UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
 

REGION IX
 

75 Hawthome Street
 

San Francisco, CA 94105·3901
 

OFFICE OF THE 

REGIONAL ADMINISTRATOR JUN 2 9 2011 

The Honorable Virgil Moose 

Chairperson 

Big Pine Paiute Shoshone Tribe of the Owens Valley 

Post Office Box 700 

841 South Main Street 

Big Pine, California 93513 

Dear Chairman Moose: 

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 behalf of the Big Pine Paiute 

Shoshone Tribe of the Owens Valley. This letter is to notify you of the U.S. Environmental Protection 

Agency's (EPA's) preliminary decision to designate the Big Pine Reservation as unclassifiablel 

attainment and to inform you of our approach for completing the designations for the revised N02 

NAAQS. 

On January 22,2010, the EPA strengthened the health-based NAAQS for N02by setting a new I-hour 

N02standard at the level of 100 parts per billion (ppb). The EPA also retained with no change, the 

annual average N02standard of 53 ppb. This suite of standards will protect public health by limiting 

people's exposures to short-term peak concentrations of N02 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 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 N02 NAAQS. This approach took into account 

that the new monitoring network requirements 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 Big Pine Reservation 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 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 Big Pine Reservation, 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 

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review. We are accepting public comments on our preliminary decisions for 30 days after a notice 

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. Sally Manning, Environmental Director