UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105-3901

Ms. Michelle R. Freeark Director ofEnvironmental Services Arizona Electric Power Cooperative, Inc. P.O. Box 2165 1000 S. Highway 80 Benson, Arizona 85602
DearMs. Freeark: 

## JUl 2 6 2012

EPA recentlyreceived correspondence expressing interest in Arizona's plan to address regional haze in protectednational parks andwilderness areas as requiredunderthe Clean AirAct (CAA). I am responding to these recent letters requesting an extension ofthe public commentperiod and additional hearings and I am providing you a copy ofourresponse.
We agree to extend the deadline for public comment and increase the number ofpublic hearings to provide ample opportunity for review and comment on the regional haze Federal Implementation Plan (FIP) regarding three powerplants in Arizona (Apache Generating Station, ChollaPowerPlant and Coronado Generating Station.) Weplan to extend the public commentperiodbytwo weeks, for a total of60 days, ending on September 18, 2012. We also planto conduct two additional public hearings, one ofwhich will be held in northern Arizona (Holbrook), and one in southern Arizona (Benson). These are scheduled for August 14 and 15, 2012, respectively. These two hearings are in addition to the public hearing in Phoenix on July 31, 2012. We will carefully and thoroughly review comments, including any additional technical information, submitted during thepublic comment periodpriorto making our final determination.
As background, under the Regional HazeRule, Arizona was required to submit a Regional Haze State Implementation Plan (SIP) in December 2007. In January 2009, well after the CAA deadline for such action, we made a formal finding that Arizona had not submitted a complete Regional Haze SIP. That finding started a two-year clock that couldbe stopped only by our approval ofa SIP orpromulgation of a FIP. In January 2011, we received a notice ofintent to sue followed by a lawsuit covering dozens of states, including Arizona, for which we hadnot approved a Regional Haze SIP orpromulgated a Regional Haze FIP under the CAA. Shortly thereafter, in February 2011, Arizona submitted a new Regional Haze SIP. Submittal ofthis plan, however, had no effect on the EPA's legal obligation to promulgate a Regional Haze FIP, unless the EPA was able to approve fully Arizona's Regional Haze SIP.
After lengthy and complex negotiations involving deadlines for numerous states, the mostrecent revision to the consent decree requires us to take actions on Arizona's SIP, or adopt a FIP, in two separate sets ofnotices. The final action date for the three powerplants in our current proposal is November 15, 2012. The fmal action for the remainder ofArizona's SIP is July 15, 2013. These dates for us to act on Arizona's SIP are among the latest in the consent decree.

Prinred 0 11 Recyrled PaperAccordingly, on July 20, 2012, we proposed a partial approval and partial disapproval ofArizona's Regional Haze SIP with respectto its determination ofBest Available Retrofit Technology (BART) to control emissions from eight units at three electric generating stations: Apache Generating Station, Cholla PowerPlant and Coronado Generating Station. We have proposed to approve the State's determination that these sources are subject to BART, and to approve the emissions limits for sulfur dioxide (S02) and particulate matter (PMto) at all the units. We also have proposed to disapprove the BARTemissions limits for nitrogen oxides (NOx) at most ofthe units. As a remedywe have proposed a FIP containing new emissions limits for NOx as well as associated compliance requirements. This proposal was published in the Federal Register on July 20, 2012 and is available at: http://www

.epa.gov/region9/ai r/actions/az.html#all.
We are committedto working with Arizona on its regional haze plan. Priorto ourJuly20, 2012 proposal, EPA worked with Arizona, the affected utilities, the National Park Service, the environmental litigants, and others to gather information useful inpreparing ourproposal. EPAprovided a prepublication version ofthe proposal that was published in the Federal Register to various parties, including the State, on July 2, 2012. States are entitled to deference to their reasoned decisions when consistent withthe CAA and the Regional Haze Rule. However, we cannot give deference to state decisions ifwe find that the state's analysis does not comply with the regional hazerequirements. In this case, where we have proposed a FIP, we are committed to continuing to work with the State ofArizona on approvable revisions to its SIP. When an approvable regional haze SIP revision is submitted to the EPA and approved, we will withdraw ourFIP.
Ifyou have further questions, please contact me oryour staffmay call Colleen McKaughan, Associate Director at 520-498-0118. Sincerely,

Director, Air Division

cc: Eric Hiser, AEPCO Counsel