STATE FACILITY_NAME ORISPL_CODE UNITID OP_YEAR ASSOC_STACKS PRG_CODE_INFO SUM_OP_TIME NUM_MONTHS_REPO

AZ Navajo Generating Station 4941 1 2001 ARP 7904.48 12

AZ Navajo Generating Station 4941 1 2002 ARP 8516.85 12

AZ Navajo Generating Station 4941 1 2003 ARP 7598.23 12

AZ Navajo Generating Station 4941 2 2001 ARP 8642.05 12

AZ Navajo Generating Station 4941 2 2002 ARP 8189.05 12

AZ Navajo Generating Station 4941 2 2003 ARP 8430.2 12

AZ Navajo Generating Station 4941 3 2001 ARP 7840.86 12

AZ Navajo Generating Station 4941 3 2002 ARP 8542.56 12

AZ Navajo Generating Station 4941 3 2003 ARP 7151.81 12

2001 to 2003 Unit 1 0.36 7616

Unit 2 0.36 8120

Unit 3 0.34 7913

tons/day Unit 1 32.8

Unit 2 34.9

Unit 3 32.2

Unit 1 0.24 7616

Unit 2 0.24 8210

Unit 3 0.24 7913

tons/day if LNB were baseline

Unit 1 21.9 90% capacity factor

Unit 2 23.6

Unit 3 22.8
SO2_MASS NOX_RATE NOX_MASSCO2_MASSHEAT_INPUT NOx lb/mmbtu avg heat input

1062.752 0.3699 10841.19 5878709 57297411.5 0.378418072 7248.726

1272.894 0.3543 11630.77 6684087 65147474.9 0.35705958 7649.245

1098.857 0.3358 10272.41 6197593 60405414.4 0.340115637 7949.932

1183.303 0.3568 12356.19 7043405 68649157.5 0.359980849 7943.62

1151.675 0.347 11677.84 6828040 66550066.1 0.350948892 8126.714

1232.274 0.3579 12686.04 7170757 69890458.7 0.363026262 8290.486

1733.476 0.3258 10822.04 6740012 65692125.8 0.329477662 8378.179

1582.628 0.3577 12260.06 6946138 67701146.3 0.362181873 7925.159

1049.112 0.3205 8661.887 5456420 53182543.7 0.325741734 7436.236
Navajo Generating Station

Unit 1 Unit 2 Unit 3 Facility Wide

Avg operating hours (01-03) 7616 8120 7913 7883

Avg Heat Input (2001-2003) 8007 8420 7845 8091

Baseline (2001-03) 0.36 0.36 0.34 0.35

Limit with LNB+SOFA 0.24 0.24 0.24 0.24

Avg emissions 01-03 10,976 12,308 10,554 33,837

Avg emissions LNB+SOFA 7,317 8,205 7,450

Emissions at 0.08 lb/MMBtu 2,439 2,735 2,483 7,657

Emissions at 0.05 lb/MMBtu 1,524 1,709 1,552 4,786

80% reduction on baseline 0.072 0.072 0.068

80% reduction on LNB 0.048 0.048 0.048

% reduction if limit is 0.08 from baseline 78% 78% 76%

% reduction if limit is 0.05 from baseline 86% 86% 85%

% reduction if limit is 0.08 from LNB+SOFA 67% 67% 67%

% reduction if limit is 0.05 from LNB+SOFA 79% 79% 79%

Hg 270 lb/yr facility wide

1.410413583
ton/day

Notes Unit 1 Unit 2 Unit 3

hr/yr

MMBtu/hr

lb/MMBtu 32.90 35.08 32.29

30-day rolling avg - PSD limit 23.06 24.25 22.59

0.299146 0.30869 0.300194

lb/MMBtu

lb/MMBtu
Table 5 from TSD for proposed BART determination for NGS

Option (#) Cost or Cost Effectiveness[1] Unit 1 Unit 2 Unit 3

Baseline Rate 0.49 0.45 0.46

Avg Heat Input (2001-2003) 7616 8120 7913

Avg operating hours (01-03) 8007 8420 7845

LNB + SOFA + SCR (Units 1 – 3) Total Capital Investment ($) $212,000,000 $281,000,000 $212,000,000 

(Option 4) Total Annual Cost ($/yr) $28,951,500 $36,945,000 $28,951,500 

Expected Emission 

(lb/MMBtu) 0.08 0.08 0.08

% NOx Reduction from 

Baseline 84% 82% 83%

TPY NOx Reduced 12,500 12,650 11,795

Cost Effectiveness $2,316 $2,921 $2,455 

LNB + SOFA on Unit 2, LNB + 

SOFA + SCR on Units 1 and 3 Total Capital Investment ($) $212,000,000 $14,000,000 $212,000,000 

(Option 3) Total Annual Cost ($/yr) $28,951,500 $1,622,000 $28,951,500 

Expected Emission 

(lb/MMBtu) 0.08 0.24 0.08

% NOx Reduction from 

Baseline 84% 47% 83%

TPY NOx Reduced 12,500 7,180 11,795

Cost Effectiveness ($/ton) $2,316 $226 $2,455 

LNB + SOFA + SNCR on Units 1 – 

3 Total Capital Investment ($) $26,000,000 $26,000,000 $26,000,000 

(Option 2) Total Annual Cost ($/yr) $8,809,333 $8,809,333 $8,809,333 

Expected Emission 

(lb/MMBtu) 0.2 0.2 0.2

% NOx Reduction from 

Baseline 59% 56% 57%

TPY NOx Reduced 8,842 8,547 8,070

Cost Effectiveness ($/ton) $996 $1,031 $1,092 

LNB + SOFA on Units 1 – 3 Total Capital Investment ($) $14,000,000 $14,000,000 $14,000,000 

(Option 1a) Total Annual Cost ($/yr) $1,622,000 $1,622,000 $1,622,000 

Expected Emission 

(lb/MMBtu) 0.2 0.2 0.2

% NOx Reduction from 

Baseline 59% 56% 57%

TPY NOx Reduced 8,842 8,547 8,070

Cost Effectiveness ($/ton) $183 $190 $201 

LNB + SOFA on Units 1 – 3 Total Capital Investment ($) $14,000,000 $14,000,000 $14,000,000 

(Option 1) Total Annual Cost ($/yr) $1,622,000 $1,622,000 $1,622,000 

Expected Emission 

(lb/MMBtu) 0.24 0.24 0.24

% NOx Reduction from 

Baseline 51% 47% 48%

TPY NOx Reduced 7,622 7,180 6,829

Cost Effectiveness ($/ton) $213 $226 $238 
[1] TPY NOx reduced (SRP) and Cost Effectiveness in $/ton (SRP) were calculated using baseline emission rates of 0.49, 0.45, and 0.46 lb/M

ates of 0.49, 0.45, and 0.46 lb/MMBtu for Units 1 – 3, respectively. TPY NOx reduced (EPA) and Cost Effectiveness in $/ton (EPA) were calculated using b

n $/ton (EPA) were calculated using baseline emission rates of 0.35, 0.37, and 0.31 lb/MMBtu for Units 1 – 3, respectively with post-SCR control NOx em

ctively with post-SCR control NOx emissions of 0.06 lb/MMBtu.
Adapted Table 5 from TSD for proposed BART determination for NGS using average baseline emission rates, heat inputs, a

Option (#) Cost or Cost Effectiveness[1] Unit 1 Unit 2 Unit 3

Baseline Rate (2004 - 2006) 0.35 0.37 0.31

Avg Heat Input (2004-2006) 8184 8050 7814

Avg operating hours (04-06) 8126 7841 8352

Baseline emissions 11,638 11,677 10,116

LNB + SOFA + SCR (Units 1 – 3) Total Capital Investment ($) $212,000,000 $281,000,000 $212,000,000 

(Option 4) Total Annual Cost ($/yr) $28,951,500 $36,945,000 $28,951,500 

Expected Emission 

(lb/MMBtu) 0.08 0.08 0.08

% NOx Reduction from 

Baseline 77% 78% 74%

TPY NOx Reduced 8,978 9,152 7,505

Cost Effectiveness $3,225 $4,037 $3,858 

LNB + SOFA on Unit 2, LNB + 

SOFA + SCR on Units 1 and 3 Total Capital Investment ($) $212,000,000 $14,000,000 $212,000,000 

(Option 3) Total Annual Cost ($/yr) $28,951,500 $1,622,000 $28,951,500 

Expected Emission 

(lb/MMBtu) 0.08 0.24 0.08

% NOx Reduction from 

Baseline 77% 35% 74%

TPY NOx Reduced 8,978 4,103 7,505

Cost Effectiveness ($/ton) $3,225 $395 $3,858 

LNB + SOFA + SNCR on Units 1 – 

3 Total Capital Investment ($) $26,000,000 $26,000,000 $26,000,000 

(Option 2) Total Annual Cost ($/yr) $8,809,333 $8,809,333 $8,809,333 

Expected Emission 

(lb/MMBtu) 0.2 0.2 0.2

% NOx Reduction from 

Baseline 43% 46% 35%

TPY NOx Reduced 4,988 5,365 3,589

Cost Effectiveness ($/ton) $1,766 $1,642 $2,454 

LNB + SOFA on Units 1 – 3 Total Capital Investment ($) $14,000,000 $14,000,000 $14,000,000 

(Option 1a) Total Annual Cost ($/yr) $1,622,000 $1,622,000 $1,622,000 

Expected Emission 

(lb/MMBtu) 0.2 0.2 0.2

% NOx Reduction from 

Baseline 43% 46% 35%

TPY NOx Reduced 4,988 5,365 3,589

Cost Effectiveness ($/ton) $325 $302 $452 

LNB + SOFA on Units 1 – 3 Total Capital Investment ($) $14,000,000 $14,000,000 $14,000,000 

(Option 1) Total Annual Cost ($/yr) $1,622,000 $1,622,000 $1,622,000 

Expected Emission 

(lb/MMBtu) 0.24 0.24 0.24

% NOx Reduction from 

Baseline 31% 35% 23%

TPY NOx Reduced 3,658 4,103 2,284

Cost Effectiveness ($/ton) $443 $395 $710 
[1] TPY NOx reduced (SRP) and Cost Effectiveness in $/ton (SRP) were calculated using baseline emission rates of 0.49, 0.45, and 0.46 lb/M
emission rates, heat inputs, and operating hours from 2004-06

Incremental Costs

Unit 1 Unit 2 Unit 3

LNB - SNCR (2009 SRP costs) $5,404 $5,693 $5,506

SNCR-SCR (2009 SRP costs) $5,048 $7,429 $5,144

LNB - SCR (2009 SRP costs) $5,137 $6,995 $5,235

baseline - LNB (2009 SRP costs) $443 $395 $710
ates of 0.49, 0.45, and 0.46 lb/MMBtu for Units 1 – 3, respectively. TPY NOx reduced (EPA) and Cost Effectiveness in $/ton (EPA) were calculated using b

$/ton (EPA) were calculated using baseline emission rates of 0.35, 0.37, and 0.31 lb/MMBtu for Units 1 – 3, respectively with post-SCR control NOx emis

vely with post-SCR control NOx emissions of 0.06 lb/MMBtu.
Adapted from TSD for proposed BART determination for NGS

Table below uses updated cost information from 2010 and 2012 from SRP

Option (#)

Cost or Cost 

Effectiveness[1] Unit 1 Unit 2 Unit 3

Baseline Rate (2001 - 2003) 0.36 0.36 0.34

Avg Heat Input (2001-2003) 7616 8120 7913

Avg operating hours (01-03) 8007 8420 7845

Baseline emissions 10,976 12,308 10,554

SCR (Units 1 – 3) Total Capital Investment $151,825,000 $205,808,000 $186,528,000 

(Option 4) Total Annual Cost ($/yr) $21,579,000 $27,835,000 $25,601,000 

Cost represents SCR only, does not 

include LNB/SOFA

Expected Emission 

(lb/MMBtu) 0.08 0.08 0.08

% NOx Reduction from 

2001 - 2003 Baseline 78% 78% 76%

TPY NOx Reduced 8,537 9,573 8,070

Cost Effectiveness of SCR 

only $2,528 $2,908 $3,172 

Cost represents SCR+LNB/SOFA Total Capital Investment of 

SCR+LNB/SOFA $166,825,000 $220,808,000 $201,528,000

Total Annual Cost of 

SCR+LNB/SOFA $23,317,000 $29,573,000 $27,339,000

Cost Effectiveness of 

SCR+LNB/SOFA $2,731 $3,089 $3,388

SNCR on Units 1 – 3 Total Capital Investment $13,066,667 $13,066,667 $13,066,667 

(Option 2) Total Annual Cost ($/yr) $7,847,333 $7,847,333 $7,847,333 

Cost represents SNCR only, does 

not include LNB/SOFA

Expected Emission 

(lb/MMBtu) 0.15 0.15 0.15

% NOx Reduction from 

2001 - 2003 Baseline 58% 58% 56%

TPY NOx Reduced 6,403 7,180 5,898

Cost Effectiveness ($/ton) $1,226 $1,093 $1,331 

Cost represents SNCR+LNB/SOFA Total Capital Investment of 

SNCR+LNB/SOFA $28,066,667 $28,066,667 $28,066,667 

Total Annual Cost of 

SNCR+LNB/SOFA $9,585,333 $9,585,333 $9,585,333 

Cost Effectiveness of 

SNCR+LNB/SOFA $1,497 $1,335 $1,625 

SNCR on Units 1 – 3 Total Capital Investment $13,066,667 $13,066,667 $13,066,667 

(Option 2a) Total Annual Cost ($/yr) $7,847,333 $7,847,333 $7,847,333 
Cost represents SNCR only, does 

not include LNB/SOFA

Expected Emission 

(lb/MMBtu) 0.18 0.18 0.18

% NOx Reduction from 

2001 - 2003 Baseline 50% 50% 47%

TPY NOx Reduced 5,488 6,154 4,966

Cost Effectiveness ($/ton) $1,430 $1,275 $1,580 

Cost represents SNCR+LNB/SOFA Total Capital Investment of 

SNCR+LNB/SOFA $28,066,667 $28,066,667 $28,066,667 

Total Annual Cost of 

SNCR+LNB/SOFA $9,585,333 $9,585,333 $9,585,333 

Cost Effectiveness of 

SNCR+LNB/SOFA $1,747 $1,558 $1,930 

LNB + SOFA on Units 1 – 3 Total Capital Investment $15,000,000 $15,000,000 $15,000,000 

(Option 1) Total Annual Cost ($/yr) $1,738,000 $1,738,000 $1,738,000 

LNB/SOFA were installed in 2009-

2011

Expected Emission 

(lb/MMBtu) 0.24 0.24 0.24

% NOx Reduction from 

2001 - 2003 Baseline 33% 33% 29%

TPY NOx Reduced 3,659 4,103 3,104

Cost Effectiveness ($/ton) $475 $424 $560 

Notes

[1] TPY NOx reduced (SRP) and Cost Effectiveness in $/ton (SRP) were calculated using baseline emission rates of 0.49, 0.45, and 0.46 lb/M

In January 20, 2012 letter from Kelly Barr (SRP) to Deborah Jordan (EPA), SRP provided updated cost estimates for LNB/SOFA, 

For EPA cost estimates, see Excel workbook in docket titled "EPA cost analysis for NGS.xlsx"
SRP Incremental Costs

Unit 1 Unit 2

LNB/SOFA to SNCR+LNB/SOFA(@0.18) $4,290 $3,826

SNCR+LNB/SOFA (@0.18)) to 

SCR+LNB/SOFA $4,504 $5,846

LNB/SOFA to SCR+LNB/SOFA $4,424 $5,089

Unit 1 Unit 2

2010 SRP total annual costs of 

SCR+LNB/SOFA(@0.08) $23,317,000 $29,573,000

2010 EPA total annual cost of 

SCR+LNB/SOFA (@0.055) $18,701,576 $23,521,090

26,180

2010 EPA total annual cost of 

SCR+LNB/SOFA (@0.08) $17,757,647 $22,577,161

tpy reduced (@0.055 lb/MMBtu) from 

01-02 baseline 9,299 10,427

EPA Average Cost effectiveness of 

SCR+LNB/SOFA (@0.055) $2,011 $2,256

EPA Average Cost effectiveness of 

SCR+LNB/SOFA (@0.08) $2,080 $2,359

$3,069

EPA Incremental Costs

Unit 1 Unit 2

LNB/SOFA to SNCR+LNB/SOFA (@0.18) $4,290 $3,826

LNB/SOFA to SCR+LNB/SOFA (@0.055) $3,008 $3,444

SNCR+LNB/SOFA (@0.18) to 

SCR+LNB/SOFA (@0.055) $2,392 $3,261

19,480

$1,216

$1,486
16,608

$1,745

10,865

$486 $480

of 0.49, 0.45, and 0.46 lb/MMBtu for Units 1 – 3, respectively. TPY NOx reduced (EPA) and Cost Effectiveness in $/ton (EPA) were calculated using baseli

 estimates for LNB/SOFA, SNCR, and SCR
Unit 3 Average

$4,214 $4,110

$5,720 $5,357

$5,155 $4,889

Unit 3 Average

$27,339,000

$21,794,549 *Note that EPA's cost estimates in other spreadsheet are for SCR only (witho

$20,850,620 *Note that EPA's cost estimates in other spreadsheet are for SCR only (witho

8,846 28,573

$2,464 $2,244 $2,240.50

$2,584 $2,341

Unit 3 Average

$4,214 $4,110

$3,493 $3,315

$3,147 $2,933
/ton (EPA) were calculated using baseline emission rates of 0.35, 0.37, and 0.31 lb/MMBtu for Units 1 – 3, respectively with post-SCR control NOx emiss
spreadsheet are for SCR only (without LNB/SOFA)

spreadsheet are for SCR only (without LNB/SOFA)
tively with post-SCR control NOx emissions of 0.06 lb/MMBtu.
SCR Costs Based on 2010 EPA revisions to SRP estimates

Total Annual Cost NOx removed 

$/year tons per year

LNB/SOFA $5,214,000 10,865

SNCR (@0.18) $23,541,999 16,608

SNCR (@0.15) $23,541,999 19,480

SCR (@0.08) $61,185,427 26,180

SCR (@0.055) $64,017,215 28,573

$0

$10,000,000

$20,000,000

$30,000,000

$40,000,000

$50,000,000

$60,000,000

$70,000,000

0 5,000 10,000 15,000 20,000 25,000 30,000 35,000

T

otal Annual C

ost (all 3 units)

Total tons per year NOx removed (all 3 units)

Least Cost Envelope (EPA estimates)

LNB/SOFA

SNCR (@0.15)

SCR (@0.05)
LNB/SOFA* SNCR+LNB/SOFA SCR+LNB/SOFA 

(EPA estimate)

Total Capital Cost ($ 

millions)

$45 $84 $541 

Total Annual Costs

($ millions)

$5 $29 $64 
SCR (SRP 

estimate)

$589 

$80