September 17,2015 

Ms. Janet G. McCabe 

Assistant Administrator, Office of Air and Radiation 

U.S. Environmental Protection Agency Headquarters 

1200 Pennsylvania Avenue, N. W. 

Mail Code 6101A 

Washington, DC 20460 

Dear Ms. McCabe: 

On behalf of Coleto Creek Power, LP (CCP), enclosed for consideration is information 

that supports the designation of the area surrounding the Coleta Creek Power Station in Goliad 

County, Texas as attainment for the National Ambient Air Quality Standard (NAAQS) for sulfur 

dioxide (S02) set in 20 10 at 196 micrograms per cubic meter (J.lg/m3

) as a 1-hour average. We 

submit this information in response to the request found in your letter dated March 20, 2015, to 

the Honorable Bryan W. Shaw, Chairman, Texas Commission on Environmental Quality 

(TCEQ). This information supports the TCEQ's continued recommendation that the area be 

designated as unclassifiable/attainment for the 1-hour S02 NAAQS based primarily on the latest 

monitoring data and secondarily on source modeling conducted by the TCEQ. 

CCP owns and operates the Co1eto Creek Power Plant. The Coleta Creek Power Plant 

includes one coal-fired, steam-electric generating unit with a total power production capacity of 

630 megawatts. In operation since 1980, the Coleto Creek Power Plant provides electricity to 

approximately 400,000 homes, employs 85 operators and staff, and is an important part of the 

North American assets and operations of CCP's corporate affiliate GDF SUEZ Energy North 

America. GDF SUEZ Energy North America manages a range of energy businesses in the U.S., 

Mexico, and Canada, including electricity generation and cogeneration, natural gas and liquefied 

natural gas distribution and sales, and retail energy sales and related services to commercial and 

industrial customers. 

CCP maintains that the area surrounding our facility must be designated as attainment or 

unclassifiable/attainment for S02. Both of these options are available to EPA under the Clean 

Air Act and we are aware of no evidence that the ambient air near our station exceeds the 

primary S02 NAAQS. None of the regulatory monitors in Texas are showing violations of the 

S02 NAAQS including the certified monitor in nearby Nueces County. An attainment or 

unclassifiable designation is clearly appropriate in these circumstances. 

The TCEQ's unclassifiable/attainment recommendation for Goliad County is also 

supported by separate AERMOD modeling analyses conducted by TCEQ and ERM Consulting 

& Engineering, Inc. (ERM) on behalfofCCP. 
Ms. Janet G. McCabe 2 September 17, 2015 

• First, as documented in the State of Texas' September 2015 submittal to EPA, 

1 the 

predicted maximum so2 design value associated with actual emissions of so2 from our 

station and nearby sources is only 99 J.tg/m3

, which approximately 50% of the S02 

standard of 196 J.tg/m3. Importantly, this air quality-protective result was reached with 

background S02 levels as measured at the ambient monitoring station in Nueces County, 

Texas, and the inherently conservative nature of AERMOD analyses, which tend to 

overpredict ambient air concentrations. The State's source modeling relied on 2012-2014 

meteorological data and actual emissions from the plant, consistent with the latest EPA 

rules and guidance on so2 dispersion modeling. 

• Second, CCP commissioned ERM to perform an independent AERMOD analysis using 

even more refined inputs to evaluate whether the plant's emissions adversely affect 

attainment of the S02 standard. ERM's modeling results, including nearby sources and 

background so2 levels, identified maximum impacts of lll J.tg/m3' which is also well 

below the so2 standard. 

CCP appreciates your consideration of this information. Based on EPA's prior responses 

to prior FOIA requests, we understand that EPA has no source modeling information that 

suggests that the Coleto Creek Power Station exceeds the S02 NAAQS. If any such information 

is submitted to EPA, we respectfully request the opportunity to review it and provide our views 

on the modeling approach. 

If you would like to discuss further, please do not hesitate to contact Kevin Cahill at 

(713) 636-1078 or me at (713) 636-1027 .. 

Attachments 

Sincerely, 

~~t:~ Vice President ofColeto GP, LLC, as 

General Partner of Coleto Creek Power, LP 

For Coleto Creek Power, LP 

cc: Ron Curry, Regional Administrator, EPA Region 6 

Guy Donaldson, Chief, Air Planning Section, EPA Region 6 

Bryan W. Shaw, Ph.D., P.E., Chairman, Texas Commission on Environmental Quality 

1 Memorandum from Daniel Menendez to David Brymer, Subject: Modeling Analysis of Sulfur Dioxide for Coleto 

Creek Power, LP - Coleto Creek Power Station (RN I 00226919) (June 5, 20 15).