obtained from Mobotec to which construction and 

other costs were added to make a comparable estimate. 

A comparison of the technologies on the basis of costs, design control efficiencies, and tons 

of NOx removed is summarized in Table 3-2, and the first-year control costs are shown in 

Figure 3-1. The complete economic analysis is contained in Appendix A. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-7
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-8

TABLE 3-2 

NOx Control Cost Comparison 

Wyodak 

Factor 

Low-NOx

Burners 

(LNBs) 

with Overfire Air 

(OFA) 

Rotating 

Opposed 

Fire Air 

(ROFA) 

LNB with 

OFA and 

Selective 

Noncatalytic 

Reduction 

(SNCR) 

LNB with OFA 

and Selective 

Catalytic 

Reduction 

(SCR) 

Total Installed Capital Costs $9.3 million $15.3 million $19.5 million $108.3 million 

Total First-year Fixed and Variable Operation 

and Maintenance Costs 

$0.1 million $2.1 million $0.9 million $2.6 million 

Total First-year Annualized Cost $0.9 million $3.6 million $2.8 million $12.9 million 

Power Consumption (megawatt) NA 5.2 0.34 2.4 

Annual Power Usage (1,000 megawatt hours 

per year ) 

NA 41.2 2.6 19.0 

Nitrogen Oxide (NOx) Design Control 

Efficiency 

25.8% 35.5% 41.9% 77.4% 

Tons NOx Removed per Year 1,482 2,038 2,409 4,447 

First-year Average Control Cost 

($/Ton of NOx Removed) 637 1,766 1,147 2,892 

Incremental Control Cost 

($/Ton of NOx Removed) 637 4,775 1,962 3,844 

Preliminary BART Selection. CH2M HILL recommends LNBs with OFA as BART for 

Wyodak based on its significant reduction in NOx emissions, reasonable control cost, and no 

additional power requirements or environmental impacts. LNB with OFA is projected to 

meet the EPA presumptive limit of 0.23 lb per MMBtu for the PRB sub-bituminous coal 

burned at the facility even though this presumptive limit does not apply. 

Step 5: Evaluate Visibility Impacts 

Please see Section 4, BART Modeling Analysis. 
FIGURE 3-1 First Year Control Cost for NOx Air Pollution Control Options 

Wyodak 

0

1,0002,0003,0004,0005,0006,000

LNB w/OFA ROFA LNB w/OFA & SNCR LNB 

Air Pollution Control Option

Control Cost ($/Ton NOx Removed)

First Year Average Control Cost First Year Incremental Control Cost

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 
BART ANALYSIS FOR WYODAK 

3.2.2 BART SO2 Analysis 

Sulfur dioxide forms in the boiler during the combustion process, and is primarily dependent 

on coal sulfur content. The BART analysis for SO2 emissions on Wyodak is described below. 

Step 1: Identify All Available Retrofit Control Technologies 

A broad range of information sources were reviewed, in an effort to identify potentially 

applicable emission control technologies for SO2 at Wyodak; this included control 

technologies identified as BACT or LAER by permitting agencies across the United States. 

The following potential SO2 control technology options were considered: 

• Upgrade existing dry lime FGD system 

• Upgrade existing dry FGD system and replace existing ESP with a new fabric filter 

• New wet FGD system with ESP 

Step 2: Eliminate Technically Infeasible Options 

Wyodak currently has an uncontrolled SO2 emission rate of 1.61 lb per MMBtu and meets a 

state emission limit of 0.50 lb per MMBtu. 

Upgrade Dry FGD with Existing ESP. The lime spray dryer injects lime slurry in the top of the 

absorber vessel with a rapidly rotating atomizer wheel. The rapid speed of the atomizer 

wheel causes the lime slurry to separate into very fine droplets that intermix with the flue 

gas. The SO2 in the flue gas reacts with the calcium in the lime slurry to form calcium sulfate 

in the form of particulate matter. At Wyodak, this dry particulate matter is captured in the 

downstream existing ESP, along with the fly ash. The lime spray dryer system produces a dry 

waste product suitable for landfill disposal. 

The dry FGD system at Wyodak currently achieves approximately 69 percent SO2 removal to 

achieve an SO2 outlet emission rate of 0.50 lb per MMBtu. To achieve 80 percent SO2

removal, the dry FGD system operation would be changed by closing the bypass damper to 

eliminate bypass flue gas flow, perform modeling to redistribute the flue gas flow to the ESP, 

adding static mixers to mix the gas prior to the ESP, increase the reagent feed ratio (that is, 

Ca:S ratio), and increase the recycle ratio. An upgraded dry scrubbing FGD system with the 

existing ESP is projected to achieve an outlet emission rate of 0.32 lb per MMBtu 

(80 percent SO2 removal) based on an average coal sulfur content of 0.65 percent by weight. 

Lime Spray Drying FGD with New Fabric Filter. If the existing ESP is replaced with a fabric 

filter located downstream of the lime spray dryer, then 90 percent SO2 removal is projected, 

allowing the facility to achieve an emissions limit of 0.16 lb SO2 per MMBtu. 

Wet Lime/Limestone FGD. Wet SO2 scrubbers operate by flowing the flue gas upward through 

a large reactor vessel that has an alkaline reagent (typically a lime or limestone slurry) 

flowing down from the top. The scrubber mixes the flue gas and alkaline reagent using a 

series of spray nozzles to distribute the reagent across the scrubber vessel. The calcium in the 

reagent reacts with the SO2 in the flue gas to form calcium sulfite and/or calcium sulfate, 

which are removed from the scrubber with the sludge, and disposed. Most wet FGD systems 

use forced oxidation to assure that only calcium sulfate sludge is produced. The wet 

lime/limestone forced oxidation process is used in most new wet FGD installations. Several 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-10
BART ANALYSIS FOR WYODAK 

variations on wet FGD technology are offered by various process developers. These 

variations include using a jet bubbling reactor as a combination SO2 absorber and calcium 

sulfite oxidation vessel and using magnesium enhanced lime as the alkaline reagent. 

Wet lime/limestone scrubbing is projected to achieve 90 to 95 percent SO2 removal. At 

Wyodak, this removal efficiency is projected to meet the presumptive limit of 0.15 lb of SO2

per MMBtu used here only as a point of reference. 

Step 3: Evaluate Control Effectiveness of Remaining Control Technologies 

Table 3-3 summarizes the projected emission rates for the FGD technologies being evaluated 

for Wyodak. 

TABLE 3-3 

SO2 Control Technology Emission Rate Ranking 

Wyodak 

Control Technology Short-Term Expected SO2

Emission Rate (lb per MMBtu) 

Presumptive BART Limit (for reference 

only) 

0.15 

Wet Lime/Limestone FGD 0.08 

Upgrade Dry FGD with Fabric Filter 0.16 

Upgrade Dry FGD with Existing ESP 0.32 

Step 4: Evaluate Impacts and Document the Results 

This step involves the consideration of energy, environmental, and economic impacts 

associated with each control technology. The remaining useful life of the plant is also 

considered during the evaluation. 

Energy Impacts. An upgraded dry FGD system with the existing ESP has the advantage of 

requiring less electric power for its operation, compared to a wet FGD system. An upgraded 

dry FGD system at Wyodak using the existing ESP would require an additional 0.1 MW of 

power, compared to an additional 1.8 MW for wet FGD. Based on a 90 percent annual plant 

capacity factor, this would equate to an annual power savings of approximately 12.9 million 

kilowatt-hour (kWh) for upgraded dry FGD versus wet FGD for Wyodak. 

Environmental Impacts. The dry FGD system has the following environmental advantages 

when compared to wet FGD technology. 

• Sulfuric Acid Mist. Sulfur trioxide (SO3) in the flue gas, which condenses to liquid 

sulfuric acid at temperatures below the acid dew point, is removed efficiently with a lime 

spray dryer system. Wet scrubbers capture less than 40 to 60 percent of SO3 and may 

require the addition of a wet ESP or hydrated lime injection when medium to high sulfur 

coal is burned in a unit, in order to remove the balance of SO3. Otherwise, the emission of 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-11
BART ANALYSIS FOR WYODAK 

sulfuric acid mist, if above a threshold value, may result in a visible plume after the vapor 

plume dissipates. 

• Plume Buoyancy. Flue gas following a dry FGD system is not saturated with water 

(30°F to 50°F above dew point), which reduces or eliminates a visible moisture plume. 

Wet FGD scrubbers produce flue gas that is saturated with water, which would require a 

gas-gas heat exchanger to reheat the flue gas if it were to operate as a dry stack. Due to 

the high capital and operating costs associated with heating the flue gas, all recent wet 

FGD systems in the United States have used wet stack operation. 

• Liquid Waste Disposal. There is no liquid waste from a dry FGD system. However, wet 

FGD systems produce a wastewater blow down stream that must be treated to limit 

chloride buildup in the absorber scrubbing loop. In some cases, a wastewater treatment 

plant must be installed to treat the liquid waste prior to disposal. The wastewater 

treatment plant would produce a small volume of solid waste, which may contain toxic 

metals requiring additional considerations for disposal. 

• Solid Waste Disposal. The creation of a wet sludge from the wet FGD process creates a 

solid waste handling and disposal challenge. This sludge needs to be handled properly to 

prevent groundwater contamination. Wet FGD systems can produce saleable gypsum (if a 

gypsum market is available), also reducing the quantity of solid waste from the power 

plant that needs to be disposed. 

• Makeup Water Requirements. Lime Spray Drying FGD has advantages over a wet 

scrubber, producing a dry waste material and requiring less makeup water in the 

absorber. Given that water is a valuable commodity in Wyoming, the reduced water 

consumption required for dry FGD is a major advantage for this technology. 

Economic Impacts. A summary of the costs and amount of SO2 removed for each technology 

is provided in Table 3-4 and the first-year control costs are shown in Figure 3-2. The 

complete economic analysis is contained in Appendix A. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-12
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-13

TABLE 3-4 

SO2 Control Cost Comparison 

Wyodak 

Factor 

Upgraded Dry 

Flue Gas 

Desulfurization 

(FGD) with 

Electrostatic 

Precipitator 

(ESP) 

(Incremental) 

Upgraded Dry 

FGD with Fabric 

Filter (FF) 

(Incremental) 

Wet FGD 

(Incremental) 

Total Installed Capital Costs $26.8 million $66.8 million $95.1 million 

Total First-year Fixed and Variable 

Operation and Maintenance Costs 

$1.3 million $1.5 million $2.8 million 

Total First-year Annualized Cost $3.9 million $7.8 million $11.8 million 

Power Consumption (megawatt) 0.1 0.2 1.8 

Annual Power Usage (1000 megawatt 

hours per year ) 

0.9 1.2 13.8 

Sulfur Dioxide (SO2) Design Control 

Efficiency 

36.0% 68.0% 84.0% 

Tons SO2 Removed per Year 3,335 6,299 7,782 

First-year Average Control Cost (dollars 

per ton [$/Ton] of SO2 Removed) 1,167 1,242 1,523 

Incremental Control Cost 

($/Ton of SO2 Removed) 1,167 1,326 2.716 

Preliminary BART Selection. CH2M HILL recommends upgrading the dry FGD system with 

the existing ESP as BART for Wyodak, based on the significant reduction in SO2 emissions, 

reasonable control costs, and the advantages of minimal additional power requirements and 

minimal non-air quality environmental impacts. 

Step 5: Evaluate Visibility Impacts 

Please see Section 4, BART Modeling Analysis. 
FIGURE 3-2 First Year Control Cost for SO2 Air Pollution Control Options 

Wyodak 

0

500

1,0001,5002,0002,5003,000

Upgraded Dry FGD Dry FGD w/Fabric Filter Wet 

Air Pollution Control Option

Control Cost ($/Ton SO2 Removed)

First Year Average Control Cost First Year Incremental Control Cost

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 
BART ANALYSIS FOR WYODAK 

3.2.3 BART PM10 Analysis 

Wyodak is currently equipped with an ESP. Electrostatic precipitators remove PM from the 

flue gas stream by charging fly ash particles with a very high direct current voltage, and 

attracting these particles to grounded collection plates. A layer of collected particulate matter 

forms on the collecting plates and is removed by periodically rapping the plates. The 

collected ash particles drop into hoppers below the precipitator and are removed periodically 

by the fly ash-handling system. The ESP at Wyodak controls PM emissions to 0.030 lb per 

MMBtu. 

The BART analysis for PM emissions on Wyodak is described below. For the modeling 

analysis to be completed in Section 4, PM10 will be used as an indicator for PM, and PM10 

includes particulate matter less than 2.5 micrometers in aerodynamic diameter (PM2.5) as a 

subset. 

Step 1: Identify All Available Retrofit Control Technologies 

Two retrofit control technologies have been identified for additional PM control: 

• Flue gas conditioning followed by existing ESP 

• New polishing fabric filter downstream of existing ESP 

• New baghouse fabric filter 

Step 2: Eliminate Technically Infeasible Options 

Flue Gas Conditioning. If the fly ash from coal has high resistivity, such as fly ash from PRB 

coal, the ash is not collected effectively in a small ESP. Adding flue gas conditioning (FGC), 

which is typically accomplished by injection of SO3, will lower the resistivity of the particles 

so that they will accept more charge and will allow the ESP to collect the ash more 

effectively. Adding FGC can account for large improvements in collection efficiency for 

small ESPs on units burning western low-sulfur coal. 

The Wyodak ESP was sized based on a conservative design. It has a large specific collecting 

area and large residence time in the collection area of the ESP. This ESP operates effectively 

without the assistance of FGC equipment; thus, a significant improvement in collection 

efficiency is not expected with the addition of FGC to Wyodak. Therefore, this option will 

not be carried forward to the next step of the BART analysis. 

Polishing Fabric Filter. Fabric filtration has been applied widely to coal combustion sources 

since the early 1970s, and consists of a number of filtering elements (bags) along with a bag 

cleaning system and dust hoppers contained in a main shell structure. Fabric filters use 

fiberglass bags as filters to collect particulate matter. The particulate-laden gas enters a fabric 

filter compartment and passes through the bags and through a layer of accumulated 

particulate matter collected on the fabric of the filter bags. The collected particulate matter 

forms a filter cake layer on the bag that enhances the bag’s filtering efficiency. However, 

excessive caking will increase the pressure drop across the fabric filter. When this occurs, the 

fabric filter is placed into a cleaning cycle and the dislodged particulate matter is removed by 

the ash-handling system. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-15
BART ANALYSIS FOR WYODAK 

Fabric filters are effective in meeting New Source Performance Standards emission 

requirements on coal-fired boilers. Fabric filters have been used as a control technology of 

choice on projects where LAER review is required. Unlike precipitators, fabric filter design 

is not based on any physical properties of the fly ash. 

A polishing fabric filter could be added downstream of the existing Wyodak ESP. This 

technology is licensed by the Electric Power Research Institute, and referred to as a Compact 

Hybrid Particulate Collector (COHPAC). The COHPAC collects the ash that is not collected 

by the ESP, thus acting as a polishing device. The ESP needs to be kept in service for the 

COHPAC fabric filter to work. 

The COHPAC fabric filter is about one-half to two-thirds the size of a full-size fabric filter, 

because the COHPAC has a higher air-to-cloth ratio (7 to 9:1), compared to a full-size pulse 

jet fabric filter (3.5 to 4:1). 

Baghouse Fabric Filter. Another available control technology is replacing the existing ESP 

with a new fabric filter. However, because the environmental benefits that would be achieved 

by a replacement fabric filter are also achieved by installing a polishing fabric filter 

downstream of the existing ESP at lower costs, installation of a full-size fabric filter 

downstream of the ESP was not considered further in the analysis. 

Step 3: Evaluate Control Effectiveness of Remaining Control Technologies 

The existing ESP at Wyodak is achieving a controlled PM emission rate of 0.030 lb per 

MMBtu. Adding a COHPAC fabric filter downstream of the existing ESP would reduce PM 

emissions to approximately 0.015 lb per MMBtu. 

Step 4: Evaluate Impacts and Document the Results 

This step involves the consideration of energy, environmental, and economic impacts 

associated with each control technology. The remaining useful life of the plant is also 

considered during the evaluation. 

Energy Impacts. Energy is required to overcome the additional pressure drop from the 

COHPAC fabric filter and associated ductwork. Therefore, a COHPAC retrofit will require 

an induced draft fan upgrade and upgrade of the auxiliary power supply system. 

A COHPAC fabric filter at Wyodak would require approximately 2.1 MW of power, 

equating to an annual power usage of approximately 16.2 million kWh, based on a 90 percent 

annual plant capacity factor. 

Environmental Impacts. There are no negative environmental impacts from the addition of a 

polishing fabric filter. 

Economic Impacts. A summary of the costs and PM removed for the fabric filter are recorded 

in Table 3-5. The complete economic analysis is contained in Appendix A. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-16
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-17

TABLE 3-5 

PM10 Control Cost Comparison 

Wyodak 

Factor Fabric Filter 

Total Installed Capital Costs $32.6 million 

Total First-year Fixed & Variable Operation and Maintenance 

Costs 

$1.1 million 

Total First-year Annualized Cost $4.2 million 

Power Consumption (megawatt) 2.1 

Annual Power Usage (1,000 megawatt hours per year) 16.2 

Particulate Matter (PM) Design Control Efficiency 50.0% 

Tons PM Removed per Year 278 

First-year Average Control Cost 

(dollars per ton [$/Ton] of PM Removed) 15,202 

Incremental Control Cost 

($/Ton of Sulfur Dioxide Removed) 15,202 

Preliminary BART Selection. CH2M HILL recommends maintaining the ESP downstream of 

the lime spray dryer as BART for Wyodak, based on the significant reduction in PM10

emissions, reasonable control costs, and the advantages of minimal additional power 

requirements and no non-air quality environmental impacts. 

Step 5: Evaluate Visibility Impacts 

Please see Section 4, BART Modeling Analysis.
4.0 BART Modeling Analysis 

4.1 Model Selection 

CH2M HILL used the CALPUFF modeling system to assess the visibility impacts of 

emissions from Wyodak at nearby Class I areas. The Class I areas potentially affected are 

located more than 50 kilometers, but less than 300 kilometers, from the Wyodak facility. 

These National Parks (NP) include: 

• Badlands NP 

• Wind Cave NP 

The CALPUFF modeling system includes the CALMET meteorological model, a Gaussian 

puff dispersion model (CALPUFF) with algorithms for chemical transformation and 

deposition, and a post-processor capable of calculating concentrations, visibility impacts, and 

deposition (CALPOST). The CALPUFF modeling system was applied in a full, refined 

mode. Version numbers of the various programs in the CALPUFF system used 

byCH2M HILL were as follows: 

• CALMET Version 5.53a, Level 040716 

• CALPUFF Version 5.711a, Level 040716 

• CALPOST Version 5.51, Level 030709 

4.2 CALMET Methodology 

4.2.1 Dimensions of the Modeling Domain 

CH2M HILL used the CALMET model to generate a three-dimensional wind field and other 

meteorological parameters suitable for use by the CALPUFF model. A modeling domain was 

established to encompass the Wyodak facility and allow for a 50-km buffer around the 

Class I areas that were within 300 km of the facility. Grid resolution was 4 kilometers. 

Figure 4-1 shows the extent of the modeling domain. Except when specifically instructed 

otherwise by the Wyoming Department of Environmental Quality – Air Quality Division 

(WDEQ-AQD), CH2M HILL followed the methodology spelled out in the WDEQ-AQD 

BART Modeling Protocol, a copy of which is included in this report as Appendix B. 

CH2M HILL used the Lambert Conformal Conic map projection for the analysis due to the 

large extent of the domain. The latitude of the projection origin and the longitude of the 

central meridian were chosen at the approximate center of the domain. Standard parallels 

were drawn to represent one-sixth and five-sixths of the north-south extent of the domain to 

minimize distortion in the north-south direction. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-1
Badlands NP

Wind Cave NP

Idaho

Utah

Wyoming

Montana

K

Colorado

Nebraska

Nevada

South Dakota

North Dakota

Oregon

Washington

0 

W

Class 

Sta

Sta

Dom

114° 5' 20.40" Longitude39° 3' 53.37" Latitude

100° 56' 34.08" Longitude45° 51' 57.22" Latitude

101° 54' 25.88" Longitude38° 54' 0.04" Latitude

114° 28' 37.96" Longitude46° 6' 26.20" Latitude

Wyodak

SLC \\SLCDB\GIS\PROJECTS\HUNTER\MAPFILES\WYODAK_CLASSI.MXD 11/9/2006 MSLAYDEN
BART ANALYSIS FOR WYODAK 

The default technical options listed in TRC Companies, Inc.’s (TRC) current example 

CALMET.inp file were used for CALMET. Vertical resolution of the wind field included 

10 layers, with vertical face heights as follows (in meters): 

• 0, 20, 40, 100, 140, 320, 580, 1020, 1480, 2220, 3500 

Other user-specified model options were set to values established by WDEQ-AQD, which 

appear in Table 3 of Appendix B. Table 4-1 lists the key user-specified options used for this 

analysis. 

TABLE 4-1 

User-specified CALMET Options 

Wyodak 

CALMET Input Parameter Value 

CALMET Input Group 2 

 Map projection (PMAP) Lambert Conformal 

 Grid spacing (DGRIDKM) 4 

 Number vertical layers (NZ) 10 

 Top of lowest layer (m) 20 

 Top of highest layer (m) 3500 

CALMET Input Group 4 

 Observation mode (NOOBS) 0 

CALMET Input Group 5 

 Prog. Wind data (IPROG) 14 

 (RMAX1) 30 

 (RMAX2) 50 

 Terrain influence (TERRAD) 15 

 (R1) 5 

 (R2) 25 

CALMET Input Group 6 

 Max mixing ht (ZIMAX) 3500 

4.2.2 CALMET Input Data 

CH2M HILL ran the CALMET model to produce 3 years of analysis: 2001, 2002, and 2003. 

WDEQ-AQD provided 12-km resolution Mesoscale Meteorological Model, Version 5 

(MM5) meteorological data fields that covered the entire modeling domain for each study 

year that covered the entire modeling domain. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-3
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-4

These three data sets were chosen because they are current and have been evaluated for 

quality. The MM5 data were used as input to CALMET as the “initial guess” wind field. The 

initial guess wind field was adjusted by CALMET for local terrain and land use effects to 

generate a Step 1 wind field, and further refined using local surface observations to create a 

final Step 2 wind field. 

Surface data for 2001 through 2003 were obtained from the National Climatic Data Center. 

CH2M HILL processed the data from the National Weather Service’s Automated Surface 

Observing System network for all stations that are in the domain. The surface data were 

obtained in abbreviated DATSAV3 format. A conversion routine available from the TRC 

Web site was used to convert the DATSAV3 files to CD-144 format for input into the 

SMERGE preprocessor and CALMET. 

Land use and terrain data were obtained from the United States Geological Survey (USGS). 

Land use data were obtained in Composite Theme Grid format from the USGS, and the 

Level 1 USGS land use categories were mapped into the 14 primary CALMET land use 

categories. Surface properties such as albedo, Bowen ratio, roughness length, and leaf area 

index were computed from the land use values. Terrain data were taken from USGS 1-degree 

Digital Elevation Model data, which primarily derive from USGS 1:250,000 scale 

topographic maps. Missing land use data were filled with values that were assumed 

appropriate for the missing area. 

Precipitation data were ordered from the National Climatic Data Center. All available data in 

fixed-length, TD-3240 format were ordered for the modeling domain. The list of available 

stations that have collected complete data varies by year, but CH2M HILL processed all 

available stations/data within the domain for each year. Precipitation data were prepared with 

the PXTRACT/PMERGE processors in preparation for use within CALMET. 

Upper-air data were prepared for the CALMET model with the READ62 preprocessor for the 

following stations: 

• Denver, Colorado 

• Salt Lake City, Utah 

• Riverton, Wyoming 

• Rapid City, South Dakota 

Figure 4-2 shows the locations of surface and upper air stations within the MM5 modeling 

domain. 
Badlands NP

Wind Cave NP

RAP (UA)

P60

WRL

TOR

SHR

RKS

RIW (UA)

RWL

LAR

LND

GEY

GCC

EVW

DGW

CYS

CPR

BYG

BPI

VEL

SLC (UA)

PUC

OGD

LGU

DLN

RXE

PIH

IDA

LLJ

BYI

RIL

EEO

LIC LXV

GJT

DEN (UA)

APA

CAG

ITR

ASE

AKO

IEN

PHP

D07

CUT

2WX

SNY

BFF

CDR

AIA

LVM

DLN

BTM

BZN BIL

Idaho

Utah

Wyoming

Montana

K

Colorado

Nebraska

Nevada

South Dakota

North Dakota

Oregon

Washington

0 

Surface and Upper 

Sta

Sta

Dom

114° 5' 20.40" Longitude39° 3' 53.37" Latitude

100° 56' 34.08" Longitude45° 51' 57.22" Latitude

101° 54' 25.88" Longitude38° 54' 0.04" Latitude

114° 28' 37.96" Longitude46° 6' 26.20" Latitude

Wyodak

SLC \\SLCDB\GIS\PROJECTS\HUNTER\MAPFILES\WYODAK_ASOS.MXD 11/9/2006 MSLAYDEN
BART ANALYSIS FOR WYODAK 

4.2.3 Validation of CALMET Wind Field 

CH2M HILL used the Program to Display Data and Results (CALDESK) data display and 

analysis system (v2.97, Enviromodeling Ltd.) to view plots of wind vectors and other 

meteorological parameters to evaluate the CALMET wind fields. The CALDESK displays 

were compared to observed weather conditions, as depicted in surface and upper-air weather 

maps (National Oceanic and Atmospheric Administration, 2006). 

4.3 CALPUFF Modeling Approach 

For the BART control technology visibility improvement modeling, CH2M HILL followed 

WDEQ-AQD guidance (WDEQ-AQD, 2006). 

CH2M HILL drove the CALPUFF model with the meteorological output from CALMET 

over the modeling domain described earlier. The CALPUFF model was used to predict 

visibility impacts for the pre-control (baseline) scenario for comparison to the predicted 

impacts for post-control scenarios for Wyodak. 

4.3.1 Background Ozone and Ammonia 

Hourly values of background ozone concentrations were used by CALPUFF for the 

calculation of SO2 and NOx transformation with the MESOPUFF II chemical transformation 

scheme. CH2M HILL obtained hourly ozone data from the following stations located within 

the modeling domain for 2001, 2002, and 2003: 

• Rocky Mountain National Park, Colorado 

• Craters of the Moon National Park, Idaho 

• Highland, Utah 

• Thunder Basin National Grasslands, Wyoming 

• Yellowstone National Park, Wyoming 

• Centennial, Wyoming 

• Pinedale, Wyoming 

For periods of missing hourly ozone data, the chemical transformation relied on a monthly 

default value of 44 parts per billion. Background ammonia was set to 2 parts per billion. Both 

of these background values were taken from the guidance document (WDEQ-AQD, 2006). 

4.3.2 Stack Parameters 

The stack parameters used for the baseline modeling reflect those that are in place under the 

current permit for Wyodak. Post-control stack parameters reflect the anticipated changes 

associated with installation of the control technology alternatives that are being evaluated. 

The maximum heat input rate of 4,700 MMBtu per hour was used to calculate a maximum 

emission rate. Measured velocities and stack flow rates were used in the modeling to 

represent a worst-case situation. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-6
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-7

4.3.3 Emission Rates 

Pre-control emission rates for Wyodak reflect peak 24-hour average emissions that may 

occur under the source’s current permit. The emission rates reflect actual emissions under 

normal operating conditions, as described by the EPA in the Regional Haze Regulations and 

Guidelines for Best Available Retrofit Technology Determinations; Final Rule (40 CFR 

Part 51). 

CH2M HILL used available continuous emission monitoring data to determine peak 24-hour 

emission rates. Data reflected operations from the most recent 3- to 5-year period, unless a 

more recent period was more representative. Allowable short-term (24-hour or shorter 

period) emissions or short-term emission limits were used if continuous emission monitoring 

data were not available. 

Emissions were modeled for the following pollutants: 

• SO2

• NOx

• Coarse particulate (PM2.5<diameter<PM10) 

• Fine particulate (diameter<PM2.5) 

• Sulfates 

Post-control emission rates reflect the effects of the emissions control scenario under 

consideration. Modeled pollutants were the same as those listed for the pre-control scenario. 

4.3.4 Post-control Scenarios 

Four post-control modeling scenarios were developed to cover the range of effectiveness for 

the combination of the individual NOx, SO2, and PM control technologies being evaluated. 

The selection of each control device was made based on the engineering analyses described 

in Section 3 for reasonable technologies that would meet or exceed the presumptive BART 

levels for each pollutant. 

• Scenario 1: New LNB with OFA, upgrading the dry FGD system, and maintaining 

performance of the existing ESP. As indicated previously, this scenario represents 

CH2M HILL’s preliminary BART recommendation. 

• Scenario 2: New LNB with OFA, upgrading the dry FGD system and a new fabric filter 

to replace the existing ESP. 

• Scenario 3: New LNB with OFA and SCR, upgrading the dry FGD system, and a new 

fabric filter to replace the existing ESP 

• Scenario 4: New LNB with OFA and SCR, a wet FGD system, and the existing ESP. 

Table 4-2 presents the stack parameters and emission rates used for the Wyodak analysis for 

baseline and post-control modeling. 
TABLE 4-2 

BART Model Input Data Wyodak 

Baseline Post-control Scenario 1 Post-c

Model Input Data 

Current Operations with Dry 

Flue Gas Desulfurization (FGD) 

and Electrostatic Precipitator 

(ESP) 

Low-NOx Burners (LNB) with 

OFA, Dry FGD, ESP 

LNB w

F

Sulfur Dioxide (SO2) Stack Emissions 

(pounds per hour [lb/hr]) 2,350 1,518 

Nitrogen Oxide (NOx) Stack Emissions (lb/hr) 1,457 1,081 

PM10 Stack Emissions (lb/hr) 141 141 

Coarse Particulate (PM2.5 <diameter< PM10) Stack Emissions (lb/hr)(a) 60.6 60.6 

Fine Particulate (diameter<PM2.5) Stack Emissions (lb/hr)(b) 80.4 80.4 Sulfuric Acid (H2SO4) Stack Emissions (lb/hr) 5.64 5.64 

H2SO4 as Sulfate (SO4) Stack Emissions (lb/hr) 5.52 5.52 

Ammonium Sulfate [(NH4)2SO4] Stack Emissions (lb/hr) 

(NH4)2SO4 as SO4 Stack Emissions (lb/hr) 

(NH4)HSO4 Stack Emissions (lb/hr) 

(NH4)HSO4 as SO4 Stack Emissions (lb/hr) 

Total Sulfate (SO4) (lb/hr) 5.52 5.52 

Stack Conditions

Stack Height (meters) 122 122 Stack Exit Diameter (meters) 6.10 6.10 Stack Exit Temperature (Kelvin) 358 353 Stack Exit Velocity (meters per second) 23.5 23.5 NOTES: 

(a)Based on AP-42, Table 1.1-6, the coarse particulates are counted as a percentage of PM10. This equates to 43 percent ESP and 57 percent baghouse. (b)Based on AP-42, Table 1.1-6, the fine particulates are counted as a percentage of PM10. This equates to 57 percent ESP and 43 percent baghouse. 

Total Sulfate (SO4) (lb/hr) = H2SO4 as Sulfate (SO4) Stack Emissions (lb/hr) + (NH4)2SO4 as SO4 Stack Emissions (lb/hr) + (NH4)HSO4 as SO4 Stack Emissions (lb/hr)
BART ANALYSIS FOR WYODAK 

4.3.5 Modeling Process 

The CALPUFF modeling for the control technology options for Wyodak followed this 

sequence: 

• Model pre-control (baseline) emissions 

• Model preferred post-control scenario (if applicable) 

• Determine degree of visibility improvement 

• Model other control scenarios 

• Determine degree of visibility improvement 

• Factor visibility results into the BART five-step evaluation 

4.3.6 Receptor Grids 

Discrete receptors for the CALPUFF modeling were placed at uniform receptor spacing 

along the boundary and in the interior of each area of concern. Class I area receptors were 

taken from the National Park Service database for Class I area modeling receptors. The TRC 

COORDS program was used to convert all latitude/longitude coordinates to Lambert 

Conformal Conic coordinates, including receptors, meteorological stations, and source 

locations. 

4.4 CALPOST 

The CALPOST processor was used to determine 24-hour average visibility results with 

output specified in deciview (dV) units. Calculations of light extinction were made for each 

pollutant modeled. The sum of all extinction values were used to calculate the delta-dV 

(ΔdV) change relative to natural background. The following default extinction coefficients 

for each pollutant were used: 

• Ammonium sulfate 3.0 

• Ammonium nitrate 3.0 

• PM coarse (PM10) 0.6 

• PM fine (PM2.5) 1.0 

• Organic carbon 4.0 

• Elemental carbon 10.0 

CALPOST visibility Method 6 was used to determine the visibility impacts. Monthly relative 

humidity factors were used in the light extinction calculations to account for the hygroscopic 

characteristics of nitrate and sulfate particles. Table 5 of the Wyoming BART Air Modeling 

Protocol (Appendix B) lists the monthly relative humidity factors for the Class I areas. These 

values were used for the particular Class I area being modeled. 

The natural background conditions as a reference for determining the ΔdV change 

represented the 20 percent best natural visibility days. The EPA BART guidance document 

provided dV values for the 10 percent best days for each Class I area, but did not provide 

individual species concentration data for the 20 percent best background conditions. Species 

concentrations corresponding to the 20 percent best days were calculated for each Class I 

area by scaling back the annual average species concentrations given in Table 2-1 of 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-9
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 4-10

Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule (EPA, 

2003). A separate scaling factor was derived for each Class I area such that, when multiplied 

by the Guidance table annual concentrations, the 20 percent best days dV value for that area 

would be calculated. This procedure was taken from Protocol for BART-Related Visibility 

Improvement Modeling Analysis in North Dakota (North Dakota Department of Health, 

2005). However, the Wyoming BART Air Modeling Protocol (Appendix B) provided natural 

background concentrations of aerosol components to use in the BART analysis. Table 4-3 

lists the annual average species concentrations from the BART protocol. 

TABLE 4-3 

Average Natural Levels of Aerosol Components 

Wyodak 

Aerosol Component 

Average Natural Concentration 

(micrograms per cubic meter) 

for Wind Cave National Park (NP) and Badlands NP 

Class I Areas 

Ammonium Sulfate 0.047 

Ammonium Nitrate 0.040 

Organic Carbon 0.186 

Elemental Carbon 0.008 

Soil 0.198 

Coarse Mass 1.191 

NOTE: 

Source: Table 6 of the Wyoming BART Air Modeling Protocol. 

4.5 Presentation of Modeling Results 

This section presents the results of the CALPUFF visibility improvement modeling analysis 

for Wyodak. 

4.5.1 Visibility Changes for Baseline vs. Preferred Scenario 

CH2M HILL modeled Wyodak for the baseline and four post-control scenarios. The 

post-control scenarios included emission rates for SO2, NOx, and PM10 that would be 

achieved if BART state-of-the-art technology were installed at Wyodak. 

Baseline (and post-control) 98th percentile results were greater than 0.5 ΔdV for the Badlands 

and Wind Cave NPs. The 98th percentile results for each Class I area are presented in 

Table 4-4. 
TABLE 4-4 Costs and Visibility Modeling Results for Baseline vs. Post-control Scenarios at Class I Areas Wyodak 

Modeling Results 

Scenario 

Total First 

Year 

Annualized 

Cost Class I Area Highest ΔdV- 98th Percentile ΔdV- Number of Days Above 0.5 dV C

2001 Baseline: Current Operation with Dry Flue Gas Badlands 1.775 0.841 27 Desulfurization (FGD), Electrostatic Precipitator (ESP) Wind Cave 1.723 1.153 41 Scenario 1: Low-NO $4,836,638 Badlands 1.302 0.595 12 $

x Burners (LNBs) with Over-fire Air 

(OFA), Dry FGD, ESP $4,836,638 Wind Cave 1.213 0.817 19 $

$8,768,522 Badlands 1.088 0.472 6 $

Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter $8,768,522 Wind Cave 0.958 0.671 11 $

$20,682,244 Badlands 0.521 0.254 1 $

Scenario 3: LNBs with OFA and SCR, Wet FGD, Fabric Filter $20,682,244 Wind Cave 0.531 0.333 2 $

$24,707,516 Badlands 0.641 0.294 1 $

Scenario 4: LNBs with OFA and SCR, Wet FGD, ESP 

$24,707,516 Wind Cave 0.586 0.396 2 $

2002 

Badlands 1.859 1.140 34 

Baseline: Current Operation with Dry FGD, ESP 

Wind Cave 2.591 1.323 38 

$4,836,638 Badlands 1.388 0.829 18 $

Scenario 1: LNBs with OFA, Dry FGD, ESP $4,836,638 Wind Cave 1.950 0.940 26 $

$8,768,522 Badlands 1.216 0.624 14 $

Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter $8,768,522 Wind Cave 1.712 0.788 17 $

$20,682,244 Badlands 0.546 0.331 2 $

Scenario 3: LNBs with OFA and SCR, Wet FGD, Fabric Filter $20,682,244 Wind Cave 0.777 0.383 5 $

$24,707,516 Badlands 0.801 0.405 3 $

Scenario 4: LNBs with OFA and SCR, Wet FGD, ESP 

$24,707,516 Wind Cave 1.085 0.519 9 $

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 
JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 

TABLE 4-4 Costs and Visibility Modeling Results for Baseline vs. Post-control Scenarios at Class I Areas Wyodak 

 Modeling Results 

Scenario 

Total First 

Year 

Annualized 

Cost Class I Area Highest ΔdV- 98th Percentile ΔdV- Number of Days Above 0.5 dV C

2003 

Badlands 2.556 1.070 31 

Baseline: Current Operation with Dry FGD, ESP 

Wind Cave 3.296 1.530 37 

$4,836,638 Badlands 1.819 0.739 20 $

Scenario 1: LNBs with OFA, Dry FGD, ESP $4,836,638 Wind Cave 2.370 1.114 28 $

$8,768,522 Badlands 1.319 0.583 13 $

Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter $8,768,522 Wind Cave 1.797 0.929 17 $

$20,682,244 Badlands 0.811 0.314 2 $

Scenario 3: LNBs with OFA and SCR, Wet FGD, Fabric Filter $20,682,244 Wind Cave 1.065 0.457 6 $

$24,707,516 Badlands 0.717 0.340 3 $

Scenario 4: LNBs with OFA and SCR, Wet FGD, ESP 

$24,707,516 Wind Cave 1.028 0.684 10 $

3-Year Averages 

Badlands 1.017 30.7 

Baseline: Current Operation with ESP 

Wind Cave 1.335 38.7 

$4,836,638 Badlands 0.721 16.7 $

Scenario 1: LNBs with OFA, dry FGD, existing ESP 

$4,836,638 Wind Cave 0.957 24.3 $$8,768,522 Badlands 0.560 11.0 $

Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter 

$8,768,522 Wind Cave 0.796 15.0 $

$20,682,244 Badlands 0.300 1.7 $

Scenario 3: LNBs with OFA and SCR, Dry FGD, Fabric Filter $20,682,244 Wind Cave 0.391 4.3 $

$24,707,516 Badlands 0.346 2.3 $

Scenario 4: LNBs with OFA and SCR, Wet FGD, Existing ESP, New Stack $24,707,516 Wind Cave 0.533 7.0 $

NOTES: Scenario 3 produces better results in visibility than Scenario 4. Therefore, Scenario 4 was not further analyzed. 

Sample Calculations: Cost per dV Reduction for Scenario 1 for 2001: = $4,836,638 / (0.841 - 0.595) = $19,661,131 Sample Calculations: Cost per Reduction in Number of Days Exceeding 0.5 dV for 2001: = $4,836,638 / (27 - 12) = $322,443 
5.0 Preliminary Assessment and 

Recommendations 

As a result of the completed technical and economic evaluations and consideration of the 

modeling analysis for Wyodak, the preliminary recommended BART controls for NOx, SO2, 

and PM are as follows:

• New LNBs and modifications to the OFA system for NOx control

• Upgrade lime spray dryer FGD for SO2 control

• Maintain the existing ESP for PM control

The above recommendations were identified as Scenario 1 for the modeling analysis 

described in Section 4. Visibility improvements for all emission control scenarios were 

analyzed, and the results are compared below, utilizing a least-cost envelope, as outlined in 

the New Source Review Workshop Manual (EPA, 1990). 

5.1 Least-cost Envelope Analysis 

The total annualized cost, cost per dV reduction, and cost per reduction in number of days 

above 0.5 dV for the scenarios modeled in Section 4 to determine the impact on the two 

Class I areas are listed in Tables 5-1 and 5-2. A comparison of the incremental costs between 

relevant scenarios is shown in Tables 5-3 through 5-4. The total annualized cost versus 

number of days above 0.5 dV, and the total annualized cost versus 98th percentile ΔdV 

reduction are shown in Figures 5-1 to 5-4 for the two Class I areas. 

5.1.1 Analysis Methodology 

On page B-41 of the draft New Source Review Manual, the EPA states that “Incremental 

cost-effectiveness comparisons should focus on annualized cost and emission reduction 

differences between dominant alternatives. Dominant set of control alternatives are 

determined by generating what is called the envelope of least-cost alternatives. This is a 

graphical plot of total annualized costs for a total emissions reductions for all control 

alternatives identified in the BACT analysis...” 

An analysis of incremental cost effectiveness has been conducted. This analysis was 

performed in the following way. First, the control option scenarios are ranked in ascending 

order of annualized total costs as shown in Tables 5-1 and 5-2. The incremental 

cost-effectiveness data, expressed per day and per dV, represents a comparison of the 

different scenarios, and is summarized in Tables 5-3 and 5-4 for each of the two Class I 

areas. Then the most reasonable smooth curve of least-cost control option scenarios is plotted 

for each analysis. Figures 5-1 through 5-4 present the two analyses (cost per dV reduction 

and cost per reduction in number of days above 0.5 dV) for each of the two Class I areas 

impacted by the operation of Wyodak. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-1
BART ANALYSIS FOR WYODAK 

TABLE 5-1 

Badlands Class I Agent Control Data 

Wyodak 

Scenario Controls 

98th

Percentile 

Deciview 

(dV) 

Reduction 

Average 

Number of 

Days 

Above 

0.5 dV 

(Days) 

Total 

Annualized 

Cost 

(Million$) 

Cost per 

dV 

Reduction 

(Million$/dV 

Reduced) 

Cost per 

Reduction in 

No. of Days 

Above 0.5 dV 

(Million$/Day 

Reduced) 

Base Current Operation with Dry 

Flue Gas Desulfurization 

(FGD), Electrostatic 

Precipitator (ESP) 

0.00 0.0 $0.0 $0.0 $0.0 

1 Low-NOx Burner (LNB) with 

Over-fire Air (OFA), Dry 

FGD, ESP 

0.30 14.0 $4.8 $16.3 $0.3 

2 LNB with OFA, Dry FGD, 

Fabric Filter 

0.46 19.7 $8.8 $19.2 $0.4 

3 LNB with OFA and SCR, 

Dry FGD, Fabric Filter 

0.72 29.0 $20.7 $28.8 $0.7 

4 LNB with OFA and SCR, 

Wet FGD, ESP 

0.67 28.3 $24.7 $36.8 $0.9 

TABLE 5-2 

Wind Caves Class I Area Control Data 

Wyodak 

Scenario Controls 

98th

Percentile 

Deciview 

(dV) 

Reduction 

Average 

Number of 

Days 

Above 

0.5 dV 

(Days) 

Total 

Annualized 

Cost 

(Million$) 

Cost per 

dV 

Reduction 

(Million$/dV 

Reduced) 

Cost per 

Reduction in 

No. of Days 

Above 0.5 dV 

(Million$/Day 

Reduced) 

Base Current Operation with Dry 

Flue Gas Desulfurization 

(FGD), Electrostatic 

Precipitator (ESP) 

0.00 0.0 $0.0 $0.0 $0.0 

1 Low-NOx Burner (LNB) with 

Over-fire Air (OFA), Dry 

FGD, ESP 

0.38 14.3 $4.8 $12.8 $0.3 

2 LNB with OFA, Dry FGD, 

Fabric Filter 

0.54 23.7 $8.8 $16.3 $0.4 

3 LNB with OFA and SCR, 

Dry FGD, Fabric Filter 

0.94 34.3 $20.7 $21.9 $0.6 

4 LNB with OFA and SCR, 

Wet FGD, ESP 

0.80 31.7 $24.7 $30.8 $0.8 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-2
BART ANALYSIS FOR WYODAK 

TABLE 5-3 

Badlands Class I Area Incremental Data 

Wyodak 

Options Compared 

Incremental 

Reduction in 

Days Above 

0.5 Deciview 

(dV) (Days) 

Incremental dV 

Reductions 

(dV) 

Incremental Cost 

Effectiveness 

(Million$/Days) 

Incremental 

Cost 

Effectiveness 

(Million$/dV) 

Baseline and Scenario 1 14.0 0.30 $0.35 $16.3 

Scenario 1 and Scenario 2 5.7 0.16 $0.69 $24.4 

Scenario 1 and Scenario 3 15.0 0.42 $1.1 $37.6 

Scenario 1 and Scenario 4 14.3 0.37 $1.4 $53.0 

NOTE: 

Because Scenario 3 produces better results in visibility than Scenario 4, Scenario 4 was not analyzed further. 

TABLE 5-4 

Wind Caves Class I Agent Incremental Data 

Wyodak 

Options Compared 

Incremental 

Reduction in 

Days Above 

0.5 Deciview 

(dV) (Days) 

Incremental dV 

Reductions 

(dV) 

Incremental Cost 

Effectiveness 

(Million$/Days) 

Incremental 

Cost 

Effectiveness 

(Million$/dV) 

Baseline and Scenario 1 14.3 0.38 $0.34 $12.8 

Scenario 1 and Scenario 2 9.3 0.16 $0.42 $24.4 

Scenario 1 and Scenario 3 20.0 0.57 $0.79 $28.0 

Scenario 1 and Scenario 4 17.3 0.42 $1.1 $46.9 

NOTE: 

Because Scenario 3 produces better results in visibility than Scenario 4, Scenario 4 was not analyzed further. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-3
BART ANALYSIS FOR WYODAK 

FIGURE 5-1 

Least-cost Envelope Badlands Class I Area Reduction 

Wyodak 

Scenario 3

Scenario 2

Scenario 1

Baseline

Scenario 4

$0.0

$5.0

$10.0

$15.0

$20.0

$25.0

$30.0

0 5 10 15 20 25 30

Reduction in Days of Exceeding 0.5 dV (days)

Total Annualized Cost (Mil $)

FIGURE 5-2 

Least-cost Envelope Badlands Class I Area 98th Percentile 

Wyodak 

Scenario 3

Scenario 2

Scenario 1

Baseline

Scenario 4

$0.0

$5.0

$10.0

$15.0

$20.0

$25.0

$30.0

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80

98th Percentile Delta-Deciview Reduction (dV)

Total Annualized Cost (Mil $)

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-4
BART ANALYSIS FOR WYODAK 

FIGURE 5-3 

Least-cost Envelope Wind Caves Class I Area Reduction 

Wyodak 

Scenario 4

Baseline

Scenario 1

Scenario 2

Scenario 3

$0.0

$5.0

$10.0

$15.0

$20.0

$25.0

$30.0

0 5 10 15 20 25 30 35

Reduction in Days of Exceeding 0.5 dV (days)

Total Annualized Cost (Mil $)

FIGURE 5-4 

Least-cost Envelope Wind Caves Class I Area 98th Percentile 

Wyodak 

Scenario 3

Scenario 2

Scenario 1

Baseline

Scenario 4

$0.0

$5.0

$10.0

$15.0

$20.0

$25.0

$30.0

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00

98th Percentile Delta-Deciview Reduction (dV)

Total Annualized Cost (Mil $)

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-5
BART ANALYSIS FOR WYODAK 

5.1.2 Analysis of Results 

Results of the least-cost analysis, shown in Tables 5-1 to 5-4 and Figures 5-1 to 5-4, confirm 

the selection of Scenario 1, based on incremental cost and visibility improvements. In 

Figure 5-1, the four scenarios are compared as a graph of total annualized cost versus number 

of days above 0.5 dV. EPA states that, “In calculating incremental costs, the analysis should 

only be conducted for control options that are dominant among all possible options.” In 

Figure 5-1, the dominant set of control options, Scenarios 1 and 3, represent the least-cost 

envelope depicted by the curvilinear line connecting them. Scenario 2 is eliminated because, 

although it lies on the curve formed by the dominant control alternative scenarios, it is an 

inferior option and should not be considered in the derivation of incremental cost 

effectiveness. Scenario 2 represents inferior controls because Scenario 1 provides 

approximately same amount of visibility impact reduction for less cost than Scenario 2. 

Similarly, Scenario 3 is projected to provide approximately the same amount of visibility 

impact reduction but at an excessive cost, both a cost per day of improvement and a cost per 

dV reduction, when compared to Scenario 1. The incremental cost effectiveness is 

determined by the difference in total annual costs between two contiguous scenarios divided 

by the difference in emissions reduction. 

Analysis of the results for the Badlands NP Class I Area in Tables 5-1 and 5-3 and 

Figures 5-1 and 5-2 illustrates the conclusions stated above. The greatest reduction in 

98th percentile dV and number of days above 0.5 dV is between the Baseline and Scenario 1. 

Table 5-3 shows that the incremental cost effectiveness for Scenario 1, compared to the 

Baseline, is at $350,000 per day and $16.3 million per dV to improve visibility at Badlands 

NP. The incremental cost effectiveness for Scenario 2 compared to Scenario 1 is at 

$0.69 million/day and $24.4 million per dV. In other words, the additional cost of Scenario 2 

is projected to gain only 0.16 dV improvement in visibility. However, Scenario 2 does reduce 

the number of days where the visibility is above 0.5 dV by 6 days a year. The incremental 

cost effectiveness for Scenario 3 compared to Scenario 1 is excessive at $1.1 million per day 

and $37.6 million per dV. A similar conclusion is reached for improving visibility at Wind 

Caves NP. Therefore, Scenario 1 represents BART for Wyodak. 

5.2 Recommendations 

5.2.1 NOx Emission Control 

CH2M HILL recommends new LNB with OFA as BART for Wyodak, based on the 

projected significant reduction in NOx emissions, reasonable control costs, and the 

advantages of no additional power requirements or non-air quality environmental impacts. 

This selection of new LNB with OFA is projected to attain an emission rate of 0.23 lb of NOx

per MMBtu. 

5.2.2 SO2 Emission Control 

CH2M HILL recommends upgrading the existing lime spray drying FGD system and the 

existing ESP as BART for Wyodak, based on the significant reduction in SO2 emissions, 

reasonable control costs, and the advantages of minimal additional power requirements and 

minimal non-air quality environmental impacts. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-6
BART ANALYSIS FOR WYODAK 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 5-7

5.2.3 PM10 Emission Control 

CH2M HILL recommends maintaining the existing ESP downstream of the lime spray dryer 

as BART for Wyodak, based on the significant reduction in PM10 emissions, reasonable 

control costs, and the advantages of no additional power requirements and no non-air quality 

environmental impacts. 

5.3 Just-Noticeable Differences in Atmospheric Haze 

Conclusions reached in the reference document “Just-Noticeable Differences in Atmospheric 

Haze” by Dr. Ronald Henry (2002), state that only dV differences of approximately 1.5 to 

2.0 dV or more are perceivable by the human eye. Deciview changes of less than 1.5 cannot 

be distinguished by the average person. Therefore, the modeling analysis results indicate that 

only minimal, if any, visibility improvements at the Class I areas studied would be expected 

under any of the scenarios. Thus, the results indicate that even though many millions of 

dollars will be spent, only minimal visibility improvements may result. 

Finally, it should be noted that none of the data were corrected for natural obscuration. 

During the period of 2001 through 2003, there were several mega-wildfires that lasted for 

many days and could have had a significant impact on visibility in these Class I areas. If 

natural obscuration were to reduce the visibility impacts modeled for the Wyodak facility, it 

would increase the costs per dV reduction that are presented in this report. 
6.0 References 

40 CFR Part 51. Regional Haze Regulations and Guidelines for Best Available Retrofit 

Technology Determinations; Final Rule. July 6, 2005. 

Energy Information Administration, 2006. Official Energy Statistics from the U.S. 

Government: Coal. http://www.eia.doe.gov/fuelcoal.html. Accessed October 2006. 

EPA, 1990. New Source Review Workshop Manual—Prevention of Significant Deterioration 

and Nonattainment Area Permitting. Draft. October 1990. 

EPA, 2003. Guidance for Estimating Natural Visibility Conditions Under the Regional Haze 

Rule. Environmental Protection Agency. EPA-454/8-03-005. September 2003. 

Henry, Ronald, 2002. “Just-Noticeable Differences in Atmospheric Haze,” Journal of the Air 

& Waste Management Association. Volume 52, p. 1238. 

National Oceanic and Atmospheric Administration, 2006. U.S. Daily Weather Maps Project. 

http://docs.lib.noaa.gov/rescue/dwm/data_rescue_daily_weather_maps.html. 

Accessed October 2006. 

North Dakota Department of Health, 2005. Protocol for BART-Related Visibility 

Improvement Modeling Analysis in North Dakota. North Dakota Department of 

Health. October 26, 2005. 

Sargent & Lundy, 2002. Multi-Pollutant Control Report. October 2002. 

Sargent & Lundy, 2006. Multi-Pollutant Control Report. Revised. October 2006. 

WDEQ-AQD, 2006. BART Air Modeling Protocol—Individual Source Visibility Assessments 

for BART Control Analyses. Wyoming Department of Environmental Quality – Air 

Quality Division. September 2006. 

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 6-1
APPENDIX A 

Economic Analysis 
PacifiCorp BART Analysis Scenarios

10

Index No. Name of Unit

1 Dave Johnston Unit 32 Dave Johnston Unit 43 Jim Bridger Unit 14 Jim Bridger Unit 25 Jim Bridger Unit 36 Jim Bridger Unit 47 Naughton Unit 18 Naughton Unit 29 Naughton Unit 3

10 Wyodak

Scenario First Year Cost Scenario

 First Year 

Cost Scenario First Year Cost Scenar

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

Scenario First Year Cost Scenario First Year Scenario First Year Cost Scenar

 N/A N/A N/A 

 N/A N/A N/A  N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A  N/A N/A N/A 

 N/A N/A N/A 

 N/A N/A N/A  N/A N/A N/A 

Scenario 3 - LNB with OFA and SCR, Dry FGD, New Fabric Filter

Scenario 1 - LNB with OFA, Dry FGD, Fabric Filter

Baseline - Current Operation with ESPScenario 1 - LNB with OFA, Dry FGD, Existing ESPScenario 2 - LNB with OFA, Dry FGD, New Fabric Filter

Jim Bridger

Select Unit:

Scenario 2 - LNB with OFA, Wet FGD, New Fabric FilterScenario 3 - LNB with OFA and SCR, Dry FGD, New Fabric FilterScenario 4 - LNB with OFA and SCR, Wet FGD, Fabric Filter

DJ Unit 4

Scenario 4 - LNB with OFA and SCR, Wet FGD, Existing ESP, New Stack

Dave Johnston

DJ Unit 3

Baseline - Current Operation with Venturi Scrubber 

JB Unit 1 JB Unit 2 JB Unit 3 

Baseline - Current Operation with Wet FGD and ESP

Baseline - Current Operation with Wet FGD and ESP

Baseline - Current Operation with Wet FGD and ESP

Baseline - Current OWet FGD and ESP

Scenario 2 - LNB with OFA, Wet FGD, New Fabric Filter

Scenario 2 - LNB with OFA, Wet FGD, New Fabric Filter

Scenario 2 - LNB witFGD, Fabric Filter

Scenario 1 - LNB with OFA, Wet FGD, ESP

Scenario 1 - LNB with OFA, Wet FGD, ESP

Scenario 1 - LNB with OFA, Wet FGD, ESP

Scenario 1 - LNB witFGD, ESP

Scenario 4 - LNB with OFA and SCR, Wet FGD, Fabric Filter

Scenario 4 - LNB with OFA and SCR, Wet FGD, Fabric Filter

Scenario 4 - LNB with OFA and SCR, Wet FGD, Fabric Filter

Scenario 4 - LNB witSCR, Wet FGD, Fab

Scenario 3 - LNB with OFA and SCR, Wet FGD, ESP

Scenario 3 - LNB with OFA and SCR, Wet FGD, ESP

Scenario 3 - LNB with OFA and SCR, Wet FGD, ESP

Scenario 3 - LNB witSCR, Wet FGD, ESP

Scenario 2 - LNB with OFA, Wet FGD, New Fabric Filter

Baseline - Current Operation with ESP

Baseline - Current OESP

NTN Unit 1 

Scenario 2 - LNB with OFA, Dry FGD, New Fabric Filter

Scenario 2 - LNB witFGD, New Fabric Fil

Scenario 1 - LNB with OFA, Dry FGD, ESP

Scenario 1 - LNB witFGD, ESP

Scenario 3 - LNB with OFA and SCR, Dry FGD, New Fabric Filter

Scenario 3 - LNB witSCR, Dry FGD, New 

Wyodak

Scenario 4 - LNB with OFA and SCR, Wet FGD, ESP, New Stack

Scenario 4 - LNB witSCR, Wet FGD, ESP

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
ECONOMIC ANALYSIS SUMMARY

Wyodak Boiler Design: Opposed Wall-Fired PC

LNB w/OFA ROFA LNB w/OFA & SNCR LNB w/OFA & SCR Upgraded 

FGD 

Case 1 2 3 4 5 6 

NOx Emission Control System LNB LNB w/OFA ROFA

LNB w/OFA & 

SNCR

LNB w/OFA & 

SCR LNB 

SO2 Emission Control System Dry FGD Dry FGD Dry FGD Dry FGD Dry FGD Upgraded Dry PM Emission Control System ESP ESP ESP ESP ESP ESP 

TOTAL INSTALLED CAPITAL COST ($) 0 9,300,000 15,252,149 19,495,654 108,280,222 26,759,01FIRST YEAR O&M COST ($)

Operating Labor ($) 0 0 0 0 0 0 Maintenance Material ($) 0 24,000 36,000 93,000 181,000 21,900 Maintenance Labor ($) 0 36,000 54,000 139,500 271,500 14,600 Administrative Labor ($) 0 0 0 0 0 0 TOTAL FIXED O&M COST 0 60,000 90,000 232,500 452,500 36,500 Makeup Water Cost 0 0 0 0 0 14,388 Reagent Cost 0 0 0 542,814 673,062 904,412 SCR Catalyst / FF Bag Cost 0 0 0 0 480,000 0 Waste Disposal Cost 0 0 0 0 0 346,184 Electric Power Cost 0 0 2,057,685 132,057 952,387 44,939 TOTAL VARIABLE O&M COST 0 0 2,057,685 674,871 2,105,449 1,309,92

TOTAL FIRST YEAR O&M COST 0 60,000 2,147,685 907,371 2,557,949 1,346,42

FIRST YEAR DEBT SERVICE ($) 0 884,689 1,450,904 1,854,579 10,300,462 2,545,52TOTAL FIRST YEAR COST ($) 0 944,689 3,598,588 2,761,950 12,858,411 3,891,94

Power Consumption (MW) 0.0 0.0 5.2 0.3 2.4 0.1 Annual Power Usage (Million kW-Hr/Yr) 0.0 0.0 41.2 2.6 19.0 0.9 

CONTROL COST ($/Ton Removed)

NOx Removal Rate (%) 0.0% 25.8% 35.5% 41.9% 77.4% 0.0% 

NOx Removed (Tons/Yr) 0 1,482 2,038 2,409 4,447 0 First Year Average Control Cost ($/Ton NOx Rem.) 0 637 1,766 1,147 2,892 0 

Incremental Control Cost ($/Ton NOx Removed) 0 637 4,775 1,962 3,844 0 

2-1 3-2 4-2 5-3

SO2 Removal Rate (%) 69.0% 0.0% 0.0% 0.0% 0.0% 36.0% 

SO2 Removed (Tons/Yr) 0 0 0 0 0 3,335 First Year Average Control Cost ($/Ton SO2 Rem.) 0 0 0 0 0 1,167 Incremental Control Cost ($/Ton SO2 Removed) Base 0 0 0 0 1,167 

6-1 

PM Removal Rate (%) 99.60% 0.00% 0.00% 0.00% 0.00% 0.00% PM Removed (Tons/Yr) 0 0 0 0 0 0 First Year Average Control Cost ($/Ton PM Rem.) 0 0 0 0 0 0 Incremental Control Cost ($/Ton PM Removed) Base 0 0 0 0 0 

PRESENT WORTH COST ($) 0 10,033,071 41,492,244 30,581,776 139,532,865 43,209,40

NOx Control 

Parameter Current Operation

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
INPUT CALCULATIONS

Wyodak Boiler Design: Opposed Wall-Fired PC

LNB w/OFA ROFA LNB w/OFA & SNCR LNB w/OFA & SCR Upgraded Dry FGD Dry 

Case 1 2 3 4 5 6 

NOx Emission Control System LNB LNB w/OFA ROFA

LNB w/OFA & 

SNCR LNB w/OFA & SCR LNB 

SO2 Emission Control System Dry FGD Dry FGD Dry FGD Dry FGD Dry FGD Upgraded Dry FGD Dry PM Emission Control System ESP ESP ESP ESP ESP ESP Unit Design and Coal CharacteristicsType of Unit PC PC PC PC PC PC Net Power Output (kW) 365,000 365,000 365,000 365,000 365,000 365,000 

Net Plant Heat Rate (Btu/kW-Hr) 12,877 12,877 12,877 12,877 12,877 12,877 Boiler Fuel

Clovis Point 

Mine

Clovis Point 

Mine

Clovis Point 

Mine

Clovis Point 

Mine

Clovis Point 

Mine Clovis Point Mine C

Coal Heating Value (Btu/Lb) 8,050 8,050 8,050 8,050 8,050 8,050 

Coal Sulfur Content (wt.%) 0.65% 0.65% 0.65% 0.65% 0.65% 0.65% 

Coal Ash Content (wt.%) 7.46% 7.46% 7.46% 7.46% 7.46% 7.46% Boiler Heat Input, each (MMBtu/Hr) 4,700 4,700 4,700 4,700 4,700 4,700 Coal Flow Rate (Lb/Hr) 583,864 583,864 583,864 583,864 583,864 583,864  (Ton/Yr) 2,301,592 2,301,592 2,301,592 2,301,592 2,301,592 2,301,592  (MMBtu/Yr) 37,055,628 37,055,628 37,055,628 37,055,628 37,055,628 37,055,628 

Emissions

Uncontrolled SO2 (Lb/Hr) 7,583 7,583 7,583 7,583 7,583 2,350  (Lb/MMBtu) 1.61 1.61 1.61 1.61 1.61 0.50  (Lb Moles/Hr) 118.36 118.36 118.36 118.36 118.36 36.68  (Tons/Yr) 29,891 29,891 29,891 29,891 29,891 9,264 SO2 Removal Rate (%) 69.0% 0.0% 0.0% 0.0% 0.0% 36.0%  (Lb/Hr) 5,233 0 0 0 0 846  (Ton/Yr) 20,627 0 0 0 0 3,335 SO2 Emission Rate (Lb/Hr) 2,350 7,583 7,583 7,583 7,583 1,504  (Lb/MMBtu) 0.50 1.61 1.61 1.61 1.61 0.32 

 (Ton/Yr) 9,264 29,891 29,891 29,891 29,891 5,929 Uncontrolled NOx (Lb/Hr) 1,457 1,457 1,457 1,457 1,457 1,457  (Lb/MMBtu) 0.31 0.31 0.31 0.31 0.31 0.31 

 (Lb Moles/Hr) 48.55 48.55 48.55 48.55 48.55 48.55  (Tons/Yr) 5,744 5,744 5,744 5,744 5,744 5,744 NOx Removal Rate (%) 0.0% 25.8% 35.5% 41.9% 77.4% 0.0% 

 (Lb/Hr) 0 376 517 611 1,128 0  (Lb Moles/Hr) 0.00 12.53 17.23 20.36 37.59 0.00  (Ton/Yr) 0 1,482 2,038 2,409 4,447 0 NOx Emission Rate (Lb/Hr) 1,457 1,081 940 846 329 1,457  (Lb/MMBtu) 0.31 0.23 0.20 0.18 0.07 0.31 

 (Ton/Yr) 5,744 4,261 3,706 3,335 1,297 5,744 Uncontrolled Fly Ash (Lb/Hr) 34,845 141 141 141 141 141  (Lb/MMBtu) 7.414 0.030 0.030 0.030 0.030 0.030  (Lb Moles/Hr) 1,161.1 4.7 4.7 4.7 4.7 4.7  (Tons/Yr) 137,359 556 556 556 556 556 Fly Ash Removal Rate (%) 99.60% 0.00% 0.00% 0.00% 0.00% 0.00% 

 (Lb/Hr) 34,704 0 0 0 0 0  (Ton/Yr) 136,803 0 0 0 0 0 Fly Ash Emission Rate (Lb/Hr) 141 141 141 141 141 141  (Lb/MMBtu) 0.030 0.030 0.030 0.030 0.030 0.030 

 (Ton/Yr) 556 556 556 556 556 556 

Parameter 

Current Operation NOx Control 

SO

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
LNB w/OFA ROFA LNB w/OFA & SNCR LNB w/OFA & SCR Upgraded Dry FGD Dry 

Case 1 2 3 4 5 6 

Parameter 

Current Operation NOx Control 

SO

General Plant DataAnnual Operation (Hours/Year) 7,884 7,884 7,884 7,884 7,884 7,884 Annual On-Site Power Plant Capacity Factor 0.90 0.90 0.90 0.90 0.90 0.90 

Economic Factors

Interest Rate (%) 7.10% 7.10% 7.10% 7.10% 7.10% 7.10% Discount Rate (%) 7.10% 7.10% 7.10% 7.10% 7.10% 7.10% Plant Economic Life (Years) 20 20 20 20 20 20 

Installed Capital Costs

NOx Emission Control System ($2006) 0 9,300,000 15,252,149 19,495,654 108,280,222 0 

SO2 Emission Control System ($2006) 0 0 0 0 0 26,759,011 

PM Emission Control System ($2006) 0 0 0 0 0 0 Total Emission Control Systems ($2006) 0 9,300,000 15,252,149 19,495,654 108,280,222 26,759,011 

NOx Emission Control System ($/kW) 0 25 42 53 297 0 SO2 Emission Control System ($/kW) 0 0 0 0 0 73 PM Emission Control System ($/kW) 0 0 0 0 0 0 Total Emission Control Systems ($/kW) 0 25 42 53 297 73 

Total Fixed Operating & Maintenance Costs

Operating Labor ($) 0 0 0 0 0 0 Maintenance Material ($) 0 24,000 36,000 93,000 181,000 21,900 Maintenance Labor ($) 0 36,000 54,000 139,500 271,500 14,600 Administrative Labor ($) 00000 0 

Total Fixed O&M Cost ($) 0 60,000 90,000 232,500 452,500 36,500 

Annual Fixed O&M Cost Escalation Rate (%) 2.00% 2.00% 2.00% 2.00% 2.00% 2.00% Water CostMakeup Water Usage (Gpm) 0 0 0 0 0 25 Unit Price ($/1000 Gallons) 1.22 1.22 1.22 0.00 1.22 1.22 

First Year Water Cost ($) 0 0 0 0 0 14,388 

Annual Water Cost Escalation Rate (%) 2.00% 2.00% 2.00% 2.00% 2.00% 2.00% Reagent Cost None None None Urea Anhydrous NH3 Lime 

Unit Cost ($/Ton) 0.00 0.00 0.00 370 400 91.25  ($/Lb) 0.000 0.000 0.000 0.185 0.200 0.046 Molar Stoichiometry 0.00 0.00 0.00 0.45 1.00 1.10 Reagent Purity (Wt.%) 100% 100% 100% 100% 100% 90% 

Reagent Usage (Lb/Hr) 0 0 0 372 427 2,514 First Year Reagent Cost ($) 0 0 0 542,814 673,062 904,412 Annual Reagent Cost Escalation Rate (%) 2.00% 2.00% 2.00% 2.00% 2.00% 2.00% SCR Catalyst / FF Bag Replacement Cost SCR Catalyst Bags 

Annual SCR Catalyst (m3) / No. FF Bags 0000 160 0 

SCR Catalyst ($/m3) / Bag Cost ($/ea.) 3,000 3,000 3,000 3,000 3,000 104 

First Year SCR Catalyst / Bag Replace. Cost ($) 0 0 0 0 480,000 0 

Annual SCR Catalyst / Bag Cost Esc. Rate (%) 2.00% 2.00% 2.00% 2.00% 2.00% 2.00% FGD Waste Disposal CostFGD Solid Waste Disposal Rate, Dry (Lb/Hr) 0 0 0 0 0 3,609 FGD Waste Disposal Unit Cost ($/Dry Ton) 24.33 24.33 24.33 24.33 24.33 24.33 

First Year FGD Waste Disposal Cost ($) 0 0 0 0 0 346,184 

Annual Waste Disposal Cost Esc. Rate (%) 2.00% 2.00% 2.00% 2.00% 2.00% 2.00% Auxiliary Power CostAuxiliary Power Requirement (% of Plant Output) 0.00% 0.00% 1.43% 0.09% 0.66% 0.03%  (MW) 0.00 0.00 5.22 0.34 2.42 0.11 Unit Cost ($2006/MW-Hr) 50.00 50.00 50.00 50.00 50.00 50.00 

First Year Auxiliary Power Cost ($) 0 0 2,057,685 132,057 952,387 44,939 

Annual Power Cost Escalation Rate (%) 2.00% 2.00% 2.00% 2.00% 2.00% 2.00% 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Input Tables

Table 1 - Cases

Existing

1 2 3 4 5 6 7 8 

1 Dave Johnston Unit 3 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR Dry FGD w/ESP 

Dry FGD w/Fabric 

Filter Wet FGD 

2 Dave Johnston Unit 4 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR N/A 

Dry FGD w/Fabric 

Filter

 Wet FGD 

Filte

3 Jim Bridger Unit 1 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR N/A N/A Upgraded 

4 Jim Bridger Unit 2 Current Operation Exist. LNB w/OFA ROFA SNCR SCR N/A N/A Upgraded 5 Jim Bridger Unit 3 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR N/A N/A Upgraded 

6 Jim Bridger Unit 4 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR N/A N/A Upgraded 

7 Naughton Unit 1 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR Dry FGD w/ESP 

Dry FGD w/Fabric 

Filter Wet FGD 

8 Naughton Unit 2 Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

 LNB w/OFA & 

SCR Dry FGD w/ESP 

Dry FGD w/Fabric 

Filter Wet FGD 

9 Naughton Unit 3 Current Operation Exist. LNB w/OFA ROFA SNCR SCR N/A N/A Upgraded 

10 Wyodak Current Operation LNB w/OFA ROFA LNB w/OFA & SNCR

LNB w/OFA & 

SCR Upgraded Dry FGD 

Dry FGD w/Fabric 

Filter Wet F

Table 2 - Unit Design and Coal Characteristics

NOx SO2 PM Boiler Design

Net Power 

Output (kW)

Net Plant Heat 

Rate (Btu/kW-Hr) Coal

Heating 

HHV (B

1 Dave Johnston Unit 3 None None ESP

3-Cell Burner, Opposed 

Wall-Fired PC 250,000 11,200 Dry Fork PRB 

2 Dave Johnston Unit 4 Windbox Mods.

Lime Added to Venturi 

Scrubber Venturi Scrubber Tangential-Fired PC 360,000 11,390 Dry Fork PRB 

3 Jim Bridger Unit 1

LNCFS-1 & 

Windbox Mods. Wet FGD ESP Tangential-Fired PC 530,000 11,320 

Bridger Mine 

Underground 

4 Jim Bridger Unit 2 LNB - TFS 2000 Wet FGD ESP Tangential-Fired PC 530,000 11,320 

Bridger Mine 

Underground 

5 Jim Bridger Unit 3

LNCFS-1 & 

Windbox Mods. Wet FGD ESP Tangential-Fired PC 530,000 11,320 

Bridger Mine 

Underground 

6 Jim Bridger Unit 4

LNCFS-1 & 

Windbox Mods. Wet FGD ESP Tangential-Fired PC 530,000 11,320 

Bridger Mine 

Underground 

7 Naughton Unit 1 None None ESP Tangential-Fired PC 173,000 10,694 Kemmerer Mine 8 Naughton Unit 2 None None ESP Tangential-Fired PC 226,000 10,574 Kemmerer Mine 9 Naughton Unit 3 LNCFS II LNB Wet FGD ESP Tangential-Fired PC 356,000 10,336 Kemmerer Mine 

10 Wyodak LNB Dry FGD ESP Opposed Wall-Fired PC 365,000 12,877 Clovis Point Mine 

Current Emission Control Systems Unit Design 

Index No. Name of UnitIndex No. Name of Unit | Case --->

NOx Control SO2 Control 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Table 3 - Emissions

Controlled 

SO2 Controlled NOx

Controlled 

PM Case 2 Case 3 Case 4 Case 5 Case 

1 Dave Johnston Unit 3 1.61 0.70 0.030 0.24 0.19 0.19 0.07 

 

2 Dave Johnston Unit 4 0.50 0.40 0.061 0.15 0.15 0.12 0.07 3 Jim Bridger Unit 1 0.27 0.45 0.045 0.24 0.22 0.20 0.07 

4 Jim Bridger Unit 2 0.27 0.24 0.074 0.24 0.22 0.20 0.07 5 Jim Bridger Unit 3 0.27 0.45 0.057 0.24 0.22 0.20 0.07 6 Jim Bridger Unit 4 0.17 0.45 0.030 0.24 0.22 0.20 0.07 7 Naughton Unit 1 1.61 0.58 0.056 0.24 0.28 0.18 0.07 

 

8 Naughton Unit 2 1.61 0.54 0.064 0.24 0.28 0.18 0.07 

 

9 Naughton Unit 3 0.50 0.45 0.094 0.35 0.30 0.25 0.07 

10 Wyodak 0.50 0.31 0.030 0.23 0.18 0.20 0.07 

Table 4 - Case 1 O&M Costs (Current Operation)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Aux. P

Usage 

1 Dave Johnston Unit 3 $ - - $ - $ - $ - None - 

2 Dave Johnston Unit 4 $ - - $ - $ $ - - None - 

3 Jim Bridger Unit 1 $ - - $ - $ $ - - None - 

4 Jim Bridger Unit 2 $ - - $ - $ $ - - None - 

5 Jim Bridger Unit 3 $ - - $ - $ $ - - None - 

6 Jim Bridger Unit 4 $ - - $ - $ $ - - None - 

7 Naughton Unit 1 $ - - $ - $ $ - - None - 

8 Naughton Unit 2 $ - - $ - $ $ - - None - 

9 Naughton Unit 3 $ - - $ - $ $ - - None - 

10 Wyodak $ - - $ - $ $ - None - - 

Table 5 - Case 2 O&M Costs (LNB w/OFA)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Aux. P

Usage 

1 Dave Johnston Unit 3 $ 40,000 - $ 60,000 $ - $ - None - 

2 Dave Johnston Unit 4 $ 36,000 - $ 54,000 $ $ - - None - 

3 Jim Bridger Unit 1 $ 28,000 - $ 42,000 $ $ - - None - 

4 Jim Bridger Unit 2 $ - - $ - $ $ - - None - 

5 Jim Bridger Unit 3 $ 28,000 - $ 42,000 $ $ - - None - 

6 Jim Bridger Unit 4 $ 28,000 - $ 42,000 $ $ - - None - 

7 Naughton Unit 1 $ 32,000 - $ 48,000 $ $ - - None - 

8 Naughton Unit 2 $ 32,000 - $ 48,000 $ $ - - None - 

9 Naughton Unit 3 $ - - $ - $ $ - - None - 

10 Wyodak $ 24,000 - $ 36,000 $ $ - None - - 

SO2 C

Index No. Name of Unit

Annual Fixed O&M Costs Variable Operating Requirements

Index No. Name of Unit

Current Emission Rates (Lb/MMBtu) NOx Control Emission Rates (Lb/MMBtu)

Index No. Name of Unit

Annual Fixed O&M Costs Variable Operating Requirements

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Table 6 - Case 3 O&M Costs (Mobotec ROFA)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Aux. P

Usage 

1 Dave Johnston Unit 3 $ 60,000 - $ 90,000 $ - $ - None - 

2 Dave Johnston Unit 4 $ 54,000 - $ 81,000 $ $ - - None - 3 Jim Bridger Unit 1 $ 42,000 - $ 63,000 $ $ - - None - 4 Jim Bridger Unit 2 $ 42,000 - $ 63,000 $ $ - - None - 5 Jim Bridger Unit 3 $ 42,000 - $ 63,000 $ $ - - None - 6 Jim Bridger Unit 4 $ 42,000 - $ 63,000 $ $ - - None - 7 Naughton Unit 1 $ 48,000 - $ 72,000 $ $ - - None - 8 Naughton Unit 2 $ 48,000 - $ 72,000 $ $ - - None - 9 Naughton Unit 3 $ 48,000 - $ 72,000 $ $ - - None - 

10 Wyodak $ 36,000 - $ 54,000 $ $ - None - - 

Table 7 - Case 4 O&M Costs (LNB w/OFA & SNCR))

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Aux. P

Usage 

1 Dave Johnston Unit 3 $ 98,000 - $ 147,000 $ - $ - Urea 0.41 

2 Dave Johnston Unit 4 $ 105,000 - $ 157,500 $ $ - - Urea 0.45 3 Jim Bridger Unit 1 $ 123,000 - $ 184,500 $ $ - - Urea 0.45 4 Jim Bridger Unit 2 $ 95,000 - $ 142,500 $ $ - - Urea 0.45 5 Jim Bridger Unit 3 $ 122,000 - $ 183,000 $ $ - - Urea 0.45 6 Jim Bridger Unit 4 $ 123,000 - $ 184,500 $ $ - - Urea 0.45 7 Naughton Unit 1 $ 83,000 - $ 124,500 $ $ - - Urea 0.45 8 Naughton Unit 2 $ 93,000 - $ 139,500 $ $ - - Urea 0.51 9 Naughton Unit 3 $ 75,000 - $ 112,500 $ $ - - Urea 0.45 

10 Wyodak $ 93,000 - $ 139,500 $ - Urea - 0.45 

Table 8 - Case 5 O&M Costs (LNB w/OFA & SCR))

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Annua

Catalyst R

(m3

1 Dave Johnston Unit 3 $ 155,000 - $ 232,500 $ - $ - Anhydrous NH3 1.00 

 

2 Dave Johnston Unit 4 $ 166,000 - $ 249,000 $ $ - - Anhydrous NH3 1.00 

 

3 Jim Bridger Unit 1 $ 190,000 - $ 285,000 $ $ - - Anhydrous NH3 1.00 

 

4 Jim Bridger Unit 2 $ 162,000 - $ 243,000 $ $ - - Anhydrous NH3 1.00 

 

5 Jim Bridger Unit 3 $ 190,000 - $ 285,000 $ $ - - Anhydrous NH3 1.00 

 

6 Jim Bridger Unit 4 $ 190,000 - $ 285,000 $ $ - - Anhydrous NH3 1.00 

 

7 Naughton Unit 1 $ 132,000 - $ 198,000 $ $ - - Anhydrous NH3 1.00 

 

8 Naughton Unit 2 $ 160,000 - $ 240,000 $ $ - - Anhydrous NH3 1.00 

 

9 Naughton Unit 3 $ 156,000 - $ 234,000 $ $ - - Anhydrous NH3 1.00 

 

10 Wyodak $ 181,000 - $ 271,500 $ $ - - Anhydrous NH3 1.00 

Annual Fixed O&M Costs Variable Operating Requirements

Index No. Name of Unit

Annual Fixed O&M Costs Variable Operating Requirements

Index No. Name of UnitIndex No. Name of Unit

Annual Fixed O&M Costs Variable Operating Requirements

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Table 9 - Case 6 O&M Costs (Dry FGD)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Annual F

Repla

1 Dave Johnston Unit 3 $ 714,175 506,128 $ 476,928 $ - $ 173 Lime 1.15 

 

2 Dave Johnston Unit 4 $ - - $ - $ $ - - Lime - 

 

3 Jim Bridger Unit 1 $ - - $ - $ $ - - Lime - 

 

4 Jim Bridger Unit 2 $ - - $ - $ $ - - Lime - 

 

5 Jim Bridger Unit 3 $ - - $ - $ $ - - Lime - 

 

6 Jim Bridger Unit 4 $ - - $ - $ $ - - Lime - 

 

7 Naughton Unit 1 $ 587,643 506,128 $ 391,762 $ $ - 120 Lime 1.40 

 

8 Naughton Unit 2 $ 860,17 506,128 $ 573,04 4 $ $ - 165 4 Lime 1.40 

 

9 Naughton Unit 3 $ - - $ - $ $ - - Lime - 

 

10 Wyodak $ 21,900 - $ 14,600 $ - 25 Lime 1.10 

Table 10 - Case 7 O&M Costs (Dry FGD w/Fabric Filter)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Annual F

Repla

1 Dave Johnston Unit 3 $ 714,175 506,128 $ 476,928 $ - $ 173 Lime 1.15 

 

2 Dave Johnston Unit 4 $ 1,102,288 506,128 $ 734,858 $ $ - 248 Lime 1.10 

 

3 Jim Bridger Unit 1 $ - - $ - $ $ - - Lime - 

 

4 Jim Bridger Unit 2 $ - - $ - $ $ - - Lime - 

 

5 Jim Bridger Unit 3 $ - - $ - $ $ - - Lime - 

 

6 Jim Bridger Unit 4 $ - - $ - $ $ - - Lime - 

 

7 Naughton Unit 1 $ 632,660 506,128 $ 459,286 $ $ - 120 Lime 1.15 

 

8 Naughton Unit 2 $ 905,190 506,128 $ 640,568 $ $ - 165 Lime 1.15 

 

9 Naughton Unit 3 $ - - $ - $ $ - - Lime - 

 

10 Wyodak $ 30,660 - $ 20,440 $ - 30 Lime 1.10 

Table 11 - Case 8 O&M Costs (Wet FGD)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Annual F

Repla

1 Dave Johnston Unit 3 $ 1,182,587 809,804 $ 788,391 $ - $ 230 Lime 1.02 

 

2 Dave Johnston Unit 4 $ 1,430,78 809,804 $ 953,856 4 $ $ - 330 Lime 1.02 

 

3 Jim Bridger Unit 1 $ 25,550 - $ 17,033 $ $ - 53 Soda Ash 1.02 

 

4 Jim Bridger Unit 2 $ 25,550 - $ 17,033 $ $ - 53 Soda Ash 1.02 

 

5 Jim Bridger Unit 3 $ 25,550 - $ 17,033 $ $ - 52 Soda Ash 1.02 

 

6 Jim Bridger Unit 4 $ 25,550 - $ 17,033 $ $ - 27 Soda Ash 1.02 

 

7 Naughton Unit 1 $ 963,589 809,804 $ 642,393 $ $ - 160 Lime 1.05 

 

8 Naughton Unit 2 $ 1,226,386 809,804 $ 817,591 $ $ - 220 Lime 1.05 

 

9 Naughton Unit 3 $ 21,900 - $ 14,600 $ $ - 66 Soda Ash 1.02 

 

10 Wyodak $ 328,496 303,677 $ 218,998 $ $ - 82 Lime 1.02 

Variable Operating RequirementsVariable Operating RequirementsVariable Operating Requirements

Index No. Name of Unit

Annual Fixed O&M Costs

Index No. Name of Unit

Annual Fixed O&M Costs

Index No. Name of Unit

Annual Fixed O&M Costs

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Table 12 - Case 9 O&M Costs (Flue Gas Conditioning)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent 

Usage (Lb/Hr)

Annual F

Repla

1 Dave Johnston Unit 3 $ - - $ - $ - $ - None - 

 

2 Dave Johnston Unit 4 $ - - $ - $ $ - - None - 

 

3 Jim Bridger Unit 1 $ - - $ 10,000 $ $ - - Elemental Sulfur 100 

 

4 Jim Bridger Unit 2 $ - - $ 10,000 $ $ - - Elemental Sulfur 100 

 

5 Jim Bridger Unit 3 $ - - $ 10,000 $ $ - - Elemental Sulfur 100 

 

6 Jim Bridger Unit 4 $ - - $ 10,000 $ $ - - Elemental Sulfur 100 

 

7 Naughton Unit 1 $ - - $ 10,000 $ $ - - Elemental Sulfur 33 

 

8 Naughton Unit 2 $ - - $ 10,000 $ $ - - Elemental Sulfur 43 

 

9 Naughton Unit 3 $ - - $ 10,000 $ $ - - Elemental Sulfur 67 

 

10 Wyodak $ - - $ - $ - - None - 

Table 13 - Case 10 O&M Costs (Fabric Filter)

Oper. Labor Maint. Materials Maint. Labor Admin. Labor

Makeup Water 

Use (Gpm) Reagent

Reagent Molar 

Stoich.

Annual F

Repla

1 Dave Johnston Unit 3 $ 45,016 - $ 67,524 $ - $ - None - 

 

2 Dave Johnston Unit 4 $ 68,133 - $ 102,199 $ $ - - None - 

 

3 Jim Bridger Unit 1 $ 51,099 - $ 76,649 $ $ - - None - 

 

4 Jim Bridger Unit 2 $ 51,099 - $ 76,649 $ $ - - None - 

 

5 Jim Bridger Unit 3 $ 51,099 - $ 76,649 $ $ - - None - 

 

6 Jim Bridger Unit 4 $ 51,099 - $ 76,649 $ $ - - None - 

 

7 Naughton Unit 1 $ 45,016 - $ 67,524 $ $ - - None - 

 

8 Naughton Unit 2 $ 45,016 - $ 67,524 $ $ - - None - 

 

9 Naughton Unit 3 $ 48,666 - $ 72,999 $ $ - - None - 

 

10 Wyodak $ 48,666 - $ 72,999 $ $ - - None - 

Table 14 - Major Materials Design and Supply Costs

2 3 4 5 6 7 8 9 

1 Dave Johnston Unit 3 $ 5,449,830 $ 3,556,617 $ 5,773,000 $ 49,355,000 $ 56,379,000 $ 85,647,000 $ 88,913,000 $ 

2 Dave Johnston Unit 4 $ 2,673,501 $ 4,343,192 $ 7,171,085 $ 66,200,000 $ - $ 137,267,000 $ 178,174,384 $ 

3 Jim Bridger Unit 1 $ 2,981,982 $ 6,056,955 $ 9,528,000 $ 80,923,000 $ - $ - $ 8,010,093 $ 

4 Jim Bridger Unit 2 $ - $ 6,056,955 $ 9,528,000 $ 80,923,000 $ - $ - $ 8,010,093 $ 

5 Jim Bridger Unit 3 $ 2,981,982 $ 6,056,955 $ 9,419,000 $ 80,923,000 $ - $ - $ 8,010,093 $ 

6 Jim Bridger Unit 4 $ 2,981,982 $ 6,056,955 $ 9,528,000 $ 93,009,000 $ - $ - $ 3,549,000 $ 

7 Naughton Unit 1 $ 2,502,123 $ 2,675,792 $ 7,257,000 $ 37,292,000 $ 26,819,000 $ 42,301,000 $ 44,000,000 $ 

8 Naughton Unit 2 $ 2,570,674 $ 3,123,533 $ 8,784,000 $ 47,934,000 $ 39,262,000 $ 57,621,000 $ 56,000,000 $ 

9 Naughton Unit 3 $ - $ 4,351,377 $ 11,203,578 $ 67,373,000 $ - $ - $ 2,963,000 $ 

10 Wyodak $ 3,187,636 $ 4,500,245 $ 7,234,860 $ 72,479,000 $ 16,487,985 $ 41,146,026 $ 58,619,840 $ 

Variable Operating Requirements

Index No. Name of Unit

Annual Fixed O&M Costs

Index No. Name of Unit

Annual Fixed O&M Costs Variable Operating Requirements

NOx Control SO2 Control 

Index No. Name of Unit | Case --->

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
CAPITAL COST

Wyodak

CaseNOx Emission Control SystemSO2 Emission Control SystemPM Emission Control System

CAPITAL COST COMPONENT Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Sour

LNB w/OFA or ROFA LNB w/OFA ROFA LNB w/OFA LNB w/OFA

Major Materials Design and Supply Vendor $3,187,636 Vendor $4,500,245 Vendor $3,187,636 Vendor $3,187,636 Vendor $0 Vendor 

Construction 85.3% $2,720,130 85.3% $3,840,228 85.3% $2,720,130 85.3% $2,720,130 85.3% $0 85.3% 

Balance of Plant 51.7% $1,647,758 51.7% $2,326,273 51.7% $1,647,758 51.7% $1,647,758 51.7% $0 51.7% Electrical (Allowance) 0.0% $0 30.0% $1,350,074 0.0% $0 0.0% $0 0.0% $0 0.0% 

Owner's Costs 13.2% $422,309 13.2% $596,208 13.2% $422,309 13.2% $422,309 13.2% $0 13.2% 

Surcharge 16.4% $523,585 16.4% $739,187 16.4% $523,585 16.4% $523,585 16.4% $0 16.4% AFUDC 12.2% $389,480 12.2% $549,861 12.2% $389,480 12.2% $389,480 12.2% $0 12.2% Subtotal $8,890,897 $13,902,076 $8,890,897 $8,890,897 $0 

Contingency 12.8% $409,103 30.0% $1,350,074 12.8% $409,103 12.8% $409,103 12.8% $0 12.8% 

Total Capital Cost for LNB w/OFA or ROFA $9,300,000 $15,252,149 $9,300,000 $9,300,000 $0 

SNCR or SCR SNCR SCR

Major Materials Design and Supply S&L Report $0 S&L Report $0 S&L Report $7,234,860 S&L Report $72,479,000 S&L Report $0 S&L ReporContingency 20.0% $0 20.0% $0 20.0% $1,446,972 10.0% $7,247,900 20.0% $0 20.0% 

Labor Premium 5.6% $0 5.6% $0 5.6% $404,646 5.6% $4,053,750 5.6% $0 5.6% EPC Premium 0.0% $0 0.0% $0 0.0% $0 8.4% $6,122,301 8.4% $0 8.4% Boiler Reinforcement (Allowance) 0.0% $0 0.0% $0 0.0% $0 0.0% $0 0.0% $0 0.0% Sales Tax 1.1% $0 1.1% $0 1.1% $79,728 1.1% $798,719 1.1% $0 1.1% 

Escalation 0.0% $0 0.0% $0 0.0% $0 0.0% $0 0.0% $0 0.0% Contingency on Adders 2.8% $0 2.8% $0 2.8% $203,083 0.0% $0 2.8% $0 2.8% 

Surcharge and AFUDC 11.4% $0 11.4% $0 11.4% $826,366 11.4% $8,278,551 11.4% $0 11.4% 

Total Capital Cost for SNCR or SCR $0 $0 $10,195,654 $98,980,222 $0 

Dry or Wet FGD, FGC or Fabric Filter Dry FGD 

Major Materials Design and Supply S&L Report $0 S&L Report $0 S&L Report $0 S&L Report $0 S&L Report $16,487,985 S&L Repor

Contingency 20.0% $0 20.0% $0 20.0% $0 20.0% $0 20.0% $3,297,597 20.0% 

Labor Premium 5.6% $0 5.6% $0 5.6% $0 5.6% $0 5.6% $922,173 5.6% 

EPC Premium 8.4% $0 8.4% $0 8.4% $0 8.4% $0 8.4% $1,392,740 8.4% 

Boiler Reinforcement (Allowance) 2.8% $0 2.8% $0 2.8% $0 2.8% $0 2.8% $463,972 2.8% 

Sales Tax 1.1% $0 1.1% $0 1.1% $0 1.1% $0 1.1% $181,698 1.1% 

Escalation 10.1% $0 10.1% $0 10.1% $0 10.1% $0 10.1% $1,666,770 10.1% 

Contingency on Adders 2.8% $0 2.8% $0 2.8% $0 2.8% $0 2.8% $462,818 2.8% 

Surcharge and AFUDC 11.4% $0 11.4% $0 11.4% $0 11.4% $0 11.4% $1,883,258 11.4% 

Total Capital Cost for Dry/Wet FGD, FGC or FF $0 $0 $0 $0 $26,759,011 

LNB w/OFA & SNCR Upgraded Dry FGD Dry FGD 

SO2 

LNB w/OFA

Dry FGD

ESP ESP

ROFA

Dry FGD

Dry FGD 

Parameter

LNB w/OFA ROFA LNB w/OFA & SCR

LNB

Upgraded Dry FGD

ESP

LNB w/OFA & SNCR

Dry FGD

ESP ESP

LNB w/OFA & SCR

Dry FGD

NOx Control

2 3 45 

6 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Wyodak LNB w/OFA

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 60,000 - - - - - - 

 

2 2015 61,200 - - - - - - 

 

3 2016 62,424 - - - - - - 

 

4 2017 63,672 - - - - - - 

 

5 2018 64,946 - - - - - - 

 

6 2019 66,245 - - - - - - 

 

7 2020 67,570 - - - - - - 

 

8 2021 68,921 - - - - - - 

 

9 2022 70,300 - - - - - - 

 

10 2023 71,706 - - - - - - 

 

11 2024 73,140 - - - - - - 

 

12 2025 74,602 - - - - - - 

 

13 2026 76,095 - - - - - - 

 

14 2027 77,616 - - - - - - 

 

15 2028 79,169 - - - - - - 

 

16 2029 80,752 - - - - - - 

 

17 2030 82,367 - - - - - - 

 

18 2031 84,014 - - - - - - 

 

19 2032 85,695 - - - - - - 

 

20 2033 87,409 - - - - - - 

 

Present Worth - 733,071 - - - - - 

 

(% of PW) 7.3% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 

Wyodak ROFA

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 90,000 - - - - 2,057,685 2,057,685 

 

2 2015 91,800 - - - - 2,098,838 2,098,838 

 

3 2016 93,636 - - - - 2,140,815 2,140,815 

 

4 2017 95,509 - - - - 2,183,631 2,183,631 

 

5 2018 97,419 - - - - 2,227,304 2,227,304 

 

6 2019 99,367 - - - - 2,271,850 2,271,850 

 

7 2020 101,355 - - - - 2,317,287 2,317,287 

 

8 2021 103,382 - - - - 2,363,633 2,363,633 

 

9 2022 105,449 - - - - 2,410,905 2,410,905 

 

10 2023 107,558 - - - - 2,459,124 2,459,124 

 

11 2024 109,709 - - - - 2,508,306 2,508,306 

 

12 2025 111,904 - - - - 2,558,472 2,558,472 

 

13 2026 114,142 - - - - 2,609,642 2,609,642 

 

14 2027 116,425 - - - - 2,661,834 2,661,834 

 

15 2028 118,753 - - - - 2,715,071 2,715,071 

 

16 2029 121,128 - - - - 2,769,373 2,769,373 

 

17 2030 123,551 - - - - 2,824,760 2,824,760 

 

18 2031 126,022 - - - - 2,881,255 2,881,255 

 

19 2032 128,542 - - - - 2,938,880 2,938,880 

 

20 2033 131,113 - - - - 2,997,658 2,997,658 

 

Present Worth - 1,099,607 - - - 25,140,488 25,140,488 1

 

(% of PW) 2.7% 0.0% 0.0% 0.0% 0.0% 60.6% 60.6% 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Wyodak LNB w/OFA & SNCR

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 232,500 - 542,814 - - 132,057 674,871 

 

2 2015 237,150 - 553,670 - - 134,698 688,368 

 

3 2016 241,893 - 564,743 - - 137,392 702,135 

 

4 2017 246,731 - 576,038 - - 140,140 716,178 

 

5 2018 251,665 - 587,559 - - 142,943 730,502 

 

6 2019 256,699 - 599,310 - - 145,802 745,112 

 

7 2020 261,833 - 611,296 - - 148,718 760,014 

 

8 2021 267,069 - 623,522 - - 151,692 775,214 

 

9 2022 272,411 - 635,993 - - 154,726 790,719 

 

10 2023 277,859 - 648,713 - - 157,820 806,533 

 

11 2024 283,416 - 661,687 - - 160,977 822,664 

 

12 2025 289,085 - 674,921 - - 164,196 839,117 

 

13 2026 294,866 - 688,419 - - 167,480 855,899 

 

14 2027 300,764 - 702,187 - - 170,830 873,017 

 

15 2028 306,779 - 716,231 - - 174,246 890,477 

 

16 2029 312,914 - 730,556 - - 177,731 908,287 

 

17 2030 319,173 - 745,167 - - 181,286 926,453 

 

18 2031 325,556 - 760,070 - - 184,912 944,982 

 

19 2032 332,067 - 775,272 - - 188,610 963,881 

 

20 2033 338,709 - 790,777 - - 192,382 983,159 

 

Present Worth - 2,840,651 6,632,018 - - 1,613,453 8,245,471 1

 

(% of PW) 9.3% 0.0% 21.7% 0.0% 0.0% 5.3% 27.0% 

Wyodak LNB w/OFA & SCR

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 452,500 - 673,062 480,000 - 952,387 2,105,449 1

 

2 2015 461,550 - 686,523 489,600 - 971,435 2,147,558 1

 

3 2016 470,781 - 700,253 499,392 - 990,864 2,190,509 1

 

4 2017 480,197 - 714,258 509,380 - 1,010,681 2,234,319 1

 

5 2018 489,801 - 728,544 519,567 - 1,030,895 2,279,005 1

 

6 2019 499,597 - 743,114 529,959 - 1,051,512 2,324,586 1

 

7 2020 509,588 - 757,977 540,558 - 1,072,543 2,371,077 1

 

8 2021 519,780 - 773,136 551,369 - 1,093,994 2,418,499 1

 

9 2022 530,176 - 788,599 562,397 - 1,115,873 2,466,869 1

 

10 2023 540,779 - 804,371 573,644 - 1,138,191 2,516,206 1

 

11 2024 551,595 - 820,458 585,117 - 1,160,955 2,566,530 1

 

12 2025 562,627 - 836,867 596,820 - 1,184,174 2,617,861 1

 

13 2026 573,879 - 853,605 608,756 - 1,207,857 2,670,218 1

 

14 2027 585,357 - 870,677 620,931 - 1,232,014 2,723,623 1

 

15 2028 597,064 - 888,090 633,350 - 1,256,655 2,778,095 1

 

16 2029 609,005 - 905,852 646,017 - 1,281,788 2,833,657 1

 

17 2030 621,186 - 923,969 658,937 - 1,307,424 2,890,330 1

 

18 2031 633,609 - 942,449 672,116 - 1,333,572 2,948,137 1

 

19 2032 646,281 - 961,298 685,558 - 1,360,243 3,007,099 1

 

20 2033 659,207 - 980,524 699,269 - 1,387,448 3,067,241 1

 

Present Worth - 5,528,579 8,223,368 5,864,570 - 11,636,127 25,724,064 10

 

(% of PW) 4.0% 0.0% 5.9% 4.2% 0.0% 8.3% 18.4% 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Wyodak Upgraded Dry FGD

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 36,500 14,388 904,412 - 346,184 44,939 1,309,923 

 

2 2015 37,230 14,676 922,500 - 353,108 45,838 1,336,122 

 

3 2016 37,974 14,969 940,950 - 360,170 46,754 1,362,844 

 

4 2017 38,734 15,269 959,769 - 367,374 47,689 1,390,101 

 

5 2018 39,508 15,574 978,965 - 374,721 48,643 1,417,903 

 

6 2019 40,298 15,886 998,544 - 382,216 49,616 1,446,261 

 

7 2020 41,104 16,203 1,018,515 - 389,860 50,608 1,475,186 

 

8 2021 41,927 16,527 1,038,885 - 397,657 51,621 1,504,690 

 

9 2022 42,765 16,858 1,059,663 - 405,610 52,653 1,534,784 

 

10 2023 43,620 17,195 1,080,856 - 413,722 53,706 1,565,480 

 

11 2024 44,493 17,539 1,102,473 - 421,997 54,780 1,596,789 

 

12 2025 45,383 17,890 1,124,523 - 430,437 55,876 1,628,725 

 

13 2026 46,290 18,248 1,147,013 - 439,046 56,993 1,661,299 

 

14 2027 47,216 18,613 1,169,953 - 447,827 58,133 1,694,525 

 

15 2028 48,160 18,985 1,193,352 - 456,783 59,296 1,728,416 

 

16 2029 49,124 19,365 1,217,219 - 465,919 60,482 1,762,984 

 

17 2030 50,106 19,752 1,241,564 - 475,237 61,691 1,798,244 

 

18 2031 51,108 20,147 1,266,395 - 484,742 62,925 1,834,209 

 

19 2032 52,130 20,550 1,291,723 - 494,437 64,184 1,870,893 

 

20 2033 53,173 20,961 1,317,557 - 504,325 65,467 1,908,311 

 

Present Worth 175,792 445,947 11,049,972 - 4,229,631 549,056 16,004,451 2

 

(% of PW) 1.0% 0.4% 25.6% 0.0% 9.8% 1.3% 37.0% 

Wyodak Dry FGD w/Fabric Filte

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 51,099 17,266 904,412 - 439,525 59,130 1,420,333 

 

2 2015 52,121 17,611 922,500 - 448,315 60,313 1,448,739 

 

3 2016 53,164 17,963 940,950 - 457,282 61,519 1,477,714 

 

4 2017 54,227 18,323 959,769 - 466,427 62,749 1,507,268 

 

5 2018 55,312 18,689 978,965 - 475,756 64,004 1,537,414 

 

6 2019 56,418 19,063 998,544 - 485,271 65,284 1,568,162 

 

7 2020 57,546 19,444 1,018,515 - 494,976 66,590 1,599,525 

 

8 2021 58,697 19,833 1,038,885 - 504,876 67,922 1,631,516 

 

9 2022 59,871 20,230 1,059,663 - 514,973 69,280 1,664,146 

 

10 2023 61,069 20,634 1,080,856 - 525,273 70,666 1,697,429 

 

11 2024 62,290 21,047 1,102,473 - 535,778 72,079 1,731,377 

 

12 2025 63,536 21,468 1,124,523 - 546,494 73,521 1,766,005 

 

13 2026 64,806 21,897 1,147,013 - 557,424 74,991 1,801,325 

 

14 2027 66,103 22,335 1,169,953 - 568,572 76,491 1,837,352 

 

15 2028 67,425 22,782 1,193,352 - 579,944 78,021 1,874,099 

 

16 2029 68,773 23,237 1,217,219 - 591,543 79,581 1,911,581 

 

17 2030 70,149 23,702 1,241,564 - 603,373 81,173 1,949,812 

 

18 2031 71,552 24,176 1,266,395 - 615,441 82,796 1,988,808 

 

19 2032 72,983 24,660 1,291,723 - 627,750 84,452 2,028,585 

 

20 2033 74,442 25,153 1,317,557 - 640,305 86,141 2,069,156 

 

Present Worth 210,951 624,325 11,049,972 - 5,370,050 722,442 17,353,415 6

 

(% of PW) 0.7% 0.2% 13.0% 0.0% 6.3% 0.9% 20.5% 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
Wyodak Wet FGD

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 851,170 47,193 704,455 - 506,310 689,850 1,947,808 

 

2 2015 868,194 48,137 718,544 - 516,437 703,647 1,986,764 

 

3 2016 885,558 49,100 732,915 - 526,765 717,720 2,026,500 

 

4 2017 903,269 50,082 747,573 - 537,301 732,074 2,067,030 

 

5 2018 921,334 51,083 762,524 - 548,047 746,716 2,108,370 

 

6 2019 939,761 52,105 777,775 - 559,008 761,650 2,150,538 

 

7 2020 958,556 53,147 793,330 - 570,188 776,883 2,193,548 

 

8 2021 977,727 54,210 809,197 - 581,592 792,421 2,237,419 

 

9 2022 997,282 55,294 825,381 - 593,223 808,269 2,282,168 

 

10 2023 1,017,227 56,400 841,889 - 605,088 824,435 2,327,811 

 

11 2024 1,037,572 57,528 858,726 - 617,190 840,923 2,374,367 

 

12 2025 1,058,323 58,679 875,901 - 629,533 857,742 2,421,855 

 

13 2026 1,079,490 59,852 893,419 - 642,124 874,897 2,470,292 

 

14 2027 1,101,080 61,049 911,287 - 654,967 892,395 2,519,698 

 

15 2028 1,123,101 62,270 929,513 - 668,066 910,242 2,570,091 

 

16 2029 1,145,563 63,516 948,103 - 681,427 928,447 2,621,493 

 

17 2030 1,168,475 64,786 967,065 - 695,056 947,016 2,673,923 

 

18 2031 1,191,844 66,082 986,407 - 708,957 965,957 2,727,402 

 

19 2032 1,215,681 67,403 1,006,135 - 723,136 985,276 2,781,950 

 

20 2033 1,239,995 68,751 1,026,257 - 737,599 1,004,981 2,837,589 

 

Present Worth 576,598 10,399,475 8,606,924 - 6,186,026 8,428,486 23,798,034 9

 

(% of PW) 8.0% 0.4% 6.7% 0.0% 4.8% 6.5% 18.4% 

Wyodak Fabric Filter

Year Date TOTAL FIXED O&M COST Makeup Water Cost Reagent Cost SCR Catalyst / FF Bag Cost Waste Disposal Cost Electric Power Cost TOTAL VARIABLE O&M COST DEBT 

0 20131 2014 121,665 - - 186,992 - 812,052 999,044 

 

2 2015 124,099 - - 190,732 - 828,293 1,019,025 

 

3 2016 126,581 - - 194,546 - 844,859 1,039,405 

 

4 2017 129,112 - - 198,437 - 861,756 1,060,193 

 

5 2018 131,694 - - 202,406 - 878,991 1,081,397 

 

6 2019 134,328 - - 206,454 - 896,571 1,103,025 

 

7 2020 137,015 - - 210,583 - 914,502 1,125,086 

 

8 2021 139,755 - - 214,795 - 932,792 1,147,588 

 

9 2022 142,550 - - 219,091 - 951,448 1,170,539 

 

10 2023 145,401 - - 223,473 - 970,477 1,193,950 

 

11 2024 148,309 - - 227,942 - 989,887 1,217,829 

 

12 2025 151,275 - - 232,501 - 1,009,685 1,242,186 

 

13 2026 154,301 - - 237,151 - 1,029,878 1,267,029 

 

14 2027 157,387 - - 241,894 - 1,050,476 1,292,370 

 

15 2028 160,535 - - 246,732 - 1,071,485 1,318,217 

 

16 2029 163,745 - - 251,667 - 1,092,915 1,344,582 

 

17 2030 167,020 - - 256,700 - 1,114,773 1,371,473 

 

18 2031 170,361 - - 261,834 - 1,137,069 1,398,903 

 

19 2032 173,768 - - 267,071 - 1,159,810 1,426,881 

 

20 2033 177,243 - - 272,412 - 1,183,006 1,455,418 

 

Present Worth - 1,486,489 - 2,284,641 - 9,921,532 12,206,173 3

 

(% of PW) 3.2% 0.0% 0.0% 4.9% 0.0% 21.4% 26.3% 

EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 
EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 

First Year Cost for Air Pollution Control Options

0

2,000,0004,000,0006,000,0008,000,000

10,000,00012,000,00014,000,000

LNB w/OFA ROFA LNB w/OFA &

SNCR

LNB w/OFA &

SCR

Upgraded Dry

FGD

Dry FGD

w/Fabric Filter

Wet 

Air Pollution Control Option

First Year Cost ($)
EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 

Present Worth Cost for Air Pollution Control Options

0

20,000,00040,000,00060,000,00080,000,000

100,000,000120,000,000140,000,000160,000,000

LNB w/OFA ROFA LNB w/OFA &

SNCR

LNB w/OFA &

SCR

Upgraded Dry

FGD

Dry FGD

w/Fabric Filter

Wet 

Air Pollution Control Options

Present Worth Cost Over Year Plant Life ($)
APPENDIX B 

2006 Wyoming BART Protocol