Public Notice
Mississippi Environmental Quality Permit Board
P. O. Box 2261 | Jackson, MS 39225
515 East Amite St. | Jackson, MS 39201
Telephone No. (601) 961-5171

Public Notice Start Date: April 2, 2025	MDEQ Contact: Jeffrey Bland

Tennessee Valley Authority, Caledonia Combustion Turbine Plant, located at South of Seed Tick Road and Caldwell Road Intersection,   in Caledonia, MS, (832) 265-0734, has applied to the Mississippi Department of Environmental Quality (MDEQ) for the following permitting action(s): Permit to Construct, Air Ref. No. 1680-00090. The applicant's operations fall within SIC Code 4911.  A Statement of Basis has been prepared that contains a discussion of the decision-making that went into the development of the permit and provides the permitting authority, the public, and other government bodies a record of the technical issues surrounding issuance of the permit. The Statement of Basis also addresses any changes to emissions and/or discharges resulting from any modification of the facility.  
Tennessee Valley Authority (TVA) is proposing to construct and operate a new power plant to provide electricity during periods of peak demand when sufficient power may not be available from other TVA generation assets, including renewable energy sources. The proposed plant would be located at the site of a former power plant referred to as Caledonia Power I, LLC, which ceased operation and was dismantled in 2007. TVA currently operates 161 kV and 500 kV electrical substations adjacent to the proposed plant and a combined cycle plant over two miles to the east, which typically provides baseload generation. The new plant, referred to hereafter as the “Caledonia Combustion Turbine Plant,” would consist of six identical simple cycle combustion turbines combusting natural gas during normal operations but capable of combusting ultra-low sulfur distillate (ULSD) during periods of natural gas curtailment. The plant would also have three natural gas-fired process heaters of less than 10 MMBtu/hr to preheat the natural gas, as needed, to bring it to a specific operational temperature before introducing it to the turbines. TVA expects the process heaters to operate no more than 3,400 hours per year. To accommodate the use of ULSD during periods of natural gas curtailment, two 1,000,000-gallon vertical fixed-roof tanks will be constructed to store the ULSD. Additionally, a 299 horsepower (hp) fire water pump engine will be installed on-site for emergency use only.
The simple cycle combustion turbines are the source of most of the emissions at the proposed facility. They will emit products of combustion when firing both natural gas and ULSD, including particulate matter (PM), PM less than 10 microns (PM10), PM less than 2.5 microns (PM2.5), nitrogen oxides (NOx), carbon monoxide (CO), sulfur dioxide (SO2), volatile organic compounds (VOCs), and hazardous air pollutants (HAPs). NOx emissions from the combustion turbines are minimized by the use of dry low NOx (DLN) combustors when combusting natural gas and water injection when combusting ULSD. The three process heaters and one fire water pump engine will also emit products of fuel combustion but at much lower potential emissions than the turbines. The 1,000,000-gallon ULSD tanks will have minimal emissions of VOCs and HAPs.
The Caledonia Combustion Turbine Plant is not one of the 28 source categories listed in 40 CFR 52.21(b)(1)(i)(a) of the PSD regulations, which are adopted by reference in 11 Miss. Admin. Code Pt. 2, Ch. 5. Therefore, the PSD major source threshold is 250 tons per year (tpy) for each regulated NSR pollutant, and fugitive emissions are not considered when determining the PSD applicability. TVA proposes to incorporate the requirements for “low load combustion turbines” from 40 CFR Part 60, Subpart TTTTa and a facility-wide limit of 245 tons per year on nitrogen oxides (NOx) and carbon monoxide (CO) to ensure the new Caledonia Combustion Turbine Plant does not exceed the PSD major source threshold. Therefore, the proposed facility meets the definition of a moderate stationary source under 11 Miss. Admin. Code Pt. 2, Ch. 2, and requires a permit to construct.

The staff of the Permit Board has developed this draft permit based on information submitted to the Permit Board by the applicant, appropriate State and Federal agencies and other interested parties. The staff of the Permit Board is soliciting all relative information pertaining to the proposed activity, including public comment, to ensure that the final staff recommendation on the draft permit complies with all State and Federal regulations. Public review and comment on the draft permit and supporting documentation is an important element in the staff evaluation and resulting recommendation to the Permit Board. The draft permit conditions have been developed to ensure compliance with all State and Federal regulations but are subject to change based on information received as a result of public participation.
Persons wishing to comment upon or object to the proposed determinations are invited to submit comments in writing to Jeffrey Bland at https://www.mdeq.ms.gov/Bland-Jeffrey/  or to the Permit Board address shown above, no later than the end of the thirty (30) day public notice. All comments received by this date will be considered in the formulation of final determinations regarding the application(s).  A public hearing will be held if the Permit Board finds a significant degree of public interest in the proposed permit(s). Persons wishing to request a public hearing may do so by submitting that request in writing to Jeffrey Bland at https://www.mdeq.ms.gov/Bland-Jeffrey/  or to the Permit Board address shown above.  The Permit Board is limited in the scope of its analysis to environmental impact.  Any comments relative to zoning or economic and social impacts are within the jurisdiction of local zoning and planning authorities and should be addressed to them.
Additional details about the application, including a copy of the draft permit, are available by writing or calling the Public Records Request Officer at the above Permit Board address and telephone number or by completing the form at the following website:  https://www.mdeq.ms.gov/about-mdeq/public-records-request/public-records-request-form/.  Additionally, a copy of the draft permit and statement of basis may be found on the MDEQ’s website at: https://opc.deq.state.ms.us/publicnotice.aspx . This information is also available for review at the office of the MDEQ at the Permit Board address shown above during normal business hours. Please bring the foregoing to the attention of persons whom you know will be interested.