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

OFFICE OF THE REGIONAL ADMINISTRATOR 

## JLlN 2 9 

## 2011
The Honorable Wanda Batchelor Chairwoman Washoe Tribe ofNevada and California 919 Highway 395 South, Gardnerville, Nevada 89410
DearChairwoman Batchelor: Thank you for your recommendation on the airquality designation for the revised primary National Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (NO

### z)on behalfofthe Washoe Tribe of Nevada and California. This letter is to notify you ofthe U.S. Environmental Protection Agency's (EPA's) preliminary decision to designate the areas that fall within the Washoe Tribe's lands as unclassifiable/attainment and to inform you ofour approach for completing the designations for the revised NO

### zNAAQS.
On January 22,2010, the EPA strengthened the health-based NAAQS for NO

### zby setting a new I-hour NO

### zstandard at the level of 100 parts perbillion (ppb). TheEPA also retained with no change, the annual average NO

### z standard of53 ppb. This suite ofstandards will protectpublic health by limiting people's exposures to short-term peak concentrations ofNO

### zand by limiting community-wide NO

### z concentrations to levels below those that have been linked to respiratory-related emergency department visits and hospital admissions in the United States.
In our November 2010 letter to you requesting designation recommendations, the EPA stated that it expected to designate most areas as "unclassifiable," indicating that there are insufficient data to determine whether ornot an area is attaining the revised NO

### zNAAQS. This approach took into account that the new monitoring network requirements established with the revised NO

### zNAAQS 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 yourrecommendations and intends to designate the Washoe Tribe's lands as "unclassifiable/attainment" rather than "unclassifiable." While the EPA acknowledges that the existing NO

### zmonitoring network does not provide adequate evidence to determine whether or not the new NAAQS is met in all areas, there currently is no evidence ofviolations anywhere. The "unclassifiablel attainment" designation better reflects the current air quality conditions. The EPA intends to redesignate areas, as appropriate, after sufficient airquality data from the new monitoring network are available. Ifyou have additional information that you want the EPA to consider with respect to the designation of the Washoe Tribe's lands, please submitit to 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

Printtd on**1(~cyd~d Pap~r** announcing the public commentperiod 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.
We look forward to a continued dialogue with you and your staffas we work together to implement the 2010 N02NAAQS. 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: Ms. Marie Barry, Environmental Director