UNITED STATES ENVIRONMENTAL PROTE CTION AGEN CY WASHINGTON , D

. C

. 20460

The Honorable Peggy M. Hatch Secretary 

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Louis i ana Department of Env ironmental Quali ty 602 N 5 111 Street Baton Rouge , Louisiana 70802
Dear M s. Hatch: O F FICE 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 Nat ional Ambient Air Quality Standard (NAA Q S) for sulfur dioxide (S0 2 ) 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 a nd exp re ssed the intent to address d esignation s for the re mainder o f the country in separate future actio n s. On M arc h 2 , 2015 , the U.S. Distr ict Court for the Northern District of Cali fornia accepted as an enforceable orde r an agr eement between the EPA and Sie rra Club and Natura l Reso urces Def ense Counci l to re so lve liti gati on conce rnin g the deadline for comp le ting the designations. The court's o rder directs the EPA to com pl ete des ignatio n s in three additio na l rounds: the first round by July 2, 20 1 6 , the se cond round by D ecember 3 1 , 2017, and the fina l round by December 31 , 2020. The EPA will complete these designations by designating areas as eithe r nonattainment, unclassifiable/ attainment , or unclassifiable

. In th e fir st round of de s i gnatio ns, the EPA w ill de sig nate two groups of areas: I ) areas that hav e newly mo nitored violations of the 20 1 0 S02 standard, and 2) areas that contain any stati onary source that acco rdin g to the EPA's Air Markets Database ei th er em itte d more than 16 , 000 tons of S02 in 2012 or em itted more than 2 , 600 tons of S 0 2 and had an emission rate of at least 0.45 lbs S O :Jmmbtu in 20 12 and that has no t been annou nced (as of March 2, 20 15) for retirement. In the enclosure to thi s letter, the EPA provides the schedule we intend to follow to meet the July 2, 2016 , deadline.
T he EPA has iden tified the follow ing electric power plant so urces in your s tate as meeting the criteria estab li shed in the court's o rd er:
2012 S0 2 20 12 so 2 S ta t e County Fac ility Name Emi ssions Emi ss ions Rate (tons) (lb/mmbtu) LA Mansfield/ Dolet Hill s P ower Station 20 , 887 0.801 DeS oto P arish

I n te rn et Ad dress (URL ) • h ttp ://w ww
. e pa

. gov Recycled/Recyclable • Pri n ted wi th Vegeta b l e O i l Base d I n ks o n 100 % Postco n sume r , Process C hl o rine Free R ecycled PaperLA Westlake / Nelson Industria l Steam 6,706 0.692 Calcasieu Parish Company LA Westlake/ R SNelson Generating Plant 1 2 , 513 0.461 Calcasieu Parish The EPA will use the most recent available information when making designation and boundary dec i sions for the indicated areas . If you would like to submit an updated recommendation and supporting information for the EPA to consider for the affected areas in your state, we request that you do so by September 18,2015.

T he EPA has updated its March 24, 2011, designation guidance for the 2010 S02 standard to support ana l ysis of designations and boundaries for these next rounds of designations. The updated guidance can

be found on the E PA's website at http:l l epa.gov/airquality /s ulfurdioxide/guidance . html. The EPA has also prov i ded two technical assistance documents tha t provide advice on the use of modeling and monitoring data when determin ing if an area is meeting or not meeting the 2010 SOz 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 comp l ete the seco nd 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 proposed rule titled, "D ata Requirements Rule for the 1-hour S02 primary NAAQS". This rule, which was proposed in the Federal Register on May 13,2014, would direct s tate and tribal air agencies to provide data to characterize

current a i r quality in areas with large sources of S0 2 if such areas do not have suftl.cient 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 ord er directs the EPA to designate all remaining areas by December 31, 2020. T he EPA will provide states with additional information on the des i gnations process associated w i th these later deadlines at a l ater date. We look fo r ward to continued dialogue with you and your staff as we work together to imple ment the 2010 S02 standard and achieve its i ntended public health protection. For add i tional 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. Sincerel y, Janet G. McCabe Acting Assistant Administrator Enclos ure cc: Ron CurryEPA Region 6 Adminis trator

### ENCLOSURE TIMELINE FOR 2010 PRIMARY S02 NAAQS DESIGNATION PROCESS FOR AREAS ASSOCIATED WITH JULY 2, 2016 , COU RT

- ORD ERED 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 E PA The EPA notifies states concerning any o/a January 22 , 20 1 6 , but absolutely no later intended modifications to their than 120 days prior to final designations, 

### i.e ., recommendation s ( 120-day letters) March 2 , 20 1 6 T he EPA pub li shes pub li c notice of state o/a Febru ary 3 , 20 16 recommendations a nd 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 addi tiona! information to o/a April 8 , 2016 demonstrate why an EPA modification is inappropriate T he EPA promulgates fina l S02 area No later than July 2 , 20 1 6 des ign ation s (no later than 16 months from Court Order)



### .. *The court's order directs the EPA to promulgate addttlonal rounds of destgnahons by December 31 , 2017 , and by December 31 , 2020.
* * o / a 

### = on or about