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

OffiCE Of THE REGIONAL ADMINISTRATOR 

## DEC 0 9 2011

Governor William Rhodes Gila River Indian Community P. O. Box 97 Sacaton, Arizona 85147 Dear GovernorRhodes: The purpose ofthis letter is to notify you ofthe U.S. Environmental Protection Agency's preliminary decision to designate Indian country ofthe Gila River Indian Community as unclassifiable/attainment for the revised 2008 ozone National Ambient Air Quality Standards, and to inform you ofour approach for completing the designations for the revised ozone NAAQS. On March 12,2008, the EPA revised the NAAQS for ground-level ozone to provide increased protection ofpublic health and the environment. The EPA lowered the primaryozone standard from 0.08 parts per million (ppm) to 0.075 ppm to protect against health effects associated with ozone exposure, including a range ofserious respiratory illnesses and increased premature death from heart or lung disease. The EPA revised 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. Within one year ofpromulgation ofa new orrevised NAAQS, the Clean AirActrequires the Governor ofeach state to submitto the EPA a list ofall areas in the state, recommending designations with respect to the new orrevised standard. Therefore, states were asked to submit their designation recommendations, including appropriate area boundaries, to the EPA byMarch 12,2009 with respect to the revised ozone standards. Tribes were not required to submit recommendations, but were encouraged to participate in the designations process, and submit recommendations ifthey chose to do so. In September 2009, the EPA announced it was reconsideringthe 2008 ozone standards. The Agency latertook steps to delay the designation process for the 2008 ozone standards pending the outcome ofthe reconsideration. In September 2011, the Office ofManagement and Budget returned to EPAthe draft final rule addressing the reconsideration ofthe 2008 ozone standards. On September 22, 2011, the EPArestarted the implementation effortby issuing a letterto clarify for state and local agencies the status ofthe 2008 ozone standards and to outline plans for moving forward to implementthem. This letter was also provided to the tribes. In addition, several national tribal conference calls were held to describe the overall designations process. TheEPA indicated that it would proceed with initial area designations for the 2008 standards,

Pn'nred un Rl'C:ycled Paperand planned to use the recommendations states and tribes made in 2009 as updated by the most current, certified air quality data from either 2008-20I0 or 2009-2011, as appropriate. While the EPA did notrequest that states and tribes submitupdated designation recommendations, the Agencyprovided the opportunity for them to do so. As required by the Clean Air Act, the EPA will designate an area as nonattainment ifit is violating the 2008 ozone standards orcontributing 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 quality monitoring data showing the area is meeting the ozone standards orthere are no monitoring data for the area, and the EPA has not made a determination thatthe area is contributingto a violation in a nearby area. After consideringrelevant technical information, including the mostrecent three years of certified airqualitydata, the EPA intends to designate the Gila River Indian Community as unclassifiable/attainment along with the surrounding state area. The EPAwill make its preliminarydesignation 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, the Agencyplans to promulgate final ozone designations in the spring of2012. EPA is committed to working withthe 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 steady progress to reduce smogforming pollution and will protectpublic health in communities across the country. We look forward to working with you and your staffto develop area designations underthe 2008 ozoneNAAQS in a timely manner. IfyourTribe has any questions about the designations process, please do not hesitate to contact me or Amy Zimpfer, Associate Director, AirDivision, ofmy staffat 415-947-4146 or zimpfer.amy@epa.gov.

Jared Blumenfeld

cc: RudyMix, Acting Director, DEQ