UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX

The Honorable Brian Sandoval State Capitol Building 101 North Carson Street Carson City, Nevada 89701
Dear Governor Sandoval: 75 Hawthorne Street San Francisco, CA 94105·3901



## AUG 19 2014 OFFICE OF THE REGIONAL ADMINISTRATOR

Thank you for your recommendation, dated December 6, 2013, ofair quality designations for the 2012 annual fine patiicleNational Ambient Air Quality Standard (2012 annual PM2.s NAAQS) throughout Nevada. This letter is to notify you ofthe U.S. Environmental Protection Agency's (EPA) preliminary response to Nevada's recommendation and to inform you ofour approach for completing the initial area designations for the 2012 annual PM2.s NAAQS.
The EPA agrees with your December 6, 2013 recommendation

. We have considered the annual PM2.s designation recommendation submitted by Nevada and have reviewed the relevant technical information, including 2011-2013 air quality data. These data do not indicate any violation ofthe 2012 annual PM2.s NAAQS in Nevada or contribution to any nearby area. Accordingly, the EPA intends to designate the entire state ofNevada as unclassifiable/attainment.
The EPA will make its preliminary designation decisions and supporting documentation available to the general public for review and comment. We will be atmouncing a 30-day public commentperiod shortly in the 

### FederalRegister. After considering the additional information we receive, the EPA plans to promulgate final annual PM2.s designations inDecember of2014.
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 ()..lg/m3) to 12.0 )..lg/m3; retained the existing 24- hour PM2.s standard at 35 )..lg/m3; retained the existing 24-hour PM10 (coarse particle) standard at 150 )..lg/m3; and retained the cunent suite ofsecondary PM standards. The EPA revised the primary ammal PM2.s standard based on an integrated assessment ofan extensive body ofnew scientific evidence, which substantially strengthens our body ofknowledge regarding PM2.s-related health effects. The revised primary annual PM2.s standard will provide increased protectionfor children, older adults, persons with pre-existing heart and lung disease, and other at-risk populations against an anay ofPM2.s-related adverse health effects, includingpremature mortality, increased hospital admissions and emergency department visits, and development and exacerbation ofchronic respiratory disease.
The EPA designates an area as "nonattainment" ifit is violating the 2012 annual PM2.s NAAQS or ifit is contributing to a violation ofthe NAAQS in a nearby area. Consistent with designations for previous PM2

.s standards, the EPA intends to use a designation category of"unclassifiable/attainment" for areas that are monitoring attainment or do nothave monitors, and that the EPAhas reason to believe are likely

Printed on Recycled Paperattainment and are not contributing to nearby violations. Additionally, the EPA intends to designate as "unclassifiable" those areas where the EPA cannot determine based on available information whether the area is meeting the NAAQS or where EPA has not determined that the area contributes to a nearby violation. At this time, the EPA is proceeding with intended initial area designations using qualityassured, certified air quality monitoring data from 2011 to 2013.
The EPA is committed to working with the states and tribes to share the responsibility ofreducing

### PM2.s air pollution. Current and upcoming federal standards and safeguards- including pollutionreduction rules for powerplants, vehicles, and fuels- will ensure steadyprogress to reduce PM2.s-forming pollution and will protectpublic health in commu11ities across the country. We look forward to a continued dialogue with you and your staffas we work togetherto implement the 2012 annual PM2 

### .s NAAQS. Should youhave any questions, please contact me, or have your staffcontact DeborahJordan ofmy staffat 415-947-8715, orjordan.deborah@epa.gov. Sincerely,

cc: Leo Drozdoff, Director, Nevada Department ofConservation and Natural Resources Colleen Cripps, PhD, Administrator, Nevada Division ofEnvironmental Protection (via email) Rob Bamford, Chief, AirPollution Control Bureau, Nevada Division of Environmental Protection (via email) Jasmine Mehta, Chief, Air Quality Planning Bureau, Nevada Division of Environmental Protection