Revised October 15, 2009 

Revised Nevada Division of Environmental Protection 

BART Determination Review of 

NV Energy’s Tracy Generating Station Units 1, 2 and 3 

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, 2 and 3 at the Tracy Generating Station (Tracy) dated October 3, 2008. Tracy consists of three 

BART eligible units with a generating capacity of 251 megawatts (MW), of which unit 1 is a 55 

MW, unit 2 is 83 MW and unit 3 is 113 MW. The Title V permit allows burning pipeline quality 

natural gas (PNG) or blended residual (No. 2 and No. 6 and non-PCB mineral oil) 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 Appendix Y, 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) 

• Unit 1 – Use of low-sulfur No. 2 fuel oil 

• Unit 2 – Use of low-sulfur No. 2 fuel oil or Spray Dryer Absorber (SDA) 

• Unit 3 - Use of low-sulfur No. 2 fuel oil or Spray Dryer Absorber (SDA) 

Potential PM10 Control Options (No PM10 controls currently implemented) 

• Unit 1 - No control proposed. 

• Unit 2 – Use of low-sulfur No. 2 fuel oil and LNB, or dry Electrostatic 

Precipitator (dry ESP), or wet Electrostatic Precipitator (wet ESP) or Fabric 

Filter 

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Revised October 15, 2009 

• Unit 3 – Use of low-sulfur No. 2 fuel oil and LNB, or dry ESP, or wet ESP or 

Fabric Filter 

STEP 2 – Eliminate technically infeasible options based on: 

• 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 

wall changes. 

 

SO2

Technical feasibility for the proposed control option was based on fuel storage delivery 

constraints, boiler configuration, and on the ability of low-sulfur No. 2 fuel oil to achieve 

SO2 reduction. 

PM10 

Unit 1 

NVE indicated that Tracy unit 1 is considered to meet BART PM10 emissions levels 

when burning either PNG or low-sulfur No. 2 fuel oil.

Units 2 and 3 

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 

when used in conjunction with SDA. Fabric filter is expected to function properly only 

with pre-coating and the increased particulate loading from the SDA operation. 

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: 

1) LNB - unit 1 at 8.4 percent, unit 2 at 38.7 percent, and unit 3 at 16.4 percent. 

2) LNB with FGR - unit 1 at 41.1 percent, unit 2 at 51.4 percent, and unit 3 at 28.8 

percent. 

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Revised October 15, 2009 

3) LNB with SNCR - unit 1 at 31.3 percent, unit 2 at 54 percent, and unit 3 at 37.3 

percent. 

4) ROFA with Rotamix - unit 1 at 49.1 percent, unit 2 at 52 percent, and unit 3 at 45.2 

percent. 

5) LNB with SCR - unit 1 at 74.5 percent, unit 2 at 85.2 percent, unit 3 at 78.3 percent.

SO2

Unit 1 

Control efficiency not estimated. NVE indicated that unit 1 is unable to burn 100 percent 

No. 2 fuel oil because capital improvements would be required. 

Units 2 and 3 

Control efficiency for SDA estimated at 84.8 percent with an emissions level of 0.10 

lb/MMBtu. NVE indicated that units 2 and 3 are unable to burn 100 percent No. 2 fuel 

oil because capital improvements would be required. 

PM10

Unit 1 

Control efficiency not stated. Unit is considered to meet BART PM10 emissions levels 

when burning either PNG or low-sulfur No. 2 fuel oil. 

Units 2 and 3 

Control efficiency for fabric filter is estimated at 76.9 percent with an emissions level of 

0.015 lb/MMBtu. Conversion to No. 2 fuel oil with LNB is estimated to meet an 

emissions level of 0.03 lb/MMBtu (3-hr average). 

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 (except the 

unit 1 report, which does not include Table 3-7) of each NVE BART determination 

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Revised October 15, 2009 

report. An economic analysis of the control options 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 55 to 239 kilowatts. SCR retrofit will 

increase pressure drop. No energy impacts for SO2 reduction are 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 for are included 

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

report for SO2 and PM10 control options. 

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 for SO2 emissions 

reduction. No negative environmental impacts are expected from the utilization of new 

LNB’s, switching to low-sulfur No. 2 fuel oil, or utilizing a fabric filter for PM10

emissions reduction. 

Remaining Useful Life

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

controls for units 1, 2 and 3. 

STEP 5 – Determine visibility impacts (improvements): 

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

• 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, 2 and 3 at 

Tracy. The NOx emission rate (0.40 lb/MMBtu) modeled by NVE is in excess of their 

proposed BART limit (0.25 lb/MMBtu for unit 1, 0.29 lb/MMBtu for unit 2 and 0.27 

lb/MMBtu for unit 3 all on an annual basis). Consequently, the modeling results show 

less 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, 2 and 3 at Tracy, with the exception of the 

installation of only LNB for control of NOx emissions at units 2 and 3, and the proposed NOx

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Revised October 15, 2009 

emission limits at all three units. For all Tracy units, BART for SO2 is use of PNG and/or lowsulfur No. 2 fuel oil with an emission limit of 0.05 lb/MMBtu, based on a 24-hr averaging 

period. For PM10, BART is also PNG and/or low-sulfur 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 

economic 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. 

TABLE 1 

NDEP ECONOMIC ANALYSIS SUMMARY

Tracy Unit 1

Current 

Operation 

(Uncontrolled) LNB w/SCR

ROFA 

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

Capital Cost $0 $21,175,000 $7,389,835 $1,820,000 $4,431,875 $1,232,000

First Year O&M Cost $0 $194,090 $129,900 $83,589 $68,330 $22,000

First Year Debt Service $0 $2,245,736 $783,736 $193,022 $470,027 $130,661

Total Annual Cost $0 $2,439,826 $913,636 $276,611 $538,357 $152,661

Base Heat Input (MMBtu) 1,772,289

Total Heat Input allowed 

(MMBtu) 6,403,560

Base emissions (tons) 221

NOx Removal Rate % 0.0% 74.5% 49.1% 41.1% 31.3% 8.4%

NOx Removed (Tons) 0 164 108 91 69 1

NOx Emission Rate (Tons) 221 56 112 130 152 202

NOx Emission Rate (lb/MMBtu) 0.064 0.127 0.147 0.171 0.228

First Year Cost ($/ton 

removed) $14,840 $8,432 $3,050 $7,794 $8,235

Incremental Cost ($/ton) $27,2 7 $36,082 -$12,103 $7,632 $8,235

NOx Control

9

2

Tracy Unit 2

Current 

Operation 

(Uncontrolled) LNB w/SCR LNB w/SNCR

ROFA 

w/Rotamix LNB w/FGR LNB

Capital Cost $0 $31,812,500 $4,624,375 $8,013,408 $2,156,000 $1,540,000

First Year O&M Cost $0 $400,266 $201,968 $317,342 $169,768 $33,200

First Year Debt Service $0 $3,373,907 $490,443 $849,870 $228,657 $163,326

Total Annual Cost $0 $3,774,173 $692,411 $1,167,212 $398,425 $196,526

Base Heat Input (MMBtu) 2,591,991

Total Heat Input allowed 

(MMBtu) 8,795,040

Base emissions (tons) 321

NOx Removal Rate % 0.0% 85.2% 54.0% 52.0% 51.4% 38.7%

NOx Removed (Tons) 0 273 173 167 165 124

NOx Emission Rate (Tons) 321 47 148 154 156 197

NOx Emission Rate (lb/MMBtu) 0.037 0.114 0.119 0.120 0.152

First Year Cost ($/ton 

removed) $13,803 $3,995 $6,994 $2,415 $1,582

Incremental Cost ($/ton) $30,7 8 -$73,973 $399,253 $4,954 $1,582

NOx Control

7

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Revised October 15, 2009 

Tracy Unit 3

Current 

Operation 

(Uncontrolled) LNB w/SCR

ROFA 

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

Capital Cost $0 $35,862,500 $9,189,145 $4,431,875 $2,072,000 $1,232,000

First Year O&M Cost $0 $593,848 $548,326 $236,432 $354,865 $45,200

First Year Debt Service $0 $3,803,433 $974,564 $470,027 $219,748 $130,661

Total Annual Cost $0 $4,397,281 $1,522,890 $706,459 $574,613 $175,861

Base Heat Input (MMBtu) 5,485,741

Total Heat Input allowed 

(MMBtu) 10,074,000

Base emissions (tons) 795

NOx Removal Rate % 0.0% 78.3% 45.2% 37.3% 28.8% 16.4%

NOx Removed (Tons) 0 622 359 296 229 130

NOx Emission Rate (Tons) 795 172 435 498 566 664

NOx Emission Rate (lb/MMBtu) 0.063 0.159 0.182 0.206 0.242

First Year Cost ($/ton 

removed) $7,067 $4,240 $2,383 $2,511 $1,349

Incremental Cost ($/ton) $10,928 $13,005 $1,952 $4,047 $1,349

NOx Control

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

determined that installation of LNB with FGR for units 1 and 2, as well as LNB with SNCR for 

unit 3, meets the BART criteria. Associated first year costs range from $2,383 to $3,050/ton of 

NOx removed. These values are considered cost effective. The cost data from the tables above 

are presented graphically for each unit 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 for units 1 and 2 increased significantly for 

LNB with SNCR, ROFA with Rotamix, and SCR with only slight improvements in visibility. 

Similarly, the $/ton of NOx removed for units 3 increased significantly for ROFA with Rotamix 

and SCR with only slight improvements in visibility. 

NDEP concludes that for NOx the installation of LNB with FGR with an emission limit of 0.15 

lb/MMBtu for unit 1 and 0.12 lb/MMBtu for unit 2, as well as LNB with SNCR with an emission 

limit of 0.19lb/MMBtu for unit 3, 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 27 to 49 percent of the rates modeled by NVE, while the 

total annual BART emissions are 50 percent of the modeled rates, therefore the visibility 

improvement due to BART should improve significantly from that modeled. 

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Revised October 15, 2009 

FIGURE 1 

LEAST COST ENVELOPE

Tracy Unit 1 

ROFA w/Rotamix

LNB w/FGR

LNB w/SNCR

LNB

$0

$500,000

$1,000,000

$1,500,000

$2,000,000

$2,500,000

$3,000,000

0 20 40 60 80 100 120 140 160 180

Tons of NOx Removed

Annual Costs ($)

Tracy Unit 2 

LNB w/SNCR

ROFA w/Rotamix

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

0 50 100 150 200 250 300

Tons of NOx Removed

Annual Costs ($)

Page 7 of 8 
Revised October 15, 2009 

Page 8 of 8 

Tracy Unit 3 

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

Tons of NOx Removed

Annual Costs ($)