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

OFFICE OF THE REGIONAL ADMINISTRATOR 

## JUN 2 9 2011 The Honorable Marjorie Mejia Chairperson Lytton Rancheria ofCalifornia 1300 N. Dutton Avenue, Suite A Santa Rosa, California 95401 DearChairperson Mejia: Thank you for your recommendation on the air quality designation for the revised primary National Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (N02) on behalfofthe Lytton Rancheria. This letteris to notify you ofthe U.S. Environmental Protection Agency's (EPA's) preliminary decision to designate the Lytton Rancheria trust lands in San Pablo, California as unclassifiable/attainment and to inform you ofour approach for completing the designations for the revised N02 NAAQS. OnJanuary 22,2010, the EPA strengthened the health-based NAAQS for N02 by setting a new I-hour N02 standard at the level of 100 parts perbillion (ppb). The EPA also retained with no change, the annual average N02 standard of53 ppb. This suite ofstandards will protectpublic health by limiting people's exposures to short-term peakconcentrations ofN02 and by limiting community-wide N02 concentrations to levels below those that have been linked to respiratory-related emergency department visits and hospital admissions in the United States. In ourNovember 2010 letter to you requesting designation recommendations, the EPA stated that it expected to designate most areas ofthe country as "unclassifiable," indicating that there are insufficient data to determine whether ornot an area is attaining the revised N02 NAAQS. This approach tookinto account that the new monitoring networkrequirements established with the revised N02 NAAQS will not be in place until January 2013 and that air quality data from these new monitors would not be available to inform these initial designations. The EPA has reviewed your recommendations and intends to designate the Lytton Rancheria trust lands as "unclassifiable/attainment" rather than "unclassifiable."While the EPA acknowledges that the existing N02monitoring network does not provide adequate evidence to determine whether or not the new NAAQS is met in all areas, there currentlyis no evidence ofviolations anywhere. The "unclassifiable/attainment" designation betterreflects the current air quality conditions. The EPA intends to redesignate areas, as appropriate, after sufficient air quality datafrom the new monitoring network are available. Ifyou have additional information that you wantthe EPA to considerwith respect to the designation of the Lytton Rancheria trust lands, please submititto us by August 29,2011. We are also making the EPA's preliminary designation decisions and supporting documentation available to the general public for review. We are accepting public comments on ourpreliminary decisions for 

### 30 days after a notice

Printed on Ruyded Paperannouncing the public comment period is published in the 

### FederalRegister. We will review any information we receive from you and the general public by this date, and we plan to promulgate the final designations by October 31, 2011. Welook forward to a continued dialogue with you and your staffas we work together to implement the 2010 N02 NAAQS. Should you have any questions, please do not hesitate to call me, orhave your staff contact Colleen McKaughan ofmy staffat 520-498-0118. Sincerely,

Cc: Mr. BrentGudzus, Environmental Director