UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 4

The Honorable Phyliss J. Anderson Chiefofthe Mississippi Band

ofChoctaw Indians P.O. Box 6010- Choctaw Branch Choctaw, Mississippi 39350

Dear ChiefAnderson: ATLANTA FEDERAL CENTER 61 FORSYTH STREET ATLANTA, GEORGIA 30303-8960 

### FEB

- 6 2013

I am writing today to inform you about theprocess for designating areas under the 2010 revision to the primaryNational Ambient Air Quality Standard for sulfur dioxide (S02). Reducing levels ofS02 pollution is an important part ofthe U.S. Environmental Protection Agency's 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's preliminaryintentions regarding yourrecommended designations.

On June 3, 2010, the EPA strengthened the health-based or "primary'' standard for S02by establishing a standard for 1-hour average S02 concentrations at a level of75 parts perbillion. The Clean AirAct requires the EPA to complete the initial designations process within two years ofpromulgating a new or revised standard. Ifthe Administratorhas insufficient information to make these designations, the EPA has the authority to extend the designation process byup to one year. OnJuly 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.

At this time, the EPA is proceeding with designating as nonattainment most areas in locations where existingmonitoring data from 2009-2011 indicate violations ofthe 1-hour S02 standard. The EPA intends to address the designations for all other areas in separate future actions. With input from a diverse group ofstakeholders, the 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 ourotherpartners at the state, tribal and local levels to ensure health-protective, commonsense implementation ofthe 1-hour so2 standard.

The EPA's review ofthe most recent monitored airquality data from 2009-2011 shows no violations of the 2010 S02 standard in any ofthe Mississippi Band ofChoctaw Indians trust lands. Consequently, the EPA is not yet prepared to propose designation action in the Mississippi Band ofChoctaw Indians trust lands and is therefore currently deferring action to designate areas in the Mississippi Band ofChoctaw Indians trust lands. The EPA expects to be able to proceed with designation action in the Mississippi Band ofChoctaw Indians trust lands once additional data are gathered pursuant to our comprehensive implementation strategy. In a separate future action oractions the EPA will notify you ofour intended

Internet Address (URL) • http://www.epa.gov Recycled/Recyclable • Printed**w~h** Vegetable 00 Based Inks on Recycled Paper (Minimum 30% Postconsumer)designations for these areas, and seek public comment onthese actions, no later than 120 days priorto promulgating any final designations.

We look forward to a continued dialogue with you and your staffas we work together to implement the 2010 primary S02standard. For additional information regarding initial designations onthe S02 standard, please visit our website at www.epa.gov/so2designations. Should you have any questions, please do not hesitate to call me at 404-562-8357 orBeverly Banister ofmy staffat 404-562-9326.

cc: Christina Wallace Environmental Staff Sincerely,

# ~~9ct Gwendolr;;.eyes Fleming Regional Administrator

Gina McCarthy, Assistant Administrator for Air and Radiation
Stephen D. Page, Director, Office ofAir Quality Planning and Standards