UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D

. C

. 20460

The Honorable Bryan W

. Shaw Chairman 

## MAR 2 0201 5

Texas Commiss ion on Environmental Quality P.O. Box 13087 Austin, Texas 787 1 1-3087
Dear Mr. Shaw: OFFICE OF AIR AND RADIATION

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

. Di str ict Court for the Northern District of California accepted as an enforceable order an agreement between the EPA and S ierra Club and Natural Resources Defense Council to resolve litigat ion concerning the deadline for completing the des ignations
. The court's order directs the EPA to complete designations in three add itional 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 designati ons by designating areas as eit her nonattainment, unclassifiable/attainment, or unclassifiable.
In the first round of designations, the EPA will designate two groups of areas: 1 ) areas that have new ly monitored vio lations oft he 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 ofS02 in 2012 or emit ted more th an 2 ,600 tons ofS02 and h ad an emission rate of at least 0.45 lbs S02/mmbtu in 2012 and that has no t been announced (as of March 2 , 20 1 5) 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 fo ll owing electric power plant sources in your state as meeting the criteria establi shed in the court 's order:
2012 S02 2012 S02 State County Facility Name Emissions Emissions Rate (tons) (lb/mmbtu) TX Freestone B ig Brown Power Plant 60,681 1 .594 TX Goliad Coleto Creek Power Station 16 ,2 18 0.615

I n ternet Address (URL) • h ttp://www.epa.gov Recycled/Recyclable • Pri n ted w i t h Vegetable Oi l Based I nks on 100% Postconsumer, Process Chlori ne Free Recycled PaperTX Potter Harrington Generating Stat i on 15,383 0.463 TX Leon L imestone Generating Station 20,671 0.359 TX Titus Montice ll o Steam E l ectric 31,447 0 . 784 Station TX Robertson Optim Energy Twin Oaks 4,038 0 . 509 Power Station TX Atascosa San M i gue l Electr i c 10,950 0 . 630 TX Milam Luminant Sandow Yorktown 22 , 5 1 1 1 . 000 Power Plant TX McLennan Sandy Creek Energy Station 4,955 1.137 TX Fort Be n d W A Parish E l ectric 37,861 0 . 493 Generating Station T X Rusk Lum i nant Power P l ant at 43,093 0.550 Martin L ake TX Lamb Tolk Generating Station 1 9,168 0 . 519 The EPA will use the most recent avai l able information when making designation and boundary decisions for the indicated areas . If you would l ike to submit updated recommendations and supporting information for the EPA to consider for the affected areas i n your state, we request t hat you do so by Sep t ember 18, 2015.

In addition, the EPA has identified the fo ll owing electr i c power plant source i n the neighboring state of Oklahoma that also meets the criteria established in the court's order, and may potent i a ll y be impacting your state: 2012 so2 2012 so2 State County Faci l ity Name Emissions Emissions Rate (tons) (lb / mmbtu) OK Choctaw Hugo Plant 8,066 0 . 603 You may wish to discuss the designation for this area with representatives of Ok l ahoma and provide your own designation recommendat i on for the potentially affected area in your state. Aga i n, please provide any information you would like us to co n s i der by September 18, 2015. The EPA h as updated its March 24, 2011, designat i on gu i dance for the 2010 S02 standard to support analysis of designations and boundaries for these next rounds of designations. The updated gu i dance can be found on the EPA's webs i te at http:/ / epa . gov/airquality / sulfurdioxide l guidance. html. The EPA has

a l so provided two technical assistance documents that provide advice on the use of modeling and monitoring data when determining if an area is meet i ng or not meeting the 20 1 0 S0 2 standard. T hese documents can be found on the EPA's website at http://epa.gov / airquality / sulfurdioxide / implement.html. The court ' s order directs the EPA to complete the second round of area designat i ons by December 3 1, 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 proposed rule titled, "Data Requirements Rule for the 1 -hour S02 primary NAAQS " . This rule, which was p r oposed in the FederalRegister on May 13, 20 14 , would direct state and tribal air agencies to provide data to characterize current air quality in areas with large sources of so2 if such areas do not have sufficient air quality monitoring in place to identify maximum S02 concentrations. The data collected as a r esult ofthis 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 wit h 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 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 ofmy staff at 919-541-5310 and mathias.sco tt @ epa.gov. Sincerely,

Janet G. McCabe Acting Assistant Administrator
Enclosure

cc: Ron Curry EPA Region 6 AdministratorENCLOSURE
TIMELINE FOR 2010 PRIMARY 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 de signations to the EPA The EPA notifies states concerning any o/a January 22, 2016 , but absolutely no later intended modification s to their than 120 days prior to final designations, 

### i.e., recommendations ( 120-day letters) March 2 , 2016 The EPA publishes public noti ce of state o/a February 3, 20 1 6 recommendations and the EPA's intended modifications and initiates 30-day public comment period End of 30-day publi c comment period o /a March 4 , 20 16 States provide addit ional information to o/a April 8 , 20 16 demonstrate why an EPA modification is inappropriate The EPA promulgate s final S02 area No later than July 2, 2016 designations (no later than 1 6 months from Court Order) 

## * The court's order directs the EPA to promul gate additional rounds of designatiOns by December 31 , 20 17 , and by December 31 , 2020. 

## * * o /a 

### = on or about