ST UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX PRO 75 Hawthorne Street San Francisco, CA 95105-3901

OFFICE OF THE REGIONAL ADMINISTRATOR

Maxine Resvaloso Chairwoman Torrez Martinez Desert Cahuilla Indians Post Office Box 1160 Thermal, California 92274 Dear Chairwoman Resvaloso: The purpose ofthis letter is to provide you with information concerning the U.S. Environmental Protection Agency’s (EPA) designations process forthe 2012 primary annual PM 2

. 5 national ambient air quality standard (NAAQS). YourTribe may find it importantto engage with us in theprocess of assigning designations for Indian country. Although yourinvolvementis notrequired, we would like to invite you to participate in the designations process andto offeryou consultation. We wantto ensure transparent and effective communication in developing area designations forthe revised PM 2

. 5 NAAQS. Arearecommendations forthe PM- NAAQS were due to EPA on December 13, 2013; however, EPA is prepared to accept designation recommendations via letterfrom tribal leaders until June 13, 2014. On December 13. 2012, EPA revisedthe PM 2

. NAAQS to increase protection ofpublic health from fine particle pollution. The annual PM 2

. 5 standard was strengthenedfrom 15 ug/m to 12 ug/m. Establishing inilial area designations is a key step in the process ofproviding the health andlorwelfareprotection intended bythe Clean AirAct (CAA). Within two years ofpromulgation ofanew orrevisedNAAQS. EPA must list and designate all areas in the country as either: Attainment

- areas that meetthe standard; Nonattainment

- areas that either do notmeetthe standard, or are contributing to anearby area that does notmeet the standard; or Unclassifiable

- areas where there is insufficientinformationto make a determination as to attainment. These designations are based on current airquality information, recommendations from state governors and tribal leaders, and otherrelevant information as discussed in the April 2013 designations guidance. initialArea Designations/or

### the 2012 RevisedPrimaryAnnualFineParticle NationalAmbientAir Qiialiri: Standard. The guidance is available on the EPA’s PM Designations website at nldLsi.1n itioi i012stmdaid docs ipii12f)I 3uid luLL pdl Additional infonnation about developing tribal air quality designations is available in the September2013 document. DevelopingDesignation Recommendations/brAreas ofIndian Country, which is available here: \ Lp i LU’!! m tiibiLdRiJLvuj2jiL 1f)LsienatIonRLLommLnd lnUi 1 oIlJ d ,noun x 1 d1 We are sending you this letterbecause Imperial County shows violations ofthe 2012 PM 2

. 5 NAAQS. EPA will be reviewing data to determine whetheranyportion ofyourTribe’s area ofIndian country Printed on Reeve/ed Papershould he designated nonattainment for the standard and you may want to engage with us through the consultation process. We will keep you informed as we finalize designations for your Tribe’s area and invite and encourage you to participate. Please notify us by June 13, 2014 if you are interested in consulting with us regarding a recommended designation. When requested, consultation will he conducted in accordance with the EPA Policy on Consultation and Coordination with Indian Tribes (www.epa. zov/tribaij consultaton’consult—pohcv.htm ). We plan to formally announce our intended designations for all areas by August 14, 2014. At that time we will send another letter to you with our intended designation and. offer an additional opportunity to consult with us on the proposed designation status of your Tribe’s area of Indian country. In accordance with section 107(d) (1)(B) of the CAA, we are required to issue final designations for the PM 2 . 5 NAAQS no later than December 12, 2014. Our designations will be based on the most recent three calendar years of certified, quality-assured monitoring data available, and any other relevant information. As the designation process moves forward, we will keep you infonned of any additional guidance or other support activities. We look forward to working with you to develop area designations under the PM 2 . 5 NAAQS in a timely manner. If your Tribe is interested in consultation or has questions about the designations process, please do not hesitate to contact me or Kerry Drake, Associate Director, Air Division, of my staff, at 415-947-4157 or drake.kerry(aepa.uo\. Sincerely, Enclosure cc: Roland FelTer, Environmental Director

### 2012 PM 2 • 5 

### NAAQS TribalDesignations Schedule
Action Date Recommendations forthe PM 25 NAAQS due December 13, 2013 to EPA (original deadline). Advance consultation opportunity offeredto LateMay 2014 (uponreceipt ofletter) tribal leaders. Deadlinetorequest advancetribal consultation. June 13, 2014 Optional tribal recommendations forthe PM 2

. 5 June 13, 2014 NAAQS due to EPA (extended deadline). Advance tribal consultation takesplace. June

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### July, 2014 EPA announces intended designations, August 14, 2014 additional consultation opportunity offeredto tribal leaders. Additional consultationtakes place. September

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### October, 2014 EPA issues final PM 75 designations. December 12, 2014