UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA**94105~3901**
OFFICE OFTHE REGIONAL ADMINISTRATOR 

## DEC 0 9 2011 The HonorableJanice Brewer State ofArizona 1700 West Washington Phoenix,Arizona 85007
Dear GovernorBrewer:
Thank you for your recommendations dated March 12,2009 and December 1,2011 on air quality designations for the revised 2008 National Ambient Air Quality Standards for ozonethroughout Arizona. I appreciate the informationArizona shared with the U.S. Environmental Protection Agency as we move forward to improve ozone air quality. Thepurpose ofthis letter is to notify you ofthe U.S. Environmental Protection Agency'spreliminary decision to designate the Phoenix area ofArizona as nonattainment for the revised 2008 ozone NAAQS, according to yourrecommendations, and to inform you ofourapproach for completingthe designations for the revised ozone NAAQS.
On March 12, 2008, the EPArevised its NAAQS for ground-level ozone to provide increased protection ofpublic health and the environment. The EPA lowered the primary 8-hour ozone standard from 0.08 parts permillion (ppm) to 0.075 ppmto protect againsthealth effects associated with ozone exposure, including a range ofserious respiratory illnesses and increased premature death from heart or lung disease. The EPArevised the secondary 8-hour ozone standard, making it identical to the primary standard, to protect against welfare effects, including impacts on sensitive vegetation and forested ecosystems. History shows us thatbetterhealth and cleaner air go**hand~in-hand** with economic growth. Working closelywith the states and tribes, the EPA is implementing the standards using a common sense approach that improves air quality and minimizes the burden on state and local governments. As part of this routine process, EPA is working with the states to identify areas in the countrythat meet the standards and those that need to take steps to reduce ozonepollution. Within one year after a newor revised air quality standard is established, the Clean Air Act requires the Governor ofeach state to submitto the EPA a list ofall areas in the state, with recommendations for whether each areameets the standard.
As a first step in implementing the 2008 ozone standards, the EPA asked states to submittheir designation recommendations, including appropriate area boundaries, byMarch 12,2009. In September 2009, the EPA announced itwas reconsidering the 2008 ozone standards. The EPA latertook steps to delay the designation process for the 2008 ozone standards pending outcome ofthe reconsideration. However, in September 20 11, the Office ofManagement and Budgetreturned to EPA the draft final rule addressing the reconsideration ofthe 2008 standards. On September 22, 20 II,the EPA restarted the implementation effort by issuing a memorandum to clarify for state and local agencies the status ofthe 2008 ozone standards and to outline plans for moving forward to implementthem. The EPA indicated that itwould proceed with initial area designations for the 2008 standards, and planned to use the recommendations states made in 2009 as updated bythe most current, certified air quality data from 2008-2010. While the EPA did not request that
Prinred on Recycled Paperstates submit updated designation recommendations, the EPA provided the opportunity for states to do so. Thankyou for the December 1, 2011 updated designation recommendation from Arizonabased on the assessment of2008-2010 air quality data.
As required by the Clean Air Act, the EPA will designate an area as nonattainment ifit is violating the 2008 ozone standards or contributing to a violation ofthe standards in a nearby area. Consistent with designations for previous ozone standards, the EPA intends to designate an area as unclassifiable/attainment ifthere are certified, quality-assured air qualitymonitoring data showing the area is meeting the ozone standards or there are no monitoring data for the area, and the EPA has not made a determination that the area is contributing to a violation in a nearby area. After considering Arizona's December 1,2011 ozone designation recommendations, which were based on 2008-2010 air quality data, as well as other relevant technical information, the EPA intends to supportArizona's recommended area designation and boundary for Phoenix-Mesa. The enclosed Technical SupportDocumentprovides a detailed analysis to support ourpreliminary decisions. The EPA intends to designate all other areas ofthe state as unclassifiable/attainment.
The EPA will continue to workwith state officials regarding the appropriate boundary for the PhoenixMesa nonattainment area in Arizona. IfArizona has additional information that you would like the EPA to consider, please submit it to us byFebruary 29,2012. The EPA will also make its preliminary designation decisions and supporting documentation available to the general public for review and comment. We will be announcing a 30-daypublic commentperiod shortly in the FederalRegister. After considering additional information we receive, the EPA plans to promulgate final ozone designations in the spring of2012.
The EPA is committed to working with the states and tribes to share the responsibility ofreducing ozone airpollution. Current and upcoming federal standards and safeguards, includingpollution reduction rules for powerplants, vehicles and fuels, will assure steadyprogress to reduce ozone-forming pollution and will protectpublic health in communities across the country. We look forward to a continued dialogue with you and your staffas we work togetherto implement the 2008 ozone standards. Should you have any questions, please do not hesitate to contact me or Amy Zimpfer, Associate Director, Air Division, ofmy staffat 415-947-4146 orzimpfer.amy@epa.gov.

Jared Blumenfeld
Enclosure

cc: HemyDarwin, Director, Arizona Department ofEnvironmental Quality Eric Massey, Director, Air QualityDivision, ArizonaDepartmentofEnvironmental Quality NancyWrona, Policy Advisor, Arizona Department ofEnvironmental Quality Donald P. Gabrielson, Director, Pinal County Air Quality Control District William Wiley, Director, Maricopa County Air QualityDepartment Dennis Smith, Executive Director, Maricopa Association ofGovemmentscc: (without enclosure)
Clinton Pattea, President, Fort McDowell Yavapai Nation MarkFrank, Environmental Specialist, Fort McDowell Yavapai Nation Diane Enos, President, Salt RiverPima-Maricopa Indian Community Daniel Daggett, Acting ENPRManager, Salt River Pima-Maricopa Indian Community Ned Norris, Jr., Chairperson, Tohono O'odham Nation ofArizona Lorinda Sam, Environmental Supervisor, Tohono O'odham Nation ofArizona

cc: (via electronic correspondence)
Gina McCarthy, Assistant Administrator for Air and Radiation Stephen D. Page, Director, Office ofAir QualityPlanning and Standards