UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105-3901

The Honorable Edmund G. Brown, Jr. State Capitol Building, Suite 1173 Sacramento, California 95814
Dear Governor Brown: 

## AUG 1 9 2014 OFFICE OF THE REGIONAL ADMINISTRATOR

Thank you for your recommendations, dated**Novemb~r** 25,2013 and July 2, 2014, ofair quality designations for the 2012 annual fine particle National Ambient Air Quality Standard (2012 annual PM2.s NAAQS) throughout California. This letter is to notify you ofthe U.S. Environmental Protection Agency's (EPA) preliminary response to California's recommendations and to inform you ofour approach for completing the initial area designations for the 2012 annual PM2.s NAAQS.
The EPA agrees with your November 25, 2013 and July 2, 2014 recommendations

. After considering California's annual PM2.s designation recommendations and other relevant technical information, including 2011-2013 air quality data;the EPA agrees with California's recommended designations and boundaries and intends to designate the PortolaValley portion ofPlumas County, the San Joaquin Valley, Los Angeles-South Coast, and a portion ofImperial County as nonattainment. A Technical SupportDocument, which provides a detailed analysis to support our preliminary decisions, is enclosed and is available on the EPA's website at: http://www.epa.gov/pmdesignations/2012standards/state.htm.
The EPA intends to designate all other areas ofthe state as unclassifiable/attainment, except for the PechangaBand ofLuisefio Mission Indians, who recommended "unclassifiable" for their portion of Indian country, which the EPA intends to designate as "unclassifiable." The EPA will continue to work with both state and tribal officials regarding the appropriate boundaries for the areas in California. If California has additional information for the EPA to consider, please submit it to us by October 29, 2014.
The EPA will make its preliminary designation dec, isions and supporting documentation available to the general public for review and comment. We will be announcing a 30-day public commentperiod shortly in the 

### Federal Register. After considering the additional information we receive, the EPA plans to promulgate final annual PM2.s designations in December of2014.
As background, on December 14, 2012, the EPA promulgated a revised primary a1mual 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 (11g/m3) to 12.0 11g/m3 ; retained the existing 24- hour PM2.s standard at 35 11g/m3; retained the existing 24-hour PM10 (coarse particle) standard at 150 11g/m3 ; and retained the current suite ofsecondary PM standards. The EPA revised the primary annual PM2.sstandard 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 protection for children, older adults, persons with pre-existing heart and lung disease, and other at-risk populations against an array ofPM2s-related

Printed on Recycled Paperadverse 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 not have monitors, and that the EPAhas reason to believe are likely attainment 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 EPAhas not determined thatthe area contributes to a nearby violation. Atthis 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 steady progress to reduce PM2.s-forming pollution and will protectpublic health in communities across the country. We look forward to a continued dialogue with you and your staffas we worktogether to implement the 2012 annual PM2.s NAAQS. Should you have any questions, please contact me, orhave your staffcontact Deborah Jordan ofmy staffat 415-947-8715, orjordan.deborah@epa.gov. Sincerely,

Enclosure

cc: Matthew Rodriguez, Secretary, CaliforniaEnvironmental Protection Agency MaryNichols, Chairman, CaliforniaAir Resources Board Richard Corey, Executive Officer, California Air Resources Board Mark A. Macarro, Chairman, PechangaBand ofLuisefio Mission Indians

cc: (via email without enclosure) Barry Wallerstein, D.Env., Executive Officer, South Coast Air Quality Management District Seyed Sadredin, Air Pollution Control Officer, SanJoaquin Valley Air Pollution Control District Brad Poiriez, Air Pollution Control Officer, Imperial County Air Pollution Control District Gretchen Bennitt, Air Pollution Control Officer, Northern SierraAir Quality Management District