Year Total NOx (tons) Heat Input (MMBtu) Emission Rate

2001 34,019 191,638,695 0.355 2002 35,569 199,398,687 0.357 2003 31,620 183,478,417 0.345 2004 33,986 197,247,286 0.345 2005 33,221 191,786,039 0.346 2006 34,744 195,629,519 0.355 2007 35,253 196,676,299 0.358 2008 34,803 199,136,340 0.3495 2009 30,501 184,315,616 0.331 2010 24,427 173,473,615 0.282 2011 19,837 180,463,627 0.220 2012 16,468 164,966,570 0.200

AVG (01-08) 34,152 194,373,910 0.351

AVG (09-12) 175,804,857This spreadsheet is from the proposed rulemaking, with the transcription error corrected in column C

Actual CAMD data Installation years Avg of 01-08 34,152

final rule effective date of 1/1/2013 as reported in

proposed rule, with transcription error Step 1: with correction of transcription error Step 2: PLUS with

adjustment of final rule effective date to 12/31/13

Year **From proposal: 5-**

**yr BART as if LNB not yet installed**  **From Proposal 5 yr**

**BART actual LNB install**  **5 yr BART actual LNB install**  **5 yr BART actual**

**LNB install**

install years by 2018 by 2018 by 2018 by 2018 2001 34,019 34,019 34,019 34,019 2002 35,569 35,569 35,569 35,569 2003 31,620 31,620 31,620 31,620 2004 33,986 33,986 33,986 33,986 2005 33,221 33,221 33,221 33,221 2006 34,744 34,744 34,744 34,744 2007 35,253 35,253 35,253 35,253 2008 34,803 34,803 34,803 34,803 2009 34,152 30,500 30,500 30,500 2010 34,152 24,427 24,427 24,427 2011 34,152 19,837 19,837 19,837 2012 34,152 23,325 23,325 23,325 2013 34,152 23,325 23,325 23,325 2014 34,152 23,325 23,325 23,325 2015 34,152 23,325 23,325 23,325 2016 34,152 23,325 23,325 23,325 2017 34,152 23,325 23,325 23,325 2018 5,345 5,343 5,345 23,325 2019 5,345 5,343 5,345 5,345 2020 5,345 5,343 5,345 5,345 2021 5,345 5,343 5,345 5,345 2022 5,345 5,343 5,345 5,345 2023 5,345 5,343 5,345 5,345 2024 5,345 5,343 5,345 5,345 2025 5,345 5,343 5,345 5,345 2026 5,345 5,343 5,345 5,345 2027 5,345 5,343 5,345 5,345 2028 5,345 5,343 5,345 5,345 2029 5,345 5,343 5,345 5,345 2030 5,345 5,343 5,345 5,345 2031 5,345 5,343 5,345 5,345 2032 5,345 5,343 5,345 5,3452033 5,345 5,343 5,345 5,345

2034 5,345 5,343 5,345 5,345 2035 5,345 5,343 5,345 5,345 2036 5,345 5,343 5,345 5,345 2037 5,345 5,343 5,345 5,345 2038 5,345 5,343 5,345 5,345 2039 5,345 5,343 5,345 5,345 2040 5,345 5,343 5,345 5,345 2041 5,345 5,343 5,345 5,345 2042 5,345 5,343 5,345 5,345 2043 5,345 5,343 5,345 5,345 2044 5,345 5,343 5,345 5,345

sum (09-44) **451,689** 358,974 359,028 377,008Step 3: PLUS with

LNB/SOFA credit

**5-yr BART as if LNB not yet**  **installed**

by 2018 34,019 35,569 31,620 33,986 33,221 34,744 35,253 34,803 34,152 34,152 34,152 34,152 34,152 34,152 34,152 34,152 34,152 34,152 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,3455,345

5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345 5,345

480,489**TWG used a different, but equivalent, method for applying the LNB/SOFA early installation credit compared to the method EPA used in the February 5, 2013 proposal**

Example from Calculation in 2/5/13 Proposal, except that it does not propagate a transcription error in the original spreadsheet from 2/5/13 Proposal ** Original spreadsheet inadvertantly, resulting from transcription error, used "5,343" instead of "5,345" in many cells

Avg of 01-08 34,152

Year **5-yr BART**

**as if LNB not yet**  **installed 5 yr BART** 

**actual LNB**  **install** Alt 1

install years by 2018 by 2018 21/22/23 2001 34,019 34,019 34,019 2002 35,569 35,569 35,569 2003 31,620 31,620 31,620 2004 33,986 33,986 33,986 2005 33,221 33,221 33,221 2006 34,744 34,744 34,744 2007 35,253 35,253 35,253 2008 34,803 34,803 34,803 2009 34,152 30,500 30,501 2010 34,152 24,427 24,427 2011 34,152 19,837 19,837 2012 34,152 23,325 23,325 2013 34,152 23,325 23,325 2014 34,152 23,325 23,325 2015 34,152 23,325 23,325 2016 34,152 23,325 23,325 2017 34,152 23,325 23,325 2018 34,152 23,325 23,325 2019 5,345 5,345 23,325 2020 5,345 5,345 23,325 2021 5,345 5,345 17,332 2022 5,345 5,345 11,338 2023 5,345 5,345 5,345 2024 5,345 5,345 5,345 2025 5,345 5,345 5,345 2026 5,345 5,345 5,345 2027 5,345 5,345 5,345 2028 5,345 5,345 5,345 2029 5,345 5,345 5,345 2030 5,345 5,345 5,345 2031 5,345 5,345 5,345 2032 5,345 5,345 5,345 2033 5,345 5,345 5,345 2034 5,345 5,345 5,345 2035 5,345 5,345 5,3452036 5,345 5,345 5,345

2037 5,345 5,345 5,345 2038 5,345 5,345 5,345 2039 5,345 5,345 5,345 2040 5,345 5,345 5,345 2041 5,345 5,345 5,345 2042 5,345 5,345 5,345 2043 5,345 5,345 5,345 2044 5,345 5,345 5,345

sum (09-44) **480,489** 377,008 430,948

**LNB credit 103,481**  **Adjusted Emissions with LNB Credit** 327,467

**EPA Method for Comparing Alternative to BART applied the LNB/SOFA Credit to the Alternative (via subtraction), such that** Total 2009-2044 BART Emissions = 377,008 Adjsuted 2009-2044 Emissions from Alternative = 327,467 Emissions from Alternative are less than BART by: 49,541

**TWG Method for Comparing Alternative to BART applied the LNB/SOFA Credit to the BART Threshold (cap) (via addition)* instead of the Alternative, such that** ***(In other words, the BART Cap is calculated "as if" LNB/SOFA were not installed early at NGS and are installed concurrently with new controls by BART compliance date)** Total 2009-2044 BART Emissions = 480,489 Adjsuted 2009-2044 Emissions from Alternative = 430,948 Emissions from Alternative are less than BART by: 49,541

**The resulting difference between BART and the Alternative to BART are equivalent using both methods. Therefore, EPA's analysis of the TWG Alternatives in the following spreadsheets use the TWG Method and apply the LNB/SOFA credit to the BART Cap/Threshold** **TWG used a different, but equivalent, method for applying the LNB/SOFA early installation credit compared to the method EPA used in the February 5, 2013 proposal**

Example from Calculation in 2/5/13 Proposal, except that it does not propagate a transcription error in the original spreadsheet from 2/5/13 Proposal ** Original spreadsheet inadvertantly, resulting from transcription error, used "5,343" instead of "5,345" in many cells**EPA Method for Comparing Alternative to BART applied the LNB/SOFA Credit to the Alternative (via subtraction), such that**

**TWG Method for Comparing Alternative to BART applied the LNB/SOFA Credit to the BART Threshold (cap) (via addition)* instead of the Alternative, such that** ***(In other words, the BART Cap is calculated "as if" LNB/SOFA were not installed early at NGS and are installed concurrently with new controls by BART compliance date)**

**Therefore, EPA's analysis of the TWG Alternatives in the following spreadsheets use the TWG Method and apply the LNB/SOFA credit to the BART Cap/Threshold**Actual CAMD data Avg NOx 01-08 34,152 NOx limit

Closure or Installation years Avg Heat Input 01-12 188,184,226 Avg NOx rate 11-12 Avg Heat Input 01-08 194,373,910

Year Actual

Emissions **5-yr BART as**

**if LNB not yet installed**  **BART Glide Path to**  **Cap EST. TWG A1**  **EST. TWG A1**

install years by 7/1/19 cumulative cumulative cumulative 2001 34,019 34,019 34,019 2002 35,569 35,569 35,569 2003 31,620 31,620 31,620 2004 33,986 33,986 33,986 2005 33,221 33,221 33,221 2006 34,744 34,744 34,744 2007 35,253 35,253 35,253 2008 34,803 34,803 34,803 2009 30,501 34,152 34,152 34,152 30,501 30,501 2010 24,427 34,152 68,304 47,316 24,427 54,928 2011 19,837 34,152 102,456 60,480 19,837 74,765 2012 16,468 34,152 136,608 73,645 16,468 91,233 2013 34,152 170,759 86,809 19,752 110,985 2014 34,152 204,911 99,973 19,752 130,737 2015 34,152 239,063 113,137 19,752 150,489 2016 34,152 273,215 126,301 19,752 170,241 2017 34,152 307,367 139,466 19,752 189,993 2018 34,152 341,519 152,630 19,752 209,745 2019 19,749 361,267 165,794 19,752 229,497 2020 5,345 366,613 178,958 13,168 242,665 2021 5,345 371,958 192,122 13,168 255,833 2022 5,345 377,303 205,287 13,168 269,001 2023 5,345 382,648 218,451 13,168 282,169 2024 5,345 387,994 231,615 13,168 295,337 2025 5,345 393,339 244,779 13,168 308,505 2026 5,345 398,684 257,944 13,168 321,674 2027 5,345 404,030 271,108 13,168 334,842 2028 5,345 409,375 284,272 13,168 348,010 2029 5,345 414,720 297,436 13,168 361,178 2030 5,345 420,065 310,600 13,168 374,346 2031 5,345 425,411 323,765 4,391 378,737 2032 5,345 430,756 336,929 4,391 383,128 2033 5,345 436,101 350,093 4,391 387,519 2034 5,345 441,447 363,257 4,391 391,910 2035 5,345 446,792 376,421 4,391 396,300 2036 5,345 452,137 389,586 4,391 400,691 2037 5,345 457,482 402,750 4,391 405,0822038 5,345 462,828 415,914 4,391 409,473

2039 5,345 468,173 429,078 4,391 413,864 2040 5,345 473,518 442,243 4,391 418,255 2041 5,345 478,864 455,407 4,391 422,646 2042 5,345 484,209 468,571 4,391 427,037 2043 5,345 489,554 481,735 4,391 431,428 2044 5,345 494,899 494,899 4,391 435,819

sum (09-44) **494,899** 435,819 AVG slope 13,1640.24

0.210

100,000 200,000 300,000 400,000 500,000 600,000200920102011201220132014201520162017201820192020202120222023202420252026202720282029203020312032203320342035203620372038203920402041204220432044**C u** **m u** **l a** **t i** **v e** **N O** **x E** **m i** **s s** **i o** **n s** 

**Year** 

# Comparison of NOx Cap with TWG Alternative A1 (1 unit closes in 2020, **no capacity incr ease,**  **2 units meet 0.07 lb/MMBtu in 2031)**

Glide Path to Cap

BART

EST. TWG A1 NOx Cap over 2009

- 2044Actual CAMD data Avg NOx 01-08 34,152 NOx limit

Closure or Installation years Avg Heat Input 01-12 188,184,226 Avg NOx rate 11-12 Avg Heat Input 01-08 194,373,910

**TWG A2 = close one unit with capacity increase up to 189 MW (19 MW + max 170 MW - depends on how much of NGS Navajo Nation buys) TWG A3 = curtail one unit by no less than 561 MW (Based on shares of (LADWP+NVE - Navajo Nation)=> 477 + 254 - (max of 170) MW = 561 MW** 

Year Actual

Emissions **5-yr BART as**

**if LNB not yet installed**  **BART Glide Path to**  **Cap EST. TWG A2**  **EST. TWG A2**

install years by 7/1/19 cumulative cumulative cumulative 2001 34,019 34,019 34,019 2002 35,569 35,569 35,569 2003 31,620 31,620 31,620 2004 33,986 33,986 33,986 2005 33,221 33,221 33,221 2006 34,744 34,744 34,744 2007 35,253 35,253 35,253 2008 34,803 34,803 34,803 2009 30,501 34,152 34,152 34,152 30,501 30,501 2010 24,427 34,152 68,304 47,316 24,427 54,928 2011 19,837 34,152 102,456 60,480 19,837 74,765 2012 16,468 34,152 136,608 73,645 16,468 91,233 2013 34,152 170,759 86,809 19,752 110,985 2014 34,152 204,911 99,973 19,752 130,737 2015 34,152 239,063 113,137 19,752 150,489 2016 34,152 273,215 126,301 19,752 170,241 2017 34,152 307,367 139,466 19,752 189,993 2018 34,152 341,519 152,630 19,752 209,745 2019 19,749 361,267 165,794 19,752 229,497 2020 5,345 366,613 178,958 14,827 244,325 2021 5,345 371,958 192,122 14,827 259,152 2022 5,345 377,303 205,287 14,827 273,979 2023 5,345 382,648 218,451 14,827 288,806 2024 5,345 387,994 231,615 14,827 303,633 2025 5,345 393,339 244,779 14,827 318,461 2026 5,345 398,684 257,944 14,827 333,288 2027 5,345 404,030 271,108 14,827 348,115 2028 5,345 409,375 284,272 14,827 362,942 2029 5,345 414,720 297,436 14,827 377,769 2030 5,345 420,065 310,600 14,827 392,597 2031 5,345 425,411 323,765 4,944 397,541 2032 5,345 430,756 336,929 4,944 402,485 2033 5,345 436,101 350,093 4,944 407,429 2034 5,345 441,447 363,257 4,944 412,373 2035 5,345 446,792 376,421 4,944 417,318 2036 5,345 452,137 389,586 4,944 422,2622037 5,345 457,482 402,750 4,944 427,206

2038 5,345 462,828 415,914 4,944 432,150 2039 5,345 468,173 429,078 4,944 437,095 2040 5,345 473,518 442,243 4,944 442,039 2041 5,345 478,864 455,407 4,944 446,983 2042 5,345 484,209 468,571 4,944 451,927 2043 5,345 489,554 481,735 4,944 456,871 2044 5,345 494,899 494,899 4,944 461,816

sum (09-44) **494,899** 461,816 AVG slope 13,164

  TWG A2 and A3 result in equivalent MW reductions**  **i.e., assuming Navajo Nation elects to purchase 170 MW, and capacity icnrease also include 19 MW to make up for LADWP and NV Energy shortfall from 1 750 MW unit Under A2, close one unit, increase capacity by 170 + 19 MW = capacity reduction of 750 - 170 MW - 19 MW = 561 MW**  **Under A3, curtail one unit by LADWP + NVEnergy - Navajo Nation share = 477 + 254 - 170 = 561 MW**0.24

0.21

**TWG A2 = close one unit with capacity increase up to 189 MW (19 MW + max 170 MW - depends on how much of NGS Navajo Nation buys) TWG A3 = curtail one unit by no less than 561 MW (Based on shares of (LADWP+NVE - Navajo Nation)=> 477 + 254 - (max of 170) MW = 561 MW** **i.e., assuming Navajo Nation elects to purchase 170 MW, and capacity icnrease also include 19 MW to make up for LADWP and NV Energy shortfall from 1 750 MW unit Under A2, close one unit, increase capacity by 170 + 19 MW = capacity reduction of 750 - 170 MW - 19 MW = 561 MW** 0

100,000 200,000 300,000 400,000 500,000 600,000200920102011201220132014201520162017201820192020202120222023202420252026202720282029203020312032203320342035203620372038203920402041204220432044**C u** **m u** **l a** **t i** **v e** **N O** **x E** **m i** **s s** **i o** **n s** 

**Year** 

# Comparison of NOx Cap with TWG Alternative A2 and A3 (1 unit closes **plus maximum capacity incr ease**  **(189 MW), or curtailment of 561 MW**  **, in 2020; and 2 units meet 0.07 lb/MMBtu in 2031)** 

Glide Path to Cap

BART

Est TWG A2 or A3 NOx Cap over 2009

- 2044Actual CAMD data Avg NOx 01-08 34,152

Installation years Avg Heat Input 01-12 188,184,226 Avg NOx rate 11-12 Avg Heat Input 01-08 194,373,910

Year Actual

Emissions **5-yr BART as**

**if LNB not yet installed**  **BART Glide Path to**  **Cap Alt B**  **Alt B**

install years by 7/1/19 cumulative cumulative Est cumulative 2001 34,019 34,019 2002 35,569 35,569 2003 31,620 31,620 2004 33,986 33,986 2005 33,221 33,221 2006 34,744 34,744 2007 35,253 35,253 2008 34,803 34,803 2009 30,501 34,152 34,152 34,152 30,501 2010 24,427 34,152 68,304 53,288 24,427 2011 19,837 34,152 102,456 72,423 19,837 2012 16,468 34,152 136,608 91,559 23,325 2013 34,152 170,759 110,695 23,325 2014 34,152 204,911 129,830 23,325 2015 34,152 239,063 148,966 23,325 2016 34,152 273,215 168,101 23,325 2017 34,152 307,367 187,237 23,325 2018 34,152 341,519 206,373 23,325 2019 19,749 361,268 225,508 23,325 2020 5,345 366,613 244,644 15,550 2021 5,345 371,958 263,780 15,550 2022 5,345 377,304 282,915 15,550 2023 5,345 382,649 302,051 15,550 2024 5,345 387,994 321,187 15,550 2025 5,345 393,339 340,322 15,550 2026 5,345 398,685 359,458 15,550 2027 5,345 404,030 378,594 15,550 2028 5,345 409,375 397,729 15,550 2029 5,345 414,720 416,865 15,550 2030 5,345 420,066 422,067 2031 5,345 425,411 427,270 2032 5,345 430,756 432,472 2033 5,345 436,101 437,674 2034 5,345 441,447 442,876 2035 5,345 446,792 448,079 2036 5,345 452,137 453,281 2037 5,345 457,482 458,483 416,8652038 5,345 462,828 463,686

2039 5,345 468,173 468,888 2040 5,345 473,518 474,090 2041 5,345 478,864 479,292 2042 5,345 484,209 484,495 2043 5,345 489,554 489,697 2044 5,345 494,899 494,899

sum (09-44) **494,899**

slope (2029 cap) 19,136 slope (2044 cap) 5,202 494,899NOx limit 0.24 Avg NOx rate 11-12 0.21

**Est. 3 SCR meeting**  **0.055 Est. 3 SCR** 

**meeting 0.055**  **Est. 3 SCR**

**meeting 0.07**  **Est. 3 SCR**

**meeting 0.07**  cumulative cumulative

30,501 30,501 30,501 30,501 24,427 54,928 24,427 54,928 19,837 74,765 19,837 74,765 16,468 91,233 16,468 91,233 19,752 110,985 19,752 110,985 19,752 130,737 19,752 130,737 19,752 150,489 19,752 150,489 19,752 170,241 19,752 170,241 19,752 189,993 19,752 189,993 19,752 209,745 19,752 209,745 19,752 229,497 19,752 229,497 19,752 249,249 19,752 249,249 19,752 269,001 19,752 269,001 19,752 288,753 19,752 288,753 19,752 308,505 19,752 308,505 19,752 328,258 19,752 328,258 19,752 348,010 19,752 348,010 19,752 367,762 15,874 363,883 19,752 387,514 11,338 375,222 15,388 402,902 6,803 382,025 10,367 413,268 6,803 388,828 5,345 418,613 6,803 395,631 5,345 423,959 6,803 402,434 5,345 429,304 6,803 409,237 5,345 434,649 6,803 416,040 5,345 439,995 6,803 422,844 5,345 445,340 6,803 429,647 5,345 450,685 6,803 436,450 5,345 456,030 6,803 443,2535,345 461,376 6,803 450,056

5,345 466,721 6,803 456,859 5,345 472,066 6,803 463,662 5,345 477,412 6,803 470,465 5,345 482,757 6,803 477,268 5,345 488,102 6,803 484,071 5,345 493,447 6,803 490,8740

100,000 200,000 300,000 400,000 500,000 600,000200920102011201220132014201520162017201820192020202120222023202420252026202720282029203020312032203320342035203620372038203920402041204220432044**C u** **m u** **l a** **t i** **v e** **N O** **x E** **m i** **s s** **i o** **n s** 

**Year** 

# Comparison of Nested NOx Caps with TWG Alternative B (assuming

**ins tallation**  **of 3 SCR to meet Nested Caps)**

Glide Path to Cap

BART Est. 3 SCR meeting 0.055 Est. 3 SCR meeting 0.07 NOx Cap over 2009

- 2044

NOx Cap over 2009

- 2029Unit # Year 2009 3 2009 2010 2 2010 2011 1 2011 2012 3 2012 2013 2 2013 2014 1 2014 2015 3 2015 2016 2 2016 2017 1 2017 2018 3 2018 2019 2 2019 2020 1 2020 2021 3 2021 2022 2 2022 2023 1 2023 2024 3 2024 2025 2 2025 2026 1 2026 2027 3 2027 2028 2 2028 2029 1 2029

Major Major

Minor

Major

Minor

Major

Minor