Diane Enos 

President 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX 

75 Hawthorne Street 

San Francisco, CA 94105·3901 

AUG 1 9 2014 

Salt River Pima Maricopa Indian Community 

10005 E. Osbourne Rd. 

Scottsdale, Arizona 85256 

Dear President Enos: 

OFFICE OF THE 

REGIONAL ADMINISTRATOR 

Thank you for your recommendation dated December 4, 2013 of air quality designations for the 2012 

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

the Salt River Pima Maricopa Indian 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 surrounding 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 7.? 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/consultation/consultpolicy.htm). , 

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

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

strengthening it from 15.0 micrograms per cubic meter ()lg/m3

) to 12.0 )lg/m3; retained the existing 24-

hour PMz.s standard at 35 )lg/m3

; retained the existing 24-hour PM1o (coarse particle) standard at 150 

)lg/m3

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

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

substantially strengthens our body of knowledge regarding PMz.s-related health effects. The revised 

primary mmual PMz.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 array ofPMz.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 "nonattainment" 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 PMz.s standards, the 

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

attainment 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, cetiified 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 staffto implement the 2012 annual PM2.s 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 415-94 7-

4157, or drake.kerry@epa.gov. 

Sincerely, 

Jared Blumenfeld 

cc: Christopher Horan, EPNR Manager, Salt River Pima Maricopa Indian Community