INFORMATION RELATIVE TO 
THE DRAFT TITLE V OPERATING PERMIT
June 2025

GENERAL FACILITY INFORMATION
Facility Name: TVA Southaven Combined Cycle Plant
Facility Address: 2882 State Line Road West, Southaven, MS 38671    
County: Desoto
SIC Code(s): 4911
NAICS Code(s): 221112  

APPLICATION SUMMARY 
Permit No.: 0680-00095
Permit Action: Renewal 
Permit Folder: PER20240001
Application Receipt Date: February 27, 2024
Application Deemed Complete: {Use administrative completeness date}
CBI Submitted? No	NSPS (Part 60): Da, Dc, GG
NESHAP (Part 61): N/A
NESHAP (Part 63): ZZZZ
112(r) / RMP: N/A
Other: Acid Rain Regulations, CSAPR	

FACILITY DESCRIPTION
The Tennessee Valley Authority (TVA), Southaven Combined Cycle Plant is an existing 900 megawatt (MW) natural gas fired electrical power generating station located in Southaven, Mississippi. The table below contains a detailed list of the significant emission points contained in the proposed permit.

Emission Point	Description	
AA-001	1,700 MMBtu/hr GE Model PG7241FA natural gas-fired combustion turbine with a heat recovery steam generator (HRSG) equipped with a 265 MMBtu/hr duct burner. The turbine is equipped with dry low-NOx burners and a selective catalytic reduction (SCR) system which uses aqueous ammonia as a reducing agent to control NOx emissions from the exhaust stream of the combined cycle system. (Ref. Generating Unit 001) 	
AA-002	1,700 MMBtu/hr GE Model PG7241FA natural gas-fired combustion turbine with a HRSG equipped with a 265 MMBtu/hr duct burner. The turbine is equipped with dry low-NOx burners and a SCR system which uses aqueous ammonia as a reducing agent to control NOx emissions from the exhaust stream of the combined cycle system. (Ref. Generating Unit 002) 	
AA-003	1,700 MMBtu/hr GE Model PG7241FA natural gas-fired combustion turbine with a HRSG equipped with a 265 MMBtu/hr duct burner. The turbine is equipped with dry low-NOx burners and a SCR system which uses aqueous ammonia as a reducing agent to control NOx emissions from the exhaust stream of the combined cycle system. (Ref. Generating Unit 003)	
AA-005	8.4 MMBtu/hr (1,109 HP / 827 kW) diesel-fired backup emergency generator used to provide emergency power for critical plant systems (Model Year 2003)	
AA-006	2.0 MMBtu/hr (240 HP / 179 kW) diesel-fired emergency fire water pump engine (Model Year 2003) 	
AA-013	17.085 MMBtu/hr natural gas-fired auxiliary boiler (Ref. Auxiliary Boiler AB-1)	

TITLE V SOURCE APPLICABILITY 
The facility’s potential-to-emit (PTE) exceeds the Title V major source threshold of 100 tons per year (tpy) for each of the following criteria air pollutants: Nitrogen Oxides (NOx), Carbon Monoxide (CO), Sulfur Dioxide (SO2), Particulate Matter less than 10 microns (PM10), and Particulate Matter less than 2.5 microns (PM2.5). The facility’s potential-to-emit hazardous air pollutants (HAPs) does not exceed the major source threshold of 25 tpy of total HAPs and 10 tpy for any individual HAP.

Facility-Wide Potential-to-Emit Summary1
Pollutant	PTE Emissions
(tons/yr)	
Particulate Matter (TSP)	316.00	
PM10	438.00	
PM2.5	438.00	
Sulfur Dioxide (SO2)	158.00	
Nitrogen Oxides (NOx)	333.00	
Carbon Monoxide (CO)	810.00	
Volatile Organic Compounds (VOC)	55.00	
Total Reduced Sulfur (TRS)	0.00	
Lead	0.01	
CFC/HCFC	0.00	
Total HAP 	11.82	
1 The PTE emissions reflect any emission limits or enforceable restrictions included in the proposed permit.
PREVENTION OF SIGNIFICANT DETERIORATION (PSD) APPLICABILITY
The facility is not one of the 28 categorical facilities listed in 40 CFR 52.21(b)(1)(i)(a); therefore, the PSD threshold for a major source is 250 tpy. The facility has the potential to emit more than 250 tpy of each of PM/PM10/PM2.5, NOx, and CO; therefore, the facility is considered a major stationary source. This permitting action will not change the current PSD status of the facility.

FACILITY MODIFICATIONS AND/OR PERMIT CHANGES
No significant changes were requested in the facility’s renewal application. Minor changes to the previous permit’s language have been made in the proposed permit. The most notable revisions include:
•	The previous permit contained a requirement for the permittee to monitor and record the hours of operation on a daily basis for Emission Point AA-013. There are no operational or emission limitations in the permit that would require such monitoring. As such, this condition has been removed from the proposed permit.

•	The previous permit had a daily fuel usage monitoring requirement from 40 CFR Subpart Dc. Since the facility only uses natural gas, the monitoring requirement has been revised to allow monthly fuel usage records as is noted in Subpart Dc.

•	A new requirement has been added to the proposed permit which requires the permittee to submit a report summarizing the hours of operation for each emergency engine during the calendar year. 

COMPLIANCE ASSURANCE MONITORING (CAM) APPLICABILITY
40 CFR Part 64 specifies the requirements for CAM. The general applicability of this rule can be found in 40 CFR 64.2 and requires a Title V source to comply with the CAM requirements if all three of the following criteria are met for a pollutant-specific emission unit (PSEU):

1.	The unit is subject to an emission limitation or standard for a regulated air pollutant other than exemptions under 40 CFR 64.2(b)(1);
2.	The unit uses a control device to comply with the standard; and
3.	The unit has pre-control emissions exceeding Title V major source threshold.

The combined cycle combustion turbines (CTs) are equipped with a control device for NOx emissions (i.e., selective catalytic reduction (SCR)) and are potentially subject to the provisions of CAM. However, the provisions of the CAM rule are not applicable to the combustion turbines since the NOx emissions are monitored using continuous emissions monitoring systems (CEMS), thereby meeting the exemption in 40 CFR 64.2(b)(1)(vi). The TVOP requires the facility to continuously monitor emissions from the combustion turbines in accordance with the applicable requirements of the Acid Rain Program to demonstrate compliance with the ppm, lbs/hr, lb/MWh, and tons/year emission limits established in the PSD Construction Permit. The CTs are also potentially subject to the provisions of CAM for PM/PM10 and CO; however, there are no controls for either pollutant. As such, the provisions of CAM are not applicable for these pollutants.

NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS (NESHAP) APPLICABILITY
•	40 CFR 63, Subpart YYYY, NESHAP for Stationary Combustion Turbines - The provisions of Subpart YYYY are applicable to stationary combustion turbines located at major sources of HAP emissions. The facility is not a major source of HAP emissions. Therefore, the facility is not subject to the provisions of Subpart YYYY

•	40 CFR 63, Subpart ZZZZ, NESHAP for Stationary Reciprocating Internal Combustion Engines - The provisions of Subpart ZZZZ are applicable to stationary reciprocating internal combustion engines located at area and major sources of HAP emissions. The facility is an area source of HAP emissions and has two (2) existing emergency engines (Emission Points AA-005 and AA-006) which are subject to Subpart ZZZZ. The applicable requirements of Subpart ZZZZ are included in the proposed permit.

•	40 CFR 63, Subpart JJJJJJ, NESHAP for Industrial, Commercial, and Institutional Boilers at Area Sources - The provisions of Subpart JJJJJJ are applicable to boilers that are located at area sources of HAP emissions. Each combustion turbine (Emission Points AA-001 through AA-003) is equipped with a heat recovery steam generator (HRSG) that provides steam to the steam turbine and generator. The facility also has a small auxiliary boiler (Emission Point AA-013). The HRSGs and the small auxiliary boiler are all fired with natural gas; therefore, they are not subject to the provisions of Subpart JJJJJJ per the exemption in 40 CFR 63.11195(e).

•	40 CFR 63, Subpart UUUUU, NESHAP for Coal and Oil-Fired Electric Utility Steam Generating Units - The provisions of Subpart UUUUU are applicable to coal or oil-fired electric utility steam generating units (EGU). The combustion turbines at the facility are considered EGUs; however, they meet the definition of a natural gas-fired EGU in 40 CFR 63.10042. Per 40 CFR 63.9983(b), these combustion turbines are not subject to the requirements of Subpart UUUUU.

NEW SOURCE PERFORMANCE STANDARDS (NSPS) APPLICABILITY
•	40 CFR 60, Subpart Da, Standards of Performance for Electric Utility Steam Generating Units - The provisions of Subpart Da are applicable to electric utility combined cycle gas turbines with a HRSG duct burner capable of combusting more than 250 MMBtu/hr heat input. The HRSG duct burners at the facility have a rated heat input of 265 MMBtu/hr; therefore, the duct burners are subject to the applicable provisions of Subpart Da. Emission Points AA-001, AA-002, and AA-003 are subject to PM, SO2, NOx, and Opacity requirements of 40 CFR 60, Subpart Da. Since the units are fired with natural gas, they meet the exemptions in 60.42Da and are not required to meet the PM or Opacity limits. The facility complies with the SO2 limit by keeping fuel purchase records that detail the sulfur content of the fuel being fired. The information collected using the NOx CEMS required under Part 75 is used to demonstrate compliance with the Subpart Da limit on NOx.

•	40 CFR 60, Subpart Dc, Standards of Performance for Small Industrial-Commercial-Institutional Steam Generating Units - The provisions of Subpart Dc are applicable to steam generating units that were constructed after June 9, 1989, and have a maximum heat input capacity of 100 MMBtu/hr or less but greater than or equal to 10 MMBtu/hr. The auxiliary boiler at the facility (Emission Point AA-013) was constructed after this date and has a rated capacity of 17.085 MMBtu/hr. While the boiler is subject to the requirements of Subpart Dc, the unit is fired with natural gas only; therefore, the only applicable requirement for the unit is to monitor and record the monthly fuel usage.

•	40 CFR 60, Subpart GG, Standards of Performance for Stationary Gas Turbines - The provisions of Subpart GG are applicable to stationary gas turbines with a heat input at peak load in excess of 10 MMBtu/hr that are constructed after October 3, 1977. The combustion turbines at the facility are subject to the requirements of Subpart GG since they were constructed after this date and have a rated heat input in excess of 10 MMBtu/hr. Emission Points AA-001, AA-002, and AA-003 are subject to the NOx and SO2 requirements under 40 CFR 60, Subpart GG. The facility uses the CEMS required under Part 75 to demonstrate compliance with the NOx limit and fuel purchase records to demonstrate compliance with the fuel sulfur content requirement.

•	40 CFR 60, Subpart IIII, Standards of Performance for Stationary Compression Ignition (CI) Internal Combustion Engines - The provisions of Subpart IIII are applicable to stationary CI engines that commenced construction after July 11, 2005, and where the engine was manufactured after April 1, 2006. Emission Points AA-005 and AA-006 were constructed and/or manufactured prior to the applicability dates so they are considered existing engines that are not subject to the requirements of Subpart IIII.

•	40 CFR 60, Subpart KKKK, Standards of Performance for Stationary Combustion Turbines - The provisions of Subpart KKKK are applicable to stationary combustion turbines with a heat input at peak load equal to or greater than 10 MMBtu/hr that commenced construction, modification, or reconstruction after February 18, 2005. The combustion turbines (Emission Points AA-001 through AA-003) were constructed prior to the applicability date, and they have not been modified or reconstructed so they are not subject to the provisions of Subpart KKKK.

•	40 CFR 60, Subpart TTTT, Standards of Performance for Greenhouse Gas Emissions for Electric Generating Units - The provisions of Subpart TTTT are applicable to stationary combustion turbines that commenced construction after January 8, 2014, or commenced modification or reconstruction after June 18, 2014. The stationary combustion turbines (Emission Points AA-001 through AA-003) were constructed prior to this date and have not been modified or reconstructed so they are not subject to the provisions of Subpart TTTT.

SPECIFIC APPLICABLE REQUIREMENTS
Emission Point No.	Pollutant	Draft Permit Emission Limits	Monitoring Requirements	
AA-001 AA-002 AA-003	PM/PM10 (filterable)	≤ 0.02 lbs/MMBtu not to exceed 24 lbs/hr based on a 3-hr rolling average and 105 TPY based on a 12-month rolling total (PSD BACT Limit)	The margin of compliance is significant and warrants no additional monitoring	
	SO2	≤ 12 lbs/hr based on a 3-hr rolling average and 52.6 TPY based on a 12-month rolling total		
	NOx	≤ 3.5 ppm @ 15% oxygen on a dry basis, not to exceed 24.1 lbs/hr, both limits based on a 3-hr average, and 105.6 TPY based on a 12-month rolling total
(PSD BACT Limit)	CEMS	
	CO	≤ 17.4 ppm @ 15% oxygen on a dry basis, not to exceed 61 lbs/hr, both limits based on a 3-hr average and 267 TPY based on a 12-month rolling total
(PSD BACT Limit)		
	Opacity	≤ 10%	Annual visual observations and VEE, if required	
	Fuel Restriction	Natural gas only	Fuel records	
	NOx	Control emissions using SCR	Keep operations records 	
	Operating Restrictions	Definition of startup, shutdown, and tuning	Monitor and maintain records of operations in each mode and during startup, shutdown, or during tuning	
		Minimize emissions during startup, shutdown, and tuning		
	NOx	STD = 0.0075*(14.4/Y) + F	CEMS	
	SO2	Sulfur content in fuel limited to ≤ 0.8% by weight (8,000 ppmw)	Fuel records	
	SO2	≤ 0.20 lbs/MMBtu	Fuel records	
	NOx	≤ 1.6 lbs/MWh (30-boiler operating day rolling average)	CEMS	
AA-005 AA-006	HAP	Operating requirements	Keep records documenting hours of operation and reason for operation	
AA-001 AA-002 AA-003 AA-013	PM 
(filterable)	E = 0.8808*I-0.1667	The margin of compliance is significant and warrants no additional monitoring	
AA-005 AA-006	PM 
(filterable)	≤ 0.6 lbs/MMBtu		
AA-013	SO2	≤ 4.8 lbs/MMBtu		

OTHER REQUIREMENTS:
Emission Points AA-001 through AA-003 are subject to the provisions of the Acid Rain Program found in 40 CFR 72-78. The permit addresses the provisions of the Acid Rain program in Section 8 of the TVOP and the proposed Phase II Acid Rain Permit is in Appendix C of the proposed TVOP.

Emission Points AA-001 through AA-003 are subject to the applicable requirements of 40 CFR 97, Subpart EEEEE, Cross-State Air Pollution Rule (CSAPR) NOx Ozone Season Group 2 Trading Program. The provisions of Subpart EEEEE are included in Section 9 of the proposed TVOP.