Ref: 8P-AR UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http:1/www.epa.gov /region08 

### FEB 062013

The Honorable Jimmy Newton, Jr., Chairman Southern Ute Indian Tribe P.O. Box 737 Ignacio, Colorado 81137-0737

Dear ChairmanNewton:
Thank you for your recommendation letters dated May 18, 2011 and November 22, 2011, on air quality designations for the Southern Ute Indian Tribe for the 2010 revision to the primaryNational Ambient Air Quality Standard for sulfur dioxide (S02). Reducing levels ofsulfur dioxide pollution is an important part ofthe U.S. Environmental Protection Agency's (EPA) commitment to a clean, healthy environment. Exposure to S02 can cause a range ofadverse health effects, including narrowing ofthe airways which can cause difficulty breathing and increased asthma symptoms. This letter is to notify you ofthe EPA'spreliminary intentions regarding your recommended designations.

On June 3, 2010, the EPA strengthened the health-based or "primary" standard for S02byestablishing a standard for 1-hour average S02concentrations at a level of7 5 parts perbillion. The Clean Air Act requires the EPA to complete the initial designations process within two years ofpromulgating a new or revised standard. Ifthe Administrator has insufficient information to make these designations, the EPA has the authority to extend the designation process by up to one year. On July 27, 2012, the EPA announced that it had insufficient information to complete the designations for the 1-hour so2standard within two years and extended the designations deadline to June 3, 2013.

Atthis time the EPA is proceeding with designating as nonattainment most areas in locations where existing monitoring data from 2009-2011 indicate violations ofthe 1-hour S02standard. The EPA intends to address the designations for all other areas in separate future actions. With input from a diverse group ofstakeholders, EPA has developed a comprehensive implementation strategy for these future actions that focuses resources on identifying and addressing unhealthy levels ofS02. The strategy is available at: http://www.epa.gov/airquality/sulfurdioxide/implement.html. The EPA will continue to work closely with you and our other partners at the state, tribal and local levels to ensure health-protective, commonsense implementation ofthe 1-hour S02 standard.

The EPA's review ofthe most recent monitored air quality data from 2009-2011 shows no violations of the 2010 S02 standard in any areas ofthe Southern Ute Indian Reservation. Consequently, the EPA is not yet prepared to propose designation action for the Southern Ute Indian Reservation, and is, therefore, currently deferring action to designate areas on the Southern Ute Indian Reservation. The EPA expectsto be able to proceed with designation action for the Reservation once additional data are gathered pursuantto our comprehensive implementation strategy. In a separate future action or actions the EPA will notify you ofour intended designations for these areas, and seekpublic comment onthese actions,
no laterthan 120 days prior to promulgating any final designations.

We look forward to a continued dialogue with you and your staffas we work togetherto implement the 2010 primary S02standard. For additional informationregarding initial designations onthe S02 standard, please visit our website at www.epa.gov/so2designations. Should you have any questions, please do nothesitate to call me, orhave your staffcontact Crystal Ostigaard ofmy staffat (303) 312-6602 orostigaard.crystal@epa.gov.

Sincerely,

# L~En(~**~** ,Regional Administrator

Enclosure

cc: Thomas (Tom) Johnson, Division Head BrendaJarrell, Air Quality Program Manager
Gina McCarthy, Assistant Administrator for Air and Radiation Stephen D. Page, Director, Office ofAir Quality Planning and Standards