UNITED STATES ENVIRONMENTAL PROTECTION AGENCY W ASHING T ON , D.C

. 2 04 60

The Honorable John P. Warren Chairman Pokagon Band of Potawatomi Indians P.O. Box 180 Dowagiac, Michigan 49047
Dear Chairman Warren: 

## MAR 2 02015

OFFICE OF AIR A N D RAD IAT IO N

I am writing to update you on the status of the U.S. Environmental Protection Agency's progress in imp lementing the primary National Ambient Air Quality Standard (NAAQS) for sulfur d i oxide (S02) set in 2010 at 75 parts per billion (ppb) as a 1-hour average. In July 2013 , the EPA identified areas in 16 states as nonatta inment and expressed the intent to address designations for the remainder ofthe country in separate future actions.
On March 2, 2015, the U.S. Di stric t Court fo r the Northern D i strict of California accepted as an e nfo rceab le order an agreement between the EPA and Sierra Club and Natural Resource s Defense Counc il to resolve litigation concerning the deadli ne for completing the designations. The co urt 's order directs th e EPA to complete designations in three additional rounds: the first round by July 2 , 2016 , the second round by December 31 , 2017 , and the final round by December 3 1 , 2020. The EPA will complete th ese designations by designating areas as either nonattainment, unclassifiable/attainment, or unclassifiable.
In the first ro und of designations, the EPA will designate two groups of areas : 1) areas that have newly monitored violations ofthe 2010 S02 standard , and 2) areas that contain any stationary source that according to the EPA's Air Markets Database either emitted more than 16,000 tons of S0 2 in 2012 or emitted more than 2,600 tons of S02 and had an emission rate of at least 0.45 lbs S02/mmbtu in 2012 and that has not been announced (as of March 2 , 20 15) fo r retirement. In the enclosure to this letter, the EPA provides the schedule we intend to follow to meet the Jul y 2, 2016, deadli ne.
Whil e there are currently no violating monito r s and no sources meeting the above criteria on your tribal land, the EPA has identified the following electric power plant source in Indiana as meeting the criteria estab li shed in the court's order. This so urc e may potenti all y be impacting your tribal land :

State County Facili ty Name 20 12 S02 Emiss i ons 2012 S02 Emiss i ons (tons) Rate (lb/mmBtu) Michigan Cit y IN LaPorte Generating S tation 11 , 584 1.006

I n ternet Address (URL) • h ttp : l/ www

. epa

. gov Recycled/Recyc lab le • Pri n ted wi t h Vegetab l e Oi l Based I nks on 100% Postcons u mer, Process Ch l ori ne Free R ecycl ed PaperYou may wish to discuss the designation for this area wi th repre s entati ves of Indiana , and provide your own designation recommendation for the potentially affected area on y our 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 potentially affected area on your tribal land , we request that y ou 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 th ese next rounds of designations. The updated guidance can be found on t he EPA's website at http: // epa.gov / airquality ls ulfurdioxide / guidance. htmf. The EPA has also provided two technical assistance documents that provide advice on the use of modeling and monitoring data when determining if an area is meeting or no t meeting the 20 1 0 S02 standard. These documents can be found on the EPA's website at http :// epa.gov/airquality / sulfurdioxide l implement.html. The court's order directs the EP A to complete the second round of area de signa t ions by December 31, 2017. These designations wou ld address areas where states ha ve not installed and begun operating a new

S02 mon i toring network meeting the EPA's specifications referenced in our propo sed rule titled, " Data Requirements Rule for the 1-hour S0 2 primary NAAQS". This rule , which was propo sed in the Federal Register on May 13, 2014, would direct state and tribal air agencies to provide data to characterize

current air quali ty in areas with lar ge sources of S02 if such areas do not have sufficient air quality monitoring in place to identify maximum S02 concentrations. The data collected as a result of thi s

proposed rule would be used in the designations process. Lastly , the court's order directs the E PA to designate all remaining areas by December 31, 2020. The EPA will provide states with additional information on the designations process associated with these later deadlines at a later date. We look forward to continued dialogue with you and your s taff as we work together to implement the 2010 S02 s tandard and achieve its intended public health protection. For additional information regarding designations for the 2010 so2 standard, please visit our website at www.epa.gov /s o2designations. Should you have any ques t ions , please do no t hesitate to call me or Scott Mathias ofmy staff at 919-541-5310 and mathias.scott@epa.gov. Sincerely , Janet G. McCabe Acting Assistant Admi nistrator Enclosure cc: Susan Hedman E PA Region 5 Administrator

### ENCLOSURE

TIMELINE FOR 2010 PRIMARY S02 NAAQS DESIGNAT IO N PROCESS FOR AREAS ASSOCIAT ED WITH JULY 2, 2016, COURT- ORDERED DEADLINE* Milestone Date** Court Order March 2, 20 1 5 States may submit updated recommendation s No later than September 18, 20 1 5 and supporting information for area designations to the EPA The EPA notifies st ates concerning any o / a January 22 , 2016 , but absolutely no later intended modifications to the ir than 120 days pr ior to final designations, 

### i.e. , re commendations ( 120-da y letters) March 2 , 20 16 The EPA publishes public notice of sta te o/ a February 3, 2016 recommendations and the EPA's intended modifications and initiates 30-day public comment per iod End of 30

- day publ ic comment period o / a March 4 , 2016 States provide additional information to 

### ola Ap ril 8 , 2016 demonstrate why an EPA modification is inappropriate The EPA promulgates final S0 2 area No later than July 2, 2016 designations (no later than 16 months from Court Order )



### .. * The court ' s order d trects the EPA to promulgate additiOnal rounds of des1gnat 10ns by December 31 , 2017, and by December 31 , 2020.
** o / a = on or about