UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , D

. C

. 20460

The Honorable John Blackhawk Chairman Winnebago Tribe ofNebraska P.O

. Box 687 Winnebago, Nebraska 68071
Dear Chairman Blackhawk: 

## MAR 2 0

## 201 5
O F FICE OF AIR AND RADIATI ON

I am writing to update you on the status of the U.S. Environmental Protection Agency's progress in implementing the primary National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (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 nonattainment and expressed the intent to address designations for the remainder of the country in separate future actions.
On March 2, 2015, the U.S. District Court for the Northern District of California accepted as an enforceable order an agreement between the EPA and Sierra Club and Natural Resources Defense Council 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 round by December 31, 2017, and the final round by December 31, 2020. The EPA will complete these designations by designating areas as either nonattainment, unclassifiab le/attainment, or unclassifiable.
In the first round of designations , the EPA will designate two groups of areas: 1) areas that have newly monitored violations of the 2010 S02 standard, and 2) areas that contain any stationary source that according to the EPA's A ir Markets Database either emitted more than 16,000 tons of S02 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 20 12 and that has not been announced (as ofMarch 2, 2015) for retirement. In the enclosure to this letter, the EPA provides the schedule we intend to follow to meet the July 2 , 2016, deadline.
While there are currently no violating monitors and no sources meeting the above criteria on your tribal land, the EPA has identified the following electric power plant source in Iowa as meeting the criteria established in the court ' s order. This source may potentially be impacting your tribal land:

State County Facility Name 2012 S02 Emissions 2012 S02 Emissions (tons) Rate (lb/mmBtu) George Neal Stati on lA Woodbury South 14,273 0.638

Internet Address (U RL) • http :// www

.epa.gov Re cycl ed/ Recyc lable • Printed w ith Vegetable Oil Based Inks on 1 00% Postcons u mer, P r ocess Chlori ne F r ee Recycled Pa perYou may w i sh to discuss the designation for this area with representatives of Iowa, 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 a nd 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 you do so by Sep tember 18, 2015. The EPA has updated its March 24 , 20 II , designation guidance for the 2010 S02 standard to suppo rt analysis of designations and boundaries for th ese next rounds of designations. The updated guidance can be found on the EPA's website at http: // epa.gov/airqualitylsu(furdioxide/guidance.html. The EPA has also provided two technical assista nce documents 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 th e EPA's website at http :// epa . gov / airquality /s ulfurdioxide / implement.html. The court's order directs the EPA to complete th e second round of area designations by December 31, 2017. The se designations would address areas where states hav e not installed and begun operating a new

S02 monitoring n etwork meeting the EPA's specifications referenced in our pro posed rule titled, " Data Requirements Rule for the I-hour S0 2 primary NAAQS". This rule, which was proposed in the Federal Register on May 13,2014, would direct s tate and triba l air agencies to provide data to characterize

current air quality in areas with large 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 this

proposed rule would b e 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 pro vide states with add itional information on the de signa tion s 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 impl ement the 2010 S02 standard and achieve its int e nd ed public health protection. For additional information regarding designations fo r the 201 0 S02 standard, please visit our website at www . epa.gov / so2designations. Should you hav e any questions, please do not hesitate to call me or Scott Mathias of my staff at 9 19 -5 41 -5310 and mathias. scott@epa.gov . Sincerely, Janet G. McCabe Acting Assistant Administrator Enclosure cc: Mark Hague

EPA Region 7 Acting AdministratorENCLOSURE
TIMELINE FOR2010 PRIMARY 

### S02 NAAQS DESIGNATION PROCESS FOR AREAS ASSOCIATED WITH JULY 2, 2016, COURT

- ORDERED D EADLINE* Milestone Date** Court Order March 2, 2015 States may submit updated recommendations No later than September 18, 2015 and supporting information for area designations to the EPA The EPA notifies states concerning any o/a January 22, 2016, but absolutely no later intended modifications to their than 120 days prior to final designations , 

### i.e. , recommendations ( 120-day letters) March 2 , 20 16 The EPA publishes public notice of state o/a February 3 , 2016 recommendations and the EPA's intended modifications and initiates 30

-day public comment period End of 30-day public comment period o/a March 4, 2016 States provide additional information to o/a April 8, 2016 demonst rate why an EPA modification is inappropriate The EPA promulga tes final 

### S02 area No later than July 2, 2016 designations (no later than 16 months from Court Order) * The court's order directs the EPA to promulgate additional rounds of designations by December 31 , 2017 , and by December 31 , 2020

. ** o/a 

## = on or about