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 of Nevada and California 

919 Highway 395 South, 

Gardnerville, Nevada 89410 

Dear Chairwoman Batchelor: 

Thank you for your recommendation on the air quality designation for the revised primary National 

Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (NOz) on behalf of the Washoe Tribe of 

Nevada and California. This letter is to notify you of the 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 of our approach for completing the designations for the 

revised NOz NAAQS. 

On January 22,2010, the EPA strengthened the health-based NAAQS for NOz by setting a new I-hour 

NOz standard at the level of 100 parts per billion (ppb). The EPA also retained with no change, the 

annual average NOz standard of 53 ppb. This suite of standards will protect public health by limiting 

people's exposures to short-term peak concentrations of NOz and by limiting community-wide NOz 

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 or not an area is attaining the revised NOz NAAQS. This approach took into account 

that the new monitoring network requirements established with the revised NOz 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 Washoe Tribe's lands as 

"unclassifiable/attainment" rather than "unclassifiable." While the EPA acknowledges that the existing 

NOzmonitoring network does not provide adequate evidence to determine whether or not the new 

NAAQS is met in all areas, there currently is no evidence of violations anywhere. The "unclassifiablel 

attainment" designation better reflects the current air quality conditions. The EPA intends to redesignate 

areas, as appropriate, after sufficient air quality data from the new monitoring network are available. 

If you have additional information that you want the EPA to consider with respect to the designation of 

the Washoe Tribe's lands, please submit it 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 our preliminary decisions for 30 days after a notice 

Printtd on 1(~cyd~d Pap~r
announcing the public comment period is published in the Federal Register. 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 staff as we work together to implement the 

2010 N02 NAAQS. Should you have any questions, please do not hesitate to call me, or have your staff 

contact Colleen McKaughan of my staff at 520-498-0118. 

Sincerely, 

cc: Ms. Marie Barry, Environmental Director