Revised October 15, 2009 

Revised Nevada Division of Environmental Protection 

BART Determination Review of 

NV Energy’s Fort Churchill Generating Station Units 1 and 2 

EXPLANATION: BOLD text below identifies the Guidelines for BART Determinations under the Regional Haze 

Rule in Appendix Y of 40 CFR 51.

BACKGROUND 

A BART analysis was completed by CH2M HILL at the request of NV Energy (NVE) for units 1 

and 2 at the Fort Churchill Generating Station (Ft. Churchill) dated October 3, 2008. Fort 

Churchill consists of two BART-eligible units with a generating capacity of 113 megawatts each. 

The fuel currently used in units 1 and 2 is pipeline quality natural gas (PNG) or blended fuel oil 

(No. 6 residual oil and No. 2 distillate fuel oil). In completing the BART analysis, technology 

alternatives were investigated and potential reductions in NOx, SO2 and PM10 emissions rates 

were identified by NVE. NVE’s BART analysis is summarized below, organized according to 

the five step analysis contained in Appendix Y of 40 CFR 51, followed by NDEP’s analysis and 

BART determination. 

NV ENERGY ANALYSIS

STEP 1 – Identify all available retrofit emissions control techniques; alternatives can be 

categorized in three ways: 

• Pollution prevention (used of inherently lower-emitting processes/practices); 

• Use of (and where already in place, improvement in the performance of) add-on 

controls; or 

• Combination of pollution prevention and add-on controls. 

NVE identified the following emission reduction scenarios: 

Potential NOx Control Options (Current controls consist of good combustion practices) 

• Low NOx Burners (LNB) 

• LNB with Flue Gas Recirculation (FGR) 

• LNB with Selective Non-Catalytic Reduction (SNCR) System 

• Rotating Opposed Fire Air (ROFA) with Rotamix 

• LNB with Selective Catalytic Reduction (SCR) System 

Potential SO2 Control Options (No SO2 controls currently implemented) 

• Use of low-sulfur No. 2 fuel oil 

• Spray Dryer Absorber (SDA) 

Potential PM10 Control Options (No PM10 controls currently implemented) 

• Use of low-sulfur No. 2 fuel oil and LNB 

• Dry Electrostatic Precipitator (dry ESP) 

• Wet Electrostatic Precipitator (wet ESP) 

• Fabric Filter 

STEP 2 – Eliminate technically infeasible options based on: 

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Revised October 15, 2009 

• Availability (commercial availability); and 

• Applicability (has it been used on the same or a similar source type). 

NOx 

Technical feasibility for the proposed control options were based on physical constraints, 

boiler configuration and emission reduction potential. However, the installation of overfire air (OFA) was the only control option eliminated due to the potential cost of boiler 

water wall changes. 

 

SO2

Technical feasibility for the proposed control options were based on fuel storage delivery 

constraints, boiler configuration and the emission reduction potential of No. 2 fuel oil. 

None of the control options were eliminated. 

PM10

Technical feasibility for the proposed control options was based on physical, chemical 

and emissions reduction potential. Dry ESP was eliminated due to the uncertainty in 

chemical and physical characteristics of the oil-fired particulate and the increased loading 

from SDA. Likewise, wet ESP was eliminated due to the potential increased particulate 

loading from an SDA not allowing the wet ESP to meet the required control efficiency. 

Fabric filter is expected to function properly only with pre-coating with the increased 

particulate loading from the SDA operation. NVE noted that the current baseline PM10

emissions while burning PNG or No. 2 fuel oil already meet BACT emissions levels. 

STEP 3 – Evaluate control effectiveness of remaining control options: 

• Make sure you express the degree of control using a metric that ensures an 

“apples to apples” comparison of emissions performance levels among options 

(e.g., lb SO2/MMBtu); and 

• Give appropriate treatment and consideration of control techniques that can 

operate over a wide range of emission performance levels (evaluate most 

stringent control level that the technology is capable of achieving plus other 

scenarios). 

NOx

NVE estimates the following control efficiencies with each control option based on firing 

with No. 6 fuel oil: 

1) LNB – 45.4 to 49.5 percent with an emissions level of 0.26 lb/MMBtu (PNG) and 

0.22 lb/MMBtu (low-sulfur No. 2 fuel oil). 

2) LNB with FGR – 53.2 to 56.7 percent with an emissions level of 0.12 lb/MMBtu 

(PNG) and 0.14 lb/MMBtu (low-sulfur No. 2 fuel oil). 

3) LNB with SNCR – 59.1 to 62.1 percent with an emissions level of 0.20 lb/MMBtu 

(PNG) and 0.17 lb/MMBtu (low-sulfur No. 2 fuel oil). 

4) ROFA with Rotamix – 63.0 to 65.7 percent with an emissions level of 0.15 

lb/MMBtu (PNG & low-sulfur No. 2 fuel oil). 

5) LNB with SCR – 86.4 to 87.4 percent with an emissions level of 0.07 lb/MMBtu 

(PNG & low-sulfur No.2 fuel oil).

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SO2

SDA is estimated to achieve 84.8 percent control efficiency and meet an emissions level 

of 0.10 lb/MMBtu. Conversion to low-sulfur No. 2 fuel oil is estimated to achieve 93 

percent control efficiency and meet an emission level of 0.05 lb/MMBtu. 

PM10

Fabric filter is estimated to achieve 46 to 53 percent control efficiency and meet an 

emissions level of 0.015 lb/MMBtu with installation of SDA. The conversion to lowsulfur No. 2 fuel oil with utilization of LNB is estimated to meet an emission level of 

0.03 lb/MMBtu. 

STEP 4 – Impact analysis: 

• Cost of compliance (identify emission units, design parameters, develop cost 

estimates); 

o Baseline emissions rate should represent a realistic depiction of anticipated 

annual emissions for the source. In general, for the existing sources subject 

to BART, the anticipated annual emissions will be estimated based upon 

actual emissions from a baseline period. 

• Energy impacts; 

o Direct energy consumption for the control device, not indirect energy 

impacts. 

• Non-air quality environmental impacts; 

o Solid or hazardous waste generation or discharges of polluted water from a 

control device. 

• Remaining useful life; 

o Can be included in the cost analysis. 

Costs of Compliance

Control options cost comparisons are presented in Tables 3-3, 3-5 and 3- 7 of each NVE 

BART determination report. A complete economic analysis for NOx, SO2 and PM10 is 

presented in the appendix to each BART determination report. 

Energy Impacts 

The installation of LNB is not expected to impact boiler efficiency or forced draft fan 

power usage substantially. Installation of ROFA with Rotamix or SNCR will result in 

additional power requirements ranging from 116 to 313 kilowatts. SCR retrofit will 

increase pressure drop. No energy impact is associated with switching to low-sulfur No. 

2 fuel oil; however additional system pressure drop will result from installation of SDA. 

There is no additional energy impact from PM10 reduction as a result of LNB or burning 

low-sulfur No. 2 fuel oil. Fabric filter and ductwork will add a pressure drop to the 

system. No energy impact costs are included for SO2 and PM10 control options in the 

economic analysis presented in the appendix to each NVE BART determination report. 

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Environmental Impacts 

SNCR, Rotamix and SCR installation could potentially create a visible stack plume, 

which may impact visibility improvements. Transport of ammonia to the site may be an 

issue in the event of an accidental release. No environmental impact is associated with 

switching to low-sulfur No. 2 fuel oil or installation of an SDA. No negative 

environmental impacts are expected from the utilization of new LNB, switching to low 

sulfur fuel, or utilizing a fabric filter. 

Remaining Useful Life

The remaining useful life is estimated to be 23 years from the installation of BART 

controls for units 1 and 2. 

STEP 5 – Determine visibility impacts (improvements): 

• Run the model at pre-control and post-control emission rates; 

• Determine net visibility improvement; 

• Compare 98th percent days for pre- and post-control runs. 

Modeling for pre-control and post-control emission rates demonstrates an improvement 

in visibility based on the BART conclusions presented by NVE for units 1 and 2 at Fort 

Churchill. The NOx emission rate (0.40 lb/MMBtu) modeled is in excess of the proposed 

NVE BART limit (0.28 lb/MMBtu - annual). Consequently, the modeling results show a 

lesser improvement in visibility than would be achieved with NVE’s proposed BART 

limit. Modeling results for other technically feasible control options were not presented. 

NDEP ANALYSIS 

Based on the information provided in NVE’s October 2008 BART determination reports, NDEP 

concurs with each BART determination for units 1 and 2 at Fort Churchill, with the exception of 

the installation of only LNB for control of NOx emissions and the associated NOx emission 

limits. For both units, BART for SO2 is use of PNG and/or low-sulfur No. 2 fuel oil with an 

emission limit of 0.05 lb/MMBtu, 24-hr average. For PM10, BART is also PNG and/or lowsulfur No. 2 fuel oil but with an emission limit of 0.03 lb/MMBtu, 3-hr average. 

For NOx, NDEP established a baseline emissions scenario using Acid Rain Data from calendar 

years 2002 through 2007. NDEP used the average of the two consecutive years of the highest 

annual NOx emissions to establish the NOx baseline emissions. NVE’s cost and control 

efficiencies presented for each control technology were taken at face-value and used in NDEP’s 

cost analysis and BART determination. The control technologies were ordered from highest to 

lowest control efficiency. NDEP’s economic analysis summary is presented in Table 1. 

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Revised October 15, 2009 

TABLE 1 

NDEP ECONOMIC ANALYSIS SUMMARY

Ft. Churchill 1

Current 

Operation 

(Uncontrolled) LNB w/SCR

ROFA 

w/Rotamix LNB w/SNCR LNB w/FGR LNB

Capital Cost $0 $35,781,250 $5,250,940 $4,416,563 $1,610,000 $1,050,000

First Year O&M Cost $0 $705,037 $695,193 $424,800 $320,219 $45,200

First Year Debt Service $0 $3,794,816 $974,564 $468,403 $170,750 $111,359

Total Annual Cost $0 $4,499,853 $1,669,757 $893,203 $490,969 $156,559

Base Heat Input (MMBtu) 5,472,541

Total Heat Input allowed 

(MMBtu) 11,561,448

Base emissions (tons) 1209

NOx Removal Rate % 0.0% 87.4% 65.7% 62.1% 56.7% 49.5%

NOx Removed (Tons) 0 1057 794 751 686 598

NOx Emission Rate (Tons) 1209 152 415 458 524 611

NOx Emission Rate 

(lb/MMBtu) 0.056 0.152 0.167 0.191 0.223

First Year Cost ($/ton 

removed) $4,259 $2,102 $1,190 $716 $262

Incremental Cost ($/ton) $10,787 $17,842 $6,161 $3,842 $262

NOx Control

Ft. Churchill 2

Current 

Operation 

(Uncontrolled) LNB w/SCR

ROFA 

w/Rotamix LNB w/SNCR LNB w/FGR LNB

Capital Cost $0 $35,781,250 $9,189,145 $4,416,563 $1,610,000 $1,050,000

First Year O&M Cost $0 $685,698 $664,514 $393,739 $320,219 $45,200

First Year Debt Service $0 $3,794,816 $974,564 $468,403 $170,750 $111,359

Total Annual Cost $0 $4,480,514 $1,639,078 $862,142 $490,969 $156,559

Base Heat Input (MMBtu) 5,197,003

Total Heat Input allowed 

(MMBtu) 11,561,448

Base emissions (tons) 862

NOx Removal Rate % 0.0% 86.4% 63.0% 59.1% 53.2% 45.4%

NOx Removed (Tons) 0 745 543 510 459 391

NOx Emission Rate (Tons) 862 117 319 353 404 471

NOx Emission Rate 

(lb/MMBtu) 0.045 0.123 0.136 0.155 0.181

First Year Cost ($/ton 

removed) $6,014 $3,017 $1,692 $1,070 $400

Incremental Cost ($/ton) $14,082 $23,103 $7,296 $4,972 $400

NOx Control

NDEP specifically reviewed the cost per ton of NOx removed for each unit at Fort Churchill and 

determined that installation of LNB with FGR meets the BART criteria, with associated first 

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year costs of $716 and $1,070/ton of NOx removed for units 1 and 2, respectively. These values 

are considered cost effective. The cost data from the tables above are presented graphically in 

Figure 1. NDEP also considered the Clean Air Act factors of expected emission rates, emissions 

performance levels, expected emissions reductions, energy impacts, non-air quality 

environmental impacts and modeled visibility impacts in Nevada’s control technology 

determination. NDEP concluded based on a review of the economic analysis that the $/ton of 

NOx removed increased significantly for LNB with SNCR, ROFA and SCR technologies with 

only slight improvements in visibility. 

FIGURE 1 

LEAST COST ENVELOPE

Ft. Churchill Unit 1 

ROFA w/Rotamix

LNB w/SNCR

LNB w/FGR

LNB $0

$500,000

$1,000,000

$1,500,000

$2,000,000

$2,500,000

$3,000,000

$3,500,000

$4,000,000

$4,500,000

$5,000,000

0 200 400 600 800 1000 1200

Tons of NOx Removed

Annual Costs ($)

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Revised October 15, 2009 

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Ft. Churchill Unit 2 

ROFA w/Rotamix

LNB w/SNCR

LNB w/FGR

LNB $0

$500,000

$1,000,000

$1,500,000

$2,000,000

$2,500,000

$3,000,000

$3,500,000

$4,000,000

$4,500,000

$5,000,000

0 100 200 300 400 500 600 700 800

Tons of NOx Removed

Annual Costs ($)

Based on this review, NDEP concludes that for NOx the installation of LNB with FGR with an 

emission level at 0.20 lb/MMBtu for unit 1 and 0.16 lb/MMBtu for unit 2, on a 12-month rolling 

average, is BART. 

NDEP anticipates greater visibility improvement upon implementation of BART than shown in 

NVE’s October 2008 BART report, which is based on a NOx emission rate of 0.40 lb/MMBtu. 

The annual NOx BART emissions are 38 to 51 percent of the rates modeled by NVE, while the 

total annual BART emissions are 53 percent of the modeled rates, therefore the visibility 

improvement due to BART should improve significantly from that modeled.