UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105



## NOV 1 7 2011

Mr. JeffYockey Tucson Electric Power 88 East Broadway Boulevard Mail Stop

- HQW602 Tucson,Aurizona 85701

DearMr. Yockey:

I am writing to inform you that EPARegion 9 is developing a partial Regional Haze Federal Implementation Plan (pIP) for the state ofAurizona. The purpose ofthe Regional Haze FIP is to improve visibility in national parks and wilderness areas in Aurizona and surrounding states as required by Section 169A ofthe Clean AirAct (Act). During the process ofdeveloping the Aurizona Regional Haze State Implementation Plan (SIP), submitted to EPA on March 2,2011, the Aurizona Department ofEnvironmental Quality (ADEQ) determined that the Irvington Generating Station was exempt from BestAvailable Retrofit Technology (BART) requirements. As partofthe FIP developmentprocess, we will revisit that determination, performing an analysis to determine whetherthis facility is subject to BARTrequirements under section 169A(b)(2)(A) ofthe Act, and EPA's implementing regulations and BARTguidelines at40 CFR Part 51, SubpartP and Appendix Y.

As we begin ourFIP analysis, we have requested that ADEQ provide us with all background materials, including subject-to-BART analyses, that were performed by them orthe affected facilities. We may also request that you provide us with additional information on the Irvington Generating Station as our analysis proceeds. Inthe meantime, we welcome the submission ofany additional, relevant information that you would like to provide to our office. Ifwe determine that this facility is subject to BARTrequirements, we will perform a five-factor BART analysis to determine whether any additional emissions controls are warranted.

EPA has entered into a consent decree thatrequires the Agency to propose approval ofArizona's Regional Haze SIP and/orpropose a Regional Haze FIP that meets the requirements ofthe Act and EPA's regional haze regulations byMay 15,2012. The consent decree also requires the Agency to take final action on the Aurizona Regional Haze SIP and/or FIP byNovember 15,2012. EPA Region 9 will hold public hearings in Aurizona and solicit public comments on a proposed Aurizona Regional Haze FIP in the months preceding theNovember 15 deadline.

Ifyou would like to submit any additional information or analysis, we request that you send it by January 31,2012. Any modeling ofthe facility shoulduse the regulatory versions ofCALPUFF (version 5.8, level 070623), CALMET (version 5.8, level 070623), and CALPOST (version

### 6.221). You maywish to prepare a modelingprotocol and consult with EPA Region 9 about the preparation ofmodeling inputs in accord with EPA guidance. Submit any information to:

Thomas Webb US EPA (AIR-2) 75 Hawthorne Street San Francisco, CA 94105

You can also reach Thomas at webb.thomas@epa.gov orbyphone at 415-947-4139.

Thank you for your attention to this matter. Ifyou have any questions, please contactThomas Webb or myself(mckaughan.colleen@epa.gov, 520-498-0118).
Sincerely,

# ~~~ Colleen McKaughan Associate Director, Air Division

cc: Henry 

### R. Darwin, ADEQ Eric Massey, ADEQ