Revised October 22, 2009 

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Revised Nevada Division of Environmental Protection

BART Determination Review of 

NV Energy’s Reid Gardner 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 Reid Gardner Generating Station (Reid Gardner) dated October 3, 2008. Reid 

Gardner consists of three BART-eligible units with a nominal generating capacity of 110 

megawatts (MW) each. A fourth unit (265 MW) is not BART-eligible. The units are wall-fired 

boilers, which burn primarily bituminous coal. 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 LNB and OFA) 

• Low NOx Burners (LNB) with Over-Fire Air (OFA) 

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

• Rotating Opposed Fire Air (ROFA) with Rotamix 

• LNB with Selective Catalytic Reduction (SCR) System

• ROFA with SCR 

Potential SO2 Control Options – (Current controls consist of soda ash scrubber for SO2) 

• Dry Flue Gas Desulfurization (FGD) System 

• Dry Sorbent Injection 

• Furnace Sorbent Injection 

• New Wet FGD System 

• Improve or upgrade wet soda ash FGD system operation 

Cost-effective scrubber upgrades considered: 

• Eliminate bypass reheat 

• Install liquid distribution rings 

• Install perforated trays 

• Use organic acid additives 

• Improve or upgrade scrubber auxiliary system equipment 
Revised October 22, 2009 

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• Redesign spray header or nozzle configuration 

Potential PM10 Control Options – (Current controls consist of a mechanical collector. As 

part of the planned environmental upgrade pursuant to a 2007 consent decree, the 

mechanical collector is being removed and new pulse jet fabric filter is being installed for 

units 1 through 3.) 

• Upgrade the Existing Mechanical Collector 

• Electrostatic Precipitator 

• Fabric Filter (presently planned for installation by July 1, 2010) 

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 was based on physical constraints, 

boiler configuration and emission reduction potential. Enhancing the existing or 

installing new LNBs and OFA is considered to be a capital cost, combustion technology 

retrofit that may require boiler water wall tube replacement. Neural Net Boiler Controls 

should be considered as a supplementary or polishing technology, but not a stand-alone 

basis. Due to previous experience with ROFA, NVE does not consider ROFA as a standalone technology option. No control options were eliminated. 

 

SO2

With the fabric filter installation, the scrubber venturi section will be opened further to 

reduce draft loss through the equipment, and the scrubber operation will be improved to 

primarily remove SO2 in the scrubber vessel. Only scrubber upgrades and new lime / 

limestone wet scrubber technology options can equal or exceed the removal efficiency of 

the current wet soda ash scrubber. Therefore, only these two alternatives were 

considered technically feasible. The new wet lime / limestone scrubber option is 

eliminated because little additional scrubber capital or operating cost is required by 

improving the current wet soda ash scrubber. No additional scrubber upgrades beyond 

those identified above were considered, as the upgrades accomplish many of the same 

purposes. 

PM10

Removal of the mechanical collector will eliminate the pressure drop and allow the full 

range of particulate sizing to the fabric filter. Upgrade to the mechanical collector will 

not yield as great a level of emission reduction as fabric filter, and therefore, the option is 

not technically feasible. The new electrostatic precipitator is not technically feasible 

either because the potential level of emissions reduction is not as great as with the fabric 

filter installation already planned. 

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 
Revised October 22, 2009 

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• 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 with OFA - unit 1 at 21.3 percent, unit 2 at 23.7 percent, and unit 3 at 6.5 

percent and an emission level of 0.39 lb/MMBtu – annual average. 

2) LNB with OFA and SNCR – unit 1 at 40.9 percent, unit 2 at 42.7 percent, and unit 3 

at 29.9 percent and an emission level of 0.23 lb/MMBtu. 

3) ROFA with Rotamix – unit 1 at 57.7 percent, unit 2 at 59.0 percent, and unit 3 at 38.3 

percent and emission levels of 0.16 lb/MMBtu for units 1 and 2, and 0.20 lb/MMBtu 

for unit 3. 

4) LNB with OFA and SCR – unit 1 at 81.6 percent, unit 2 at 82.2 percent, unit 3 at 78.2 

percent and an emission level of 0.07 lb/MMBtu.

5) ROFA with SCR – unit 1 at 81.6 percent, unit 2 at 82.2 percent, unit 3 at 78.2 percent 

and an emission level of 0.07 lb/MMBtu.

SO2

The projected emission rate for an upgraded wet soda ash FGD system is 95 percent SO2 

removal or less than 0.15 lb/MMBtu. 

PM

The guaranteed PM10 control technology emission rate is 0.015 lb/MMBtu with 

installation of fabric filter. 

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, you will estimate the anticipated annual emissions 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 cost comparisons are presented for NOx and PM10 in Tables 3-2 and 3-4, 

respectively of each NVE BART determination report for units 1 through 3 at Reid 
Revised October 22, 2009 

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Gardner. An economic analysis for NOx is presented in the appendix to each BART 

determination report. There will be no economic impacts due to improving the current 

wet soda ash scrubber operation for SO2. A comparison of technologies on the basis of 

costs, design control efficiencies, and tons of PM10 removed was not done because fabric 

filter is considered to be BART. 

Energy Impacts 

The installation of LNB with OFA for NOx control is not expected to impact the boiler 

efficiency to a large degree or force draft fan power usage. Installation of ROFA with 

Rotamix will result in additional power requirements ranging from 343 to 746 kilowatts. 

SCR retrofit will increase pressure drop. Upgrading the existing wet soda ash FGD 

system operation for SO2 control will not require additional power. The energy impacts 

are included in the economic analysis presented in the appendix to each NVE BART 

determination report. Fabric filter installation for PM10 control is expected to result in a 

net energy reduction due to removal of the mechanical collector. 

Environmental Impacts 

CO emissions would be the same or lower than prior levels with ROFA. SNCR and SCR 

installation could impact the salability and disposal of fly ash due to ammonia levels and 

could potentially create a visible stack plume. Transport of ammonia to the site may be 

an issue in the event of an accidental release. No environmental impacts are anticipated 

in improving the wet soda ash scrubber operation or installation of fabric filter. The 

environmental impacts have not been quantified in the economic analysis presented in the 

appendix to each NVE BART determination report. 

 

Remaining Useful Life

The remaining useful life is estimated to be 20 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 through 3 at 

Reid Gardner. The NOx emission rate (0.46 lb/MMBtu) modeled is in excess of the 

proposed NVE BART limit (0.39 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

NDEP’s review of NVE’s October 2008 BART determination reports for Reid Gardner resulted 

in revisions to all of NVE’s BART determinations except the control technologies proposed as 
Revised October 22, 2009 

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BART for SO2 and PM10. NDEP concurs that BART for SO2 is the existing wet soda ash FGD 

and BART for PM10 is a fabric filter, for the three BART units. 

Nevada utilized NVE’s cost and control efficiencies, as presented for each control technology in 

NDEP’s NOx BART economic analysis and control technology determination. The control 

technologies were ordered in range of efficiency from highest to lowest control efficiency. 

NDEP’s economic analysis summary for NOx is presented in Table 1. 

TABLE 1 

NDEP ECONOMIC ANALYSIS SUMMARY

Reid-Gardner Unit 1

Current 

Operation 

(Uncontrolled) ROFA w/SCR

LNB w/OFA 

& SCR

ROFA 

w/Rotamix

LNB w/OFA 

& SNCR LNB w/OFA

Capital Cost $0 $38,484,900 $35,048,000 $7,884,900 $6,945,500 $4,448,000

First Year O&M Cost $0 $1,313,191 $1,029,801 $613,952 $396,248 $80,000

First Year Debt Service $0 $4,081,555 $3,717,051 $836,241 $736,612 $471,737

Total Annual Cost $0 $5,394,746 $4,746,852 $1,450,193 $1,132,860 $551,737

Base Heat Input (MMBtu) 9,815,313

Total Heat Input allowed 

(MMBtu) 10,643,400

Base emissions (tons) 2,267

NOx Removal Rate % 0.0% 81.6% 81.6% 57.7% 40.9% 21.3%

NOx Removed (Tons) 0 1850 1850 1308 927 483

NOx Emission Rate (Tons) 2267 417 417 959 1340 1784

NOx Emission Rate (lb/MMBtu) 0.085 0.085 0.195 0.273 0.364

First Year Cost ($/ton 

removed) $2,916 $2,566 $1,109 $1,222 $1,143

Incremental Cost ($/ton) $7,280 $6,085 $833 $1,308 $1,143

NOx Control

Reid-Gardner Unit 2

Current 

Operation 

(Uncontrolled) ROFA w/SCR

LNB w/OFA 

& SCR

ROFA 

w/Rotamix

LNB w/OFA 

& SNCR LNB w/OFA

Capital Cost $0 $38,484,900 $35,048,000 $7,884,900 $6,945,500 $4,448,000

First Year O&M Cost $0 $1,388,071 $1,078,551 $661,760 $418,657 $80,000

First Year Debt Service $0 $4,081,555 $3,717,051 $836,241 $736,612 $471,737

Total Annual Cost $0 $5,469,626 $4,795,602 $1,498,001 $1,155,269 $551,737

Base Heat Input (MMBtu) 10,501,749

Total Heat Input allowed 

(MMBtu) 10,643,400

Base emissions (tons) 2,445

NOx Removal Rate % 0.0% 82.2% 82.2% 59.0% 42.7% 23.7%

NOx Removed (Tons) 0 2010 2010 1443 1044 580

NOx Emission Rate (Tons) 2445 435 435 1003 1401 1866

NOx Emission Rate (lb/MMBtu) 0.083 0.083 0.191 0.267 0.355

First Year Cost ($/ton 

removed) $2,721 $2,386 $1,038 $1,106 $952

Incremental Cost ($/ton) $7,001 $5,813 $860 $1,299 $952

NOx Control
Revised October 22, 2009 

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Reid-Gardner Unit 3

Current 

Operation 

(Uncontrolled) ROFA w/SCR

LNB w/OFA 

& SCR

ROFA 

w/Rotamix

LNB w/OFA 

& SNCR LNB w/OFA

Capital Cost $0 $38,484,900 $35,048,000 $7,884,900 $6,945,500 $4,448,000

First Year O&M Cost $0 $1,320,114 $1,000,893 $543,568 $345,970 $80,000

First Year Debt Service $0 $4,081,555 $3,717,051 $836,241 $736,612 $471,737

Total Annual Cost $0 $5,401,669 $4,717,944 $1,379,809 $1,082,582 $551,737

Base Heat Input (MMBtu) 10,063,851

Total Heat Input allowed 

(MMBtu) 10,836,120

Base emissions (tons) 2,268

NOx Removal Rate % 0.0% 78.2% 78.2% 38.3% 29.9% 6.5%

NOx Removed (Tons) 0 1774 1774 869 678 147

NOx Emission Rate (Tons) 2268 494 494 1400 1590 2121

NOx Emission Rate (lb/MMBtu) 0.098 0.098 0.278 0.316 0.421

First Year Cost ($/ton 

removed) $3,045 $2,660 $1,588 $1,596 $3,742

Incremental Cost ($/ton) $4,444 $3,688 $1,560 $1,000 $3,742

NOx Control

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

determined that installation of ROFA with Rotamix for units 1 through 3 is BART for NOx, with 

associated first year costs of $1,038 to $1,588/ton of NOx removed, depending on the unit 

evaluated. 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 the LNB with OFA and SNCR, and ROFA 

with SCR technologies without correspondingly significant improvements in visibility. 

In order to determine the BART emission limits for NOx and PM10, NDEP established baseline 

emissions scenarios for NOx using acid rain data and for PM10 using annual emissions reported 

to NDEP, from calendar years 2001 through 2007. NDEP used the average of the two 

consecutive years of the highest annual emissions to establish the baseline emissions for NOx and 

PM10 in lb/MMBtu. The control efficiencies provided in NVE’s BART analyses were then 

applied to the baseline NOx emission rates to calculate the BART emission limits. The BART 

emission limits for PM10 were also calculated using the capacity factors presented in NVE’s 

BART analyses and the NDEP baseline data. 

To determine the BART emission limits for SO2, NDEP initially (for the January 2009 FLM 

review draft) used acid rain data from 2001 through 2007 in establishing a baseline emissions 

scenario for SO2. The SO2 acid rain data for Reid Gardner contained periods of invalid data 

which NDEP omitted from the calculation of baseline SO2 emissions. In light of the long 

operational history of the SO2 controls, NDEP then used the 98th percentile emissions values to 

establish SO2 BART emission limits of 0.25 lb/MMBtu for Reid Gardner’s units. These BART 

emission limits allowed for future operation within 98 percent of historical emissions (after 

discard of the invalid data) and provided some flexibility during transition to a different postBART operating scenario including operation under a balanced draft versus force draft scenario 

due to the installation of the fabric filter and a potential change in coal type. 
Revised October 22, 2009 

Page 7 of 8 

FIGURE 1 

LEAST COST ENVELOPE

Reid-Gardner Unit 1 

ROFA w/Rotamix

LNB w/OFA

LNB w/OFA & SCR

LNB w/OFA & 

SNCR

$0

$1,000,000

$2,000,000

$3,000,000

$4,000,000

$5,000,000

$6,000,000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Tons of NOx Removed

Annual Costs ($)

Reid-Gardner Unit 2 

ROFA w/Rotamix

LNB w/OFA

LNB w/OFA & SCR

LNB w/OFA & 

SNCR

$0

$1,000,000

$2,000,000

$3,000,000

$4,000,000

$5,000,000

$6,000,000

0 500 1000 1500 2000 2500

Tons of NOx Removed

Annual Costs ($)
Revised October 22, 2009 

Page 8 of 8 

Reid-Gardner Unit 3 

ROFA w/Rotamix

LNB w/OFA

LNB w/OFA & SCR

LNB w/OFA & 

SNCR

$0

$1,000,000

$2,000,000

$3,000,000

$4,000,000

$5,000,000

$6,000,000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Tons of NOx Removed

Annual Costs ($)

However, based on USEPA, FLM and NGO comments on the public review draft regarding the 

BART SO2 emission limits for Reid Gardner, NDEP re-evaluated NV Energy’s BART analyses 

for Reid Gardner and the use of acid rain data. In light of Nevada’s further evaluation of the acid 

rain data, which is not a compliance dataset, Nevada decided to incorporate recent emissions data 

collected under the 40 CFR Part 60 requirements, which is a compliance dataset. The BART 

analyses submitted by NV Energy depended on emissions data representing the period prior to 

the installation of pulse jet fabric filter (a requirement of the consent decree described in section 

6.5.2.2 of Nevada’s RH SIP). 

Baghouses were installed at Reid Gardner in late 2008 and early 2009 upstream of the FGD 

system, so there is now a limited emission dataset considering the performance of baghouses 

coupled with wet soda ash FGD and flue balancing. These data, particularly the Part 60 data, 

provided a higher level of confidence that the facility can not only comply with the 0.25 

lb/MMBtu limit, but also indicated that the BART limit can be lowered to 0.15 lb/MMBtu 

without jeopardizing compliance with the limit. 

NDEP concludes that for NOx the installation of ROFA with Rotamix with an emission level at 

0.20 lb/MMBtu for unit 1 and unit 2, and 0.28 lb/MMBtu for unit 3, on a 12-month rolling 

average, is BART. NDEP concludes that BART for SO2 is the existing wet soda ash FGD with 

emission limits of 0.15 lb/MMBtu, 24-hour average, for all three units and BART for PM10 is 

fabric filter with emission limits of 0.015 lb/MMBtu, 3- hour average, for all three units. 

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 0.46 lb/MMBtu, 

an SO2 rate of 0.40 lb/MMBtu, and a PM10 rate of 0.03 lb/MMBtu. 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.