Francisco,

AEPCO appreciates the opportunity to clarify information submitted to EPA on August 23, 3012 based 

on EPA’s data request dated August 6, 2012. Please do not hesitate to contact me if you need any 

further clarifications. 

Q: We understand from the response to question #4 from EPA that AEPCO has no 

"scheduled or planned EGU retirement dates". Also, AEPCO has indicated that the 

remaining life of the units was 8 years. Is there a relationship between the length of the 

electricity sales contracts (up to 2020) and the remaining life of the units (8 years) as 

included in the analysis of financial impacts from SCR installation and operation in the 

response to question #1? If so, please elaborate and explain if it is not possible to 

consider a remaining life for the units beyond 2020. 

A: AEPCO’s ST1 has a current contract life through 2020. AEPCO supplies all or the 

majority portion of the power needs of its six Class A member distribution cooperatives 

under wholesale power contracts. AEPCO’s operations are driven by the needs of our 

members. The contract life of the asset is not an indication of its useful life. With 

respect to the three steam units, the contract life was modeled within the financial 

forecast, regardless of the forecast period.

Q: AEPCO's financial analysis in the response to question #1 reflects a time horizon of 15 

years. For our standard analysis of SCR, EPA assumes a time horizon of 20 years for the 

useful life of the equipment. What is AEPCO's justification for assuming a 15-year time 

horizon? 

A: The analysis completed by AEPCO in response to the data request from EPA was based 

on our current financial forecasts. AEPCO maintains a twenty year forecast and 

therefore the year 2031 was the last year of our current forecast. 

Thanks,

Michelle Freeark

Director of Environmental Services

Arizona Electric Power Cooperative, Inc. 

(520) 586-5122

mfreeark@ssw.coop

This message and any attached documents are privileged and/or confidential. If you are not the 

intended recipient, do not copy, distribute, or retain this information. If you have received this 

transmission in error, kindly notify the sender by reply e-mail. This electronic signature in no way 

denotes an offer or acceptance to contract.

RE: Additional questions for Arizona regional haze analysis

Michelle Freeark 

to:

Francisco Donez

09/17/2012 05:07 PM

Cc:

Colleen McKaughan, Larry Sorrels, Margaret Alkon, Thomas Webb

Hide Details 

From: Michelle Freeark <mfreeark@ssw.coop>

To: Francisco Donez/R9/USEPA/US@EPA, 

Cc: Colleen McKaughan/R9/USEPA/US@EPA, Larry Sorrels/RTP/USEPA/US@EPA, 

Margaret Alkon/R9/USEPA/US@EPA, Thomas Webb/R9/USEPA/US@EPA

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From: Francisco Donez [mailto:Donez.Francisco@epamail.epa.gov] 

Sent: Monday, September 17, 2012 3:12 PM

To: Michelle Freeark

Cc: Colleen McKaughan; Larry Sorrels; Margaret Alkon; Thomas Webb

Subject: RE: Additional questions for Arizona regional haze analysis

Hi Michelle:

Yes, of course noon on September 18 is fine. Thank you!

Francisco

Francisco Dóñez, Ph.D.

US Environmental Protection Agency

On detail to Air Planning Office (AIR-2)

600 Wilshire Blvd., Suite 1460

Los Angeles, CA 90017

Tel. (213) 244-1834

http://www.epa.gov/region9/air/index.html

http://www.epa.gov/region9/socal/about-us.html

From: Michelle Freeark <mfreeark@ssw.coop>

To: Francisco Donez/R9/USEPA/US@EPA, 

Cc: Thomas Webb/R9/USEPA/US@EPA, Margaret Alkon/R9/USEPA/US@EPA, Larry Sorrels/RTP/USEPA/US@EPA, Colleen 

McKaughan/R9/USEPA/US@EPA

Date: 09/17/2012 08:29 AM

Subject: RE: Additional questions for Arizona regional haze analysis

Francisco,

Is it acceptable for AEPCO to have an answer to EPA by noon on September 18, 2012? Our offices our closed on Fridays 

which creates some problems.

Thanks,

Michelle Freeark

From: Francisco Donez [mailto:Donez.Francisco@epamail.epa.gov] 

Sent: Thursday, September 13, 2012 10:12 AM

To: Michelle Freeark

Cc: Thomas Webb; Margaret Alkon; Larry Sorrels; Colleen McKaughan

Subject: Additional questions for Arizona regional haze analysis

Dear Michelle:

Sorry, I got our requested submission date wrong in my previous message below. What I meant to request is that 

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you send AEPCO's responses to these clarification questions by COB this Monday, September 17. If at all 

possible, we would like to get this information into the docket before the comment period closes on September 18. 

Apologies for any confusion, and please let me know if this requested deadline is problematic.

Best,

Francisco

Francisco Dóñez, Ph.D.

US Environmental Protection Agency

On detail to Air Planning Office (AIR-2)

600 Wilshire Blvd., Suite 1460

Los Angeles, CA 90017

Tel. (213) 244-1834

http://www.epa.gov/region9/air/index.html

http://www.epa.gov/region9/socal/about-us.html

__________________

Dear Michelle:

Sorry for the delay in getting these additional questions to you. See below. If it is possible to send responses to 

these by close of business on Monday, September 27, that would be great. 

 We understand from the response to question #4 from EPA that AEPCO has no "scheduled or planned 

EGU retirement dates". Also, AEPCO has indicated that the remaining life of the units was 8 years. Is there 

a relationship between the length of the electricity sales contracts (up to 2020) and the remaining life of the 

units (8 years) as included in the analysis of financial impacts from SCR installation and operation in the 

response to question #1? If so, please elaborate and explain if it is not possible to consider a remaining life 

for the units beyond 2020. 

 AEPCO's financial analysis in the response to question #1 reflects a time horizon of 15 years. For our 

standard analysis of SCR, EPA assumes a time horizon of 20 years for the useful life of the equipment. 

What is AEPCO's justification for assuming a 15-year time horizon?



Please contact me if you need more information. Thank you!

Best,

Francisco

Francisco Dóñez, Ph.D.

US Environmental Protection Agency

On detail to Air Planning Office (AIR-2)

600 Wilshire Blvd., Suite 1460

Los Angeles, CA 90017

Tel. (213) 244-1834

http://www.epa.gov/region9/air/index.html

http://www.epa.gov/region9/socal/about-us.html

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