UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX 

Gregory Mendoza 

Governor 

Gila River Indian Community 

P. 0. Box 97 

Sacaton, Arizona 85147 

Dear Governor Mendoza: 

75 Hawthorne Street 

San Francisco, CA 94105·3901 

AUG 1 9 2014 

OFFICE OF THE 

REGIONAL ADMINISTRATOR 

Thank you for your recommendation, dated November 15, 2013, of air quality designations for the 2012 

annual fine pmiicle National Ambient Air Quality Standard (2012 annual PM2.5 NAAQS) on behalf of 

the Gila River India11 Community. This letter is to notify you of the U.S. Environmental Protection 

Agency's (EPA) preliminary decision to agree with your recommendation and to inform you of our 

approach for completing the designations. Although your involvement is not required, we would like to 

invite you to further participate in the designations process and to offer you consultation. 

Based on your recommendation and other relevant teclmical information, including 2011-2013 air 

quality data, the EPA intends to designate your area of Indian country as unclassifiable/attainment along 

with the sulTounding state area. If you have additional information that the EPA should consider, we ask 

that you submit it to us by October 29, 2014. 

Please notify us by September 29, 2014 if you are interested in consulting with us regarding the 

designations process. When requested, consultation will be conducted in accordance with the EPA 

Policy on Consultation and Coordination with Indian Tribes (www.epa.gov/tribal/consultationlconsultpolicy.htm). 

As background, on December 14, 2012, the EPA promulgated a revised primary annual PM2.s NAAQS 

(78 FR 3086, January 15, 2013).-In that action, the EPA revised the primary annual PM2.s standard, 

strengthening it from 15.0 micrograms per cubic meter (J..Lg/m3

) to 12.0 j..tg/m3; retained the existing 24-

hour PM2.s standard at 35 j..tg/m3

; retained the existing 24-hour PM10 (coarse particle) standard at 150 

j..tg/m3

; and retained the current suite of secondary PM standards. The EPA revised the primary annual 

PM2.s standard based on an integrated assessment of an extensive body of new scientific evidence, which 

substa11tially strengthens our body of knowledge regarding PM2.s-related health effects. The revised 

primary annual PM2.s standard will provide increased protection for children, older adults, persons with 

pre-existing heart and lung disease, and other at-risk populations against an atTay of PM2.s-related 

adverse health effects, including premature mortality, increased hospital admissions and emergency 

department visits, and development and exacerbation of chronic respiratory disease. 

As required by the Clean Air Act, the EPA promulgates designations for all areas across the country. 

The EPA designates an area as "nonattaimnent" if it is violating the NAAQS or if it is contributing to a 

violation of the NAAQS in a nearby area. Consistent with designations for previous PM2.s standards, the 

EPA intends to use a designation category of "unclassifiable/attainn1ent" for areas that are monitoring 

attainn1ent or do not have monitors, and that the EPA has reason to believe are likely attainment and are 

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not contributing to nearby violations. Additionally, the EPA intends to designate as "unclassifiable" 

those areas where the EPA either cannot determine based on available information whether the area is 

meeting the NAAQS, or has not determined whether the area contributes to a nearby violation. At this 

time, the EPA is proceeding with intended initial area designations using quality-assured, ce1iified air 

quality monitoring data from 2011 to 2013. 

The EPA will make its preliminary designation decisions and supporting documentation available to the 

general public for review and comment. We will be announcing a 30-day public comment period shortly 

in the Federal Register. After considering additional information we receive, the EPA plans to 

promulgate final annual PM2.s designations in December of2014. 

The EPA is committed to working with the states and tribes to share the responsibility of reducing PM2.s 

air pollution. Current and upcoming federal standards and safeguards- including pollution reduction 

rules for power plants, vehicles, and fuels- will assure steady progress to reduce PM2.s-forming 

pollution and will protect public health in communities across the country. We look forward to working 

together with you and your staff to implement the 2012 annual PM2.5 NAAQS. If your Tribe is 

interested in consultation or participating in further discussions or meetings with the EPA officials about 

the designations process, please contact me or have your staff contact Kerry Drake of my staff at 415-

947-4157, or drake.kerry@epa.gov. 

Sincerely, 

Jared Blumenfeld 

cc: Ondrea Barber, Executive Director, DEQ, Gila River Indian Community