DEPARTMENT OF ENVIRONMENTAL QUALITY AIR QUALITY DIVISION

BART Application Analysis

AP

- 604 5

August 4 , 2008

NAME OF FIRM: FMC Wyoming Corporation

NAME OF FACILITY: Westvaco Facility

FACILITY LOCATION: Sections 14, 15, 22

, and 23, T19N, R110W Sweetwater County, Wyoming

TYPE OF OPERATION: Trona Mine and Sodium Products Plant

RESPONSIBLE OFFICIAL: Otto Schnauber

, Environmental Team Leader

MAILING ADDRESS: PO Box 872 Green River, WY 82935

TELEPHONE NUMBER: (307) 872

- 2257

REVIEW ERS : Cole Anderson , Air Quality Engineer Josh Nall, Air Quality Modeler

PURPOSE OF APPLICATION:

Sections 169A and 169B of the 1990 Clean Air Act Amendments require states to improve visibility at

Class I areas. On July 1, 1999

, EPA first published the Reg ional Haze Rule, which provid ed specific details regarding the overall program requirements to improve visibility

. The goal of the regional haze program is to achie ve natural conditions by 2064.

Section 30 8 of the Regional Haze Rule (40 CFR 51) includes discuss ion on control strategies for improving visibility impairment. One of these strategies is the requirement under 40 CFR 51.308(e) for certain stationary sources to install Best Available Retrofit Technology (BART) to reduce emissions of three (3) vi sibility impairing pollutants , nitrogen oxides ( NO

x ), particulate matter (PM), and sulfur dioxide ( SO 2 )

. EPA published Appendix Y to p art 51

- Guidelines for BART Determinations Under the Regional Haze Rule in the July 6, 2005 Federal Register to provide guidance to regulatory authorities for making BART determinations

. Chapter 6

, Section 9

, Best Available Retrofit Technology was adopted into the Wyoming Air Quality Standards and Regulations (WAQSR) and became effective on December 5, 2006. The Wyoming D epartment of Environmental Quality, Air Quality Division (Division) will

determine BART for NO

x and PM 10 for each source subject to BART and includ e each determination in

the § 30 8 Wyoming Regional Haze State Implementation Plan (SIP)

.

Section 309 of the R egional Haze Rule (40 CFR 51), Requirements related to the Grand Canyon Visibility Transport Commission , provides s tates that are included within the Transport Region addressed by the Grand Canyon Visibility Transport Commission ( i.e., Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah, and Wyoming ) an alternative to the requirements established in 40FMC Wyoming Corporation

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CFR 51.308. This alternative con trol strategy for improving visibility contains special provisions for addressing SO 2 emissions , which in clude a Market Trading program and a provision for a 2018 SO 2 Milestone. Wyoming submitted a 3 09 Regional Haze SIP to EPA o n December 29, 2003 . As of the date of this analysis, EPA has not taken action on the SIP. Sources that are subject to BART are re quired to
address SO 2 emission s as part of the BART analysis.

On March 8, 2007 FMC Wyoming Corporation (FMC) submitted a BART application for two existing

coal

- fired boilers and one existing natural gas

- fired boiler at the Westvaco Facility in accordance with the requirements of WAQSR Chapter 6 Section 9 ( e )(i)

. A map of FMC Westvaco Facility‟s location is attached as Appendix A.

On April 14, 2008 FMC submitted an addendum to the BART application to address visibility impacts on

an i ndividual unit basis. Updated visibility modeling was performed as part of the application addendum.

BART ELIGIBILITY DETERMINATION :

In August of 2005 the Wyoming Air Quality Division began an internal review of sources that could be subject to BART. This initial effort f ollowed the methods prescribed in 40 CFR p art 51, Appendix Y: Guidelines for BART Determinations U nder the Regional Haze Rule to identify sources and facilities

. The rule requires that States identify and list BART

- eligible sources, which are sources that fall within the 26 source categories, ha ve emission units which were in existence on August 7, 1977 but not in operation before August 7, 1962 and have the potential to emit more than 250 tons per year (tpy) of any visibility impairing pollutant when emis sions are aggregated from all el igible emission units at a stationary source. One hundred two (102) sources at fourteen (14) facilities were identified that could be subject to BART in Wyoming.

The next step for the Air Quality Division was to identify B ART

- eligible sources that may emit any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility. Three pollutants are identified by 4 0 CFR p art 51, Appendix Y as visibility impairing pollutants. They

are su lfur dioxide ( SO 2 )

, nitrogen oxides (NO

x ), and particulate matter (PM). Particulate matter with an aerodynamic diameter of 10 microns or less (PM 10 ) was used as an indicator of PM. In order to determine visibility impairment of each source, a screening a nalysis was performed using CALPUFF. Sources that

emitted over 40 tons of SO 2 or NO

x or 15 tons of PM 10 were included in the screening analysis. Using three years of meteorological data, the screening analysis calculated visibility impacts from sources a t nearby Class I areas. Sources whose modeled 98 th percentile 24

- hour impact or 8 th highest modeled impact, by year, was equal to or greater than 0.5 deciviews (dv) above natural background conditions were determined to be subject to BART. For additional information on the Division‟s screening analysis

see the Visibility Improvement Determination: Screening Modeling section of this analysis

. FMC Westvaco Facility‟s two existing coal

- fired boilers and one existing natural gas

- fired boiler were

determined to be subject to BART. FMC was notified in a letter dated June 14, 2006 of the Division‟s finding.FMC Wyoming Corporation

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DESCRIPTION OF BART ELIGIBLE SOURCES:

FMC Westvaco Facility‟s two existing coal

- fired boilers (NS

- 1A and NS

- 1B) are located at the mono powerhouse . The existing natural gas

- fired boiler (PH

- 3) is located at the sequi powerhouse. All three

units supply 600 lb steam to a common steam hea der for the facility

. High pressure steam is initially fed

into six turbines to generate plant electricity. The s team e xit s the turbines at a pressure of approximately

20 0 lbs and is distributed as process steam to the sequi, mono, ELDM (Evaporation, Lime neutralization, Decahydrate crystallization , and Monohydrate crystallization) , and ca ustic plants that comprise the

Wes tvaco Facility

.

NS

- 1A and NS

- 1B have a design heat input rate of 887 MMBtu/hr and were constructed in 1975. The y

are both wall

- fired, wet

- bottom boilers burning subbituminous coal

. At the time this BART application

was filed combustion air control was u sed to reduce NO

x emissions from the boilers. P articulate matter

emissions from each of the boilers were controlled using an electrostatic precipitator (ESP). SO 2 emission s were controlled by alkaline wet scrubbers

.

Table 1: NS

- 1A and NS

- 1B Coal

- fired B oilers ’ Baseline Operations

Operating Permit 3

- 1

- 1 32 Emission Limits

Source Firing Rate

(MMBtu/hour) Existing

Controls NO

x

(lb/MMBtu) SO 2

(lb/MMBtu) PM/PM 10

(lb/MMBtu)

NS

- 1A 887 Combustion air,

d ry ESP, alkali

wet scrubber 0.7

(3

- hour rolling) 1.2

( 2

- hour fixed) 0.05 (a)

NS

- 1B 887 Combustion air,

d ry ESP, alkali

wet scrubber 0.7

(3

- hour rolling) 1.2

(2

- hour fixed) 0.05 (a)

(a) Operating P ermit 3

- 1

- 132 PM/PM 10 limit for the two boilers is 0.10 lb/MMBtu, however each unit is limited to 45 lb/hr whi ch equates to a 0.0507 lb/MMBtu rate when divided by the maximum heat input rate.

On December 26, 2006 FMC filed a Chapter 6, Section 4 permit application to modify NS

- 1A and NS

- 1B

boilers with the installation of low NO

x burners (LNB) , enhanced overfire air (OFA) , and upgrade s to the two existing alkali wet scrubbers. Air Quality Permit MD

- 5723 was issued July 17, 2007 authorizing the

modifications to the boilers. New emission limits for NO

x , CO, PM, and SO 2 were established in this permitting action th at take effect upon installation of the LNB on each boiler and completion of the wet scrubber upgrades. FMC notified the Division by letter dated August 24 , 2007 that the LNB with OFA and wet scrubber upgrades were installed on NS

- 1A and the unit had succ essfully started up on August 22, 2007 . The new emission limits permitted in MD

- 5723 , as shown in Table 2, are in effect for NS

- 1A.

FMC anticipates installing LNB, OFA, and upgrades to the existing alkali wet scrubber on unit NS

- 1B during the scheduled 2 008 turnaround. Installation of these control measures will subject NS

- 1B to the

emission levels established in MD

- 5723 , as shown in Table 2 below.FMC Wyoming Corporation

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Table 2: NS

- 1A and NS

- 1B Coal

- fired Boilers ’ Modified Operations

Permit MD

- 5723 Emission Limits

Sour ce Permitted

Controls NO

x

(lb/MMBtu) SO 2

(lb/MMBtu) PM/PM 10

(lb/MMBtu ) / (lb/hr)

NS

- 1A LNB, dry ESP,

modified alkali

wet scrubber 0.39

(30

- day rolling) 1.2

(2

- hour fixed)
0.54 (30 day rolling) 0.05 / 45

NS

- 1B LNB, dry ESP,

modified alkali

wet scrubbe r 0.39

(30

- day rolling) 1.2

(2

- hour fixed)
0.54
(30

- day rolling) 0.05 / 45

The natural gas

- fired boiler, PH

- 3

, has a design heat input rate of 336 MMBtu/hr and was constructed in

1967. Clean combustion of natural gas does not typically produce apprec iable amounts of SO 2 or PM 10

. Therefore the boiler is not currently required to control SO 2 or PM 10 emissions through any additional

add

- on control devices. NO

x emissions from PH

- 3 are controlled through combustion air control.

Emissions from PH

- 3 are l isted in Table 3 below. While the unit is not subject to limited operation, it is required to perform an emission test if it operates over 3,000 hours in a calendar year and at least once in

the term of Title V Operating Permit 3

- 1

- 132 permit ending on Se ptember 15, 2009.

Table 3: PH

- 3 Natural Gas

- Fired Boiler Operations

Operating Permit 3

- 1

- 132 Emission Limits

Source Control NO

x (lb/MMBtu) PM/PM 10 (lb/hr)

PH

- 3 Combustion Air

Control 0. 23 8.40

CHAPTER 6, SECTION 9

– BEST AVAILABLE RETROFIT TECHNOLOG Y (BART)

A BART determination is an emission limit based on the application of a continuous emission reduction technology for each visibility impairing pollutant emitted by a source. It is established on a case

- by

- case basis taking into consideration six factors for each proposed BART control. The six factors are : (1) The available retrofit control options, (2) Any pollution control equipment in use at the source , (3) The costs of compliance with control options, (4) The remaining useful life of the faci lity, (5) The energy and non

air quality environmental impacts of control options, and (6) The visibility impacts analysis. A BART determination must address air pollution control measures for each emissions unit or pollutant emitting activity subject to review.FMC Wyoming Corporation

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Visibility control options presented in the application for each of the emissions unit were reviewed using the methodology prescribed in 40 CFR 51 s ubpart Y, as required in WAQSR Chapter 6 Section 9(c)(i). This methodolog y is comprised of five basic steps:

Step 1: Identify all 1 available retrofit control technologies Step 2: Eliminate technically infeasible options Step 3: Evaluate control effectiveness of remaining control technologies Step 4: Evaluate impacts and document the results

Ste p 5: Evaluate visibility impacts

The five steps were applied to each pollutant emitted from the coal

- fired boilers to determine a BART

control measure for NO

x , PM, and SO 2

. Refined modeling of PH

- 3 for this BART analysis shows visibility impacts are belo w screening levels and therefore not subject to additional BART controls. This

conclusion is covered in more detail with in the visibility section of this analysis.

NO

x : INDENTIFY AVAILABLE RETROFIT CONTROL TECHNOLOGIES

FMC identified two primary types o f NO

x controls: combustion control techniques and add

- on control technologies. Fourteen combustion control techniques are indentified in the application. T hese controls focus on reducing combustion temperatures below the NO

x formation temperature of appr oximately

29 0 0 F. O verfire air and low NO

x burners are two commonly used technologies. Both technologies

increase the amount of combustion air to reduce peak combustion temperatures there by lowering NO

x emissions.

In addition to the fourteen combustio n controls, FMC identified three add

- on controls :

1. Selective Catalytic Reduction (SCR)

– SCR is a post combustion control technique in which vaporized ammonia or urea is injected into the flue g as upstream of a catalyst

. NO

x entrained in the flue gas is r educed to molecular nitrogen ( N 2 ) and water. The use of a catalyst facilitates the

reaction at an exhaust temperature range of 300 to 110 0 F

, depending on the type of catalyst

used. When catalyst temperatures are not in the optimal range for the reaction or when too much ammonia is injected into the proces s
, unreacted ammonia can be released to the atmosphere through the stack. This release is commonly referred to as ammonia slip

.

2. Selective Non

- Catalytic Reduction (SNCR )

– S NCR is similar to SCR in that it involves the injection of a reducing agent such as ammonia or urea into the flue gas stream. The reduction chemistry, however, takes place without the aid of a catalyst. SNCR systems rely on appropriate injection temperatures, proper mixing of the re agent and flue gas

, and prolonged retention time in place of the catalyst. SNCR operates at higher temperatures than SCR. The effective temperature range for SNCR is 1500 to 2100 F. SNCR systems are ve ry sensitive to temperature changes and typically ha ve lower NO

x emissions reduction (up to fifty or sixty percent) and higher ammonia slip than SCR systems.

1 Footnote 12 of 40 CFR 51 Appendix Y defines the intended use of „all‟ by stating “...you must identify the most stringent option and a reasonable set of options f or analysis that reflects a comprehensive list of available technologies.”FMC Wyoming Corporation

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3. Sorption (adsorption)

– A post combustion control in which NO

x in the flue gas contacts a carbon, ceramic, or z eolite substrate that contains an ads orbent and chemically binds on the

surface of the material as a nitrate. NO

x adsorption occurs in a temperature range of 350 to

70 0 F. Once the adsorbent has reached saturation, the nitrate

- containing material can be replaced or regenerated. This techno logy is typically applied to internal combustion eng ines and not boilers, therefore only a limited amount of information is available for NO

x adsorption applications on utility or process boilers.

In addition to applying these controls separately, they ca n be combined to increase the overall NO

x reduction

. FMC evaluated LNB and OFA in combination with both SNCR and SCR add

- on controls.

NO

x : ELIMINATE TECHNICALLY INFEASIBLE OPTIONS

FMC did not el i minate any of the seventeen individual control technolog ies as technically infeasible. A review of EPA‟s RACT/BACT/LAER Clearinghouse (RBLC) was done to identify recent control

determinations for modified coal

- fired boilers subject to Prevention of Significant Deterioration (PSD)

review at existing facilities. FMC listed four such modified units in the application, which are presented

in the table below.

Table 4 : RBLC Modification s for Nitrogen Oxides

Facility Firing Rate (MMBtu/hour) Control NO

x (lb/MMBtu)

Mansfield Mill 645 LNB (staged) 0.7

TECO

- Big Bend Station 645 Equipment design

and operation 0.6

W.A. Parish Electric Generating

Station Unit 8 6700 Combustion Tuning (CT), LNB, OFA, &

SCR 0.43

Limestone Electric Generating

Station Units 1 & 2 7863 Water Injection 0.5

After reviewing the RBLC databas e, FMC concluded that LNB with enhanced OFA, LNB with SNCR,

and LNB with SCR are the three dominant technologies used to retro fit existing coal

- fired boilers for controlling NO

x emissions. Based on this conclusion, FMC proposed control option 1 as LNB wit h enhanced OFA. LNB could be installed with no modification to the existing boilers or boiler windboxes. The existing OFA ports would be enlarged to accommodate new har dware to control the air flow.

FMC proposed control option 2 as the installation of S NCR in addition to LNB with enhanced OFA. SNCR would consist of urea injection directly into the combustion zone of the furnace. SNCR injection ports would b e installed through the enhanced OFA ports. The existing ESP on each boiler would be

used to con trol any additional increase in PM 10 emissions.

FMC‟s final control option, option 3, is the installation of SCR in combination with LNB and enhanced

OFA. This option would r equir e the most structural modification because of limited amount of available

s pace to install the associated control equipment. FMC would decommission an existing precipitator to house SCR hardware and install a new pulse jet fabric filter to control particulate emissions.FMC Wyoming Corporation

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NO

x : EVALUATE EFFECTIVENESS OF REMAINING CONTROL TECHNOLOG IES

In the original BART application, FMC proposed a NO

x reduction of approximately 63%, which equates to an emission level of 0.26 lb/MMBtu, based on a performance guarantee from Advanced Combustion Technology, Incorporated. The guarantee was issued bas ed on computational fluid modeling of the coal

combustion process inside each boiler. As mentioned earlier, FMC has already installed LNB and OFA

on unit NS

- 1A . Operational information gathered over the past eight months ind icates that unit NS

- 1A

can onl y achieve the 0.26 lb/MMBtu NO

x emission level when the unit is fully loaded. NS

- 1A is a process boiler and therefore often subject to changing steam demands from plant operations, which is different from a utility boiler that typically operates near full load. NS

- 1A demonstrated that on an 8

- month average of 30

- day rolling averages, the unit can achieve a 0.33 lb/MMBtu NO

x emission rate. In the BART application addendum, FMC proposed that the application of LNB with enhanced OFA could

control NO

x emissi on s to a maximum rate of 0.35 lb/MMBtu , or a 50% reduction in NO

x emissions,

based on the current 0.70 lb/MMBtu N ew S ource P erformance S tandard (NSPS) s ubpart D limit

. Installation of SNCR when used in combination with LNB and enhanced OFA provides an add itional

20% NO

x reduction , which equates to an emission rate of 0.21 lb/MMBtu from each boiler. Using option 3, the installation of SCR, FMC projects a total NO

x reduction efficiency of 85% when operated in

combination with LNB and OFA. The resulting NO

x emission rate with the application of SCR would be

0.1 lb/MMB tu from each boiler.

Table 5 : NO

x Emission Rate s Per Boiler

Control Option Control Technology Resulting NO

x Emission Rate (lb/MMBtu)

Baseline Good Combustion Practices 0.70 (a)

1 LNB, OFA 0. 35 (b)

2 LNB, OFA, SNCR 0.21 ( c )

3 LNB, OFA, SCR 0.1 ( c )

(a) 4 0 CFR part 60

, s ubpart D

, limit

(b) Emission level based on actual operations of the installed control on NS

- 1A

( c ) Advanced Combustion Technology, Inc. performance guarantee

NO

x : EVALUATE I MPACTS AND DOCUMENT RESULTS

FMC evaluated the economic, environmental, and energy impacts associated with the three proposed control options for both NS

- 1A and NS

- 1B

. Vendors‟ quotes were obtained by FMC for control equipment capital costs for each of th e proposed control options. The capital recovery factor used to estimate the annual cost of control was based on a 7% interest rate and a control life of 15 years. Current FMC labor and service costs were used to calculate the annual operating and mainte nance costs. Annual power costs and annualized capital costs associated with downtime for installation of pollution controls

were not included. Economic and environmental costs are summarized in the following two tables.FMC Wyoming Corporation

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Table 6 : NS

- 1A & NS

- 1B Economi c Costs Per Boiler

Cost Baseline Option 1: LNB,

enhanced OFA Option 2: LNB,

enhanced OFA,

SNCR Option 3: LNB,

enhanced OFA,

SCR

Control Equipment Capital Cost $0 $ 1

, 721,091 $ 3,160,918 $ 44

, 719

, 163

Capital Recover Factor N/A 0.1098 0.1098 0.1098

Annual C apital Recovery Costs $0 $ 188,976 $ 347,069 $ 4

, 910

, 164

Annual O&M Costs $0 $ 224,169 $934,782 $ 3

, 231 ,0 13

Annual Cost of Control $0 $ 413,145 $ 1

, 281

, 851 $ 8

, 141

, 177

Table 7 : NS

- 1A & NS

- 1B Environmental Costs Per Boiler

Baseline Option 1: LNB,

enhanced OFA Option 2: LNB,

enhanced OFA,

SNCR Option 3: LNB,

enhanced OFA,

SCR

NO

x Emission Rate (lb/MMBtu) 0.7 0. 35 0.21 0.1

Annual NO

x Emission (tpy) (a) 2719.5 1359.8 815.9 388.5

Annual NO

x Reduction (tpy) (a) N/A 1359. 7 1903.6 2331.0

Annual Cost of Control $0 $ 413,145 $ 1

, 281

, 851 $ 8

, 141

, 177

Cost per ton of R eduction N/A $ 304 $ 673 $ 3,493

Incremental C ost per ton of R eduction N/A $304 $1,597 $16,051

(a) Annual emission s based on individual heat input rate of 887 MMBtu/hr for 8,760 hours of operation per year.

The final step in the BART determination process, Step 5: Evaluate visibility impacts

, for NO

x is

addressed in a comprehensive visibility analysis covering all three visibility impairing pollutants and associate control options

. Th e visibility analysis f ollows Steps 1

- 4 for SO 2 emissions in this application analysis.

PM 10 : INDENTIFY AVAILABLE RETROFIT CONTROL TECHNOLOGIES

FMC reviewed EPA‟s RBLC to identify recent particulate control determinations for modified coal

- fired boilers subject to PSD review a t existing facilities. FMC listed six such modified units in the application, which are presented in the table below. After reviewing the RBLC, FMC proposed four applicable technologies for controlling PM 10 emissions from the two boilers. They are fabri c filters or baghouses, wet and dry ESPs, mechanical collectors (MC), and wet scrubbers (WS).

1. Fabric filters (FF)

– FF are woven pieces of material that collect particles with sizes ranging from

submicron to several hundred microns in diameter at efficien cies generally in excess of 99 % . The layer of dust trapped on the surface of the fabric, commonly referred to as dust cake, is primarily responsible for such high efficiency. Joined pores within the cake act as barrier s to trapFMC Wyoming Corporation

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particulate matter too lar ge to flow through the pores as it travels through the cake. Limitations are imposed by the temperature and corrosivity of the gas and the by adhesive properties of the particles. Most of the energy used to operate the system appears as pressure drop acr oss the bags and associated hardware and ducting.

2. Electrostatic precipitators

– ESPs use electrical forces (charge) to move particulate matter out the gas stream onto collection plates. The particles are given an electrical charge by directing the gas

st ream through a corona, or region in which gaseous ions flow. The charged particles acted upon by an induced electrical field from high voltage electrodes in the gas flow that forces the m to the

walls or collection plates . Once the particles couple with t he collection plates, they must be

removed without re

- entraining them into the gas stream. In dry ESP applications, t his is usually accomplished by physically knocking them loose from the plates and into a hopper for disposal

. Wet ESPs use water to wash the particles from the collector plates into a sump. The efficiency of an ESP is primarily determined by the resistivity of the particle, which is dependent on chemical composition, and also by the ability to clean the collector plates without reintroduci ng the particles back into the gas stream.

3. Mechanical collectors ( cyclones )

– Cyclones funnel the exhaust gas into a vortex where centrifugal force pushes the particulate matter to the sides of a conical shaped vessel. The particles fall down the walls t o a collection point at the bottom. Cyclones are very effective at controlling large particles where the inertial force overwhelms the drag force of the particle and drives the particle to the vessel wall. Smaller particles have stronger drag forces and are more likely to be carried out of the vessel with the exhaust gas. Cyclones do not typically attain

removal efficiencies of either the fabric filter or the ESP on similar applications.

4. Wet scrubber

– Each boiler is currently equipped with an alkali we t scrubber to remove acid gas

and SO 2 emissions from the gas stream. Particulate matter is also controlled by the scrubber. Wet scrubbers can remove particulate matter through impaction, diffusion, interception and/or absorption. Impaction occurs when t he velocity of the particle is high and it collides with the water droplets in the scrubber. Interception is similar to impaction, but when the particle is traveling at lower velocities the surface tension of the water droplet can capture the particle.

D iffusion and absorption occur at lower particle velocities and are affected by chemical composition of both the particle and the water droplet. Wet scrubbers can achieve high particulate matter removal efficienc ies , but they are limited to lower exhaust g as flow rates and temperatures than ESPs or fabric filters. They can also increase stack corrosi on by saturating the

wet scrubber exit gas stream with water , reducing the gas velocity , and lowering the flue gas

temperature to promote co ndensation in the e xhaust stack

.FMC Wyoming Corporation

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Table 8 : RBLC Modifications for Particulate Matter

Facility Firing Rate (MMBtu/hour) Control PM (lb/MMBtu) Inland Paperboard and Packaging, Inc.

Rome Linerboard Mill 565 E lectrostatic Precipitator (ESP) 0.05

Mansfield Mill 645 Single Sta ge Dust

Collector/ESP 0.10

W.A. Parish Electric Generating Station

Unit 7 6700 Fabric Filter 0.085

W.A. Parish Electric Generating Station

Unit 8 6700 Fabric Filter 0.03

W.A. Parish Electric Generating Station

Units 5 & 6 7400 Fabric Filter 0.088

Limes tone Electric Generating Station

Units 1 & 2 7863 Cold Side ESP 0.03

PM 10 : ELIMINATE TECHNICALLY INFEASIBLE OPTIONS

FMC did not eliminate any of the four control technolog ies as technically infeasible. Two of the proposed c ontrols, a hot side dry ESP a nd an alkali wet scrubber, are currently installed on each boiler to
control PM 10 emissions. Based on the current allowable PM emission rate of 45 lb/hr, the boilers are controlled to 0.0507 lb/MMBtu when dividing the emission rate by the maximum heat inp ut of 887 MMBtu/hr. This emission rate is comparable with the PSD determinations identified as possible retrofit technologies in the previous section. FMC states that since the boilers are already equipped with highly efficient particulate controls, they focused on augmenting the current controls with additional control

measures.

FMC proposed the installation of a fabric filter on the wet scrubber bypass stream to reduce PM 10 emissions as o ption 1. The polishing filter would reduce PM 10 emissions withou t significantly lowering the exhaust gas temperature, which is needed to reheat the gas stream leaving the wet scrubber to above the dew point temperature to prevent stack corrosion.

FMC proposed a second option, o ption 2, the installation of an additiona l wet ESP down stream of the

wet scrubber. The existing scrubber bypass would be removed and 100% of the gas stream from the hot

side ESP would be routed to the wet scrubber and the new wet ESP. Treating the inside of the stack with

a corrosion inhibitor helps protect it from the flue gas exiting the wet ESP.

FMC‟s final proposed c ontrol option, o ption 3, is to remove the existing hot

- side ESPs and install new pulse jet fabric filter s t o control particulate emissions emitted from the boilers. The FFs wo uld be installed upstream of the existing wet scrubbers . The higher removal efficiencies of the fabric filters would increase the overall effectiveness of the entire system, including the wet scrubbers.FMC Wyoming Corporation

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PM 10 : EVALUATE EFFECTIVENESS OF REMAINING CONTROL TECHNOLOGIES

Option 1 will treat only the alkali wet scrubber bypass portion of the total exhaust gas stream. Based on operational information provided by FMC, the reduction in PM emissions equates to approximately a 0.01 lb/MMBtu reduction resulting a n et emission rate of 0.04 lb/MMBtu. Redirecting all exhaust gas through the wet scrubber and adding an additional wet ESP after the wet scrubber , option 2, will reduce particulate emissions by 0.0317 lb/MMBtu to 0.019 lb/MMBtu per boiler. Finally, removin g the existing dry ESP a nd installing a fabric filter, o ption 3, will reduce emissions by 0.0357 lb/MMBtu from current operations. This reduction results in a final emission rate of 0.015 lb PM /MMBtu from each boiler.

Table 9 : PM 10 Emission Rates Per Bo iler

Control Option Control Technology Resulting PM 10 Emission Rate (lb/MMBtu)

Baseline Existing hot side ESP and WS 0. 0507 (a)

1 FF on WS bypass 0.04 (b)

2 Wet ESP after WS (c) 0.019 (b)

3 FF control before WS 0.015 (b)

(a) Current permit limit of 4 5 lb/hr divided by maximum heat input rate

(b) “ Emissions Control Analysis Evaluation of Al t ernatives ” prepared by CH2M Hill

( c ) Based upon 100% of the flue gas routed through wet scrubber

PM 10 : EVALUATE IMPACTS AND DOCUMENT RESULTS

FMC evaluated the eco nomic, environmental, and energy impacts associated with the three proposed control options for both NS

- 1A and NS

- 1B. FMC based control equipment capital costs for each of the proposed control options on a technical evaluation study performed by CH2M Hill and equipment vendor

quotes. The same capital recovery factor used to estimate the annual cost of NO

x control was also used to

estimate annual cost to control PM 10 . Current FMC labor and service costs were used to calculate the annual operating and main tenance costs. Annual power costs and annualized capital costs associated with downtime for installation of pollution controls were not included. The following two tables summarize

the e conomic and environmental costs

.FMC Wyoming Corporation

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Table 10 : NS

- 1A & NS

- 1B Economic Costs Per Boiler

Cost Baseline Option 1: FF on WS bypass Option 2: Wet

ESP after WS Option 3:

Replace ESP

with FF

Control Equipment Capital Cost $0 $ 9

, 486

, 434 $ 20

, 766

, 772 $ 23

, 273

, 405

Capital Recover Factor N/A 0.1098 0.1098 0.1098

Annual Capital Recov ery Costs $0 $ 1 ,0 41

, 610 $ 2,280,192 $ 2,555,420

Annual O&M Costs $0 $ 749

, 754 $ 1

, 227

, 425 $ 1

, 560

, 616

Annual Cost of Control $0 $ 1

, 791

, 364 $ 3,507,617 $ 4

, 116

, 036

Table 1 1 : NS

- 1A & NS

- 1B Environmental Costs Per Boiler

Baseline Option 1: FF on

WS bypass Opti on 2: Wet

ESP after WS Option 3:

Replace ESP

with FF

PM 10 Emission Rate (lb/MMBtu) 0.0507 0.04 0.019 0. 0 1 5

Annual PM 10 Emission (tpy) (a) 197.1 155.4 73.8 58.3

Annual PM 10 Reduction (tpy) (a) N/A 41.7 123.3 138.8

Annual Cost of Control $0 $ 1,791,364 $ 3

, 5 07

, 617 $ 4

, 116

, 036

Cost per ton of Reduction N/A $ 4 2

, 958 $ 28,4 48 $ 29,654

Incremental Cost per ton of Reduction N/A $ 4 2

, 958 $ 21

, 033 $ 39,253

(a) Annual emission s based on maximum heat input rate of 887 MMBtu/hr for 8,760 hours of operation per year.

Giv en the high cost of control, FMC did not proceed further to Step 5: Evaluate visibility impacts for

PM 10 . Previous visibility modeling analyses indicate that the contribution in visibility degradation from

PM / PM 10 is minor when compared to the contributin g effects of NO

x and SO 2

. Results from the screening analysis confirmed this conclusion and are discussed in further detail within the comprehensive visibility analysis. The Division did not require FMC to perform additional visibility analyses for the

t hree PM control options.

SO 2 : INDENTIFY AVAILABLE RETROFIT CONTROL TECHNOLOGIES

FMC identified three processes for controlling SO 2 emissions: (1) reducing the sulfur content in the fuel, (2) adsorption of sulfur compounds in the flue gas , and (3) absorpt ion of sulfur compounds

. Wyoming coal typically has lower sulfur content than coal produced in most other states, which makes it difficult to

further reduce the sulfur content. Coal blending can be used to reduce the overall amount of sulfur

combusted in a boiler, but again it is most effective when low sulfur coal is mixed with high sulfur coal.FMC Wyoming Corporation

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A dsorption control systems are designed to capture SO 2 as either a sulfate or sulfite at the surface of a sorbent. Dry alkaline powder, often lime, is injecte d into the exhaust gas upstream of a particulate control

device such as a fabric filter. SO 2 in the gas binds to the surface of the alkaline powder and is captured by the particulate control device for disposal. This control method works best in low mois ture gas streams and when the sorbent has a high affinity for SO 2

.

The absorption process can be categorized as physical or chemical. Physical absorption occurs when the absorbed compound dissolves in the solvent . C hemical absorption occurs when the abs orbed compound

and the solvent react. SO 2 absorption c ontrol tec hnologies identified by FMC are discussed below.

1. A lkali wet scrubber s

– WS remove SO 2 through a bsorption by mass transfer as sol uble SO 2 in the

exhaust gas mixture is dissolved in an alkalin e water solvent that has low volatility under the process conditions. SO 2 diffuses from the gas into the scrubber water when the liquid contains less than the equilibrium concentration of the gaseous SO 2

. The rate of SO 2 mass transfer between the two pha ses is largely dependent on the surface area exposed and the time of contact. A properly designed alkali wet scrubber or gas absorber will provide sufficient contact between the gas and the liquid solvent to allow diffusion of SO 2 . Once the SO 2 enters th e alkaline water phase, it will form a weak acid and react with the alkaline component dissolved in the scrubber

water to form a sulfite or sulfite. The acid/alkali chemical reaction prevents the SO 2 from diffusing back into the flue gas stream. When the alkaline scrubber water is saturated with sulfur compounds , it can be converted to a wet gypsum by

- product that may be sold. SO 2 removal efficiencies for wet scrubbers can be as high as 99%.

2. Spray dryer dry scrubbers

– Dry scrubbers are similar to adsor ption injection systems, however the dry scrubber provides greater contact area and enhances chemical reactivity. A spray dryer dry scrubber sprays an atomize d alkaline slurry into the flue gas upstream of particulate control system, often a fabric filter . Water in the slurry evaporates, hydrolizing the SO 2 into a weak acid,

which reacts with the alkali to form a sulfate or sulfite. The resulting dry product is captured in the particulate control and physically moved from the exhaust gas into a storage b in. The dry by

product maybe dissolved back into the lime slurry or dried and sold as a gypsum product. Spray dryer dry scrubbers typically require lower capital cost than a wet scrubber. They also require

less flue gas after

- treatment. When exha ust ga s leaves the wet scrubber, it is at or near saturation. A wet scrubber can lower exhaust gas temperatures down a temperature range of 110 to 14 0 F, which may lead to condensation in the exhaust stack, causing corrosion. A spray dryer dry

scrubber does no t enhance stack corrosion like a wet scrubber because it will not saturate the

exhaust gas or lower the gas temperature. Removal efficiencies for spray dryer dry scrubbers are in the range of 70% to 95%.FMC Wyoming Corporation

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SO 2 : ELIMINATE TECHNICALLY INFEASIBLE OPTIONS

FM C did not eliminate any of the controls listed above as technically infeasible. However, each boiler currently has an existing alkali wet scrubber installed. Since wet scrubbers are a proven and efficient SO 2 control technology, they focused on ways to e nhance operations of the existing wet scrubbers.

SO 2 : EVALUATE EFFECTIVENESS OF REMAINING CONTROL TECHNOLOGIES

Condensation of the exhaust gas is a critical design factor for the wet scrubbers. About 50% of the exhaust gas from each boiler bypasses the wet scrubber and is used to reheat the gas exiting the wet scrubber to above condensation temperature. FMC investigated ways to increase the amount of exhaust gas routed through the wet scrubber, while maintaining sufficient exhaust temperature to avoid

c ondensation in the exhaust stack. Option 1 is upgrading the wet scrubber by replacing the top section and installing new mist eliminator and wash water system. This upgrade would allow up to 85% of the exhaust gas to enter the wet scrubber. Option 2 inc ludes the same wet scrubber u pgrades as option 1 and

adds a flue gas reheat system prior to the exhaust stack. Reheating the flue gas allows an addition 5% to 10% of the gas to enter the wet scrubber while maintaining the flue gas temperature above conden sation

as it exits the exhaust stack.

The existing wet scrubbers were designed to meet the 40 CFR part 60

, s ubpart D

, emission limit for SO 2 of 1.2 lb/MMBtu. Based on operational experience and design evaluations, FMC proposes that by upgrading the wet s crubber according to option 1, the new emission level will be 0.45 lb/MMBtu. Adding an exhaust gas reheat system and modifying the wet scrubber according to option 2 will reduce

SO 2 emission to 0.30 lb/MMBtu.

Table 1 2 : Emission Rates Per Boiler

Control Option Control Technology Resulting SO 2 Emission Rate (lb/MMBtu)

Existing WS 1.2 (a)

1 WS upgrade 0.45 (b)

2 WS upgrade and stack reheat 0.30 (b)

(a) 4 0 CFR part 60

, s ubpart D

, limit

(b) Advanced Combustion Technology, Inc. performance guarantee

SO 2 : EVALUATE IMPACTS AND DOCUMENT RESULTS

FMC evaluated the economic, environmental, and energy impacts associated with the three proposed control options for both NS

- 1A and NS

- 1B. FMC based control equipment capital costs for each of the proposed control op tions on technical evaluation and equipment vendor quotes. The same capital recovery factor based on 7% interest rate and control life of 15 years used to estimate the annual cost of

NO

x and PM 10 control was also used to estimate annual cost to control SO 2 . Current FMC labor and service costs were used to calculate the annual operating and maintenance costs. Annual power costs and annualized capital costs associated with downtime for installation of pollution controls were not included. The following tw o tables summarize the economic and environmental costs.FMC Wyoming Corporation

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Table 1 3 : NS

- 1A & NS

- 1B Combined Economic Costs

Cost Baseline Option 1: WS upgrade Option 2: WS

upgrade and

stack reheat

Control Equipment Capital Cost $0 $4,660,211 $8,086,762

Capital Recover Fa ctor N/A 0.1098 0.1098

Annual Capital Recovery Costs $0 $511,691 $887,926

Annual O&M Costs $0 $555,291 $ 2

, 625

, 112

Annual Cost of Control $0 $ 1,066,982 $ 3

, 513

, 039

Table 1 4 : NS

- 1A & NS

- 1B Combined Environmental Costs

Baseline Option 1: WS

upgrade Opti on 2: WS

upgrade and

stack reheat

SO 2 Emission Rate (lb/MMBtu) 1.2 0.45 0.30

Annual SO 2 Emission (tpy) (a) 9324.2 3496.6 2331.0

Annual SO 2 Reduction (tpy) (a) N/A 5827.6 6993.2

Annual Cost of Control $0 $1,066,982 $3,513,039

Cost per ton of Reduction N/A $ 183 $ 502

Incremental Cost per ton of Reduction N/A $ 183 $2,099

(a) Annual emission s based on individual heat input rate of 887 MMBtu/hr for 8,760 hours of operation per year.

Step 5: Evaluate visibility impacts for SO 2 is addressed in the comprehen sive visibility analysis covering all three visibility impairing pollutant s and associated control options is shown below

.

VISIBILITY IMPROVEMENT DETERMINATION :

The fifth of five steps in a BART determination analysis, as required by 40 CFR part 51 Appen dix Y, is the degree of Class I area visibility improvement that results from the possible options for control technology. This factor was evaluated for the FMC Westvaco facility by using an EPA

- approved dispersion modeling system (CALPUFF) to predict the change in Class I area visibility. The Division had previously determined that the FMC Westvaco facility was subject to BART based on the results of initial screening modeling that was conducted using current (baseline) emissions from the facility. The screening modeling, as well as m ore refined modeling conducted by the applicant

, is described in detail

below.

Bridger Wilderness Area (WA) and Fitzpatrick WA are the two closest Class I areas to the FMC

Westvaco facility, as shown in F igure 1 below. B ridger W A is located approximately 11 8 kilometers (km) northeast of FMC Westvaco and Fitzpatrick WA is located approximately 15 1 km northeast of the facility.FMC Wyoming Corporation

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Only those Class I areas most likely to be impacted by the Westvaco sources were modeled, as

de termined by source/Class I area locations, distances to each Class I area, and professional judgment considering meteorological and terrain factors. A reas greater than 300 km from Westvaco were excluded

from consideration . All source

- Class I area distanc es from Westvaco to Bridger WA and Fitzpatrick WA exceed 50 km and are less than 300 km, thus falling within the range of recommended CALPUFF application. If impacts are less than the BART threshold for the Class I areas modeled, it can be reasonably assu med that areas at a greater distance and in directions of less frequent plume transport will not experience significant impacts.FMC Wyoming Corporation

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Figure 1

SCREENING MODELING

To determine if the FMC Westvaco facility would be subject to BART, the Division conducted CALPUFF modeling using three years of meteorological data. These data, from 1995

- 1996 and 2001, consisted of surface and upper

- air observations and gridded output from the Mesoscale Model ( MM5 )

. Resolution of the MM5 data was 36

- km for all three of the m odeled years. S ources input to the modeling

included the potential emissions (current operation) from t hree emission units at the Westvaco facility, the

coal

- fired boilers NS

- 1A and NS

- 1B and the gas

- fired boiler PH

- 3

.FMC Wyoming Corporation

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Results of the modeling showed tha t the 98 th percentile value for the change in visibility (delta deciview [Δdv]) was above 0.5 Δ dv for Bridger W A for all three years of meteorolog y, and above 0.5 Δ dv for Fitzpatrick WA for 1996 and 2001 meteorology . As defined in EPA‟s final BART rule, a 98 th perc entile

0.5 Δ dv impact or more from a given source indicates that the source contributes to visibility impairment, and therefore is subject to BART. The results of the screening modeling are shown in the table below.

Results of the Class I Area Screening Modeling

Class I Area Maximum

Modeled Value (Δdv) 98 th

Percentile Value (Δdv)

1995 Bridger WA 2.06 0.75 Fitzpatrick WA 1.00 0.36

1996 Bridger WA 2.79 1.30 Fitzpatrick WA 1.81 0.54

2001 Bridger WA 2.21 1.43 Fitzpatrick WA 1.24 0.63

Δdv = delta deciview

WA = wilderness area

REFINED MODELING

Because of the results of the Division‟s screening modeling, FMC was required to conduct a refined BART analysis that included CALPUFF visibility modeling for the facility. The modeling approach

followe d the requirements described in the Division‟s BART modeling protocol, BART Air Modeling

Protocol

- Individual Source Visibility Assessments for BART Control Analyses (WDEQ

- AQD, September 2006)

.

CALPUFF System

Predicted visibility impacts from the FMC W estvaco sources were determined with the EPA CALPUFF modeling system, which is the EPA

- preferred modeling system for long

- range transport. As described in the EPA Guideline on Air Qualit y Models (Appendix W of 40 CFR p art 51), long

- range transport is

defi ned as modeling with source

- receptor distances greater than 50 km . Because all modeled areas are located more than 50 km from the sources in question, the CALPUFF system was appropriate for use.

The CALPUFF modeling system consists of a meteorological da ta pre

- processor (CALMET), an air dispersion model (CALPUFF), and post

- processor programs (POSTUTIL, CALSUM, CALPOST). The CALPUFF model was developed as a non

- steady

- state air quality modeling system for assessing the

effects of time

- and space

- varying m eteorological conditions on pollutant transport, transformation, and

removal.

CALMET is a diagnostic wind model that develops hourly wind and temperature fields in a three

dimensional, gridded modeling domain. Meteorological inputs to CALMET can include surface and

upper

- air observations from multiple meteorological monitoring stations. Additionally, the CALMETFMC Wyoming Corporation

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model can utilize gridded analysis fields from various mesoscale models such as MM5 to better represent regional wind flows and complex terrain circulations. Associated two

- dimensional fields such as mixing height, land use, and surface roughness are included in the input to the CALMET model. The CALMET model allows the user to “weight” various terrain influence parameters in the vertical and ho rizontal directions by defining the radius of influence for surface and upper

- air stations.

CALPUFF is a multi

- layer, Lagrangian puff dispersion model. CALPUFF can be driven by the three

dimensional wind fields developed by the CALMET model (refined mo de), or by data from a single surface and upper

- air station in a format consistent with the meteorological file s used to drive steady

- state dispersion models. All far

- field modeling assessments described here were completed using the

CALPUFF model in a re fined mode.

CALSUM is a post

- processing program that can operate on multiple CALPUFF output files to combine the results for further post

- processing. POSTUTIL is a post

- processing program that processes

CALPUFF concentrations and wet/dry flux files . The POSTUTIL model operates on one or more output data files from CALPUFF to sum, scale, and/or compute species derived from those that are modeled , and outputs selected species to a file for further post

- processing . C ALPOST is a post

- processing program that can read the CALPUFF (or POSTUTIL or CALSUM) output files, and calculate the impacts to visibility.

All of the refined CALPUFF modeling was conducted with the version of the CALPUFF system that was recognized as the EPA

- approved release at the time of the development of the Division‟s modeling protocol. Version designations of the key programs are listed in the table below.

Key Programs in CALPUFF System
Program Version Level

CALMET 5.53a 040716

CALPUFF 5.711a 040716

CALPOST 5.51 030709

Meteorol ogical Data Processing (CALMET)

As required by the Division‟s modeling protocol, the CALMET model was used to construct the initial

three

- dimensional windfield using data from the MM5 model . Surface and upper

- air data were also input

to CALMET to adjust the initial windfield, but because of the relative scarcity of observations in the modeling domain, the influence of the observations was minimized . Because the MM5 data were afforded a high degree of influence on the CALMET windfields, the Division obtain ed MM5 data at 12

- km resolution that spanned the years 2001

- 2003. Surface, upper

- air, and precipitation data for the domain was incorporated into the CALMET windfield. Locations of the various observations are shown in the figure below. The Division prov ided the BART applicants all raw meteorological inputs for the CALMET

model.

Default settings were used in the CALMET input files for most of the technical options. The following table lists the key user

- defined CALMET settings that were selected.FMC Wyoming Corporation

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Key User

- Defined CALMET Settings

Variable Description Value

PMAP Map projection LCC

DGRIDKM Grid spacing (km) 4

NZ Number of layers 10

ZFACE Cell face heights (m) 0, 20, 40, 100, 140, 320, 580, 1020, 1480, 2220, 3 4 00

RMIN2 Minimum di stance for extrapolation

- 1

IPROG Use gridded prognostic model output 14

RMAX 1 Maximum radius of influence (surface

layer, km) 30

RMAX 2 Maximum radius of influence (layers

aloft, km) 50

TERRAD Radius of influence for terrain (km) 15

R1 Relative weighting of first guess wind field and observations (km) 5

R2 Relative weighting aloft (km) 25FMC Wyoming Corporation

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CALPUFF Modeling Setup

To allow chemical transformations with the recommended CALPUFF chemistry mechanism (MESOPUFF II), the mode l required input of background ozone and ammonia. For ozone, hourly data collected from the following stations were used:

Rocky Mountain National Park (NP) , Colorado
Craters of the Moon National Monument, Idaho Highland, Utah Thunder Basin, Wyoming

Yello wstone NP, Wyoming Centennial, Wyoming Pinedale, Wyoming

For any hour that was missing ozone data from all stations, a default value of 44 parts per billion (ppb) was used by the model as a substitute. For ammonia, a domain

- wide background value of 2 ppb was used.

Discrete receptors for the Class I areas that were modeled (Bridger WA and Fitzpatrick WA) were provided by the Division.

CALPUFF Inputs

– Baseline and Control Options

The first step in the refined modeling analysis was to perform visibili ty modeling for current operation s at the facility (baseline) , followed by modeling for the various control options

. Baseline source release parameters and emissions are shown in the table below , followed by table s with data for the control options.FMC Wyoming Corporation

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Source Parameters and Emissions for the Baseline Scenario

Parameter Baseline

#6 Coal

- Fired

Boiler NS

- 1A #7 Coal

- Fired

Boiler NS

- 1B #4 Gas

- Fired

Boiler PH

- 3

SO 2 Control

- Wet Scrubber

NO

x Control

- Combustion

Controls

PM Control

- ESP SO 2 Control

-

none NOx Control

- Combustion

Controls

PM Control

-

none Heat Input (MMBtu/hr) 887 887 333.6

Base Elevation (m) 1922 1922 1899
Stack Height (m) 91.4 91.4 21.3

Stack Diameter (m) 3.51 3.51 2.29

Stack Te mperature (K) 414.8 414.8 394.3
Exit Velocity (m/s) 17.56 17.56 8.34

SO 2 Emissions (lb/MMBtu) 1.2 0.45 0 .0006

SO 2 Emissions (lb/hr) 1064.4 1064.4 0 .2

H 2 SO 4 Emissions (lb/MMBtu) 0.015 0.015 0

H 2 SO 4 Emissions (lb/hr) 13.4 13.4 0

NO

x Emissions (lb/MMBtu ) 0.7 0.7 0.23

NO

x Emissions (lb/hr) 620.9 620.9 76.7

PM F Emissions (lb/MMBtu) 0.05 07 0.05 07 0.0075

PM F Emissions (lb/hr) 45.0 45.0 2.5

Note: H 2 SO 4 emissions modeled in CALPUFF as SO 4 [H 2 SO 4 * (96/98)] ESP = electrostatic precipitator

K = Kelvin

lb/hr = pounds per hour lb/MMBtu = pounds per million British thermal units

m = meters m/s = meters per second MMBtu/hr = million British thermal units per hour

NO

x = nitrogen oxides

P M F = fine p articulate matter

SO 2 = sulfur dioxideFMC Wyoming Corporation

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Source Parameters and Emissions for BART Control Options

Parameter BART Control

Scenario 1 BART Control

Scenario 2 BART Control

Scenario 3 BART Control

Scenario 4 BART Control

Scenario 5

NO

x Option 1

- LNB/OFA (Baseline SO 2 ) NO

x Option 2

-

LNB/OFA &

SNCR (Baseline SO 2 ) NO

x Option 3

-

LNB/OFA & SCR (Baseline SO 2 ) SO 2 Option 1

–

Scrubber Upgrade, New Bypass (Baseline NO

x ) SO 2 Option 2

–

Scrubber Upgrade, New Bypass &

Reheat (Baseline NO

x )

Boiler

NS

- 1A Boiler

NS

- 1B Boiler

NS

- 1A Boiler

NS

- 1B Boiler

NS

- 1A Boiler

NS

- 1B Boiler

N S

- 1A Boiler

NS

- 1B Boiler

NS

- 1A Boiler

NS

- 1B

SO 2 Emissions (lb/MMBtu) 1.2 1.2 1.2 1.2 1.2 1.2 0.45 0.45 0.30 0.30

SO 2 Emissions (lb/hr) 1064.4 1064.4 1064.4 1064.4 1064.4 1064.4 399.2 399.2 266.1 266.1

HS 2 O 4 Emissions (lb/hr) 13.4 13.4 13.4 13.4 13.4 13. 4 10.3 10.3 9.6 9.6

NO

x Emissions (lb/MMBtu) 0.35 0.35 0.21 0.21 0.1 0.1 0.7 0.7 0.7 0.7

NO

x Emissions (lb/hr) 310.4 310.4 186.3 186.3 88.7 88.7 620.9 620.9 620.9 620.9

PMF Emissions (lb/hr) 45.0 45.0 45.0 45.0 45.0 45.0 45.0 45.0 45.0 45.0

Note: H 2 SO 4 emissions (sulfuric acid mist) modeled in CALPUFF as SO 4 [H 2 SO 4 * (96/98)] lb/hr = pounds per hour lb/MMBtu = pounds per million British thermal units

LNB/OFA = low NO

x burners/overfire air

NO

x = nitrogen oxides

PM F = particulate matter

SCR = selective ca talytic reduction

SNCR = selective non

- catalytic reduction

SO 2 = sulfur dioxideFMC Wyoming Corporation

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Source Parameters and Emissions for the Proposed BART Option

Parameter Proposed BART

SO 2 Option 1

- Scrubber Upgrade

NO

x Option 1

- LNB/OFA

Boiler

NS

- 1A Boiler

NS

- 1B
Stack Temperature (K) 349.8 349.8
Exit Velocity (m/s) 17.56 17.56

SO 2 Emissions (lb/MMBtu) 0.45 0.45

SO 2 Emissions (lb/hr) 399.2 399.2

HS 2 O 4 Emissions (lb/hr) 10.3 10.3

NO

x Emissions (lb/MMBtu) 0. 35 0. 35

NO

x Emissions (lb/hr) 310.4 310.4

PMF Emissions (lb/hr) 45.0 45.0

Note: H 2 SO 4 emissions (sulfuric acid mist)

modeled in CALPUFF as SO 4 [H 2 SO 4 * (96/98)]

K = Kelvin lb/hr = pounds per hour

LNB/OFA = low NO

x burners/overfire air m/s = meters per second

lb/ MMBtu = pounds per million British t hermal units

NO

x = nitrogen oxides PMF = particulate matter

SO 2 = sulfur dioxide

Note that the gas

- fired boiler is not included in the table s for the control option modeling. This is because baseline modeling demonstrated that the contribution to visibil ity impairment from that source was negligible, as described later.

Visibility Post

- Processing (CALPOST) Setup

The changes in visibility were calculated using Method 6 within the CALPOST post

- processor. Method 6 requires input of monthly relative humid ity factors [f(RH)] for each Class I area. Monthly f(RH) factors that were used for Bridger WA and Fitzpatrick WA are shown in the table

below.FMC Wyoming Corporation

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Relative Humidity Factors for CALPOST

Month Bridger WA

Fitzpatrick WA

January 2.50

February 2.30

Ma rch 2.30

April 2.10

May 2.10

June 1.80

July 1.50

August 1.50

September 1.80

October 2.00

November 2.50

December 2.40

According to the final BART rule, n atural background conditions as a reference for determination

of t he Δdv change within CALPOST should be representative of the 20% best natural visibility days. EPA BART guidance provides the 20% best days deciview values for each Class I area on an annual basis, but does not provide species concentration data for the 2 0% best background

conditions.

S pecies concentrations corresponding to the 20% best days were calculated for each Class I area by scaling back the annual average concentrations given in Table 2

- 1 of the EPA document Guidance for Estimating Natural Visibi lity Conditions Under the Regional Haze Rule. A separate scaling factor was derived for each Class I area such that, when multiplied by the g uidance table annual concentrations, the 20% best days dv value for that particular Class I area would be

calculate d. The scaled aerosol concentrations were averaged for the Bridger WA and Fitzpatrick WA because of their geographical proximity and similar annual background visibility. The 20% best days aerosol concentrations that were used for each month are listed in the table below.FMC Wyoming Corporation

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Natura l Background Aerosol Concentrations (μg/m 3 )

Aerosol Component Fitzpatrick WA

Bridger WA

Ammonium Sulfate 0 .045

Ammonium Nitrate 0 .038

Organic Carbon 0 .178

Elemental Carbon 0 .008

Soil 0 .189

Coarse Mass 1.136

Visibility Post

- Processing Results

The r esults of the baseline and control option visibility modeling for each of the two coal

- fired

boilers are shown in the table s below. Baseline 98 th percentile results for each of those units

exceeded 0.05 Δdv at Bridger WA for 2001 and 2003 meteorology. T h e contribution f rom the

gas

- fired boiler (PH

- 3) is negligible. The highest predicted 98 th percentile impact from PH

- 3 for any of the three years is only 0.05 Δdv at Bridger WA and only 0.02 Δdv at Fitzpatrick WA , and

therefore PH

- 3 does not contribute to Class I area visibility impairment

. The conclusion drawn from the baseline modeling was that further modeling for the BART control options would focus on reducing emissions from the coal

- fired boilers NS

- 1A and NS

- 1B.

The refined modeling also focused on reductions in NO

x and SO

x emissions rather than reductions in particulate (PM) emissions. This is because the effect of reduced PM from the proposed control options was not significant. Even with the most stringent control option (fabric filter

before s crubber), the difference in the predicted 98 th percentile visibility impact from the baseline

condition from both coal

- fired units combined using 2001 meteorology was only 0.0 3 Δdv at Bridger WA and 0.0 2 Δdv at Fitzpatrick WA.

The control option proposed by FMC as BART results in an average reduction of 0.3 Δdv in the

98 th percentile result at Bridger WA as compared to the baseline conditions for each unit, and a

reduction of 0.2 Δdv in the 98 th percentile result at Fitzpatrick WA as compared to the baseli ne conditions for each unit. As for the predicted number of days above 0.5 Δdv at Bridger WA and Fitzpatrick WA, the average reduction is 7 days and 2 days, respectively, between the baseline and the proposed option for each unit. These results show that under each control option, the facility would not contribute to Class I area visibility impairment (i.e., the 98 th percentile results

are less than 0.5 Δdv ).FMC Wyoming Corporation

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CALPUFF Visibility Modeling Results: NS

- 1A

Scenario/

Class I Area 2001 2002 2003

98th

Percentile

Value (Δdv) Total

No. of Days >

0.5 Δdv 98th

Percentile

Value (Δdv) Total

No. of Days >

0.5 Δdv 98th

Percentile

Value (Δdv) Total

No. of Days >

0.5 Δdv

Baseline
Bridger WA 0.566 10 0.429 5 0.538 11
Fitzpatrick WA 0.327 4 0.311 2 0.263 1

NO

x Control Option 1

– LNB/OFA
Bridger WA 0.432 5 0.302 3 0.393 2
Fitzpatrick WA 0.252 2 0.247 1 0.206 0

NO

x Control Option 2

– LNB/OFA & SNCR
Bridger WA 0.368 5 0.256 2 0.340 1
Fitzpatrick WA 0.221 1 0.203 1 0.181 0

NO

x Control Option 3

– SCR
Bridger WA 0.321 2 0.225 1 0.295 1
Fitzpatrick WA 0.194 1 0.191 1 0.161 0

SO 2 Control Option 1

– Scrubber Upgrade, New Bypass

Bridger WA 0.404 6 0.358 4 0.386 2
Fitzpatrick WA 0.241 1 0.234 1 0.187 0

SO 2 Control Option 2

- Scrubber Upgrade, New Bypass & Rehe at
Bridger WA 0.384 5 0.339 4 0.34 8 2
Fitzpatrick WA 0.215 1 0.219 1 0.169 0
Proposed BART

– LNB/OFA (NO

x ), Scrubber Upgrade/New Bypass (SO 2 )
Bridger WA 0.275 3 0.179 1 0.260 1
Fitzpatrick WA 0.143 1 0.123 1 0.128 0

Δdv = delta deciview

LNB/OFA = low NO

x burners/overfire air

WA = wilderness areaFMC Wyoming Corporation

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CALPUFF Visibility Modeling Results: NS

- 1B

Scenario/

Class I Area 2001 2002 2003

98th

Percentile

Value (Δdv) Total

No. of Days >

0.5 Δdv 98th

Percentile

Value (Δdv) Total

No. of Days >

0.5 Δdv 98th

Percentile

Value (Δdv) Total

No. of Days >

0.5 Δdv

Baseline
Bridger WA 0.566 10 0.429 5 0.536 11
Fitzpatrick WA 0.327 4 0.312 2 0.263 1

NO

x Control Option 1

– LNB/OFA
Bridger WA 0.432 5 0.303 3 0.394 2
Fitzpatrick WA 0.252 2 0.248 1 0.206 0

NO

x Control Option 2

– LNB/OFA & SNCR
Bridger WA 0.368 5 0.256 2 0.340 1
Fitzpatrick WA 0.221 1 0.204 1 0.181 0

NO

x Control Option 3

– SCR
Bridger WA 0.321 2 0.225 1 0.295 1
Fitzpatrick WA 0.193 1 0.192 1 0.162 0

SO 2 Control Option 1

– Scrubber Upgrade , New Bypass
Bridger WA 0.404 6 0.357 4 0.386 2
Fitzpatrick WA 0.241 1 0.235 1 0.187 0

SO 2 Control Option 2

- Scrubber Upgrade, New Bypass & Reheat

Bridger WA 0.384 5 0.339 4 0.349 2
Fitzpatrick WA 0.216 1 0.219 1 0.169 0
Proposed BART

– LNB/OFA (NO

x ), Scrubber Upgrade/New Bypass (SO 2 )
Bridger WA 0.275 3 0.179 1 0.260 1
Fitzpatrick WA 0.143 1 0.123 1 0.129 0

Δdv = delta deciview

LNB/OFA = low NO

x burners/overfire air

WA = wilderness area

BART DETERMINATION :

NATURAL GAS

- FIRED BOILER (PH

- 3)

The h ighest predicted 98 th percentile impact from PH

- 3 for any of the three years is only 0.05 Δdv at Bridger WA and only 0.02 Δdv at Fitzpatrick WA, significantly below the 0.5 Δdv threshold

. Based on the results of the baseline visibility modeling, the Divis ion determined that the gas

- fired

boiler (PH

- 3) at the Westvaco facility does not contribute to Class I area visibility impairment at

the B ridger WA and Fitzpatrick WA and no additional controls are required by BART for PH

- 3.FMC Wyoming Corporation

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- 6045 BART Application Analysis Page 30

COAL

- FIRED BOILERS (NS

- 1A an d NS

- 1B)

FMC‟s proposed BART control option results in an average reduction of 0.3 Δdv in the 98 th
percentile result at Bridger WA as compared to the baseline conditions for each unit, and a

reduction of 0.2 Δdv in the 98 th percentile result at Fitzpatrick WA as compared to the baseline

conditions for each unit. The 98 th percentile valu es for both units, NS

- 1A and NS

- 1B, were below a 0.3 Δdv increase from background conditions for all three years of meteorology

. Therefore, the proposed BART controls for each unit reduce visibility impacts below the 0.5 Δdv

threshold used in the screenin g analysis to determine if sources contribute to visibility impairment. Based on the results of this analysis, the Division has deter mined that the

installation of l ow NO

x burners with enhanced OFA meeting NO

x emission limit s of 0. 35

lb/MMBtu ( 30

- day roll ing average ) and 310. 5 lb/hr (30

- day rolling) represent s BART for each of

the coal

- fired boilers, N S

- 1A and NS

- 1B . No additional controls are required by BART for

PM/PM 10 emissions from the two boilers and they will continue to meet a PM/ PM 10 emission

lim it of 0.05 lb/MMBtu as set in Air Quality Permit MD

- 5723.

WESTERN BACKSTOP SULFUR DIOXIDE TRADING PROGRAM:

Wyoming is a §309 state and will participate in the Western Backstop S ulfur D ioxide T rading

P rogram should it be triggered. FMC Westvaco evaluated a n SO 2 emission rate of 0.45

lb/MMBtu from the coal

- fired boiler s with upgrades to the existing alkali wet scrubbers in the

BART application and determined that the emission rate is achievable . I n accordance with Wyoming‟s §309 Regional Haze SIP and WAQS R Chapter 6, Section 9, FMC will not be required to meet the proposed emission limit under BART. Instead , FMC will be required to participate in the em ission trading program authorized under Chapter 14 of the WAQSR should

the program be triggered.

CHAPTE R 6, SECTION 4

– PREVENTION OF SIGNIFICANT DETERIORATION (PSD):

FMC‟s Westvaco Facility is a “major emitting facility” under Chapter 6, Section 4

, of the Wyoming Air Quality Standards and Regulations because emissions of a criteria pollutant are

greater t han 250 tpy . Installation of the LNB and OFA as required by BART will result in a CO emission increase above 40 tpy. Under Chapter 6, Section 4

, FMC would be required to submit a permit application addressing the increase in CO emissions and Prevention o f Significant Deterioration (PSD) applicability prior to commencing const ruction to install the LNB and OFA

controls. However, FMC has already permitted the installation of the controls determined to be BART, for both units NS

- 1A and NS

- 1B in Air Quality Permit MD

- 5723. Upon installation of the permitted controls, NS

- 1A and NS

- 1B will be subject to a NO

x limit of 0.39 lb/MMBtu on a

30

- day rolling average, a CO limit of 0.29 lb/MMBtu, SO 2 limits of 1.2 lb/MMBtu on a 2

- hour fixed average and 0.54 lb/MMBtu o n a 30

- day rolling average, and a PM limit of 0.05 lb/MMBtu

or 45 lb/hr. As of August 22, 2007 t hese limits are in effect for NS

- 1A because FMC installed LNB and wet alkali scrubber upgrade s on the unit.FMC Wyoming Corporation

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- 6045 BART Application Analysis Page 31

CHAPTER 5, SECTION 2

– NEW SOURCE PERFORMANCE STA NDARDS (NSPS):

The installation of t he LNB and OFA and wet alkali scrubber upgrades will not change New

Source Performance Standard applicability for the two coal

- fired boilers NS

- 1A and NS

- 1B at the Westvaco Facility

.

CHAPTER 5, SECTION 3

– NATIONAL EMI SSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS (NESHAPs) AND CHAPTER 6, SECTION 6

– HAZARDOUS AIR POLLUTANT (HAP) EMISSIONS AND MAXIMUM AVAILABLE CONTROL TECHNOLOGY (MACT):

The installation of the LNB and OFA and wet alkali scrubber u pgrades will not change 40 CFR

p art 63 applicability for the two coal

- fired boilers NS

- 1A and NS

- 1B at the Westvaco Facility.

CHAPTER 6, SECTION 3

– OPERATING PERMIT:

The Westvaco Facility is a major source under Chapter 6, Section 3 of the Wyoming Air Q uality Standards and Regulations. Operating Permit 3

- 1

- 132 was issued for the facility on October 24,

2007. In accordance with Chapter 6, Section 3 of the Wyoming Air Quality Standards and Regulations (WAQSR), FMC Wyoming Corporation will need to modify their operating permit to include the changes authorized in this permitting action.

CONCLUSION:

The Division is satisfied that the FMC Wyoming Corporation‟s Westvaco Facility will comply with all applicable Wyoming Air Quality Standards and Regulations. The Division proposes to

issue a BART Air Quality Permit for the Westvaco Facility modification.

PROPOSED PERMIT CONDITIONS:

The Division proposes to issue an Air Quality Permit to FMC Wyoming Corporation for the

modification of the Westvaco Facility wi th the following conditions:

1. Authorized representatives of the Division of Air Quality be given permission to enter and inspect any property, premise or place on or at which an air pollution source is located or is being constructed or installed for th e purpose of investigating actual or potential sources of air pollution, and for determining compliance or non

- compliance with any rules, standards, permits or orders.

2. All substantive commitments and descriptions set forth in the application for this p ermit, unless superseded by a specific condition of this permit, are incorporated herein by this reference and are enforceable as conditions of this permit.

3. That FMC Wyoming Corporation shall modify their Operating Permit in accordance with Chapter 6, Section 9(e)(iv) and Chapter 6, Section 3 of the WAQSR.FMC Wyoming Corporation

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- 6045 BART Application Analysis Page 32

4. All notifications, reports and correspondence associated with this permit shall be submitted to the Stationary Source Compliance Program Manager, Air Quality Division, 122 West 25th Street, Cheye nne, WY 82002 and a copy shall be submitted to the District Engineer, Air Quality Division, 510 Meadowview Drive, Lander, WY 82520.

5

. Effective January 1, 2009, e missions from boiler NS

- 1A shal l not exceed the level s below. The l imit s shall apply during all operating periods

.

Pollutant lb/MMBtu lb/hr tpy

NO

x 0. 35 ( 30

- day rolling) 310.5 (30

- day rolling) 1 360 .0

6

. Effective J uly 1, 2009, emissions from boiler NS

- 1 B shall not exceed the level s below.

The l imit s shall apply during all operating periods

.

Pollutant lb/MMBtu lb/hr tpy

NO

x 0. 35 ( 30

- day rolling) 310.5 (30

- day rolling) 1 360 .0

7

. P erformanc e tests shall be conducted prior to the effective dates set forth in conditions 5

and 6 and shall consist of the following:

i. Coal

- fired Boilers (NS

- 1A, NS

- 1B):

NO

x Emissions

– Compliance with the NO

x 30

- day rolling average shall be determined using a continuous emissions monitoring system (CEMS ) certified in accordance with 40 CFR part 60.

8

. Prior to any performance testing required by this permit, a test protocol shall be submitted to the Division for approval, at least 30 days prior to testing. Results of the tests shall be submitted to this office within 45 days of completing the tests.

9

. If the Western Backstop S ulfur D ioxide T rading P rogram is triggered in accordance with Chapter 14 then FMC Wyoming Corporation shall participate in the trading program as required by Chapter 14, Section 2(c)(i).FMC Wyoming Corporation

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- 6045 BART Application Analysis Page 33

1 0

. After the effective dates set forth in conditions 5 and 6, compliance with the limits set

for th in this permit for the NS

- 1A and NS

- 1B coal

- fired boilers shall be determined with

data from the existing continuous monitoring systems as follows:

a. Exceedances of the NO

x limits shall be defined as follows:

i. Any 30

- day rolling average of NO

x emissio ns which exceeds the

lb/MMBtu limit s calculated in accordance with 40 CFR part 60 , subpart

D.

ii. Any 30

- day rolling average calculated using valid data (output concentration and average hourly volumetric flowrate) from the existing CEM equipment which exceed s the lb/hr NO

x limit established in this permit. Valid data shall meet the requirem ents of WAQSR, Chapter 5,

Section 2(j) and follow the compliance provisions and monitoring requirements of §60.4 8Da and §60.4 9Da

. The 30

- day average emission

rate shall b e calculated as the arithmetic average o f hourly emissions with valid data during the previous 30

- day period.

b. FMC Wyoming Corporation shall comply with all reporting and record keeping requirements as specified in WAQSR

, Chap ter 5, Section 2(g) and 40 CFR p art 60, s ubpart D. All excess emissions shall be reported using the procedures and reporting format specified in WAQSR

, Chapter 5, Section 2(g).

1 1

. Records required by this permit shall be maintained for a period of at least five (5) years

and shal l be made available to the Division upon request

.

# Appendix A

Facility Location