ENERGY AND ENVIRONMENT CABINET OFFICE OF THE SECRETARY Steven L. Beshear Governor Ms. Heather McTeer Toney Regional Administrator US EPA, Region

4 Sam Nunn Atlanta Federal Center 61 Forsyth St, SW Atlanta, Georgia 30303-8960

500 Mero Street l2
1 h Floor, Capital Plaza Tower Frankfort, Kentucky 40601 Phone: (502) 564-3350 Fax: (502) 564-7484 http://eec.ky .gov September 16, 2015
Leonard K. Peters Secretary RE: Submission
of additional information for Kentucky's recommendations relating
tothe 2010 1-hour S02 NAAQS Dear Ms. McTeer Toney: In accordance with Section 107(d)(l)(A)

of the Clean Air Act (CAA), statesmust submit toU.S. EPA (EPA), within one year following promulgation

of aneworrevised National Ambient Air Quality Standard (NAAQS),

alist of all areasin the state, recommending designations
for each as attainment, nonattainment,

orunclassifiable.

In aletter dated March 28, 2011,

I wasinformed that the proposed designation recommendations

for Kentucky weredue June 3, 2011, for the 1-hour NAAQS for sulfur dioxide (S0 2 ) published

in the Federal Register June 22, 2010 (75 FR 35520). On June 2, 2011,

I provided EPA with recommended designations for all areasof the state relative tothe revised S02 NAAQS. In aletter dated March 20, 2015, Acting Assistant Administrator Janet McCabe updated Commissioner Bruce Scott onthe statusof U.S. EPA's progress
in implementing
the primary NAAQS for S02. The letter detailed the agreement between EPA, the Sierra Club, and the Natural Resources Defense Council that was accepted
asanenforceable order by the U.S. District Court for the Northern District of California. The court's order and the agreement direct EPA to complete designations

in three additional rounds, with the first round due by July 2, 2016. In the first additional round of area designations, EPA will designate two groupsof areas: (1) areasthat have newly monitored violations
of the 2010 S0 2 NAAQS, and 2) areasthatMs. Heather McTeer Toney Page No.2 September 16, 2015 contain any stationary sourcethat according
tothe EPA's Air Markets Database either emitted morethan 16,000 tonsof SOz oremitted morethan 2,600 tonsof SOz and had anemission rateof atleast 0.45lbs SOz/mmbtu

in 2012 and that has notbeen announced for retirement (as of March
2, 2015). The purposeof this letter is tosubmit updated area designation recommendations
and supporting information
nolater than the September 18, 2015 deadline,

as established

in the court order. As stated in its March 20, 2015 letter, EPA identified two electric generating sourcesas meeting the criteria established

in the court order, DB Wilson Generating Station located in Ohio County and JohnS. Cooper Power Station located in Pulaski County. As requested by Kentucky's Division for Air Quality, the identified sources provided significant, technical information

to characterize the air quality in the areas surrounding their sources. In amemorandum dated March 20,2015, from Stephen D. Page tothe Regional Air Division Directors ("Updated Guidance for Area Designations
for the 2010 Primary Sulfur Dioxide NAAQS"), the EPA recommended that statesusefive factors in making designation recommendations:

1) ambient air quality data or dispersion modeling,

2) emissions and emissions-related data, 3) meteorology,

4) geography/topography,

and 5) jurisdictional boundaries. Kentucky used these factors aswell asthe EPA's guidance onthe useof source modeling

asoutlined
in the SOz NAAQS Designations Modeling Technical Assistance Document (Modeling TAD). In summary,the following modeled results of the areas' concentrations

of S0 2 ,which included the recommended factors setforth by the March 20, 2015 memorandum, indicate that the identified facilities arein compliance with the 1-hour S0 2NAAQS: Averaging NAAQSMaximum Facility Location
Impact Period **(~g!m3) (~g!m3)**  D. B. Ohio Wilson GeneratingCounty, 1-Hour
196 186.5 Station
KY JohnS. Pulaski Cooper County, 1-Hour
196 173.1 Power Station
KY As aresult of the information provided above and accompanying this submittal, Kentucky finds that the two facilities located within Ohio and Pulaski Counties areinMs. Heather McTeer Toney Page No.3 September 16, 2015 compliance with the 2010 SOz NAAQS. Further, Kentucky recommends that the EPA designate these areasasattainment. Kentucky

is including additional information regarding the compliance demonstration (copies of the modeling files and reports)
tofurther supportour recommendations. Modeling files and reportsfor both facilities arealso available for downloaded

atthe following URL: ftp://eec121321R2:5rdxCFTA7ygv@ftp

.cot.ky.gov/EECDAQ121321/eecdagJM/KYS02DEMO Pursuant
to40 CFR 51.1204,the Division for Air Quality will establish federallyenforceable emission limitations through the source's title V permits, respectively,

toensure compliance with the 2010 S0 2NAAQS. We look forward
to continued dialogue with youand yourstaff aswework together
to implement the 2010 SOz NAAQS.

If youshould have any questions
orneed additional information regarding the designations
for the 2010 SOz NAAQS, please do nothesitate tocontactmeorMr. Sean Alteri, Director for the Division for Air Quality at (502) 564-3999.
Secretary LKP/mrwlbac