Testimony of Elizabeth Bisbey-Kuehn

Page 1 of 19

STATE OF NEW MEXICO

BEFORE THE ENVIRONMENTAL IMPROVEMENT BOARD

IN THE MATTER OF PROPOSED REVISIONS

TO THE STATE IMPLEMENTATION PLAN

FOR THE SAN JUAN GENERATING STATION

BEST AVAILABLE RETROFIT TECHNOLOGY

DETERMINATION 

No. EIB 13- 02(R)

_____________________________________________________________________________

NMED EXHIBIT 11 – WRITTEN TESTMONY OF 

ELIZABETH BISBEY-KUEHN

______________________________________________________________________________

Statement of Witness Qualifications

Elizabeth Bisbey-Kuehn is currently the Acting Technical Services Manager for the Air 

Quality Bureau of the New Mexico Environment Department (NMED). She has served in the 

Bureau since February of 2005 as a Permit Specialist – a role she continues to perform in 

addition to her managerial responsibilities. She also served as Acting Minor Source Section 

Manager from May through October of 2012. Ms. Bisbey-Kuehn holds a Bachelor of Science 

degree in Environmental Studies from the University of Iowa. Her resume is attached as Exhibit 

11a.

Testimony

Background

1 The visibility provisions of the Clean Air Act (CAA) include a requirement that States 

2 determine the Best Available Retrofit Technology (BART) for certain large stationary sources, 

3 and require those sources to install and operate such technology as expeditiously as possible. 

4 BART-eligible sources are those sources which (1) have the potential to emit 250 tons 

5 per year or more of a visibility impairing air pollutant; (2) were put in place between August 7, 

6 1962 and August 7, 1977; and (3) whose operations fall within one or more of 26 specifically 

7 listed source categories.
Testimony of Elizabeth Bisbey-Kuehn

Page 2 of 19

1 For fossil-fueled generating power plants having a total generating capacity in excess of 

2 750 megawatts (MW), the Act requires that States determine BART pursuant to guidelines 

3 developed by the Environmental Protection Agency (EPA). CAA § 169A(b)(2). EPA 

4 promulgated such guidelines in 2005, and they are codified at Appendix Y to 40 CFR Part 51. 

5 As described in more detail below, Appendix Y sets forth a 5-step procedure for considering the 

6 factors required by the CAA when making BART determinations.

7 In addition to providing guidance for BART determinations for greater-than-750 MW 

8 power plants, the BART guidelines at Appendix Y also provide guidance on how to determine 

9 which sources in a state are BART-eligible, and which of those sources are subject to BART 

10 requirements based on their visibility impacts.

11 Appendix D to New Mexico’s 2011 regional haze State Implementation Plan (SIP),

12 submitted pursuant to 40 CFR § 51.309(g), described New Mexico’s findings and determinations 

13 with respect to BART, which were made in accordance with Appendix Y. Specifically, 

14 Appendix D contained a description of the process by which NMED analyzed the BART eligible 

15 sources within the State and determined that only one such source, the San Juan Generating 

16 Station (San Juan or SJGS), is subject to BART requirements. Appendix D also contained the 

17 BART determinations for San Juan for particulate matter (PM) and nitrogen oxides (NOx). 

18 (New Mexico’s BART obligations with respect to sulfur dioxide (SO2) were satisfied by 

19 implementation of a voluntary backstop SO2 trading program pursuant to 40 CFR 51.309(d)(4).)

20 In this 2013 proposed SIP revision, Appendix D has been revised to include within the 

21 BART analysis for San Juan a new scenario (the “State Alternative”) involving the voluntary 

22 shutdown of two of San Juan’s four units. This scenario, which was the result of negotiations 
Testimony of Elizabeth Bisbey-Kuehn

Page 3 of 19

1 between NMED, Public Service Company of New Mexico (PNM), and EPA, is a new alternative 

2 not previously considered by the Department. 

3 Much of Appendix D as revised remains unchanged from the 2011 determination. The 

4 sections that remain unchanged include the determination of sources eligible and subject to 

5 BART; the description of the SJGS; the background of the BART regulation; the history of 

6 submissions made by PNM in response to NMED requests, with the exception of an addition of a 

7 2013 update; the 5-step analysis and BART determination for PM; and the conclusion of the 5-

8 step analysis for NOx as of 2011.

9 The 5-step analysis for NOx has been revised to include consideration of PNM’s revised 

10 BART analysis in accordance with the State Alternative. This analysis included an updated cost 

11 estimate for installing selective non-catalytic reduction (SNCR) on Units 1 and 4 and installing 

12 selective catalytic reduction (SCR) on Units 1 through 4. The cost estimates were based on 

13 vendor quotes and represent the most current cost analyses by air pollution control equipment 

14 vendors and engineering firms. The analysis also included updated emissions reduction 

15 information that would result from the shutdown of Units 2 and 3, and the continued operation of 

16 Units 1 and 4, and new visibility modeling to demonstrate the visibility improvements achieved 

17 by the new scenario. 

18 Determination of Sources “Eligible” for and Subject to BART

19 Certain large stationary sources that are on a list of defined source categories in the 

20 CAAlean Air Act, which were not in operation prior to August 7, 1962, and were in existence on 

21 August 7, 1977, and that have the potential to emit over 250 tons per year of a defined visibility 

22 impairing pollutant are considered to be a BART eligible source. Visibility impairing pollutants 

23 include, but are not limited to, NOx, SO2, and PM. 
Testimony of Elizabeth Bisbey-Kuehn

Page 4 of 19

1 In 2006, the Department reviewed all sources for BART eligibility using the criteria 

2 required in Appendix Y. The Department first developed a list of all sources operating in New 

3 Mexico under the Department’s regulatory jurisdiction. We then screened the list for only those 

4 sources that are on the defined list of source categories in the CAAlean Air Act. We then 

5 reviewed the startup date and status of operation of the remaining sources. Finally, the 

6 Department reviewed the potential to emit for those remaining sources that have the potential to 

7 emit over 250 tons per year of any visibility impairing pollutant. New Mexico identified 11 

8 sources as BART-eligible sources as part of this review. 

9 Once the Department determined which sources were BART eligible, the Department 

10 needed to determine which sources were subject to the BART rule requirements. The BART 

11 rule allows States to either make BART determinations for all BART-eligible sources or 

12 consider exempting some sources because they may not be reasonably anticipated to cause or 

13 contribute to visibility impairment at any nearby Class I area. 

14 The Department determined that it would perform an initial examination to identify

15 which BART-eligible sources cause or contribute to visibility impairment at subject Class I 

16 areas. The guidelines direct that States that choose this option need only perform a full BART 

17 analysis for those sources shown to cause or contribute to visibility impairment at any of the 

18 subject Class I areas. 

19 The first step to determine which sources cause or contribute to visibility impairment is to 

20 establish a threshold in deciviews to measure the impact of a source’s operation. A deciview

21 (dv) is a measurement of visibility impairment. A single source that shows greater than 1 dv 

22 impact is considered to cause visibility impairment and a source that shows less than 1 dv impact 

23 may contribute to visibility impairment. States need to evaluate how many BART-eligible 
Testimony of Elizabeth Bisbey-Kuehn

Page 5 of 19

1 sources impact any of the subject Class I areas to determine an appropriate threshold. If there are 

2 multiple sources impacting Class I areas, States may choose to establish a threshold less than or 

3 equal to 0.5 dv. The rule states that the threshold to determine if a source contributes to visibility 

4 impairment should not be larger than 0.5 dv. The Department reviewed the number of BART5 eligible sources and the sources’ proximity to subject Class I areas. The Department concluded 

6 that the BART eligible sources in the State were not concentrated in one region, and therefore 

7 were not concentrating impacts at any one of the subject Class I areas. Based on this review, the 

8 Department established a 0.5 dv threshold for determining whether a BART-eligible source 

9 contributed to visibility impairment.

10 The next step was performing the visibility modeling of each BART-eligible source’s 

11 emissions to determine the level of impact the source had on any subject Class I area. The 

12 Department worked with the Western Regional Air Partnership (WRAP) to perform the initial 

13 BART modeling for the state of New Mexico. The WRAP modeled NOx, SO2 and PM 

14 emissions for the 11 BART eligible facilities using the CALPUFF model. Of the 11 source 

15 complexes analyzed, only one source’s visibility impact at any subject Class I area due to 

16 combined SO2, NOx, and PM emissions exceeded the 0.5 dv threshold. This source was PNM 

17 San Juan Generating Station, Boilers #1-4 (“SJGS”). The applicable Class I areas that were

18 evaluated in the BART process for SJGS are located within 300 km of the SJGS; there are 16 

19 Class I areas that meet this criteria. 

20 On November 9, 2006, the Department informed PNM that the modeling performed by 

21 the WRAP indicated the visibility impairment from the SJGS was over the 0.5 dv threshold, and 

22 SJGS was therefore subject to a BART analysis. In response, Black & Veatch (B&V), on behalf 

23 of PNM, submitted the BART modeling protocol to the Department for review. 
Testimony of Elizabeth Bisbey-Kuehn

Page 6 of 19

1 The modeling protocol describes the CALPUFF modeling methodologies and procedures 

2 for the visibility impact assessment that will be performed for the BART analysis. The protocol 

3 contains all the meteorological and terrain data that will be used as well as the source specific 

4 data for the SJGS. The protocol outlines where the receptors will be located at the subject Class 

5 I areas to determine visibility impacts. The protocol was reviewed and the Department found 

6 one area of concern regarding the use of average visibility improvement. PNM updated its

7 analysis and the Department determined that the protocol was approvable. 

8 BART determination for PNM

9 Source Description

10 The SJGS consists of four coal-fired generating units and associated support facilities. 

11 Each coal-fired unit burns pulverized coal and No. 2 diesel oil (for startup) in a boiler and 

12 produces high-pressure steam, which powers a steam turbine coupled with an electric generator. 

13 Electric power produced by the units is supplied to the electric power grid for sale. Coal for the 

14 units is supplied by the adjacent San Juan Mine and is delivered to the facility by conveyor.

15 The SJGS Boiler Units 1 and 2 have a unit capacity of 350 and 360 MW, respectively. 

16 Units 3 and 4 each have a unit capacity of 544 MW.

17 Five-Factor Analysis

18 The NOx and PM BART determinations for San Juan were performed in accordance with 

19 the 5-Step Process set forth in Appendix Y. In brief, the process is as follows:

20 Step 1 – Identify All Available Retrofit Control Technologies

21 Step 2 – Eliminate Technically Infeasible Options

22 Step 3 – Evaluate Control Effectiveness of Remaining Control Technologies

23 Step 4 – Evaluate Impacts and Document the Results

24 a) Costs of Compliance

25 b) Energy Impacts

26 c) Non-air environmental impacts

27 d) Remaining useful life
Testimony of Elizabeth Bisbey-Kuehn

Page 7 of 19

1 Step 5 – Evaluate Visibility Impacts

2

3 The NOx and PM BART determinations for San Juan involved numerous requests and 

4 responses for more information from PNM, over a period of years (from June of 2006 through 

5 May of 2013). Below is a description of how each step in the 5-step process was satisfied.

6 Step 1 – Identify All Available Retrofit Control Technologies

7 The main strategies for reducing NOx emissions take two forms: 1) modification to the 

8 combustion process to control fuel and air mixing and reduce flame temperatures, and 2) post9 combustion treatment of the flue gas to remove NOx. Particulate matter emissions can only be 

10 controlled by post-combustion control technologies. 

11 In the original BART submittal, PNM identified fourteen separate available retrofit NOx 

12 control technologies and four separate available retrofit PM control technologies that have 

13 potential application at the SJGS. The Department reviewed the list of NOx control technologies 

14 and did not identify any additional alternative technologies that should have been considered in 

15 the analysis. The Department reviewed the PM control technologies and requested that PNM 

16 consider wet electrostatic precipitator (WESP) in Step 1 of the BART analysis. PNM 

17 subsequently submitted a complete five factor analysis for this technology in a submittal dated 

18 August 29, 2008. 

19 Please refer to Appendix D and the exhibits for the list of identified available retrofit 

20 control technologies and a description of how each of the controls operates. 

21 Step 2 – Eliminate Technically Infeasible Options

22 Step 2 of the 5-step process eliminates technology that is considered technically 

23 infeasible. The basis for technical infeasibility is defined in the regulation and may be due to 

24 limited application at sources similar to the BART-subject source or to technology that is 
Testimony of Elizabeth Bisbey-Kuehn

Page 8 of 19

1 commercially unavailable. Other considerations for technical infeasibility include limitations 

2 due to source-specific design factors. 

3 PNM initially proposed elimination of SNCR, rotating opposed fire air (ROFA), and 

4 Rotamix technology because the control technology would not achieve the presumptive NOx 

5 emission limits prescribed in the BART rule. The Department did not agree that SNCR, ROFA, 

6 or Rotamix should have been determined to be technically infeasible NOx control technology

7 and so requested PNM to perform a full five-factor analysis for these technologies. 

8 PNM submitted an updated Final SNCR analysis to the Department on May 30, 2008 and 

9 a Final ROFA-Rotamix analysis on August 29, 2008. PNM also submitted an updated SNCR 

10 analysis on February 9, 2011 and an update to the analysis on February 11, 2011. This submittal

11 described and included new information on the lowest achievable emission rate for this 

12 technology, and included a ratepayer impact analysis. 

13 The Department did agree that six types of NOx control technology should be considered 

14 technically infeasible and agreed that those technologies should not be considered in the 

15 remaining five-factor analysis. Five of these technologies have limited or no application at 

16 sources similar to the SJGS and the sixth, natural gas reburn, is infeasible due to limited boiler 

17 space and resulting insufficient residence time in the natural gas reburn zone. 

18 PNM eliminated all additional PM retrofit technologies because either the controls would 

19 not achieve better emissions reduction than the pulse jet fabric filters (PJFF) that were currently 

20 installed at the SJGS, or there was limited application of the technology. The Department 

21 determined that two of the remaining PM control technologies should be considered in the five22 factor analysis and requested PNM to include the WESP technology and an enhanced pulse jet 
Testimony of Elizabeth Bisbey-Kuehn

Page 9 of 19

1 fabric filter (PJFF) installation in an updated submittal. An updated analysis of the two PM 

2 control technologies was submitted on August 29, 2008. 

3 Step 3 – Evaluate Control Effectiveness of Remaining Control Technologies

4 Step 3 of the BART analysis includes a control effectiveness evaluation of the remaining 

5 NOx and PM control technologies. PNM contracted with B&V and Sargent & Lundy (S&L) to 

6 determine the control effectiveness of each remaining available NOx and PM control technology 

7 for Units 1-4.

8 The original analysis included only SCR and SNCR/SCR Hybrid NOx control 

9 technology in Step 3. The control effectiveness evaluation for the remaining NOx and PM 

10 technologies were submitted as updates to the Department in separate submittals.

11 The control effectiveness analyses of SNCR, ROFA, and Rotamix was included in the 

12 Final SNCR and Final Nalco-Mobotec analyses submitted May 30 and August 29, 2008. The 

13 control effectiveness analyses of PJFF and WESP technology was submitted August 29, 2008.

14 PNM submitted in 2011 another updated control effectiveness analysis for SNCR based 

15 on a new manufacturer guaranteed emission rate of 0.23 lb/MMbtu. 

16 The control effectiveness of the PM and NOx control technologies considered are 

17 presented in Appendix D, Tables 2-9.

18 Step 4 – Evaluate Impacts and Document the Results

19 The Guidelines require States to consider four types of impact analysis in Step 4 of the 

20 BART analysis. These four types of impacts consider the costs of compliance, energy impacts, 

21 non-air quality environmental impacts, and remaining useful life of the facility. These impacts 

22 are included in the cost-effectiveness of each additional control technology and allow 
Testimony of Elizabeth Bisbey-Kuehn

Page 10 of 19

1 comparisons to be made between the remaining controls. B&V performed an impact analysis for 

2 the remaining NOx and PM control technologies in accordance with the Guidelines.

3 B&V and S&L prepared the design parameters and developed estimates of capital and 

4 annual costs for the application of SCR, SNCR, SCR/SNCR Hybrid, ROFA, Rotamix, 

5 ROFA/Rotamix, PJFF, and WESP technologies. B&V relied on a number of sources to prepare 

6 the design parameters, including information from the Nalco Mobotec equipment vendors, SCR 

7 and SNCR equipment vendors, EPA cost manuals, engineering and performance data, and 

8 B&V’s own in-house engineering estimates. 

9 PNM evaluated the energy impacts, non-air quality environmental impacts, and 

10 remaining useful life of all additional technically feasible control options for NOx and PM. 

11 Energy impacts from control equipment that consume auxiliary power during operation were 

12 considered for all control options. For SCR, SNCR and SCR/SNCR Hybrid technology, the non13 air quality environmental impacts included the consideration of water usage and waste generated 

14 from each control technology. For WESP technology, PNM considered the auxiliary power 

15 consumption to operate the WESP and fans, and the additional water consumption and waste 

16 water disposal requirements from operating the WESP. Lastly, the remaining useful life was 

17 defined as 20 years, except for the 2013 analysis for 4 SCR, 4 SNCR and 2 SNCR/2 Shutdown,

18 which used a remaining useful life of 30 years. Therefore, no additional cost adjustments for a 

19 short remaining useful boiler life need to be considered. 

20 The original submittal contained an impact analysis for only the SCR and SNCR/SCR 

21 Hybrid technologies. The impact analyses for all remaining technologies were submitted as 

22 separate updates to the Department.
Testimony of Elizabeth Bisbey-Kuehn

Page 11 of 19

1 In the original submittal, the cost estimates for SCR and the SNCR/SCR Hybrid 

2 technology were based on engineering estimates prepared by B&V, without a detailed 

3 explanation of the line items submitted in the estimate. PNM responded to a request for 

4 additional information on July 11, 2007, with updated cost estimates for both SCR and the 

5 SNCR/SCR Hybrid technology. The update included additional details on the basis of 

6 assumptions in the cost estimate. 

7 On September 14, 2007 PNM submitted additional information to the Department in 

8 response to a National Park Service letter dated August 16, 2007 and a U.S. Forest Service letter 

9 dated August 23, 2007. In this update, PNM provided additional explanation of the cost estimate 

10 development, and of the $/ton metric. 

11 In a letter dated December 21, 2007, the Department requested PNM perform an updated 

12 cost analysis for SCR based on the EPA’s Control Cost Manual. The Department requested this 

13 information because we did not find that PNM provided fully sufficient justification for using 

14 engineering-based cost estimates in lieu of the Control Cost Manual, which is the recommended 

15 methodology to use when possible. 

16 PNM responded with the Discussion of OAQPS Control Cost Manual submitted March 

17 29, 2008. In their response, PNM discussed why the Control Cost Manual is not a sufficient 

18 methodology for estimating the costs of air quality control equipment, provided a scope of items 

19 that are missing from the manual for SCR, and provided a comparison between the estimated

20 costs based on the manual and the B&V estimate used in PNM’s cost analysis.

21 In a letter dated April 25, 2008, the Department requested PNM prepare and submit a full 

22 five-factor analysis for ROFA, Rotamix, and SNCR technology. The Department received the 

23 full five-factor analysis for SNCR technology on May 30, 2008, and the full 5 factor analysis for 
Testimony of Elizabeth Bisbey-Kuehn

Page 12 of 19

1 ROFA and Rotamix technology on August 28, 2008. Both of these updates contained an 

2 updated engineering and impact analysis. 

3 On December 29, 2009, the Department requested additional information regarding acid 

4 mist emissions from PNM. Acid mist emissions result from the conversion of SO2 to SO3 across 

5 the SCR catalyst. The Department requested that PNM consider the inherent removal of SO3 

6 generated from SCR technology. The inherent removal is based on the existing air pollution 

7 control devices and other process equipment. In addition, the Department requested PNM to 

8 consider the combined effect of SO3 removal from existing technologies and with the installation 

9 of sorbent injection control technology. Sorbent injection removes SO3 in the flue gas by 

10 reaction of the SO3 with an alkaline sorbent material to form a particulate that can be removed by

11 the PM control device.

12 PNM submitted the requested update on March 16, 2009. This analysis considered SO3

13 emissions removal both from existing equipment and sorbent injection technology, as requested 

14 by the Department. The analysis quantified the SO3 emissions and calculated the cost of the 

15 sorbent injection system and included these costs into the cost estimates of the SCR and 

16 SNCR/SCR Hybrid technology. 

17 On February 9, 2011, PNM submitted an updated engineering and impacts analysis based 

18 on new information related to SNCR technology. The submittal included new cost estimates 

19 based on 2010 dollars and a new manufacturer guaranteed NOx emission rate of 0.23 lb/MMbtu. 

20 This slightly lower emission rate was a result of better emission control effectiveness for the 

21 technology. The submittal also included an updated impact analysis and cost effectiveness 

22 estimates for SCR, SNCR/SCR Hybrid, ROFA/Rotamix, Rotamix (SNCR), SNCR (Fuel Tech) 

23 and ROFA. 
Testimony of Elizabeth Bisbey-Kuehn

Page 13 of 19

1 On February 11, 2011, PNM submitted an additional update that replaced the February 9, 

2 2011 submittal. This new update included a unit-specific level of information with respect to 

3 visibility and cost effectiveness. PNM also submitted information regarding the updated rate 

4 impact costs for SNCR and SCR plus sorbent injection to PNM customers based on PNM’s 

5 ownership share of 46.3% of SJGS. 

6 On April 1, 2013, PNM submitted an updated impacts analysis based on new information 

7 related to a voluntary shutdown of two units (Units 2 and 3). This update considers the impacts 

8 analysis from three specific control scenarios at the SJGS; the installation of SCR on all four 

9 units, the installation of SNCR on all four units, and the installation of SNCR on Units 1 and 4 

10 and shutdown on Units 2 and 3.

11 For the 2013 submittal, PNM contracted with (S&L) to develop a conceptual design, 

12 project cost estimate, and technical portions of an Engineering, Procurement and Construction 

13 specification for SCR control systems on SJGS Units 1-4. Site specific factors that had a 

14 significant effect on the SCR design basis and costs include the site congestion at SJGS, NOx 

15 emission reduction requirements, balanced draft conversion and the inclusion of a sorbent 

16 injection system to meet sulfuric acid mist emission limits. 

17 In the analysis S&L updated the cost analysis to reflect the approach described in the 

18 EPA’s Control Cost Manual. The NMED reviewed the cost analysis based on the methodology 

19 in the Control Cost Manual and finds that the cost estimation methodology is acceptable to the 

20 Department. The cost estimates in the report provide an overview of the approach, the design 

21 parameters, and the basis for the assumptions used to develop the costs estimates. The Control 

22 Cost Manual does not allow the consideration of a number of specific types of cost, including 
Testimony of Elizabeth Bisbey-Kuehn

Page 14 of 19

1 owner’s costs and Allowance for Funds Used During Construction (AFUDC), and these costs

2 were specifically excluded from the cost estimates prepared by S&L. 

3 Lower cost estimates for SCR installation have been provided for a four unit SCR 

4 installation by the National Park Service (NPS). The Department does not necessarily agree with

5 the methodology of the NPS cost analysis. Nonetheless, the Department reviewed those 

6 estimates and finds that this information would not impact the Department’s final 

7 recommendation for BART at the SJGS. For example, the NPS estimates submitted to the 

8 Department indicate the total capital investment for SCR technology would be around 

9 $374,152,055 for a four unit installation. However, the total capital investment estimated for the 

10 2 SNCR/2 Unit shutdown scenario is only $34,556,000, making this proposal the most cost 

11 effective proposal, especially considering the emissions reduction and visibility improvement 

12 that would be achieved by this proposed alternative. 

13 Step 5 – Evaluate Visibility Impacts

14 The Guidelines require States to assess visibility improvement based on the modeled 

15 change in visibility impacts for the pre-control and post-control emission scenarios. This is Step 

16 5 of the 5-factor BART analysis. As noted previously, visibility impacts were reviewed for 16 

17 Class I areas located within 300 km of the SJGS. There were multiple updates to the original 

18 visibility modeling analysis that was submitted to the Department. 

19 The first visibility analysis of additional control technology was submitted in the original 

20 BART submittal. In the original submittal, only SCR and SCR/SNCR Hybrid technology was 

21 reviewed as technically feasible additional control technology. The analysis was based on a 

22 constant ammonia background concentration and nitrate repartitioning. Because PNM had 

23 recently installed low NOx burners and overfire air (OFA) technology at the SJGS as the result 
Testimony of Elizabeth Bisbey-Kuehn

Page 15 of 19

1 of a consent decree, the analysis also considered the pre-consent decree and post-consent decree 

2 emissions to determine the visibility improvement achieved by the technology retrofit. 

3 In an email dated June 30, 2007, the NMED requested that PNM update their $/deciview 

4 impact analysis to be based on the maximum visibility improvement, and not on average 

5 visibility improvement as had been originally submitted. On August 23, 2007, PNM submitted 

6 the updated visibility cost-effectiveness data to the Department.

7 On November 5, 2007, PNM submitted an additional refined BART modeling report to 

8 the Department. PNM had investigated nitrate repartitioning and ammonia background 

9 concentration refinements in the air dispersion modeling analysis and determined these 

10 refinements more accurately predicted visibility modeling results. Nitrate repartitioning 

11 eliminates impacts from overlapping puffs and the background ammonia concentration was 

12 modified to assume monthly variable concentrations instead of a continuous 1 ppb background 

13 amount. 

14 In a letter dated December 21, 2007, the NMED requested additional modeling analyses 

15 to determine plant-wide and individual unit specific visibility impact analysis. PNM submitted 

16 the updated analysis on March 31, 2008. The report considered both plant-wide and individual 

17 unit specific impacts as well as both the refined and unrefined ammonia background and nitrate 

18 repartitioning analysis.

19 On May 30, 2008, PNM submitted an additional modeling analysis to include SNCR 

20 technology, which the NMED had determined should have been reviewed in the full 5-factor 

21 analysis. As in the March 31, 2008 update, PNM submitted two reports, one including the 

22 constant ammonia background with nitrate repartitioning and the other report with variable 

23 ammonia background with the new nitrate repartitioning methodology. 
Testimony of Elizabeth Bisbey-Kuehn

Page 16 of 19

1 On August 29, 2008, PNM submitted an additional visibility modeling analysis to include 

2 Nalco Mobotec NOx control technologies. Specifically, the NMED requested modeling of 

3 ROFA with Rotamix, Rotamix, and ROFA control technologies. Rotamix and ROFA are a 

4 variant of SNCR and overfire technologies, respectively, and the NMED determined these 

5 technologies should have been evaluated in the full 5-factor analysis. This report also contained 

6 an update of the discussion of PM control technologies. A full visibility impact analysis of 

7 WESP technology was submitted as part of this updated report.

8 On December 29, 2008, the NMED requested additional information regarding the acid 

9 mist emissions from the SJGS and how these emissions impact the modeling analysis. To 

10 comply with the NMED’s request, PNM submitted an updated modeling analysis on March 16, 

11 2009, that included consideration of the inherent removal of SO3 emissions from existing control 

12 technologies and consideration of the installation of a sorbent injection system control 

13 technology that would control acid gas emissions.

14 On February 9 and 11, 2011, PNM submitted a full new 5-factor analysis of SNCR 

15 technology after PNM received a lower vendor guaranteed emission rate from an equipment 

16 vendor. For consistency, PNM assumed the monthly variable ammonia concentration and the 

17 nitrate repartitioning methodology based on the November 6, 2007 modeling refinements.

18 On April 1, 2013, PNM submitted new, updated modeling to reflect the voluntary 

19 shutdown of Units 2 and 3, and a lower federally enforceable SO2 emission rate of 0.10 

20 lb/MMbtu at the remaining Units 1 and 4. In this modeling analysis, PNM relied on many of the 

21 modeling assumptions used in the EPA’s modeling of the Federal Implementation Plan (FIP), 

22 including constant ammonia background concentration, to allow for comparisons to be made 

23 between modeling by both EPA and PNM. The three control technology scenarios modeled 
Testimony of Elizabeth Bisbey-Kuehn

Page 17 of 19

1 were the proposed SIPtate Implementation Plan (SNCR on Units 1-4), the FIP (SCR on Units 1-

2 4) and a new State Alternative (SNCR on Units 1 and 4, shutdown Units 2 and 3).

3 The updated visibility analysis for the installation of SCR on all four units and SNCR on 

4 all four units incorporated the SO2 and total particulate matter (TPM) emission rates of 0.15 

5 lb/MMBtu and 0.034 lb/MMBtu, respectively, from the current NSR Permit issued August 31, 

6 2012. The updated visibility analysis for the installation of SNCR on Units 1 and 4 and a two7 unit retirement incorporated the new TPM emission rate of 0.034 lb/MMBtu and an SO2

8 emission rate of 0.10 lb/MMBtu. This new SO2 emission rate will be incorporated into the 

9 facility’s NSR permit as a federally-enforceable permit condition should this scenario be 

10 determined as BART for the source.

11 Conclusion of analysis (Determination of BART)

12 In accordance with Section 169A(g)(7) of the CAAlean Air Act, the Department 

13 considered the five statutory factors in the BART analysis for the SJGS: (1) the costs of 

14 compliance; (2) energy and non-air quality environmental impacts of compliance; (3) any 

15 existing pollution control technology in use at the source; (4) the remaining useful life of the 

16 source; and (5) the degree of improvement in visibility which may reasonably by anticipated to 

17 result from the use of such technology.

18 PM BART Assessment

19 The Department’s BART determination for PM in Appendix D is unchanged from 2011, 

20 and was approved by the EPA in November 2012. 77 FR 64,908 (Nov. 27, 2012).

21 2011 NOx BART Determination

22 Based on the five-factor analysis, the Department determined in 2011 that, for the facility 

23 comprising Units 1, 2, 3, and 4, BART for NOx is SNCR technology at an emission rate of 0.23 
Testimony of Elizabeth Bisbey-Kuehn

Page 18 of 19

1 lb/MMBtu on a 30-day rolling average. The Department’s determination of BART was based on 

2 the results of the five-factor analysis.

3 2013 NOx BART Determination.

4 The Department analyzed the scenario contained in the non-binding agreement (Term 

5 Sheet) between the EPA, NMED and PNM, signed February 15, 2013 (the “State Alternative”), 

6 and the resulting significant environmental improvements of this alternative. The Department 

7 revised the BART analysis to compare this scenario to the 4 SNCR and 4 SCR scenarios 

8 previously evaluated. The Department’s determination of BART was based on consideration of 

9 the BART statutory factors in the context of the elements of the State Alternative (2 SNCR/2 

10 Shutdown).

11 1) PNM will retire Units 2 and 3 by December 31, 2017. These retirements do not 

12 give rise to control equipment costs requiring amortization. The remaining useful life of 

13 the source is defined as 30 years for the three scenarios described (4 SCR, 4 SNCR, 2 

14 SNCR/2 Shutdown). Therefore, the statutory factor of the remaining useful life of the 

15 source does not weigh in favor of any option over another.

16 2) PNM will obtain the necessary construction permit modification to limit the SO2

17 emission rates at Units 1 and 4 to 0.10 lb/MMBtu on a daily rolling 30-day average basis. 

18 These SO2 emission reductions occur separately and apart from the SO2 backstop trading 

19 program that EPA has already approved as satisfying BART. In addition to increased 

20 visibility improvement, these SO2 reductions will lead to non-air quality environmental 

21 benefits, such as decreased acid deposition.

22 3) The retirement of Units 2 and 3 will reduce the facility annual NOx emissions by 

23 an additional 10,550 tons. When added to the controlled emission rate of Units 1 and 4, 
Testimony of Elizabeth Bisbey-Kuehn

Page 19 of 19

1 total annual NOx emission will be reduced by 12,989 tons. Additionally, PNM will 

2 conduct performance testing to determine if the SNCRs installed on Units 1 and 4 can 

3 achieve significantly less than 0.23 lb/MMBtu.

4 4) The 2 SNCR/2 Shutdown scenario would result in less material usage than the 4 

5 SCR and 4 SNCR scenarios. See Table 23 in Appendix D. This will result in less 

6 limestone required to be transported and mined, less diesel fuel that would need to be 

7 refined for this power plant, less coal mining and processing, and less carbon that would 

8 need to be activated. Closure of two units will result in up to 53 percent less water used, 

9 from 21,000 acre-feet to 10,161 acre-feet; wastewater generated will be reduced by up to 

10 50 percent, from 41 million gallons to 21 million gallons; and solid waste generated will 

11 be reduced by up to 50 percent, from 1.71 million tons per year to 854,130 tons per year.

12 Based on this analysis, the Department determined that BART for NOx at the SJGS is the 

13 installation of SNCR technology on Units 1 and 4, with performance testing, coupled with the 

14 retirement of Units 2 and 3, as outlined in the Term Sheet.