UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

The Honorable Jim Macy Director 

## MAR 202015

Nebraska Department of Environmenta l Qu ality 1200 N Street, Suite 400 P.O. Box 98922 Lincoln, Nebraska 68509-8922
Dear Mr. Macy: OFFICE OF AIR AND RADIATION

I am writing to update you on the status ofthe U.S. Environmental Protection Agency's progress in implementing the primary National Ambient Air Quality S tandard (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 ofthe 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 wi ll complete these designations by designating areas as either nonattainment, unclassitiable/attainment, or unclassifiable.
In the first round of designations , the EPA will designate two groups of areas: 1) areas that have newly monitored vio lations of the 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 ofS02 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 of March 2, 20 15) for retirement. In the enclosure to this letter, the EPA provides the schedule we intend to follow to meet the July 2, 2016, deadline

. The EPA has identified the following electric power plant sources in your state as meeting the criteria established in the court's order:
2012 so2 2012 so2 State County Facility Name Emissions Emissions Rate (tons) (lb/mmbtu) NE Lincoln Gerald Gentleman Station 26,438 0

.591 

## NE Lancaster Sheldon Station 

### 2)60 

### 0.458 NE Otoe Nebraska City Station 16,766 0.354

Internet Address ( URL) • http ://www.epa

.gov Recycled/Recyclable • Prin ted w ith Vegetable Oil Based I nks on 100% Postconsumer, Process Chlorine Free Recycled PaperThe EPA will use the most recent available information when making de s ignation and boundary decisions for the indicated areas. If you would li ke to s ubmit updated recommendations and supporting information for th e EPA to consider fo r the affected areas i n your state, we request tha t you do so by

September 18,2015. In addit ion , the EPA has identified the followin g electr i c power plant source in the neighboring state of Iowa that also meets the c riteria established in the court ' s order, and may potentially be i mpacting your state: 2012 so 2 2012 S02 State County Facility Name Emissions Em issions Rate (tons) (lb/mmbtu) lA Woodbury George Neal Station South 14,273 0.638

You may wish to discuss the designation for this area with representati ves oflowa and provide your own de sig nation recommendation for the potentially affecte d area in your state. Again , please provide a n y information you would like us to consider by September 1 8,2015. The EPA has updated it s March 24, 2011, designation guidance for the 2010 S02 standard to support analysis of designation s and boundaries for these next rounds of designation s. T he updated guidance can be found on the EPA's website at http://epa.gov/airquality/sul(urdioxide/guidance. html. The EPA ha s also provided two technica l assistance document s that provide advice on the u se of modeling and monitoring data when determining if an area is meeting or not meeting the 20 I 0 S02 standard. These documents can be found on the EPA's website at http :// epa.gov / airquality/sul(urdioxide l implement.html. The court's order directs the EPA to complete the seco nd round of area designations by December 3 1 , 2017. These designations would address areas where states have not install ed and begun operating a new

S02 monitoring network m eet ing the EPA's specifications referenced in our proposed rule titled , "Data Requirements Rule for the 1-hour S02 primary NAAQS". Th i s ru l e, which was proposed in the Federal R eg ister on May 13 , 2014 , would direct state and triba l air agencies to provide data to charac t er i ze current air quality in areas with large sources of S02 if such areas do not hav e sufficie nt air quality monitoring in place to identify maximum S02 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 s t ates with additional inf o r mation 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 2010 so2 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 : Mark Hague EPA Region 7 Acting Administrator

### ENCLOSURE
TIMELINE FOR 2010 PRlMARY S02 NAAQS DESIGNATION PROCESS FOR AREAS ASSOCIATED WITH JULY 2, 2016, COURT

- ORDERED DEADLINE* 

### Milestone Date** Court Order March 2, 20 15 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, 2016 The EPA publishes public notice of state o/a February 3, 2016 recommendations and the EPA's intended modifications and initi ates 30-day public comment period End of 30-day public comment period o/a March 4 , 2016 States provide additional inf ormation to o/a April 8, 2016 demonstrate why an EPA modification is inappropriate The EPA promulgates 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 additi onal rounds of designatiOns by December 31, 20 17 , and by December 3 1, 2020. 

## ** o/a =on or about