UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASH I NGTON , D

. C

. 20460

The Honorable Aaron A. Payment Chairperson Sault St. Marie Tribe of Chippewa Indians 523 Ashmun Street Sault St. Marie, Michigan 49783
Dear Chairperson Payment: 

## MAR 2 02015

OF F I CE OF A I R AN D RAD IATION

I am writing to update you on the status ofthe U.S

. Environmenta l Protection Agency's progress in implementing the pr imary National Ambient Air Quality Standa rd (NAAQS) for sulfur dioxide (S02) set in 20 10 at 75 parts per bi lli on (ppb) as a 1- hour average . In July 2013, the EPA identified areas in 16 states as nonattainment and expressed the intent to address designations for the re m ainder of the count ry in separate future actions. On March 2, 2015, the U.S. District Court for the Northern District of California accepted as an enforceab le order an agreement between the EPA and Sierra Club and Natural Resources Defense Counci l to resolve litigation concerning the deadline for completing the designations. The court's order directs the EPA to complete designations in three additional rounds : the first round by July 2 , 2016, the second ro u n d by December 31, 2017 , and the final round by December 31, 2020. T he EPA will complete these designations by designating areas as either nonattainment, unclassifiable/ attainment, or u nclassifiable.
In the first round of designations, the EPA will designate two groups of areas : 1) areas that have newly moni tored violations oft he 2010 S02 standard, and 2) areas that contain any station ary source that acco rding to the EPA ' s A ir Markets D atabase either emitted more than 16 , 000 tons of S02 in 2012 or emitted more than 2,600 tons ofS02 and had an emission rate of at least 0.45 lbs S02/mmbtu in 2012 and that has not been announced (as ofMarch 2 , 2015) for re tirement. In the enclosure to this letter, the EPA provides the schedule we intend to follow to meet the July 2 , 2016, deadli ne. W hil e there are currently no violating monitors and no sources meeting the above criteria on your tribal land, the EPA h as ident ified the following electric power p lant source in Mic hi gan as meeting the criteria established in the court's order. This source may potentially be impacting your tribal land :
State County Facility Name 20 12 S02 Emissions 20 12 S02 Emissions (tons) Rate (lb/mmBtu) Presque Isle M I Marquette Power Plant 6,028 0.513

I n te rn et Address (URL) • h ttp: // www
. epa
. gov Recycled/Recyc l able • P rin ted w i t h Ve g etable O i l Based I nks o n tOO% Postco n sumer, P rocess Ch l orine Free R ecycled PaperYou may wish to discuss the designation for this area with representatives of Michigan, and provide your own designation recommendation for the potentially affected area on your tribal land. The EPA will use the most recent available information when making area designation and boundary decisions for the indicated area. If you would like to submit information or recommendations for the pot e ntially affected area on your tribal land , we request that you do so by September 18, 2015. The EPA has updated its March 24, 2011 , designation guidance for the 2010 S02 standard to support analysis of designations and boundaries for t hese next rounds of designations. The updated guidance can be found on the EPA ' s website at http :// epa.gov / airquality l sulfurdioxidelguidance.html. The EPA has also provided two technical assistance documen t s that provide advice on the use of modeling and monitoring data when determining if an area is meeting or not meeting the 2010 S02 standard. These documents can be found on the EPA ' s website at http: // epa.gov/airquality / su(furdioxide / implement.html. The court ' s order directs the EPA to complete the second round of area designations by December 31 , 2017. These designations would address areas where states have not installed and begun operating a new

S02 monitoring network meeting the EPA ' s specifications referenced in our propos e d rule titled , "Data Requirements Rule for the 1-hour S02 primary NAAQS " . This rule , which was proposed in the Federal Register on May 13 , 2014, would direct state and tribal air agencies to provide data to characterize

current air quality in areas with large sources of S0 2 if such areas do not have sufficient air quality moni t oring in place to identify maximum S0 2 concentrations. The data collected as a result of this proposed rule would be used in the designations process. Lastly, the court's order directs the EPA to designate all remaining areas by December 31 , 2020. The EPA will provide states with additional informat i on on the designations process associated with these later deadlines at a later date. We look forward to continued dialogue with you and your staff as we work together to implement the 2010 S02 standard and achieve its intended public health protection. For additional information regarding designations for the 20 1 0 S02 standard, please visit our website at www.epa.gov / so2designations. Should you have any questions, please do not hesitate to call me or Scott Mathias of my staff at 919-541 - 5310 and mathias . scott @ epa.gov. Sincerely, Janet G. McCabe Acting Assistant Administrator Enclosure cc: Susan Hedman EPA Region 5 AdministratorENCLOSURE
TIMELINE FOR 201 0 PRIMARY S02 NAAQS DESIGNATION PROCESS FOR AREAS AS SOCIA TED WITH JULY 2, 2016, COURT-ORDERED DEADLINE* Milestone Date** Court Order March 2, 2015 States may s ubmit updated recommendations No later than September 18 , 2015 and supporting information for area des ignations to the E PA T he EPA notifies sta tes concerning any o/a January 22, 2016, but absolutely no later intended modifications to their than 120 days prior to fina l designations, i

. e., recommendations ( 120

- day letters) March 2 , 2016 The EPA publishes public notice of state o/ a February 3, 2016 recommendations and the EPA's intended modifications and initiates 30

- day pub li c comment period End of 30

- day public comment period o / a March 4 , 2016 States provide additional information to o /a April 8 , 2016 demonstrate why an E PA modification is inappropriate The EPA promulgates final S02 area No later than July 2 , 2016 designations (no later than 16 months from Court Order) 

## * T he court's order directs the EPA to promulgate additiona l rounds of designations by December 3 1 , 20 17 , and by December 31,2020. 

## ** o/a = on or about