# 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 a nd Best Available Retrofit Technology (BART)

regulations and guidelines, CH 2M 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 (NO

x 

# ), sulfur dioxide (SO 2 

# ),

and particulate matter less than 10 mi crometers in aerodynamic diameter (PM 10 

# ). The Wyodak

station consists of one unit with a tota l 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 Un ited States Environmental Protection Agency’s

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

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

compliance date of 2014 was assumed for this analysis.

In completing the BART analysis, technology a lternatives were inve stigated a nd potential

reductions in NO

x 

# , SO 2 

# , and PM 10 

# emissions rates were identified. The following technology

alternatives were investigat ed, listed below by pollutant:

• NO

x 

# emission controls:

− Low-NO

x 

# burners (LNBs) with over-fire air (OFA)

− Rotating opposed fire air (ROFA)

− LNBs with selective non-catal ytic reduction system (SNCR)

− LNBs with selective catalytic reduction (SCR) system

• SO 2 

# emission controls:

− Upgrade existing dry lime flue ga s desulfurization (FGD) system

− Upgrade existing dry FGD system and repl ace existing electrostatic precipitator

(ESP) with a new fabric filter

− New wet FGD system with ESP

• PM 10 

# emission controls:

− Sulfur trioxide (SO 3 

# ) 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 engineer ing analysis are identified in the Code of Federal

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

• The identification of available, techni cally feasible, retr ofit 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 envi ronmental 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, techni cally feasible, retr ofit control options

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

the applicability of optio ns and their impacts)

• Step 3 – Evaluate Control Effectiven ess 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 envi ronmental 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 NO

x 

# , SO 2 

# , and PM 10 

# emissions. All costs included

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

2014 BART implementation date.



# Recommendations

CH2M HILL recommends instal ling 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.



# NO

x 

# 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 NO

x 

# emissions, reasonable control

costs, and the advantages of no additi onal 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).



# SO 2 

# Emission Control

CH2M HILL recommends upgrading the existin g lime spray drying FGD system with the

existing ESP as BART for Wyodak, ba sed on the significant reduction in SO 2 

# 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.



# PM 10



# Emission Control

CH2M HILL recommends maintaining the perf ormance of the existing ESP as BART for

Wyodak, based on the PM 10 

# 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 syst em to assess the visibility impacts of

emissions from Wyodak at Class I areas. The Cl ass 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 NO

x 

# , SO 2 

# , and PM 10 

# emissions, four

post-control atmospheric dispersi on modeling scenarios were deve loped to cover the range of

effectiveness for combining the individual NO

x 

# , SO 2 

# , and PM 10 

# 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 contro l 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 reasonabl e, cost-effective c ontrols. Incremental

cost-effectiveness comparisons focus on annuali zed cost and emission reduction differences

between dominant alternatives. The dominant se t of control alternatives is determined by

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

total annualized costs for total emissions reduction s for all control altern atives identified in

the BART analysis.

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

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

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

costs between relevant scenario s for the two Class I areas; th e total annualized cost versus

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

# percentile Δ dV

reduction.

Results of the least-cost envel ope analysis validate the sele ction 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 hi gh incremental costs, on the basis

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

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

Scenario 1, the projected improvement is le ss 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 th at demonstrate only dV differe nces 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 im provements at the Class I areas studied would

be expected under any of the c ontrol scenarios. Thus, the resu lts indicate that even though

PacifiCorp will be spending many millions of do llars 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 NO

x 

# Analysis.................................................................... 3-2

3.2.2 BART SO 2 

# Analysis .................................................................. 3-10

3.2.3 BART PM 10 

# 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 NO

x 

# Emission Control ................................................................. 5-6

5.2.2 SO 2 

# Emission Control.................................................................. 5-6

5.2.3 PM 10 

# 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 NO

x 

# Control Technology Emission Rate Ranking

3-2 NO

x 

# Control Cost Comparison

3-3 SO 2 

# Control Technology Emission Rate Ranking

3-4 SO 2 

# Control Cost Comparison

3-5 PM 10 

# 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 NO

x 

# Air Pollution Control Options

3-2 First Year Control Cost for SO 2 

# 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 Badl ands Class I Area Reduction

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

# Percentile

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

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

# Percentile

Appendices

A Economic Analysis

B 2006 Wyoming BART Protocol

# Acronyms and Abbreviations

oF Degree Fahrenheit

BACT Best Availa ble Control Technology

BART Best Availabl e Retrofit Technology

CALDESK Program to Display Data and Results

CALMET Meteorological Data Pr eprocessing Program for CALPUFF

CALPOST Post-processing Program fo r Calculating Visibility Impacts

CALPUFF Gaussian Puff Dispersion Model

CFR Code of Federal Regulations

CO Carbon Monoxide

COHPAC Compact Hybrid Particulate Collector

dV Deciview

Δ dV Delta Deciview, Change in Deciview

ESP Electrostatic Precipitator

EPA United States Environmental Protection Agency

FGC Flue Gas Conditioning

FGD Flue Gas Desulfurization

H 2 

# SO 4 

# Sulfuric Acid

kW Kilowatt

kWh Kilowatt-hour

LAER Lowest Achievable Emission Rate

lb Pound

LNB Low-NO

x 

# Burner

MMBtu Million British Thermal Units

MM5 Mesoscale Meteorologi cal Model, Version 5

MW Megawatt

NH 4 

# Ammonium

(NH 4 

# )HSO 4 

# Ammonium Bisulfate

(NH 4 

# ) 2 

# SO 4 

# Ammonium Sulfate

NO

x 

# 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

PM 2.5 

# Particulate Matter less than 2.5 Micrometers in Aerodynamic Diameter

PM 10 

# Particulate Matter less than 10 Mi crometers 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

SO 2 

# Sulfur Dioxide

SO 3 

# 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 Envir onmental Quality – Air Quality Division

# 1.0 Introduction

Best Available Retrofit Technol ogy (BART) guidelines were esta blished 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 pr ovide 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 Qu ality (WDEQ) BART re gulations state that

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

December 15, 2006. PacifiCorp received an exte nsion 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 justificat ion 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 forma lly 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 i ssue of emissions for the identified facilities:

• Any existing pollution control tech nology in use at the source

• The cost of the controls

• The remaining useful life of the source

• The energy and non-air quality envi ronmental 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 (NO

x 

# ), sulfur dioxide (SO 2 

# ),

and particulate matter less than 10 mi crometers in aerodynamic diameter (PM 10 

# ) because

they are the primary criteria pollu tants that affect visibility.

Section 2 of this report provi des a description of the pres ent 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 methodol ogy 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-fire d boiler manufactured by Babcock & Wilcox.

A Babcock & Wilcox Rothemuhle weighted wire el ectrostatic 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 Emer son 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 plan t site. The coal is ranked sub-bituminous.

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

2042; however, this analysis is based on a 20-ye ar 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 da te 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: minut e: second) 44:17:16.36

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

Annual Unit Capacity Fa ctor (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 (NO

x 

# ) Controls Good Combustion Practices

Pre-project NO

x 

# Emission Rate (lb per MMBtu) (b) 

# 0.31

Current Sulfur Dioxide (SO 2 

# ) Controls Lime Based Spray Dryer

Pre-project SO 2 

# Emission Rate (lb per MMBtu) 0.50

Current Particulate Matter less than 10 micrometers (PM 10 

# )

Controls Electrostatic Precipitator

Pre-project PM 10 

# 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 requi red 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 engineer ing analysis are identified in the Code of Federal

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

• The identification of available, techni cally feasible, retr ofit 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 envi ronmental 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 Availabl e Retrofit Control Technologies

• Step 2 – Eliminate Technically Infeasible Options

− The identification of available, techni cally feasible, retr ofit control options

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

the applicability of optio ns and their impacts)

• Step 3 – Evaluate Control Effectiven ess 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 envi ronmental impacts of compliance

• Step 5 – Evaluate Visibility Impacts

− The degree of visibility improvement th at is anticipated from using BART

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

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

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

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

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

Separate cost analyses have been conducted for NO

x 

# , SO 2 

# , and PM 10 

# 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 NO

x 

# Analysis

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

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

Formation of NO

x



# During coal combustion, NO

x 

# is formed in three different ways. The dominant source of NO

x 

# formation is the oxidation of fuel-bound n itrogen (also referred to as fuel NO

x 

# ). During

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

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

partially oxidized to nitrogen oxides (nitric ox ide and nitrogen dioxide) and partially reduced

to molecular nitrogen. A smaller part of NO

x 

# formation is due to hi gh temperature fixation of

atmospheric nitrogen in the combus tion air. A very small amount of NO

x 

# is called prompt

NO

x 

# . Prompt NO

x 

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

In a conventional pulverized co al burner, air is introduced wi th turbulence to promote good

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

is used for combustion. Some of the oxygen comb ines with the fuel nitrogen to form NO

x 

# .

Coal characteristics directly and significantly impact NO

x 

# 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-bitumi nous to bituminous and on to anthracite. Lower

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

lower NO

x 

# emissions than higher rank bituminous co als, due to their higher reactivity and

lower nitrogen content. The fi xed carbon to volatile matter ra tio (fuel ratio), coal oxygen

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

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

rank bituminous coals. When used with low-NO

x 

# burners (LNBs), sub-bituminous coals

create a longer time for the kinetics to pr omote more stable mol ecular nitrogen, and hence

result in lower NO

x 

# emissions.

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

and low NO

x 

# production characteristics described pr eviously. Based on data from the Energy

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

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

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-2

# BART ANALYSIS FOR WYODAK



# Administration, 2006). Most references to west ern coal and sub-bituminous coal infer PRB

origin and characteristics. Emissions standards differentia ting between bituminous and

sub-bituminous coals are presumed to use P RB 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 NO

x 

# limit for

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

thermal units (MMBtu). The current NO

x 

# emission rate at Wyodak is 0.31 lb per MMBtu.

The BART analysis for NO

x 

# emissions from Wyodak is described in this section.

Step 1: Identify All Availabl e Retrofit Control Technologies

The first step of the BART process is to evaluate NO

x 

# control technologies with practical

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

Available Control Technology (BACT) or lo west 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 potentia lly applicable emission control technologies.

Wyodak NO

x 

# emissions are currently controlled through the use of good combustion

practices.

The following potential NO

x 

# control technology options were considered:

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

• Mobotec rotating opposed fire air (ROFA)

• Conventional selectiv e 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, techni cal feasibility will

primarily be determined by physical constrai nts and boiler configur ation. Wyodak’s current

NO

x 

# emission rate is 0.31 lb per MMBtu.

For this BART analysis, information pertaini ng 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 addi tional emissions data and costs developed

by boiler vendors for LNBs and OFA. Also, CH 2M HILL solicited a proposal from Mobotec

for their ROFA technology.

With SNCR, an amine-based reagent such as a mmonia, 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 NO

x 

# 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 reducti on is typically applied on sma ller 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 NO

x 

# emission rates.

JMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC 3-3

# BART ANALYSIS FOR WYODAK



# TABLE 3-1



# NO

x 

# 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-NO

x

# 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 Effectiven ess of Remaining Control Technologies

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

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

proposals include inherent uncer tainties. These proposals are us ually 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 de tailed 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 NO

x 

# with LNBs is to stage the

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

combustion is not diverted to combine with nitrogen and form NO

x 

# . Fuel-rich conditions

favor the conversion of fuel nitrogen to N 2 

# instead of NO

x 

# . Additional air (or OFA) is then

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

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

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

expected NO

x 

# emission rate of 0.23 lb per MMBtu. Paci fiCorp has indicated that this rate

corresponds to a vendor guarantee plus an a dded operating margin, no t 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 NO

x 

# emission rate of 0.31 lb

per MMBtu and meets the presumptive NO

x 

# 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 asym metrically 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 combus tion process. In addition, the swirling action

reduces the maximum temperature of the fl ames and increases heat absorption. The

combustion air is also mixed more effectivel y.” 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 NO

x 

# emission rate of 0.18 lb per MMBtu using ROFA

technology. An operating margin of 0.02 lb per MMB tu 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 eq uipment, the operation of existing LNB and

OFA ports will be analyzed. While a typical in stallation 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 quantit y and location of new ROFA ports. The

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

provide installation services be cause 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 consider ed in the post-contro l modeling scenarios.

SNCR. Selective non-catalytic redu ction is generally utilized to achieve modest NO

x 

# reductions on smaller units. With SNCR, an am ine-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 NO

x 

# to nitrogen and water. NO

x 

# 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 NO

x 

# , 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 a mmonia to create problems

downstream. The ammonia may render fly ash unsa leable, react with su lfur 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 NO

x 

# reduction generally resulting in

lower reagent utilization and higher operating cost.

Reductions from higher baseline concentrations (inlet NO

x 

# ) are lower in cost per ton, but

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

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

capable of achieving a projected NO

x 

# emission rate of 0.23 lb per MMBtu

. At a further

reduction of 20 percent in NO

x 

# emission rates for SNCR would re sult 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 difficultie s 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 NO

x 

# to nitrogen and

water. Unlike the high temperatures require d 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 configurat ion 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 NO

x 

# emission levels as much as possible through

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

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

modifications, including LN Bs and OFA, providing a NO

x 

# 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 NO

x 

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

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

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

level of NO

x 

# emissions needed to achieve compliance c onsistently with an established goal, a

review of typical NO

x 

# emissions from coal-fired generati ng units was completed. As a result

of this review, it was noted that NO

x 

# emissions can vary signif icantly 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 NO

x 

# emissions value from vendor.

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

• Review and evaluate unit physical and opera tional characteristics and restrictions. The

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

variant the NO

x 

# emissions are.

• For each technology expected value, there is a corresponding potential for actual NO

x 

# emissions to vary from this expected va lue. 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 cons ideration 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 si gnificantly. Therefore, these technologies will

not have energy impacts.

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

ROFA fan.

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

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

gauge increase. Total additional power requir ements 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 resu lt 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 S CR systems could impact the sale ability and disposal of fly

ash due to ammonia levels, and could potential ly 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 tran sportation 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, de veloped using S&L’s internal proprietary

database, and supplemented (as needed) by ve ndor-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 obt ained 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 NO

x 

# removed is summarized in Table 3-2, and the first-year contro l costs are shown in

Figure 3-1. The complete economic anal ysis 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



# NO

x 

# Control Cost Comparison

Wyodak

Factor Low-NO

x 

# 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 millio n $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 millio n $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 (NO

x 

# ) Design Control

Efficiency 25.8% 35.5% 41.9% 77.4%

Tons NO

x

# Removed per Year 1,482 2,038 2,409 4,447

First-year Average Control Cost

($/Ton of NO

x

# Removed) 637 1,766 1,147 2,892

Incremental Control Cost

($/Ton of NO

x

# Removed) 637 4,775 1,962 3,844



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

Wyodak based on its signif icant reduction in NO

x 

# emissions, reasonable control cost, and no

additional power requirements or environmenta l 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.BART ANALYSIS FOR WYODAKFIGURE 3-1First Year Control Cost for NOxAir Pollution Control OptionsWyodak01,0002,0003,0004,0005,0006,000LNB w/OFAROFALNB w/OFA & SNCRLNB w/OFA & SCRAir Pollution Control Option

Control Cost ($/Ton NOx Removed)First Year Average Control CostFirst Year Incremental Control CostJMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC3-9

# BART ANALYSIS FOR WYODAK



# 3.2.2 BART SO 2 

# Analysis

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

on coal sulfur content. The BART analysis for SO 2 

# emissions on Wyodak is described below.

Step 1: Identify All Availabl e Retrofit Control Technologies

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

applicable emission control technologies for SO 2 

# at Wyodak; this included control

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

The following potential SO 2 

# control technology options were considered:

• 

# Upgrade existing dry lime FGD system

• 

# Upgrade existing dry FGD system and repla ce existing ESP with a new fabric filter

• 

# New wet FGD system with ESP

Step 2: Eliminate Technically Infeasible Options

Wyodak currently ha s an uncontrolled SO 2 

# 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 atom izer wheel. The rapid speed of the atomizer

wheel causes the lime slurry to separate into ve ry fine droplets that in termix with the flue

gas. The SO 2 

# 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 SO 2 

# removal to

achieve an SO 2 

# outlet emission rate of 0.50 lb pe r MMBtu. To achieve 80 percent SO 2 

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

eliminate bypass flue gas flow, pe rform modeling to redistribute th e flue gas flow to the ESP,

adding static mixers to mix the gas prior to the ESP, increase th e 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 SO 2 

# removal) based on an average coal su lfur 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 SO 2 

# removal is projected,

allowing the facility to achiev e an emissions limit of 0.16 lb SO 2 

# per MMBtu.

Wet Lime/Limestone FGD. Wet SO 2 

# scrubbers operate by flowi ng the flue gas upward through

a large reactor vessel that has an alkaline r eagent (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 SO 2 

# in the flue gas to form calcium sulfite and/or calcium sulfate,

which are removed from the sc rubber 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 offe red by various process developers. These

variations include using a jet bubb ling reactor as a combination SO 2 

# absorber and calcium

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

Wet lime/limestone scrubbing is project ed to achieve 90 to 95 percent SO 2 

# removal. At

Wyodak, this removal efficiency is projected to meet the presumptive limit of 0.15 lb of SO 2 

# per MMBtu used here only as a point of reference.

Step 3: Evaluate Control Effectiven ess of Remaining Control Technologies

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

for Wyodak.

TABLE 3-3



# SO 2 

# Control Technology Emission Rate Ranking

Wyodak

Control Technology Short-Term Expected SO 2 

# 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 cons ideration 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 existi ng ESP would require an additional 0.1 MW of

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

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

kilowatt-hour (kWh) for upgraded dr y 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 (SO 3 

# ) in the flue gas, which condenses to liquid

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

spray dryer system. Wet scrubbers capt ure less than 40 to 60 percent of SO 3 

# and may

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

coal is burned in a unit, in or der to remove the balance of SO 3 

# . 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 syst em 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 wastewat er blow down stream that must be treated to limit

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

plant must be installed to treat the liqui d 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 need s to be handled properly to

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

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

plant that needs to be disposed.

• Makeup Water Requirements. Lime Spray Drying FGD ha s 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 SO 2 

# 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



# SO 2 

# 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 (SO 2 

# ) Design Control

Efficiency 36.0% 68.0% 84.0%

Tons SO 2 

# Removed per Year 3,335 6,299 7,782

First-year Average Control Cost (dollars

per ton [$/Ton] of SO 2 

# Removed) 1,167 1,242 1,523

Incremental Control Cost

($/Ton of SO 2 

# 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, ba sed on the significant reduction in SO 2 

# 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.BART ANALYSIS FOR WYODAKFIGURE 3-2First Year Control Cost for SO2Air Pollution Control OptionsWyodak05001,0001,5002,0002,5003,000Upgraded Dry FGDDry FGD w/Fabric FilterWet FGDAir Pollution Control Option

Control Cost ($/Ton SO2 Removed)First Year Average Control CostFirst Year Incremental Control CostJMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC3-14

# BART ANALYSIS FOR WYODAK



# 3.2.3 BART PM 10



# Analysis

Wyodak is currently equipped with an ESP. Elect rostatic 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 pl ates. A layer of collected particulate matter

forms on the collecting plates and is rem oved 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 Wy odak controls PM emissions to 0.030 lb per

MMBtu.

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

analysis to be completed in Section 4, PM 10 

# will be used as an indicator for PM, and PM 10 

# includes particulate matter less than 2.5 micrometers in aerodynamic diameter (PM 2.5 

# ) as a

subset.

Step 1: Identify All Availabl e Retrofit Control Technologies

Two retrofit control t echnologies 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 re sistivity, 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 SO 3 

# , 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 conserva tive design. It has a la rge specific collecting

area and large residence time in the collection ar ea 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 ne xt 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 colle ct particulate matter. The partic ulate-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 th e filter bags. The collected particulate matter

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

excessive caking will increase the pressure drop ac ross 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 requi red. Unlike precipitators , fabric filter design

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

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

technology is licensed by the Electric Power Res earch Institute, and refe rred to as a Compact

Hybrid Particulate Collector (COHPAC). The C OHPAC 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 fi lter 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 contro l 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 fu ll-size fabric filter

downstream of the ESP was not cons idered further in the analysis.

Step 3: Evaluate Control Effectiven ess of Remaining Control Technologies

The existing ESP at Wyodak is achieving a co ntrolled 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 cons ideration 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 a ssociated 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 approx imately 2.1 MW of power,

equating to an annual power usage of appr oximately 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 an alysis 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



# PM 10



# 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 Wyoda k, based on the significant reduction in PM 10 

# emissions, reasonable control costs, and th e 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 syst em to assess the visibility impacts of

emissions from Wyodak at nearby Class I areas. The Class I areas pote ntially 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 algor ithms for chemical transformation and

deposition, and a post-processor ca pable of calculating co ncentrations, visib ility 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 genera te 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 facili ty and allow for a 50-km buffer around the

Class I areas that were within 300 km of th e 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 E nvironmental Quality – Air Quality Division

(WDEQ-AQD), CH2M HILL followed the me thodology 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 orig in and the longitude of the

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

were drawn to represent one-six th 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 4-1Badlands NPWind Cave NPIdahoUtahWyomingMontanaKansasColoradoNebraskaIowaNevadaSouth DakotaMinnesotaNorth DakotaMissouriOregonWashingtonWisconsinLEGEND300 KilometersClass I AreasCALMET DomainStandard Parallels0 100 200 300KilometersFigure 4-1Wyodak Source-SpecificClass I Areas to be AddressedStandard Parallel 1: 40 12' 2.30"Standard Parallel 2: 45 14' 28.09"Domain Dimensions 1060 x 780 KM114° 5' 20.40" Longitude39° 3' 53.37" Latitude100° 56' 34.08" Longitude45° 51' 57.22" Latitude101° 54' 25.88" Longitude38° 54' 0.04" Latitude114° 28' 37.96" Longitude46° 6' 26.20" LatitudeWyodakSLC \\SLCDB\GIS\PROJECTS\HUNTER\MAPFILES\WYODAK_CLASSI.MXD 11/9/2006 MSLAYDEN

# BART ANALYSIS FOR WYODAK



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

CALMET.inp file were used for CALMET. Ver tical 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 se t to values established by WDEQ-AQD, which

appear in Table 3 of Appendix B. Table 4-1 lists the key user-sp ecified 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 pr oduce 3 years of analysis: 2001, 2002, and 2003.

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

(MM5) meteorological data fi elds 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 th ey 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 refine d 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 Na tional 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 avai lable 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 pr imarily 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 fo r 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 CALM ET 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 NPWind Cave NPRAP (UA)P60WRLTORSHRRKSRIW (UA)RWLLARLNDGEYGCCEVWDGWCYSCPRBYGBPIVELSLC (UA)PUCOGDLGUDLNRXEPIHIDALLJBYIRILEEOLICLXVGJTDEN (UA)APACAGITRASEAKOIENPHPD07CUT2WXSNYBFFCDRAIALVMDLNBTMBZNBILIdahoUtahWyomingMontanaKansasColoradoNebraskaIowaNevadaSouth DakotaMinnesotaNorth DakotaMissouriOregonWashingtonWisconsinLEGENDClass I AreasCALMET DomainASOS Surface StationsUpper Air Station0 100 200 300KilometersFigure 4-2Surface and Upper Air Stations Used in theWyodak BART AnalysisStandard Parallel 1: 40 12' 2.30"Standard Parallel 2: 45 14' 28.09"Domain Dimensions 1060 x 780 KM114° 5' 20.40" Longitude39° 3' 53.37" Latitude100° 56' 34.08" Longitude45° 51' 57.22" Latitude101° 54' 25.88" Longitude38° 54' 0.04" Latitude114° 28' 37.96" Longitude46° 6' 26.20" LatitudeWyodakSLC \\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 Da ta and Results (CALDESK) data display and

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

meteorological parameters to evaluate th e CALMET wind fields. The CALDESK displays

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

maps (National Oceanic and At mospheric 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 wa s used to predict

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

impacts for post-control scenarios for Wyodak.



# 4.3.1 Background Ozone and Ammonia

Hourly values of background ozone concen trations were used by CALPUFF for the

calculation of SO 2 

# and NO

x 

# 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 a mmonia 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 mode ling 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 alterna tives that are being evaluated.

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

emission rate. Measured veloci ties 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 reflec t 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 emissi on 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:

• SO 2



# • NO

x



# • Coarse particulate (PM 2.5 

# <diameter<PM 10 

# )

• Fine particulate (diameter<PM 2.5 

# )

• Sulfates

Post-control emission rates reflect the effect s 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 develo ped to cover the range of effectiveness for

the combination of the individual NO

x 

# , SO 2 

# , and PM control technol ogies 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 indicat ed 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, upgrad ing 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 em ission rates used for the Wyodak analysis for

baseline and post-control modeling.TABLE 4-2BART Model Input DataWyodakBaselinePost-control Scenario 1 Post-control Scenario2 Post-control Scenario 3 Post-control Scenario 4Model Input DataCurrent Operations with DryFlue Gas Desulfurization (FGD)and Electrostatic Precipitator(ESP)Low-NOxBurners (LNB) withOFA, Dry FGD, ESPLNB with OFA, Dry FGD,Fabric FilterLNB with OFA and SCR,Dry FGD, Fabric FilterLNB with OFA and SCR, WetFGD, ESPSulfur Dioxide (SO2) StackEmissions(pounds per hour [lb/hr])2,350 1,518 759 759 380Nitrogen Oxide (NOx) Stack Emissions (lb/hr) 1,4571,0811,081329329PM10Stack Emissions (lb/hr)141 141 70.5 70.5 141Coarse Particulate (PM2.5<diameter< PM10) Stack Emissions (lb/hr)(a)60.6 60.6 40.2 40.2 60.6Fine Particulate (diameter<PM2.5) Stack Emissions (lb/hr)(b)80.4 80.4 30.3 30.3 80.4Sulfuric Acid (H2SO4) Stack Emissions (lb/hr) 5.645.645.649.40105H2SO4as Sulfate (SO4) Stack Emissions (lb/hr) 5.52 5.52 5.52 9.21 103Ammonium Sulfate [(NH4)2SO4] Stack Emissions (lb/hr)1.085.45(NH4)2SO4as SO4Stack Emissions (lb/hr)0.79 3.96(NH4)HSO4Stack Emissions (lb/hr)1.93 9.54(NH4)HSO4as SO4Stack Emissions (lb/hr)1.617.96Total Sulfate (SO4) (lb/hr)5.52 5.52 5.52 11.6 115Stack ConditionsStack Height (meters)122 122 122 122 122Stack Exit Diameter (meters)6.10 6.10 6.10 6.10 6.10Stack Exit Temperature (Kelvin)358 353 350 350 322Stack Exit Velocity (meters per second)23.5 23.5 23.5 23.5 23.5NOTES:(a)Based on AP-42, Table 1.1-6, the coarse particulates are countedas 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) = H2SO4as Sulfate (SO4) Stack Emissions (lb/hr) + (NH4)2SO4as SO4Stack Emissions (lb/hr) + (NH4)HSO4as SO4Stack Emissions (lb/hr)

# BART ANALYSIS FOR WYODAK



# 4.3.5 Modeling Process

The CALPUFF modeling for the control tec hnology options for W yodak 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 ar ea 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 rece ptors, meteorological stations, and source

locations.



# 4.4 CALPOST

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

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

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

( Δ dV) change relative to natura l background. The following default extinction coefficients

for each pollutant were used:

• Ammonium sulfate 3.0

• Ammonium nitrate 3.0

• PM coarse (PM 10 

# ) 0.6

• PM fine (PM 2.5 

# ) 1.0

• Organic carbon 4.0

• Elemental carbon 10.0

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

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

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

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

values were used for the partic ular Class I area being modeled.

The natural background conditions as a reference for determining the Δ dV change

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

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

individual species concentration data for th e 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 fo r each Class I area such that, when multiplied

by the Guidance table annual concen trations, 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 component s to use in the BART analysis. Table 4-3

lists the annual average species conc entrations 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 resu lts 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 baselin e and four post-control scenarios. The

post-control scenarios included emission rates for SO 2 

# , NO

x 

# , and PM 10 

# that would be

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

Baseline (and post-control) 98 th 

# percentile results we re greater than 0.5 Δ dV for the Badlands

and Wind Cave NPs. The 98 th 

# percentile results for each Class I area are presented in

Table 4-4.BART ANALYSIS FOR WYODAKTABLE 4-4Costs and Visibility Modeling Results for Baseline vs. Post-control Scenarios at Class I AreasWyodakModelingResultsScenarioTotal FirstYearAnnualizedCostClass I AreaHighestΔdV-98thPercentileΔdV-Number of DaysAbove 0.5 dVCost per dVReductionCost per Reductionin No. of DaysAbove 0.5 dVIncrementalCost per dVReductionIncremental Cost perReduction in No. ofDays Above 0.5 dV2001Badlands1.7750.84127----Baseline: Current Operation with Dry Flue GasDesulfurization (FGD), Electrostatic Precipitator (ESP)Wind Cave1.7231.15341----$4,836,638Badlands1.3020.59512$19,661,130$322,443Scenario 1: Low-NOxBurners (LNBs) with Over-fire Air(OFA), Dry FGD, ESP$4,836,638Wind Cave1.2130.81719$14,394,756$219,847$8,768,522Badlands1.0880.4726$23,762,932$417,549$31,966,537$655,314Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter$8,768,522Wind Cave0.9580.67111$18,191,954$292,284$26,930,712$491,486$20,682,244Badlands0.5210.2541$35,233,806$795,471$54,650,101$2,382,744Scenario 3: LNBs with OFA and SCR, Wet FGD, FabricFilter$20,682,244Wind Cave0.5310.3332$25,222,249$530,314$35,247,698$1,323,747$24,707,516Badlands0.6410.2941$45,169,133$950,289NANAScenario 4: LNBs with OFA and SCR, Wet FGD, ESP$24,707,516Wind Cave0.5860.3962$32,638,727$633,526NANA2002Badlands1.8591.14034----Baseline: Current Operation with Dry FGD, ESPWind Cave2.5911.32338----$4,836,638Badlands1.3880.82918$15,551,891$302,290Scenario 1: LNBs with OFA, Dry FGD, ESP$4,836,638Wind Cave1.9500.94026$12,628,298$403,053$8,768,522Badlands1.2160.62414$16,993,260$438,426$19,179,922$982,971Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter$8,768,522Wind Cave1.7120.78817$16,389,761$417,549$25,867,658$436,876$20,682,244Badlands0.5460.3312$25,565,197$646,320$40,661,167$992,810Scenario 3: LNBs with OFA and SCR, Wet FGD, FabricFilter$20,682,244Wind Cave0.7770.3835$22,002,387$626,735$29,416,598$992,810$24,707,516Badlands0.8010.4053$33,615,668$797,017NANAScenario 4: LNBs with OFA and SCR, Wet FGD, ESP$24,707,516Wind Cave1.0850.5199$30,730,741$851,983NANAJMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC4-11BART ANALYSIS FOR WYODAKJMS EY102007001SLC\BART_WYODAK_OCT2007_FINAL.DOC4-12TABLE 4-4Costs and Visibility Modeling Results for Baseline vs. Post-control Scenarios at Class I AreasWyodakModelingResultsScenarioTotal FirstYearAnnualizedCost Class I Area HighestΔdV- 98thPercentileΔdV-Number of DaysAbove 0.5 dVCost per dVReductionCost per Reductionin No. of DaysAbove 0.5 dVIncrementalCost per dVReductionIncremental Cost perReduction in No. ofDays Above 0.5 dV2003Badlands2.5561.07031----Baseline: Current Operation with Dry FGD, ESPWind Cave3.2961.53037----$4,836,638Badlands1.8190.73920$14,612,199$439,694Scenario 1: LNBs with OFA, Dry FGD, ESP$4,836,638Wind Cave2.3701.11428$11,626,534$537,404$8,768,522Badlands1.3190.58313$18,005,179$487,140$25,204,385$561,698Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter$8,768,522Wind Cave1.7970.92917$14,589,887$438,426$21,253,427$357,444$20,682,244Badlands0.8110.3142$27,357,466$713,181$44,288,929$1,083,066Scenario 3: LNBs with OFA and SCR, Wet FGD, FabricFilter$20,682,244Wind Cave1.0650.4576$19,275,158$667,169$25,240,936$1,083,066$24,707,516Badlands0.7170.3403$33,845,912$882,411NANAScenario 4: LNBs with OFA and SCR, Wet FGD, ESP$24,707,516Wind Cave1.0280.68410$29,205,102$915,093NANA3-Year AveragesBadlands1.01730.7Baseline: Current Operation with ESPWind Cave1.33538.7$4,836,638Badlands0.72116.7$16,339,993$345,474Scenario 1: LNBs with OFA, dry FGD, existing ESP$4,836,638Wind Cave0.95724.3$12,784,065$337,440$8,768,522Badlands0.56011.0$19,173,153$445,857$24,371,182$693,862Scenario 2: LNBs with OFA, Dry FGD, Fabric Filter$8,768,522Wind Cave0.79615.0$16,258,075$370,501$24,421,640$421,273$20,682,244Badlands0.3001.7$28,832,125$713,181$45,822,008$1,276,470Scenario 3: LNBs with OFA and SCR, Dry FGD, FabricFilter$20,682,244Wind Cave0.3914.3$21,901,423$602,395$29,416,598$1,116,911$24,707,516Badlands0.3462.3$36,840,233$872,030NANAScenario 4: LNBs with OFA and SCR, Wet FGD, ExistingESP, New Stack$24,707,516Wind Cave0.5337.0$30,794,577$780,237NANANOTES:Scenario 3 produces better results in visibility than Scenario 4. Therefore, Scenario4 was not further analyzed.Sample Calculations: Cost per dV Reduction for Scenario 1 for 2001: = $4,836,638 / (0.841 - 0.595) = $19,661,131Sample 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 NO

x 

# , SO 2 

# , and PM are as follows:

• 

# New LNBs and modifications to the OFA system for NO

x 

# control

• 

# Upgrade lime spray dryer FGD for SO 2 

# 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 improveme nts 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 Se ction 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 th rough 5-4. The total annualized cost versus

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

# percentile Δ dV

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 focu s 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 annua lized costs for a total emissions reductions for all control

alternatives identified in the BACT analysis...”

An analysis of incremental cost effectiv eness has been conducted. This analysis was

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

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

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

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

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

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

and cost per reduction in number of days a bove 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 98 th



# 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-NO

x

# 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 98 th



# 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-NO

x

# 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 98 th



# 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 98 th



# 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 Ta bles 5-1 to 5-4 and Figur es 5-1 to 5-4, confirm

the selection of Scenario 1, based on incremen tal 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 calc ulating incremental cost s, 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, repr esent the least-cost

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

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

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

effectiveness. Scenario 2 represents infe rior controls becaus e Scenario 1 provides

approximately same amount of visibility im pact 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 co sts between two contiguo us 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 illustrate s the conclusions stated above. The greatest reduction in

98 th 

# 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 e ffectiveness 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 NO

x 

# Emission Control

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

projected significant reduction in NO

x 

# emissions, reasonable control costs, and the

advantages of no additional power requirement s 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 NO

x 

# per MMBtu.



# 5.2.2 SO 2 

# Emission Control

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

existing ESP as BART for Wyodak, ba sed on the significant reduction in SO 2 

# 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 PM 10



# Emission Control

CH2M HILL recommends maintaining the exis ting ESP downstream of the lime spray dryer

as BART for Wyodak, based on the significant reduction in PM 10 

# emissions, reasonable

control costs, and the advantages of no a dditional 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 onl y dV differences of approximately 1.5 to

2.0 dV or more are perceivable by the human ey e. 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 minima l 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 im pact on visibility in these Class I areas. If

natural obscuration were to reduce the visibil ity impacts modeled for the Wyodak facility, it

would increase the costs per dV reducti on that are presente d in this report.

# 6.0 References

40 CFR Part 51. Regional Haze Regulations and Guide lines 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 Visibil ity Conditions Under the Regional Haze

Rule . Environmental Protection Agency. EPA-454/8-03-005. September 2003.

Henry, Ronald, 2002. “Just-Noticeable Di fferences in Atmospheric Haze,” Journal of the Air

& Waste Management Association. Volume 52, p. 1238.

National Oceanic and Atmospheric Administra tion, 2006. U.S. Daily Weather Maps Project.

http://docs.lib.noaa.gov/rescue/dwm/d ata_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—Individu al 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 AnalysisPacifiCorp BART Analysis Scenarios10Index No. Name of Unit1 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 310 WyodakScenario First Year Cost ScenarioFirst YearCost Scenario First Year Cost Scenario First Year Cost Scenario First Year CostN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AN/A N/A N/A N/A N/AScenario First Year Cost Scenario First Year Scenario First Year Cost Scenario First Year Cost Scenario First Year Cost$ 4,836,638N/A N/A N/A N/A$ 4,836,638N/A N/A N/A N/AN/A N/A N/A N/A$ 8,768,522$ 8,768,522N/A N/A N/A N/AN/A N/A N/A N/A$ 20,682,244N/A N/A N/A N/A $ 20,682,244N/A N/A N/A N/A $ 24,707,516N/A N/A N/A N/A $ 24,707,516N/A N/A N/A N/AN/A N/A N/A N/AN/A N/A N/A N/AN/A N/A N/A N/AScenario 3 - LNB with OFA andSCR, Dry FGD, New Fabric FilterScenario 1 - LNB with OFA, DryFGD, Fabric FilterBaseline - Current Operation withESPScenario 1 - LNB with OFA, DryFGD, Existing ESPScenario 2 - LNB with OFA, DryFGD, New Fabric FilterJim BridgerSelect Unit:Scenario 2 - LNB with OFA, WetFGD, New Fabric FilterScenario 3 - LNB with OFA andSCR, Dry FGD, New Fabric FilterScenario 4 - LNB with OFA andSCR, Wet FGD, Fabric FilterDJ Unit 4Scenario 4 - LNB with OFA andSCR, Wet FGD, Existing ESP,New StackDave JohnstonDJ Unit 3Baseline - Current Operation withVenturi ScrubberJB Unit 1 JB Unit 2 JB Unit 3 JB Unit 4Baseline - Current Operation withWet FGD and ESPBaseline - Current Operation withWet FGD and ESPBaseline - Current Operation withWet FGD and ESPBaseline - Current Operation withWet FGD and ESPScenario 2 - LNB with OFA, WetFGD, New Fabric FilterScenario 2 - LNB with OFA, WetFGD, New Fabric FilterScenario 2 - LNB with OFA, WetFGD, Fabric FilterScenario 1 - LNB with OFA, WetFGD, ESPScenario 1 - LNB with OFA, WetFGD, ESPScenario 1 - LNB with OFA, WetFGD, ESPScenario 1 - LNB with OFA, WetFGD, ESPNaughtonScenario 4 - LNB with OFA andSCR, Wet FGD, Fabric FilterScenario 4 - LNB with OFA andSCR, Wet FGD, Fabric FilterScenario 4 - LNB with OFA andSCR, Wet FGD, Fabric FilterScenario 4 - LNB with OFA andSCR, Wet FGD, Fabric FilterScenario 3 - LNB with OFA andSCR, Wet FGD, ESPScenario 3 - LNB with OFA andSCR, Wet FGD, ESPScenario 3 - LNB with OFA andSCR, Wet FGD, ESPScenario 3 - LNB with OFA andSCR, Wet FGD, ESPScenario 2 - LNB with OFA, WetFGD, New Fabric FilterBaseline - Current Operation withESPBaseline - Current Operation withESPBaseline - Current Operation with WetFGD and ESPNTN Unit 1 NTN Unit 2 NTN Unit 3Scenario 2 - LNB with OFA, DryFGD, New Fabric FilterScenario 2 - LNB with OFA, DryFGD, New Fabric FilterScenario 2 - LNB with OFA, Wet FGD,New Fabric FilterScenario 1 - LNB with OFA, DryFGD, ESPScenario 1 - LNB with OFA, DryFGD, ESPScenario 1 - LNB with OFA, Wet FGD,ESPScenario 4 - LNB with OFA and SCR, WetFGD, Fabric FilterScenario 3 - LNB with OFA andSCR, Dry FGD, New Fabric FilterScenario 3 - LNB with OFA andSCR, Dry FGD, New Fabric FilterScenario 3 - LNB with OFA and SCR, WetFGD, ESPScenario 4 - LNB with OFA and SCR, WetFGD, ESPWyodakScenario 3 - LNB with OFA and SCR, DryFGD, Fabric FilterScenario 2 - LNB with OFA, Dry FGD,Fabric FilterScenario 1 - LNB with OFA, Dry FGD,ESPBaseline - Current Operation with DryFGD, ESPWyodakWyodakScenario 4 - LNB with OFA andSCR, Wet FGD, ESP, New StackScenario 4 - LNB with OFA andSCR, Wet FGD, ESP, New StackEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls1 of 1ECONOMIC ANALYSIS SUMMARYWyodakBoiler Design: Opposed Wall-Fired PCLNB w/OFA ROFALNB w/OFA& SNCRLNB w/OFA& SCRUpgraded DryFGDDry FGDw/Fabric FilterWet FGD Fabric FilterCase1 2 3 4 5 6 7 8 10NOx Emission Control SystemLNB LNB w/OFA ROFALNB w/OFA &SNCRLNB w/OFA &SCR LNB LNB LNB LNBSO2 Emission Control SystemDry FGD Dry FGD Dry FGD Dry FGD Dry FGD Upgraded Dry FGD Dry FGD w/Fabric Filter Wet FGD Dry FGDPM Emission Control SystemESP ESP ESP ESP ESP ESP ESP ESP Fabric FilterTOTAL INSTALLED CAPITAL COST ($)0 9,300,000 15,252,149 19,495,654 108,280,222 26,759,011 66,777,531 95,136,483 32,630,832FIRST YEAR O&M COST ($)Operating Labor ($) 0 0 0 0 0 0 0 303,677 0Maintenance Material ($) 0 24,000 36,000 93,000 181,000 21,900 30,660 328,496 48,666Maintenance Labor ($) 0 36,000 54,000 139,500 271,500 14,600 20,440 218,998 72,999Administrative Labor ($) 0 0 0 0 0 0 0 0 0TOTAL FIXED O&M COST 0 60,000 90,000 232,500 452,500 36,500 51,099 851,170 121,665Makeup Water Cost 0 0 0 0 0 14,388 17,266 47,193 0Reagent Cost 0 0 0 542,814 673,062 904,412 904,412 704,455 0SCR Catalyst / FF Bag Cost 0 0 0 0 480,000 0 0 0 186,992Waste Disposal Cost 0 0 0 0 0 346,184 439,525 506,310 0Electric Power Cost 0 0 2,057,685 132,057 952,387 44,939 59,130 689,850 812,052TOTAL VARIABLE O&M COST0 0 2,057,685 674,871 2,105,449 1,309,923 1,420,333 1,947,808 999,044TOTAL FIRST YEAR O&M COST 0 60,000 2,147,685 907,371 2,557,949 1,346,423 1,471,432 2,798,979 1,120,709FIRST YEAR DEBT SERVICE ($)0 884,689 1,450,904 1,854,579 10,300,462 2,545,526 6,352,401 9,050,127 3,104,100TOTAL FIRST YEAR COST ($)0 944,689 3,598,588 2,761,950 12,858,411 3,891,949 7,823,833 11,849,105 4,224,809Power Consumption (MW) 0.0 0.0 5.2 0.3 2.4 0.1 0.2 1.8 2.1Annual Power Usage (Million kW-Hr/Yr) 0.0 0.0 41.2 2.6 19.0 0.9 1.2 13.8 16.2CONTROL COST ($/Ton Removed)NOx Removal Rate (%)0.0% 25.8% 35.5% 41.9% 77.4% 0.0% 0.0% 0.0% 0.0%NOx Removed (Tons/Yr) 0 1,482 2,038 2,409 4,447 0 0 0 0First Year Average Control Cost ($/Ton NOx Rem.)0 637 1,766 1,147 2,892 0 0 0 0Incremental Control Cost ($/Ton NOx Removed) 0 637 4,775 1,962 3,844 0 0 0 02-1 3-2 4-2 5-3SO2 Removal Rate (%)69.0% 0.0% 0.0% 0.0% 0.0% 36.0% 68.0% 84.0% 0.0%SO2 Removed (Tons/Yr) 0 0 0 0 0 3,335 6,299 7,782 0First Year Average Control Cost ($/Ton SO2 Rem.) 0 0 0 0 0 1,167 1,242 1,523 0Incremental Control Cost ($/Ton SO2 Removed) Base 0 0 0 0 1,167 1,326 2,716 06-1 7-6 8-7PM Removal Rate (%) 99.60% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 50.00%PM Removed (Tons/Yr) 0 0 0 0 0 0 0 0 278First Year Average Control Cost ($/Ton PM Rem.) 0 0 0 0 0 0 0 0 15,202Incremental Control Cost ($/Ton PM Removed) Base 0 0 0 0 0 0 0 15,20210-1PRESENT WORTH COST ($)0 10,033,071 41,492,244 30,581,776 139,532,865 43,209,408 84,755,271 129,333,992 46,323,493PM ControlNOx ControlParameterCurrentOperationSO2 ControlEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls1 of 1INPUT CALCULATIONSWyodakBoiler Design:Opposed Wall-Fired PCLNB w/OFA ROFALNB w/OFA& SNCRLNB w/OFA& SCRUpgraded DryFGDDry FGD w/FabricFilterWet FGD Fabric FilterCase1 2 3 4 5 6 7 8 10NOx Emission Control SystemLNB LNB w/OFA ROFALNB w/OFA &SNCR LNB w/OFA & SCRLNB LNB LNB LNBSO2 Emission Control SystemDry FGDDry FGD Dry FGD Dry FGD Dry FGDUpgraded Dry FGD Dry FGD w/Fabric Filter Wet FGDDry FGDPM Emission Control SystemESPESP ESP ESP ESP ESP ESP ESPFabric FilterUnit Design and Coal CharacteristicsType of UnitPC PC PC PC PC PC PC PC PCNet Power Output (kW)365,000 365,000365,000 365,000 365,000 365,000 365,000 365,000 365,000Net Plant Heat Rate (Btu/kW-Hr)12,87712,877 12,877 12,877 12,877 12,877 12,877 12,877 12,877Boiler FuelClovis PointMineClovis PointMineClovis PointMineClovis PointMineClovis PointMine Clovis Point MineClovis Point MineClovis Point MineClovis Point MineCoal Heating Value (Btu/Lb)8,0508,050 8,050 8,050 8,050 8,050 8,050 8,050 8,050Coal Sulfur Content (wt.%)0.65%0.65%0.65%0.65%0.65%0.65%0.65%0.650%0.65%Coal Ash Content (wt.%)7.46%7.46%7.46%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 4,700 4,700 4,700Coal Flow Rate (Lb/Hr)583,864 583,864 583,864 583,864 583,864 583,864 583,864 583,864 583,864(Ton/Yr)2,301,592 2,301,592 2,301,592 2,301,592 2,301,592 2,301,592 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 37,055,628 37,055,628 37,055,628EmissionsUncontrolled SO2 (Lb/Hr)7,583 7,583 7,583 7,583 7,583 2,350 2,350 2,350 7,583(Lb/MMBtu)1.61 1.61 1.61 1.61 1.61 0.50 0.50 0.50 1.61(Lb Moles/Hr)118.36 118.36 118.36 118.36 118.36 36.68 36.68 36.68 118.36(Tons/Yr)29,891 29,891 29,891 29,891 29,891 9,264 9,264 9,264 29,891SO2 Removal Rate (%)69.0%0.0%0.0%0.0%0.0%36.0%68.0%84.0%0.0%(Lb/Hr)5,233 0 0 0 0 846 1,598 1,974 0(Ton/Yr)20,627 0 0 0 0 3,335 6,299 7,782 0SO2 Emission Rate (Lb/Hr)2,350 7,583 7,583 7,583 7,583 1,504 752 376 7,583(Lb/MMBtu)0.501.61 1.61 1.61 1.610.32 0.16 0.081.61(Ton/Yr)9,264 29,891 29,891 29,891 29,891 5,929 2,964 1,482 29,891Uncontrolled NOx (Lb/Hr)1,457 1,457 1,457 1,457 1,457 1,457 1,457 1,457 1,457(Lb/MMBtu)0.310.31 0.31 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 48.55 48.55 48.55(Tons/Yr)5,744 5,744 5,744 5,744 5,744 5,744 5,744 5,744 5,744NOx Removal Rate (%)0.0%25.8%35.5%41.9%77.4%0.0%0.0%0%0%(Lb/Hr)0 376 517 611 1,128 0 0 0 0(Lb Moles/Hr)0.00 12.53 17.23 20.36 37.59 0.00 0.00 0.00 0.00(Ton/Yr)0 1,482 2,038 2,409 4,447 0 0 0 0NOx Emission Rate (Lb/Hr)1,457 1,081 940 846 329 1,457 1,457 1,457 1,457(Lb/MMBtu)0.310.23 0.20 0.18 0.070.31 0.31 0.31 0.31(Ton/Yr)5,744 4,261 3,706 3,335 1,297 5,744 5,744 5,744 5,744Uncontrolled Fly Ash (Lb/Hr)34,845 141 141 141 141 141 141 141 141(Lb/MMBtu)7.414 0.030 0.030 0.030 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 4.7 4.7 4.7(Tons/Yr)137,359 556 556 556 556 556 556 556 556Fly Ash Removal Rate (%)99.60%0.00%0.00%0.00%0.00%0.00%0.00%0.00%50.00%(Lb/Hr)34,704 0 0 0 0 0 0 0 71(Ton/Yr)136,803 0 0 0 0 0 0 0 278Fly Ash Emission Rate (Lb/Hr)141 141 141 141 141 141 141 141 71(Lb/MMBtu)0.0300.030 0.030 0.030 0.030 0.030 0.030 0.0300.015(Ton/Yr)556 556 556 556 556 556 556 556 278ParameterCommentsCurrentOperationSO2 ControlNOx Control PM ControlEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls1 of 2LNB w/OFA ROFALNB w/OFA& SNCRLNB w/OFA& SCRUpgraded DryFGDDry FGD w/FabricFilterWet FGD Fabric FilterCase1 2 3 4 5 6 7 8 10ParameterCommentsCurrentOperationSO2 ControlNOx Control PM ControlGeneral Plant DataAnnual Operation (Hours/Year)7,884 7,884 7,884 7,884 7,884 7,884 7,884 7,884 7,884Annual On-Site Power Plant Capacity Factor0.900.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90Economic FactorsInterest Rate (%)7.10%7.10%7.10%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%7.10%7.10%7.10%Plant Economic Life (Years)2020 20 20 20 20 20 20 20Installed Capital CostsNOx Emission Control System ($2006)09,300,000 15,252,149 19,495,654108,280,222 0 0 0 0SO2 Emission Control System ($2006)00 0 0 0 26,759,011 66,777,531 95,136,483 0PM Emission Control System ($2006)00 0 0 0 0 0 0 32,630,832Total Emission Control Systems ($2006)0 9,300,000 15,252,149 19,495,654108,280,222 26,759,011 66,777,531 95,136,483 32,630,832NOx Emission Control System ($/kW)0 25 42 53 297 0 0 0 0SO2 Emission Control System ($/kW)0 0 0 0 0 73 183 261 0PM Emission Control System ($/kW)0 0 0 0 0 0 0 0 89Total Emission Control Systems ($/kW)0 25 42 53 297 73 183 261 89Total Fixed Operating & Maintenance CostsOperating Labor ($)0 0 0 0 0 0 0 303,677 0Maintenance Material ($)0 24,000 36,000 93,000 181,000 21,900 30,660 328,496 48,666Maintenance Labor ($)0 36,000 54,000 139,500 271,500 14,600 20,440 218,998 72,999Administrative Labor ($)00000 0 0 0 0Total Fixed O&M Cost ($)0 60,000 90,000 232,500 452,500 36,500 51,099 851,170 121,665Annual Fixed O&M Cost Escalation Rate (%)2.00%2.00%2.00%2.00%2.00%2.00%2.00%2.00%2.00%Water CostMakeup Water Usage (Gpm)0 0 0 0 0 25 30 82 0Unit Price ($/1000 Gallons)1.221.22 1.22 0.00 1.22 1.22 1.22 1.22 1.22First Year Water Cost ($)0 0 0 0 0 14,388 17,266 47,193 0Annual Water Cost Escalation Rate (%)2.00%2.00%2.00%2.00%2.00%2.00%2.00%2.00%2.00%Reagent CostNone None None UreaAnhydrous NH3Lime Lime Lime NoneUnit Cost ($/Ton)0.00 0.00 0.00 370 400 91.25 91.25 91.25 0.00($/Lb)0.000 0.000 0.000 0.185 0.200 0.046 0.046 0.046 0.000Molar Stoichiometry0.00 0.00 0.00 0.45 1.00 1.10 1.10 1.02 0.00Reagent Purity (Wt.%)100%100%100%100%100%90%90%90%90%Reagent Usage (Lb/Hr)0 0 0 372 427 2,514 2,514 1,958 0First Year Reagent Cost ($)0 0 0 542,814 673,062 904,412 904,412 704,455 0Annual Reagent Cost Escalation Rate (%)2.00%2.00%2.00%2.00%2.00%2.00%2.00%2.00%2.00%SCR Catalyst / FF Bag Replacement CostSCR Catalyst Bags Bags Bags BagsAnnual SCR Catalyst (m3) / No. FF Bags0000160 0 0 0 1,798SCR Catalyst ($/m3) / Bag Cost ($/ea.)3,0003,000 3,000 3,000 3,000104104 104 104First Year SCR Catalyst / Bag Replace. Cost ($)0 0 0 0 480,000 0 0 0 186,992Annual SCR Catalyst / Bag Cost Esc. Rate (%)2.00%2.00%2.00%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 4,582 5,278 0FGD Waste Disposal Unit Cost ($/Dry Ton)24.3324.33 24.33 24.33 24.33 24.33 24.33 24.33 24.33First Year FGD Waste Disposal Cost ($)0 0 0 0 0 346,184 439,525 506,310 0Annual Waste Disposal Cost Esc. Rate (%)2.00%2.00%2.00%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%0.04%0.48%0.56%(MW)0.00 0.00 5.22 0.34 2.42 0.11 0.15 1.75 2.06Unit Cost ($2006/MW-Hr)50.0050.00 50.00 50.00 50.00 50.00 50.00 50.00 50.00First Year Auxiliary Power Cost ($)0 0 2,057,685 132,057 952,387 44,939 59,130 689,850 812,052Annual Power Cost Escalation Rate (%)2.00%2.00%2.00%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.xls2 of 2Input TablesTable 1 - CasesExisting1 2 3 4 5 6 7 8 9 101 Dave Johnston Unit 3Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR Dry FGD w/ESPDry FGD w/FabricFilter Wet FGD w/ESP N/A Fabric Filter2 Dave Johnston Unit 4Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR N/ADry FGD w/FabricFilterWet FGD w/FabricFilter N/A Fabric Filter3 Jim Bridger Unit 1Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR N/A N/A Upgraded Wet FGDFlue GasConditioning Fabric Filter4 Jim Bridger Unit 2Current Operation Exist. LNB w/OFA ROFA SNCR SCR N/A N/A Upgraded Wet FGDFlue GasConditioning Fabric Filter5 Jim Bridger Unit 3Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR N/A N/A Upgraded Wet FGDFlue GasConditioning Fabric Filter6 Jim Bridger Unit 4Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR N/A N/A Upgraded Wet FGDFlue GasConditioning Fabric Filter7 Naughton Unit 1Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR Dry FGD w/ESPDry FGD w/FabricFilter Wet FGD w/ESPFlue GasConditioning Fabric Filter8 Naughton Unit 2Current Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR Dry FGD w/ESPDry FGD w/FabricFilter Wet FGD w/ESPFlue GasConditioning Fabric Filter9 Naughton Unit 3Current Operation Exist. LNB w/OFA ROFA SNCR SCR N/A N/A Upgraded Wet FGDFlue GasConditioning Fabric Filter10 WyodakCurrent Operation LNB w/OFA ROFA LNB w/OFA & SNCRLNB w/OFA &SCR Upgraded Dry FGDDry FGD w/FabricFilter Wet FGD N/A Fabric FilterTable 2 - Unit Design and Coal CharacteristicsNOx SO2 PM Boiler DesignNet PowerOutput (kW)Net Plant HeatRate (Btu/kW-Hr) CoalHeating Value,HHV (Btu/Lb)Sulfur Content(Wt.%)AshContent(Wt.%)1 Dave Johnston Unit 3None None ESP3-Cell Burner, OpposedWall-Fired PC250,000 11,200Dry Fork PRB7,784 0.47% 5.01%2 Dave Johnston Unit 4Windbox Mods.Lime Added to VenturiScrubber Venturi Scrubber Tangential-Fired PC360,000 11,390Dry Fork PRB7,784 0.47% 5.01%3 Jim Bridger Unit 1LNCFS-1 &Windbox Mods. Wet FGD ESP Tangential-Fired PC530,000 11,320Bridger MineUnderground9,660 0.58% 10.30%4 Jim Bridger Unit 2LNB - TFS 2000 Wet FGD ESP Tangential-Fired PC530,000 11,320Bridger MineUnderground9,660 0.58% 10.30%5 Jim Bridger Unit 3LNCFS-1 &Windbox Mods. Wet FGD ESP Tangential-Fired PC530,000 11,320Bridger MineUnderground9,660 0.58% 10.30%6 Jim Bridger Unit 4LNCFS-1 &Windbox Mods. Wet FGD ESP Tangential-Fired PC530,000 11,320Bridger MineUnderground9,660 0.58% 10.30%7 Naughton Unit 1None None ESP Tangential-Fired PC173,000 10,694Kemmerer Mine9,970 0.60% 4.64%8 Naughton Unit 2None None ESP Tangential-Fired PC226,000 10,574Kemmerer Mine9,970 0.60% 4.64%9 Naughton Unit 3LNCFS II LNB Wet FGD ESP Tangential-Fired PC356,000 10,336Kemmerer Mine9,970 0.60% 4.64%10 WyodakLNB Dry FGD ESP Opposed Wall-Fired PC365,000 12,877Clovis Point Mine8,050 0.65% 7.46%Coal QualityUnit DesignCurrent Emission Control SystemsIndex No. Name of UnitIndex No. Name of Unit | Case --->NOx Control SO2 Control PM ControlEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls1 of 5Table 3 - EmissionsControlledSO2 Controlled NOxControlledPM Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9 Case 101 Dave Johnston Unit 31.61 0.70 0.030 0.24 0.190.190.07 0.220.150.10N/A0.0152 Dave Johnston Unit 40.50 0.40 0.061 0.15 0.150.120.07 N/A0.150.10N/A0.0153 Jim Bridger Unit 10.27 0.45 0.045 0.24 0.220.200.07 N/AN/A0.100.030 0.0154 Jim Bridger Unit 20.27 0.24 0.074 0.24 0.220.200.07 N/AN/A0.100.030 0.0155 Jim Bridger Unit 30.27 0.45 0.057 0.24 0.220.200.07 N/AN/A0.100.030 0.0156 Jim Bridger Unit 40.17 0.45 0.030 0.24 0.220.200.07 N/AN/A0.100.030 0.0157 Naughton Unit 11.61 0.58 0.056 0.24 0.280.180.07 0.180.150.100.040 0.0158 Naughton Unit 21.61 0.54 0.064 0.24 0.280.180.07 0.180.150.100.040 0.0159 Naughton Unit 30.50 0.45 0.094 0.35 0.300.250.07 N/AN/A0.100.040 0.01510 Wyodak0.50 0.31 0.0300.230.200.180.070.320.160.08N/A0.015Table 4 - Case 1 O&M Costs (Current Operation)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Aux. PowerUsage (MW)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-$ -$ -$$ --None--Table 5 - Case 2 O&M Costs (LNB w/OFA)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Aux. PowerUsage (MW)1 Dave Johnston Unit 3-$ 40,000$ 60,000$ -$ -None - -2 Dave Johnston Unit 4-$ 36,000$ 54,000$ $ - -None - -3 Jim Bridger Unit 1-$ 28,000$ 42,000$ $ - -None - -4 Jim Bridger Unit 2-$ -$ -$ $ - -None - -5 Jim Bridger Unit 3-$ 28,000$ 42,000$ $ - -None - -6 Jim Bridger Unit 4-$ 28,000$ 42,000$ $ - -None - -7 Naughton Unit 1-$ 32,000$ 48,000$ $ - -None - -8 Naughton Unit 2-$ 32,000$ 48,000$ $ - -None - -9 Naughton Unit 3-$ -$ -$ $ - -None - -10 Wyodak-$ 24,000$ 36,000$$ --None--SO2 Control Emission Rates (Lb/MMBtu)Index No. Name of UnitAnnual Fixed O&M Costs Variable Operating RequirementsPM Emission Rates (Lb/MMBtu)Index No. Name of UnitCurrent Emission Rates (Lb/MMBtu) NOx Control Emission Rates (Lb/MMBtu)Index No. Name of UnitAnnual Fixed O&M Costs Variable Operating RequirementsEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls2 of 5Table 6 - Case 3 O&M Costs (Mobotec ROFA)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Aux. PowerUsage (MW)1 Dave Johnston Unit 3-$ 60,000$ 90,000$ -$ -None - 2.762 Dave Johnston Unit 4-$ 54,000$ 81,000$ $ - -None - 4.333 Jim Bridger Unit 1-$ 42,000$ 63,000$ $ - -None - 6.414 Jim Bridger Unit 2-$ 42,000$ 63,000$ $ - -None - 6.415 Jim Bridger Unit 3-$ 42,000$ 63,000$ $ - -None - 6.416 Jim Bridger Unit 4-$ 42,000$ 63,000$ $ - -None - 6.417 Naughton Unit 1-$ 48,000$ 72,000$ $ - -None - 1.428 Naughton Unit 2-$ 48,000$ 72,000$ $ - -None - 2.619 Naughton Unit 3-$ 48,000$ 72,000$ $ - -None - 4.4710 Wyodak-$ 36,000$ 54,000$$ --None-5.22Table 7 - Case 4 O&M Costs (LNB w/OFA & SNCR))Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Aux. PowerUsage (MW)1 Dave Johnston Unit 3-$ 98,000$ 147,000$ -$ -Urea 0.41 0.232 Dave Johnston Unit 4-$ 105,000$ 157,500$ $ - -Urea 0.45 0.333 Jim Bridger Unit 1-$ 123,000$ 184,500$ $ - -Urea 0.45 0.534 Jim Bridger Unit 2-$ 95,000$ 142,500$ $ - -Urea 0.45 0.535 Jim Bridger Unit 3-$ 122,000$ 183,000$ $ - -Urea 0.45 0.526 Jim Bridger Unit 4-$ 123,000$ 184,500$ $ - -Urea 0.45 0.537 Naughton Unit 1-$ 83,000$ 124,500$ $ - -Urea 0.45 0.168 Naughton Unit 2-$ 93,000$ 139,500$ $ - -Urea 0.51 0.229 Naughton Unit 3-$ 75,000$ 112,500$ $ - -Urea 0.45 0.3310 Wyodak-$ 93,000$ 139,500$--Urea0.450.34Table 8 - Case 5 O&M Costs (LNB w/OFA & SCR))Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.AnnualSCRCatalyst Replace.(m3)Aux. PowerUsage (MW)1 Dave Johnston Unit 3-$ 155,000$ 232,500$ -$ -Anhydrous NH31.00 1281.572 Dave Johnston Unit 4-$ 166,000$ 249,000$ $ - -Anhydrous NH31.00 1232.293 Jim Bridger Unit 1-$ 190,000$ 285,000$ $ - -Anhydrous NH31.00 1983.284 Jim Bridger Unit 2-$ 162,000$ 243,000$ $ - -Anhydrous NH31.00 1983.255 Jim Bridger Unit 3-$ 190,000$ 285,000$ $ - -Anhydrous NH31.00 2003.226 Jim Bridger Unit 4-$ 190,000$ 285,000$ $ - -Anhydrous NH31.00 2143.367 Naughton Unit 1-$ 132,000$ 198,000$ $ - -Anhydrous NH31.00 670.988 Naughton Unit 2-$ 160,000$ 240,000$ $ - -Anhydrous NH31.00 1011.349 Naughton Unit 3-$ 156,000$ 234,000$ $ - -Anhydrous NH31.00 1671.9910 Wyodak-$ 181,000$ 271,500$$ --Anhydrous NH31.001602.42Annual Fixed O&M Costs Variable Operating RequirementsIndex No. Name of UnitAnnual Fixed O&M Costs Variable Operating RequirementsIndex No. Name of UnitIndex No. Name of UnitAnnual Fixed O&M Costs Variable Operating RequirementsEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls3 of 5Table 9 - Case 6 O&M Costs (Dry FGD)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Annual FF BagReplace.Aux. PowerUsage (MW)1 Dave Johnston Unit 3506,128$ 714,175$ 476,928$ -$ 173Lime1.15 -2.492 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 1506,128$ 587,643$ 391,762$ $ - 120Lime1.40 -1.648 Naughton Unit 2506,128$ 860,174$ 573,044$ $ - 165Lime1.40 -2.259 Naughton Unit 3-$ -$ -$ $ - -Lime- --10 Wyodak-$ 21,900$ 14,600$-25Lime1.10-0.11Table 10 - Case 7 O&M Costs (Dry FGD w/Fabric Filter)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Annual FF BagReplace.Aux. PowerUsage (MW)1 Dave Johnston Unit 3506,128$ 714,175$ 476,928$ -$ 173Lime1.15 1,4573.882 Dave Johnston Unit 4506,128$ 1,102,288$ 734,858$ $ - 248Lime1.10 1,7984.543 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 1506,128$ 632,660$ 459,286$ $ - 120Lime1.15 8652.668 Naughton Unit 2506,128$ 905,190$ 640,568$ $ - 165Lime1.15 1,1933.639 Naughton Unit 3-$ -$ -$ $ - -Lime- --10 Wyodak-$ 30,660$ 20,440$-30Lime1.10-0.15Table 11 - Case 8 O&M Costs (Wet FGD)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Annual FF BagReplace.Aux. PowerUsage (MW)1 Dave Johnston Unit 3809,804$ 1,182,587$ 788,391$ -$ 230Lime1.02 -3.452 Dave Johnston Unit 4809,804$ 1,430,784$ 953,856$ $ - 330Lime1.02 1,7986.293 Jim Bridger Unit 1-$ 25,550$ 17,033$ $ - 53Soda Ash1.02 -0.534 Jim Bridger Unit 2-$ 25,550$ 17,033$ $ - 53Soda Ash1.02 -0.535 Jim Bridger Unit 3-$ 25,550$ 17,033$ $ - 52Soda Ash1.02 -0.526 Jim Bridger Unit 4-$ 25,550$ 17,033$ $ - 27Soda Ash1.02 -0.537 Naughton Unit 1809,804$ 963,589$ 642,393$ $ - 160Lime1.05 -2.408 Naughton Unit 2809,804$ 1,226,386$ 817,591$ $ - 220Lime1.05 -3.309 Naughton Unit 3-$ 21,900$ 14,600$ $ - 66Soda Ash1.02 -0.3310 Wyodak303,677$ 328,496$ 218,998$$ -82Lime1.02-1.75Variable Operating RequirementsVariable Operating RequirementsVariable Operating RequirementsIndex No. Name of UnitAnnual Fixed O&M CostsIndex No. Name of UnitAnnual Fixed O&M CostsIndex No. Name of UnitAnnual Fixed O&M CostsEY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls4 of 5Table 12 - Case 9 O&M Costs (Flue Gas Conditioning)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagentUsage (Lb/Hr)Annual FF BagReplace.Aux. PowerUsage (MW)1 Dave Johnston Unit 3-$ -$ -$ -$ -None- --2 Dave Johnston Unit 4-$ -$ -$ $ - -None- --3 Jim Bridger Unit 1-$ -$ 10,000$ $ - -Elemental Sulfur100 -0.054 Jim Bridger Unit 2-$ -$ 10,000$ $ - -Elemental Sulfur100 -0.055 Jim Bridger Unit 3-$ -$ 10,000$ $ - -Elemental Sulfur100 -0.056 Jim Bridger Unit 4-$ -$ 10,000$ $ - -Elemental Sulfur100 -0.057 Naughton Unit 1-$ -$ 10,000$ $ - -Elemental Sulfur33 -0.058 Naughton Unit 2-$ -$ 10,000$ $ - -Elemental Sulfur43 -0.059 Naughton Unit 3-$ -$ 10,000$ $ - -Elemental Sulfur67 -0.0510 Wyodak-$ -$ -$--None---Table 13 - Case 10 O&M Costs (Fabric Filter)Oper. Labor Maint. Materials Maint. Labor Admin. LaborMakeup WaterUse (Gpm) ReagentReagent MolarStoich.Annual FF BagReplace.Aux. PowerUsage (MW)1 Dave Johnston Unit 3-$ 45,016$ 67,524$ -$ -None- 1,4571.382 Dave Johnston Unit 4-$ 68,133$ 102,199$ $ - -None- 1,7982.353 Jim Bridger Unit 1-$ 51,099$ 76,649$ $ - -None- 2,8853.394 Jim Bridger Unit 2-$ 51,099$ 76,649$ $ - -None- 2,8853.375 Jim Bridger Unit 3-$ 51,099$ 76,649$ $ - -None- 2,8273.336 Jim Bridger Unit 4-$ 51,099$ 76,649$ $ - -None- 2,8853.397 Naughton Unit 1-$ 45,016$ 67,524$ $ - -None- 8651.018 Naughton Unit 2-$ 45,016$ 67,524$ $ - -None- 1,1931.389 Naughton Unit 3-$ 48,666$ 72,999$ $ - -None- 1,7992.0610 Wyodak-$ 48,666$ 72,999$$ --None-1,7982.06Table 14 - Major Materials Design and Supply Costs2 3 4 5 6 7 8 9 101 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 $ - $ 18,359,0002 Dave Johnston Unit 4$ 2,673,501 $ 4,343,192 $ 7,171,085 $ 66,200,000 $ - $ 137,267,000 $ 178,174,384 $ - $ 30,853,5303 Jim Bridger Unit 1$ 2,981,982 $ 6,056,955 $ 9,528,000 $ 80,923,000 $ - $- $ 8,010,093 $ - $ 29,814,0004 Jim Bridger Unit 2$ - $ 6,056,955 $ 9,528,000 $ 80,923,000 $ - $- $ 8,010,093 $ - $ 29,814,0005 Jim Bridger Unit 3$ 2,981,982 $ 6,056,955 $ 9,419,000 $ 80,923,000 $ - $- $ 8,010,093 $ - $ 29,814,0006 Jim Bridger Unit 4$ 2,981,982 $ 6,056,955 $ 9,528,000 $ 93,009,000 $ - $- $ 3,549,000 $ - $ 29,814,0007 Naughton Unit 1$ 2,502,123 $ 2,675,792 $ 7,257,000 $ 37,292,000 $ 26,819,000 $ 42,301,000 $ 44,000,000 $ 800,000 $ 15,482,0008 Naughton Unit 2$ 2,570,674 $ 3,123,533 $ 8,784,000 $ 47,934,000 $ 39,262,000 $ 57,621,000 $ 56,000,000 $ 800,000 $ 18,359,0009 Naughton Unit 3$ - $ 4,351,377 $ 11,203,578 $ 67,373,000 $ - $- $ 2,963,000 $ 800,000 $ 20,106,00010 Wyodak$ 3,187,636 $ 4,500,245 $ 7,234,860 $ 72,479,000 $ 16,487,985 $ 41,146,026 $ 58,619,840 $ - $ 20,106,000Variable Operating RequirementsIndex No. Name of UnitAnnual Fixed O&M CostsIndex No. Name of UnitAnnual Fixed O&M Costs Variable Operating RequirementsNOx Control SO2 Control PM ControlIndex No. Name of Unit | Case --->EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls5 of 5CAPITAL COSTWyodakCaseNOx Emission Control SystemSO2 Emission Control SystemPM Emission Control SystemCAPITAL COST COMPONENTFactor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source Cost Factor/Source CostLNB w/OFA or ROFALNB w/OFA ROFA LNB w/OFA LNB w/OFAMajor Materials Design and SupplyVendor $3,187,636Vendor $4,500,245Vendor $3,187,636Vendor $3,187,636Vendor $0Vendor $0Vendor $0Vendor $0Vendor $0Construction85.3%$2,720,13085.3%$3,840,22885.3%$2,720,13085.3%$2,720,13085.3%$085.3%$085.3%$085.3%$085.3%$0Balance of Plant51.7%$1,647,75851.7%$2,326,27351.7%$1,647,75851.7%$1,647,75851.7%$051.7%$051.7%$051.7%$051.7%$0Electrical (Allowance)0.0%$030.0%$1,350,0740.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$0Owner's Costs13.2%$422,30913.2%$596,20813.2%$422,30913.2%$422,30913.2%$013.2%$013.2%$013.2%$013.2%$0Surcharge16.4%$523,58516.4%$739,18716.4%$523,58516.4%$523,58516.4%$016.4%$016.4%$016.4%$016.4%$0AFUDC12.2%$389,48012.2%$549,86112.2%$389,48012.2%$389,48012.2%$012.2%$012.2%$012.2%$012.2%$0Subtotal $8,890,897 $13,902,076$8,890,897 $8,890,897 $0 $0 $0 $0 $0Contingency12.8%$409,10330.0%$1,350,07412.8%$409,10312.8%$409,10312.8%$012.8%$012.8%$012.8%$012.8%$0Total Capital Cost for LNB w/OFA or ROFA $9,300,000 $15,252,149 $9,300,000 $9,300,000 $0 $0 $0 $0 $0SNCR or SCRSNCR SCRMajor Materials Design and SupplyS&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 Report $0 S&L Report $0 S&L Report $0 S&L Report $0Contingency20.0%$020.0%$020.0%$1,446,97210.0%$7,247,90020.0%$020.0%$020.0%$020.0%$020.0%$0Labor Premium5.6%$05.6%$05.6%$404,6465.6%$4,053,7505.6%$05.6%$05.6%$05.6%$05.6%$0EPC Premium0.0%$00.0%$00.0%$08.4%$6,122,3018.4%$08.4%$08.4%$08.4%$08.4%$0Boiler Reinforcement (Allowance)0.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$0Sales Tax1.1%$01.1%$01.1%$79,7281.1%$798,7191.1%$01.1%$01.1%$01.1%$01.1%$0Escalation0.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$00.0%$0Contingency on Adders2.8%$02.8%$02.8%$203,0830.0%$02.8%$02.8%$02.8%$02.8%$02.8%$0Surcharge and AFUDC11.4%$011.4%$011.4%$826,36611.4%$8,278,55111.4%$011.4%$011.4%$011.4%$011.4%$0Total Capital Cost for SNCR or SCR $0 $0 $10,195,654 $98,980,222 $0 $0 $0 $0 $0Dry or Wet FGD, FGC or Fabric FilterDry FGD Dry FGD w/FF Wet FGD FGC Fabric FilterMajor Materials Design and SupplyS&L Report $0 S&L Report $0 S&L Report $0 S&L Report $0 S&L Report $16,487,985S&L Report $41,146,026S&L Report $58,619,840 S&L Report $0 S&L Report $20,106,000Contingency20.0%$020.0%$020.0%$020.0%$020.0%$3,297,59720.0%$8,229,20520.0%$11,723,96820.0%$020.0%$4,021,200Labor Premium5.6%$05.6%$05.6%$05.6%$05.6%$922,1735.6%$2,301,2975.6%$3,278,6085.6%$05.6%$1,124,529EPC Premium8.4%$08.4%$08.4%$08.4%$08.4%$1,392,7408.4%$3,475,6058.4%$4,951,6188.4%$08.4%$1,698,354Boiler Reinforcement (Allowance)2.8%$02.8%$02.8%$02.8%$02.8%$463,9722.8%$1,157,8492.8%$1,649,5622.8%$02.8%$565,783Sales Tax1.1%$01.1%$01.1%$01.1%$01.1%$181,6981.1%$453,4291.1%$645,9911.1%$01.1%$221,568Escalation10.1%$010.1%$010.1%$010.1%$010.1%$1,666,77010.1%$4,159,45210.1%$5,925,88010.1%$010.1%$2,032,516Contingency on Adders2.8%$02.8%$02.8%$02.8%$02.8%$462,8182.8%$1,154,9692.8%$1,645,4592.8%$02.8%$564,375Surcharge and AFUDC11.4%$011.4%$011.4%$011.4%$011.4%$1,883,25811.4%$4,699,69911.4%$6,695,55811.4%$011.4%$2,296,507Total Capital Cost for Dry/Wet FGD, FGC or FF $0 $0 $0 $0 $26,759,011 $66,777,531 $95,136,483 $0 $32,630,832Fabric Filter8LNBFabric Filter10LNBDry FGDLNBDry FGDN/ADry FGD w/Fabric FilterUpgraded Dry FGDLNB w/OFA & SNCRSO2 ControlWet FGDWet FGDESPLNB w/OFADry FGDESP ESPROFADry FGDLNBDry FGD w/Fabric FilterParameterLNB w/OFA ROFA LNB w/OFA & SCRESPLNBUpgraded Dry FGDESPLNB w/OFA & SNCRDry FGDESP ESPLNB w/OFA & SCRDry FGDPM ControlN/ANOx Control45 76293EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls1 of 1WyodakLNB w/OFAYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton NOx Removed)0 20131 2014 60,000------884,689944,6896372 2015 61,200------884,689945,8896383 2016 62,424------884,689947,1136394 2017 63,672------884,689948,3616405 2018 64,946------884,689949,6356416 2019 66,245------884,689950,9346427 2020 67,570------884,689952,2596428 2021 68,921------884,689953,6106439 2022 70,300------884,689954,98864410 2023 71,706------884,689956,39464511 2024 73,140------884,689957,82864612 2025 74,602------884,689959,29164713 2026 76,095------884,689960,78364814 2027 77,616------884,689962,30564915 2028 79,169------884,689963,85765016 2029 80,752------884,689965,44165117 2030 82,367------884,689967,05665218 2031 84,014------884,689968,70365419 2032 85,695------884,689970,38465520 2033 87,409------884,689972,097656Present Worth733,071------9,300,00010,033,071338(% of PW)7.3% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 92.7% 100.0%WyodakROFAYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton NOx Removed)0 20131 2014 90,000----2,057,6852,057,6851,450,9043,598,5881,7662 2015 91,800----2,098,8382,098,8381,450,9043,641,5421,7873 2016 93,636----2,140,8152,140,8151,450,9043,685,3551,8084 2017 95,509----2,183,6312,183,6311,450,9043,730,0441,8305 2018 97,419----2,227,3042,227,3041,450,9043,775,6271,8536 2019 99,367----2,271,8502,271,8501,450,9043,822,1211,8757 2020 101,355----2,317,2872,317,2871,450,9043,869,5451,8998 2021 103,382----2,363,6332,363,6331,450,9043,917,9181,9229 2022 105,449----2,410,9052,410,9051,450,9043,967,2591,94710 2023 107,558----2,459,1242,459,1241,450,9044,017,5861,97111 2024 109,709----2,508,3062,508,3061,450,9044,068,9191,99612 2025 111,904----2,558,4722,558,4721,450,9044,121,2802,02213 2026 114,142----2,609,6422,609,6421,450,9044,174,6872,04814 2027 116,425----2,661,8342,661,8341,450,9044,229,1632,07515 2028 118,753----2,715,0712,715,0711,450,9044,284,7282,10216 2029 121,128----2,769,3732,769,3731,450,9044,341,4042,13017 2030 123,551----2,824,7602,824,7601,450,9044,399,2142,15918 2031 126,022----2,881,2552,881,2551,450,9044,458,1812,18719 2032 128,542----2,938,8802,938,8801,450,9044,518,3262,21720 2033 131,113----2,997,6582,997,6581,450,9044,579,6752,247Present Worth1,099,607----25,140,48825,140,48815,252,14941,492,2441,018(% of PW)2.7% 0.0% 0.0% 0.0% 0.0% 60.6% 60.6% 36.8% 100.0%EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls1 of 4WyodakLNB w/OFA & SNCRYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton NOx Removed)0 20131 2014 232,500-542,814--132,057674,8711,854,5792,761,9501,1472 2015 237,150-553,670--134,698688,3681,854,5792,780,0971,1543 2016 241,893-564,743--137,392702,1351,854,5792,798,6081,1624 2017 246,731-576,038--140,140716,1781,854,5792,817,4881,1705 2018 251,665-587,559--142,943730,5021,854,5792,836,7461,1786 2019 256,699-599,310--145,802745,1121,854,5792,856,3901,1867 2020 261,833-611,296--148,718760,0141,854,5792,876,4261,1948 2021 267,069-623,522--151,692775,2141,854,5792,896,8631,2039 2022 272,411-635,993--154,726790,7191,854,5792,917,7081,21110 2023 277,859-648,713--157,820806,5331,854,5792,938,9711,22011 2024 283,416-661,687--160,977822,6641,854,5792,960,6591,22912 2025 289,085-674,921--164,196839,1171,854,5792,982,7801,23813 2026 294,866-688,419--167,480855,8991,854,5793,005,3451,24814 2027 300,764-702,187--170,830873,0171,854,5793,028,3601,25715 2028 306,779-716,231--174,246890,4771,854,5793,051,8351,26716 2029 312,914-730,556--177,731908,2871,854,5793,075,7811,27717 2030 319,173-745,167--181,286926,4531,854,5793,100,2051,28718 2031 325,556-760,070--184,912944,9821,854,5793,125,1171,29719 2032 332,067-775,272--188,610963,8811,854,5793,150,5281,30820 2033 338,709-790,777--192,382983,1591,854,5793,176,4471,319Present Worth2,840,651-6,632,018--1,613,4538,245,47119,495,65430,581,776635(% of PW)9.3% 0.0% 21.7% 0.0% 0.0% 5.3% 27.0% 63.7% 100.0%WyodakLNB w/OFA & SCRYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton NOx Removed)0 20131 2014 452,500-673,062480,000-952,3872,105,44910,300,46212,858,4112,8922 2015 461,550-686,523489,600-971,4352,147,55810,300,46212,909,5702,9033 2016 470,781-700,253499,392-990,8642,190,50910,300,46212,961,7522,9154 2017 480,197-714,258509,380-1,010,6812,234,31910,300,46213,014,9772,9275 2018 489,801-728,544519,567-1,030,8952,279,00510,300,46213,069,2682,9396 2019 499,597-743,114529,959-1,051,5122,324,58610,300,46213,124,6442,9527 2020 509,588-757,977540,558-1,072,5432,371,07710,300,46213,181,1282,9648 2021 519,780-773,136551,369-1,093,9942,418,49910,300,46213,238,7412,9779 2022 530,176-788,599562,397-1,115,8732,466,86910,300,46213,297,5062,99010 2023 540,779-804,371573,644-1,138,1912,516,20610,300,46213,357,4473,00411 2024 551,595-820,458585,117-1,160,9552,566,53010,300,46213,418,5873,01812 2025 562,627-836,867596,820-1,184,1742,617,86110,300,46213,480,9503,03213 2026 573,879-853,605608,756-1,207,8572,670,21810,300,46213,544,5593,04614 2027 585,357-870,677620,931-1,232,0142,723,62310,300,46213,609,4413,06115 2028 597,064-888,090633,350-1,256,6552,778,09510,300,46213,675,6213,07516 2029 609,005-905,852646,017-1,281,7882,833,65710,300,46213,743,1243,09117 2030 621,186-923,969658,937-1,307,4242,890,33010,300,46213,811,9773,10618 2031 633,609-942,449672,116-1,333,5722,948,13710,300,46213,882,2083,12219 2032 646,281-961,298685,558-1,360,2433,007,09910,300,46213,953,8433,13820 2033 659,207-980,524699,269-1,387,4483,067,24110,300,46214,026,9103,154Present Worth5,528,579-8,223,3685,864,570-11,636,12725,724,064108,280,222139,532,8651,569(% of PW)4.0% 0.0% 5.9% 4.2% 0.0% 8.3% 18.4% 77.6% 100.0%EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls2 of 4WyodakUpgraded Dry FGDYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton SO2 Removed)0 20131 2014 36,50014,388904,412-346,18444,9391,309,9232,545,5263,891,9491,1672 2015 37,23014,676922,500-353,10845,8381,336,1222,545,5263,918,8781,1753 2016 37,97414,969940,950-360,17046,7541,362,8442,545,5263,946,3451,1834 2017 38,73415,269959,769-367,37447,6891,390,1012,545,5263,974,3611,1925 2018 39,50815,574978,965-374,72148,6431,417,9032,545,5264,002,9381,2006 2019 40,29815,886998,544-382,21649,6161,446,2612,545,5264,032,0861,2097 2020 41,10416,2031,018,515-389,86050,6081,475,1862,545,5264,061,8171,2188 2021 41,92716,5271,038,885-397,65751,6211,504,6902,545,5264,092,1431,2279 2022 42,76516,8581,059,663-405,61052,6531,534,7842,545,5264,123,0751,23610 2023 43,62017,1951,080,856-413,72253,7061,565,4802,545,5264,154,6261,24611 2024 44,49317,5391,102,473-421,99754,7801,596,7892,545,5264,186,8081,25512 2025 45,38317,8901,124,523-430,43755,8761,628,7252,545,5264,219,6341,26513 2026 46,29018,2481,147,013-439,04656,9931,661,2992,545,5264,253,1161,27514 2027 47,21618,6131,169,953-447,82758,1331,694,5252,545,5264,287,2681,28615 2028 48,16018,9851,193,352-456,78359,2961,728,4162,545,5264,322,1031,29616 2029 49,12419,3651,217,219-465,91960,4821,762,9842,545,5264,357,6341,30717 2030 50,10619,7521,241,564-475,23761,6911,798,2442,545,5264,393,8771,31818 2031 51,10820,1471,266,395-484,74262,9251,834,2092,545,5264,430,8441,32919 2032 52,13020,5501,291,723-494,43764,1841,870,8932,545,5264,468,5501,34020 2033 53,17320,9611,317,557-504,32565,4671,908,3112,545,5264,507,0101,351Present Worth445,947175,79211,049,972-4,229,631549,05616,004,45126,759,01143,209,408648(% of PW)1.0% 0.4% 25.6% 0.0% 9.8% 1.3% 37.0% 61.9% 100.0%WyodakDry FGD w/Fabric FilterYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton SO2 Removed)0 20131 2014 51,09917,266904,412-439,52559,1301,420,3336,352,4017,823,8331,2422 2015 52,12117,611922,500-448,31560,3131,448,7396,352,4017,853,2621,2473 2016 53,16417,963940,950-457,28261,5191,477,7146,352,4017,883,2791,2514 2017 54,22718,323959,769-466,42762,7491,507,2686,352,4017,913,8971,2565 2018 55,31218,689978,965-475,75664,0041,537,4146,352,4017,945,1261,2616 2019 56,41819,063998,544-485,27165,2841,568,1626,352,4017,976,9811,2667 2020 57,54619,4441,018,515-494,97666,5901,599,5256,352,4018,009,4731,2718 2021 58,69719,8331,038,885-504,87667,9221,631,5166,352,4018,042,6141,2779 2022 59,87120,2301,059,663-514,97369,2801,664,1466,352,4018,076,4181,28210 2023 61,06920,6341,080,856-525,27370,6661,697,4296,352,4018,110,8991,28811 2024 62,29021,0471,102,473-535,77872,0791,731,3776,352,4018,146,0691,29312 2025 63,53621,4681,124,523-546,49473,5211,766,0056,352,4018,181,9421,29913 2026 64,80621,8971,147,013-557,42474,9911,801,3256,352,4018,218,5331,30514 2027 66,10322,3351,169,953-568,57276,4911,837,3526,352,4018,255,8551,31115 2028 67,42522,7821,193,352-579,94478,0211,874,0996,352,4018,293,9241,31716 2029 68,77323,2371,217,219-591,54379,5811,911,5816,352,4018,332,7551,32317 2030 70,14923,7021,241,564-603,37381,1731,949,8126,352,4018,372,3621,32918 2031 71,55224,1761,266,395-615,44182,7961,988,8086,352,4018,412,7611,33519 2032 72,98324,6601,291,723-627,75084,4522,028,5856,352,4018,453,9681,34220 2033 74,44225,1531,317,557-640,30586,1412,069,1566,352,4018,496,0001,349Present Worth624,325210,95111,049,972-5,370,050722,44217,353,41566,777,53184,755,271673(% of PW)0.7% 0.2% 13.0% 0.0% 6.3% 0.9% 20.5% 78.8% 100.0%EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls3 of 4WyodakWet FGDYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton SO2 Removed)0 20131 2014 851,17047,193704,455-506,310689,8501,947,8089,050,12711,849,1051,5232 2015 868,19448,137718,544-516,437703,6471,986,7649,050,12711,905,0851,5303 2016 885,55849,100732,915-526,765717,7202,026,5009,050,12711,962,1841,5374 2017 903,26950,082747,573-537,301732,0742,067,0309,050,12712,020,4251,5455 2018 921,33451,083762,524-548,047746,7162,108,3709,050,12712,079,8311,5526 2019 939,76152,105777,775-559,008761,6502,150,5389,050,12712,140,4251,5607 2020 958,55653,147793,330-570,188776,8832,193,5489,050,12712,202,2311,5688 2021 977,72754,210809,197-581,592792,4212,237,4199,050,12712,265,2731,5769 2022 997,28255,294825,381-593,223808,2692,282,1689,050,12712,329,5761,58410 2023 1,017,22756,400841,889-605,088824,4352,327,8119,050,12712,395,1651,59311 2024 1,037,57257,528858,726-617,190840,9232,374,3679,050,12712,462,0661,60112 2025 1,058,32358,679875,901-629,533857,7422,421,8559,050,12712,530,3051,61013 2026 1,079,49059,852893,419-642,124874,8972,470,2929,050,12712,599,9081,61914 2027 1,101,08061,049911,287-654,967892,3952,519,6989,050,12712,670,9041,62815 2028 1,123,10162,270929,513-668,066910,2422,570,0919,050,12712,743,3191,63816 2029 1,145,56363,516948,103-681,427928,4472,621,4939,050,12712,817,1831,64717 2030 1,168,47564,786967,065-695,056947,0162,673,9239,050,12712,892,5241,65718 2031 1,191,84466,082986,407-708,957965,9572,727,4029,050,12712,969,3721,66719 2032 1,215,68167,4031,006,135-723,136985,2762,781,9509,050,12713,047,7571,67720 2033 1,239,99568,7511,026,257-737,5991,004,9812,837,5899,050,12713,127,7101,687Present Worth10,399,475576,5988,606,924-6,186,0268,428,48623,798,03495,136,483129,333,992831(% of PW)8.0% 0.4% 6.7% 0.0% 4.8% 6.5% 18.4% 73.6% 100.0%WyodakFabric FilterYear DateTOTAL FIXEDO&M COSTMakeupWater CostReagent CostSCR Catalyst / FFBagCostWasteDisposal CostElectricPower CostTOTAL VARIABLEO&M COSTDEBT SERVICETOTAL ANNUALCOSTControl Cost($/Ton PM Removed)0 20131 2014 121,665--186,992-812,052999,0443,104,1004,224,80915,2022 2015 124,099--190,732-828,2931,019,0253,104,1004,247,22315,2823 2016 126,581--194,546-844,8591,039,4053,104,1004,270,08615,3654 2017 129,112--198,437-861,7561,060,1933,104,1004,293,40615,4495 2018 131,694--202,406-878,9911,081,3973,104,1004,317,19215,5346 2019 134,328--206,454-896,5711,103,0253,104,1004,341,45415,6217 2020 137,015--210,583-914,5021,125,0863,104,1004,366,20115,7108 2021 139,755--214,795-932,7921,147,5883,104,1004,391,44315,8019 2022 142,550--219,091-951,4481,170,5393,104,1004,417,19015,89410 2023 145,401--223,473-970,4771,193,9503,104,1004,443,45115,98811 2024 148,309--227,942-989,8871,217,8293,104,1004,470,23816,08512 2025 151,275--232,501-1,009,6851,242,1863,104,1004,497,56116,18313 2026 154,301--237,151-1,029,8781,267,0293,104,1004,525,43016,28314 2027 157,387--241,894-1,050,4761,292,3703,104,1004,553,85716,38615 2028 160,535--246,732-1,071,4851,318,2173,104,1004,582,85216,49016 2029 163,745--251,667-1,092,9151,344,5823,104,1004,612,42716,59617 2030 167,020--256,700-1,114,7731,371,4733,104,1004,642,59416,70518 2031 170,361--261,834-1,137,0691,398,9033,104,1004,673,36416,81619 2032 173,768--267,071-1,159,8101,426,8813,104,1004,704,74916,92920 2033 177,243--272,412-1,183,0061,455,4183,104,1004,736,76217,044Present Worth1,486,489--2,284,641-9,921,53212,206,17332,630,83246,323,4938,334(% of PW)3.2% 0.0% 0.0% 4.9% 0.0% 21.4% 26.3% 70.4% 100.0%EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls4 of 4EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 1 of 1First Year Cost for Air Pollution Control Options02,000,0004,000,0006,000,0008,000,00010,000,00012,000,00014,000,000LNB w/OFA ROFA LNB w/OFA &SNCRLNB w/OFA &SCRUpgraded DryFGDDry FGDw/Fabric FilterWet FGD Fabric FilterAir Pollution Control Option

First Year Cost ($)EY102007001SLC\App A_PCorp Wyodak BART Economic Analysis_01-28-07_gdb_09-26-07.xls 1 of 1Present Worth Cost for Air Pollution Control Options020,000,00040,000,00060,000,00080,000,000100,000,000120,000,000140,000,000160,000,000LNB w/OFA ROFA LNB w/OFA &SNCRLNB w/OFA &SCRUpgraded DryFGDDry FGDw/Fabric FilterWet FGD Fabric FilterAir Pollution Control Options

Present Worth Cost Over Year Plant Life ($)

# APPENDIX B 

# 2006 Wyoming BART Protocol