çIJ ST. 1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX pRO

1 c 75 Hawthorne Street San Francisco, GA 95105-3901

OFFICE OF THE REGIONAL ADMINISTRATOR GregoryMendoza Governor Gila River Indian Community Post 

### Office Box 97 Sacaton, Arizona 85147 Dear Governor Mendoza: 

### The purpose of

### this 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 itimportantto engage with us in the process of assigning designations for Indian country. Although yourinvolvementis notrequired, we would like to invite you to participate in the designations process and to offeryou consultation. We wantto ensure transparent and effective communication in developing area designations forthe revised PM 2

. 5 NAAQS. On December 13, 20l2. EPArevised the PM 2

. 5 NAAQS to increase protection ofpublic health from tine particlepollution. The annual PM 2

. standard was strengthened from 15 ug/m 3 to 12 ug/m’. Establishing initial area designations is a key step in theprocess ofproviding the health and/orwelfare protection intendedby the Clean AirAct (CAz). Within two years ofpromulgation ofanew orrevised NAAQS. EPA must list and designate all areas in the country as either: Attainment

- areas thatmeet the standard; Nonattainment

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

- areas where there is insufficientinformation to make a determination as to attainnient. These designations are based on current air quality information, recommendations from state governors and tribal leaders, and otherrelevant infi)rmation as discussed in the April 2013 designations guidance. 

### initialArea

### Designations/orthe 2012 RevisedPrimaryAnimalFine ParticleNationalAmbientAir 

### Qua/ui’ Standard. The guidance is available onthe EPA’s PM Designations website at w\v.4a.uov iesnations,2g _stwkardsthjpriI2Ul 3uidmec.pdL Additional information ahotit developing tribal air quality designations is available in the September 2013 document, DevelopingDesignalion 

### Recommendations Jr

### Areas ofIndian 

### Country, which is available here: iJJJ.2 \‘\\“P O\ iii ‘nih ii puRLpingdksiun Lthin1ommLndiI1on1oIlndIan(nmuIJ We are sending you this letterbecause yourTribe has Treatment in the Same Manner as a State (TAS) status for designation provisions ofthe CAA and we received arecommendation ofattainment for your area. We will keep you informed as we finalize designations foryourTribe’s area and invite and encourage you to participate. Please notify us by June 13, 2014 ifyou are interested in consulting with Prnited an Rn vt/ed Paperus regarding a recommended designation. When requested, consultation will be conducted in accordance with the EPA Policy on Consultation and Coordination wit/i indian Tribes iev4j. We plan to fonTlally 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 any modifications EPA proposes make to your Tribe’s recommendation. 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 informed of any additional guidance or other support activities. We look forxvard 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 Sincerel , lurifeld Enclosure cc: Ondrea Barber, Executive Director DEQ

### 2012 PM 2 • 5 

### NAAQS Tribal Designations 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. Deadlineto request advancetribal consultation. June 13, 2014 Optional tribal recommendations forthe PM 2

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

- 

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

- 

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