5301 Northshore Drive 

Little Rock, AR 72118 

Dayana Medina 

U.S. Environmental Protection Agency, Region 6 

Multimedia Planning and Permitting Division 

Air Planning Section (6PD-L) 

1445 Ross A venue 

Dallas, TX 75202 

Re: BART Determination for S02 and NOx 

Flint Creek Power Plant, Gentry, Arkansas (AFIN 04-00107) 

Dear Ms. Pettyjohn and Ms. Medina: 

Below are the responses to each of the questions/requests sent to Southwestern Electric Power 

Company (SWEPCO) on May 22, 2013, regarding the BART five factor analysis for the Flint 

Creek Power Plant. We have borrowed text used in your May 22, 2013 email to set off the 

specific responses. We have numbered the each issue for the sake of clarity. 

1a. It does not appear that any new information was provided related to the cost estimate for 

the NOx control options. As we indicated in comments provided on 02/08/2013, very little 

documentation has been provided for the capital and operating costs for the LNBIOFA and SCR 

control options. In particular, for the LNB/OFA option, there is no breakdown provided for the 

estimated capital and installation costs. A breakdown of these costs should be provided, along 

with a copy of any pertinent documents related to the "Public Service Commission Docket 12-

008-U" referenced under footnote 1, and any other documentation to support the LNB/OFA cost 

estimate. 

1 b. The cost estimate for the SCR option also provides no breakdown of the capital costs and 

very little detail of the O&M costs. Footnote 1 indicates that the SCR capital and O&M cost 

estimates were developed by AEP based on engineering estimates that were informed by AEP's 

experience with SCR installation at other plants owned by AEP. Please provide documentation 

to support the SCR cost estimate. 

We use a phased approach to project cost estimating that generally follows the Association for 

the Advancement of Cost Engineers (AACE) recommended practice on major environmental 

compliance projects. The costing information we have presented is considered an AACE Class 5 

estimate with no site specific feasibility or conceptual engineering and design. AEP's Class 5 
The current AACE Class 5 capital direct cost estimate of $16MM for the LNB/OF A option was 

developed by AEP Region Engineering in early 2012. This information is included in 

Attachment A on the enclosed CD. The estimate indicates a 2015-2016 cash flow, but it has 

been revised and escalated to the current AEP/SWEPCO long range plan (LRP) cash flow years 

of 2017-2018. At this project phase, the material estimate is based on the assumed highest cost 

burner technology proposed and available from the OEM, B&W. The $16MM ($381Kiburner) 

cost estimate for Flint Creek is roughly comparable- on a total cost and cost per burner basis 

(adjusted for escalation)- to actual costs experienced by AEP for Amos 1 in 2011 for $17.4MM 

($483klburner), Amos 2 in 2010 for $16.4MM ($456klburner) and Rockport I in 2004 for 

$20.1MM ($205klburner). 

The operating costs for the LNB/OFA option are relatively minor compared to the capital cost 

for this option, and for the purpose of the BART analysis these costs are based on 

guidance/methods in the EPA's CCM. 

The current AACE Class 5 capital direct cost estimate of $121MM for the SCR option was 

developed using a levelized $/kW total cost approach by interpolation between two other Class 5 

SCR estimates in the AEP LRP: Rockport at $203/kW and Conesville 6 at $234/kW (2016 

basis). A levelized $230/kw direct cost was selected. No other breakdown of capital and 

installation costs are available for the Flint Creek SCR option. The Flint Creek SCR cost 

estimate was the subject of several interrogatory questions and answers associated with the 

APSC Docket 12-008-U. Relevant excerpts from the docket are included as Attachment Bon 

the enclosed CD. The same $230/kW SCR direct cost estimate was used by witness Scott 

Weaver in the AEP Strategist cost analysis model discussed in his testimony. 

The operating costs for the SCR option are based on estimates obtained from AEP experience for 

catalyst replacement, commodity (urea) use, and fixed operations and maintenance. For 

example, the catalyst replacement is based on a yearly levelized cost of 50 percent of the 1300-

MW Rockport plant SCR catalyst replacement. The information that formed the basis of the 

SCR O&M cost estimates is included as Attachment Con the enclosed CD. 

2. We also note that the LNB/OFA cost estimate assumes a 15 year equipment life. Unless 

proper documentation is provided to demonstrate that the anticipated equipment life of this 

control option is limited to 15 years, we believe that an anticipated 30 year equipment life would 

be more appropriate to use in the cost analysis. 

Since EPA's Control Cost Manual (CCM) does not provide equipment life information for 

combustion controls, we referenced the WRAP guidance document, Analysis of Combustion 
consistent with our recent experience, where improved controls have been installed in response 

to more stringent environmental requirements sometimes in less than 15 years. Extending the 

equipment life of the combustion controls to 30 years would not change the outcome of the 

BART analysis. 

3. In addition, we note that the SCR cost estimate assumes a 20 year equipment life. Unless 

proper documentation is provided to demonstrate that the anticipated equipment life of SCR is 

limited to 20 years, we believe that an anticipated 30 year equipment life would be more 

appropriate to use in the cost analysis. 

The EPA Control Cost Manual (CCM) explicitly assumes an economic life of 20 years for SCR. 1 

The above comment contradicts a previous directive to conform our equipment life assumptions 

to those used in the CCM. Comment #5 in Ms. Dayana Medina's November 1, 2012 email to 

Ms. Mary Pettyjohn states: 

The OAQPS Control Cost Manual (CCM) assumes an economic lifetime of20 

years for an SNCR system. Therefore, unless AEP provides proper documentation 

to demonstrate that the anticipated equipment life is limited to I 5 years, AEP 

should assume a 20 year equipment life for SNCR. 

As a result of the November 1, 2012 comments, we prepared a revised BART report that 

assumed 20-year economic life values for both SNCR and SCR. Moreover, it is our 

understanding that 20 years is typical in BART analyses for SNCR and SCR. 

4. In addition, as we noted in previous written comments, additional justification should be 

provided for the selection of0.23 lb/MMBtu as the NOx BART emission limit using LNBIOFA. 

The BART report states that this limit was selected based on experience with similar boilers and 

vendor discussions. A vendor quote should be provided or a list of similarly configured boilers 

should be compiled along with emissions data from CAMD for these similar boilers in support of 

the 0.23 lb/MMBtu NOx BART emission limit for the Flint Creek unit. 

AEP has solicited an OEM (Babcock & Wilcox, B&W) proposal for LNB/OFA that supports the 

performance used in the LRP and BART analysis. We have obtained a non-confidential, 

redacted version of this proposal from B&W and are providing a copy as Attachment Din the 

enclosed CD. 

OEM marketing information boasts NOx performance guarantees less than the 0.23 lb/MMBtu 

1 See Section 4.2, Chapter 2, page 2-48. 
configuration. Actual NOx performance data on these units were taken from CAMD, and this 

information is included as Attachment E on the enclosed CD. The NOx performance guarantee 

specified in the OEM marketing information are based on specific operating conditions that 

cannot be consistently achieved in practice as the CAMD data indicates. We must take into 

consideration the total impact on NOx level due to fuel supply flexibility, plant operating 

conditions, test versus CEMS NOx measuring equipment, and actual installed LNB/OFA 

operating performance. Further, based on the OEM proposal, the expected NOx emission rate 

spans a range of possible performance of between 0.145 lb/MMBtu and 0.218lb/MMBtu. 

5. Please provide a copy of the EPRI calculations used to estimate S04 emissions for all 

modeling scenarios. 

The calculations are included in the "Consolidated Spreadsheet_2013-04-05.xlsx" (cells 

H19:N22 of the 'Inputs' tab) provided to Ms. Mary Pettyjohn on April 11, 2013. 

We hope that this information will satisfactorily address your questions and concerns. If you 

have additional questions, AEP/SWEPCO reiterates its offer to meet with EPA and ADEQ in 

Dallas. Please contact me at (214) 777-1113 to make arrangements for such a meeting, or to 

provide any additional information you may require. 

Kristen P. Gaus 

Encl: CD containing: 

Attachment A - LNB/OF A capital cost estimate 

Attachment B- Excerpts from APSC Docket 12-008-U regarding the SCR cost estimate 

Attachment C- B&W proposal for LNB/OFA 

Attachment D - SCR O&M cost estimates 

Attachment E- Comparable NOx data from CAMD