PERMIT REVIEW SUMMARY

Permit Writer:	Chappell Ford			Date:	November 13, 2025

Company Name:	Gulf South Pipeline Company LLC, Kosciusko Compressor Station

Facility Location:	Kosciusko, MS

Source Number:	0120-00042

County: 		Attala

FACILITY DESCRIPTION

Gulf South Pipeline Company, LLC (Gulf South) proposes to construct a new natural gas compressor station in Attala County, Mississippi (MS). The Kosciusko Compressor Station will consist of three (3) natural gas-fire combustion turbines, each driving a centrifugal natural gas compressor as well as ancillary sources. 

Construction is anticipated to begin around January 2028 with all equipment in operation around April 2029. Gulf South’s operations are classified under SIC 4922, Natural Gas Transmission, and NAICS 486210, Pipeline Transportation of Natural Gas.

A table of emission points is listed below.

Emission Point	Facility ID	Description	
AA-001	T-1	Turbine #1, a Solar Taurus 70-10802S, an 83.17 MMBTU/hr, 11,501 hp, non-emergency, simple cycle, dry seal, natural gas compressor turbine	
AA-002	T-2	Turbine #2, a Solar Mars 100-16000S, a 121.35 MMBTU/hr, 16,420 hp, non-emergency, simple cycle, dry seal, natural gas compressor turbine	
AA-003	T-3	Turbine #3, a Solar Titan 250-31900S, a 209.49 MMBTU/hr, 33,372 hp, non-emergency, simple cycle, dry seal, natural gas compressor turbine	
AA-004	EG-1	Emergency Generator #1, a 7.40 MMBTU/hr, 966 hp, <10L displacement per cylinder, spark ignition, 4-stroke, lean burn emergency engine	
AA-005	EG-2	Emergency Generator #2, a 7.40 MMBTU/hr, 966 hp, <10L displacement per cylinder, spark ignition, 4-stroke, lean burn emergency engine	
AA-006	H-1	Catalytic Fuel Gas Heater #1, a 1.037 MMBTU/hr flameless catalytic heater	
AA-007	H-2	Catalytic Fuel Gas Heater #2, a 1.037 MMBTU/hr flameless catalytic heater	
AA-008	H-3	Catalytic Fuel Gas Heater #3, a 2.074 MMBTU/hr flameless catalytic heater	
AA-009	ST-1	Condensate Storage Tank, a 5,022-gallon horizontal fixed roof storage tank	
AA-010	ST-2	Oily Water Storage Tank, a 5,022-gallon horizontal fixed roof storage tank	
AA-011	L-1	Condensate Truck Loading	
AA-012	V-1	Turbine #1 Compressor Blowdowns	
AA-013	V-2	Turbine #2 Compressor Blowdowns	
AA-014	V-3	Turbine #3 Compressor Blowdowns	
AA-015	FUG	Fugitive Components	
AA-016	-	 Centrifugal Compressor driven by Emission Point AA-001	
AA-017	-	 Centrifugal Compressor driven by Emission Point AA-002	
AA-018	-	 Centrifugal Compressor driven by Emission Point AA-003	

PROJECT/PERMIT ACTION DESCRIPTION

The proposed compressor station will consist of three (3) natural gas-fire combustion turbines, each driving a centrifugal natural gas compressor as well as ancillary sources.

Gulf South is seeking an Air Permit to Construct and a True Minor Designation.

EMISSION SUMMARY

Pollutant	PTE (tpy)	PSD Major Source threshold (tpy)	PSD Permitting required?	Title V threshold (tpy)	Title V Permitting required?	
CO	87.39	250	No	100	No	
NOX	77.04	250	No	100	No	
PM10	0.59	250	No	100	No	
PM2.5	0.37	250	No	100	No	
SO2	0.88	250	No	100	No	
VOC	9.21	250	No	100	No	
Formaldehyde1	4.583	--	--	10	No	
GHG (as CO2e)	208,022	100,000	Not triggered unless required by another pollutant--No	--	No	
Total HAPs	5.103	N/A	N/A	25	No	
1.	Formaldehyde is the largest individual HAP emitted from the source

APPLICABLE/PROPOSED PERMIT LIMITATIONS

The facility is a True Minor Source with all emissions under 100 tpy for Criteria Pollutants and under 25 tpy for Total HAPs and under 10 tpy for each Individual HAP. 

As shown in the table above, the facility’s uncontrolled emissions fall under the Title V threshold of 100 tpy for all Criteria Pollutants and VOCs, 10 tpy for any individual HAP, and 25 tpy for all aggregated HAPs. Due to this, the facility is not required to undertake any type of enforceable emissions limit and meets the applicability to be classified as a True Minor Source. 

Under 11 Miss. Admin. Code Pt. 2. R, 2.2.13.E, the facility’s classification as a true minor source exempts them from the further requirement to obtain a permit to operate. However, under 11 Miss. Admin. Code 2.12.D(5), the facility does not meet the exclusion to be exempt from the requirement to obtain a permit to construct due to their emissions being greater than 10% of the Title V major threshold. 

NSPS APPLICABILITY

40 CFR 60 Subpart Dc – Standards of Performance for Small Industrial-Commercial-
Institutional Steam Generating Units
40 CFR 60, Subpart Dc is applicable to each steam generating unit for which construction, modification, or reconstruction is commenced after June 9, 1989, and that has a maximum design heat input capacity of 29 MW (100 MMBtu/hour) or less, but greater than or equal to 2.9 MW (10 MMBtu/hour). The facility does not operate any steam generating units with maximum design heat input capacity greater than or equal to 10 MMBtu/hour, and therefore, is NOT subject to NSPS Subpart Dc

40 CFR 60, Subpart GG—Standards of Performance for Stationary Gas Turbines
40 CFR 60, Subpart GG applies to all stationary gas turbines with a heat input at peak load equal to or greater than 10.7 gigajoules (10 million BTU) per hour based on the lower heating value of the fuel fired which commences construction, modification, or reconstruction after October 3, 1977. The facility plans to install one (1) natural gas-fired stationary turbine with a maximum heat input of 164.49 MMBTU/hr. The facility is potentially subject to Subpart GG. However, the facility is also subject to Subpart KKKKa which exempts turbines that are regulated under Subpart KKKKa from the requirements of Subpart GG. Therefore, the facility is NOT subject to the requirements of Subpart GG. 

40 CFR 60, Subpart Kc—Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After October 4, 2024
40 CFR 60, Subpart Kc applies to a facility with a storage vessel with a capacity greater than or equal to 20,000 gallons that is used to store volatile organic liquids, and which is constructed, reconstructed, or modified after October 4, 2023. The facility has proposed two (2) storage tanks with a capacity of 5,022  gallons each. Therefore, Subpart Kc is NOT applicable.

40 CFR 60, Subpart IIII—Standards of Performance for Stationary Compression Ignition Internal Combustion Engines
40 CFR 60, Subpart IIII applies to stationary compression ignition internal combustion engines (CI ICE) that commence construction, modification, or reconstruction after July 11, 2005. The facility will only operate spark ignition (SI) ICE. Therefore, Subpart IIII is NOT applicable.

40 CFR 60, Subpart JJJJ—Standards of Performance for Stationary Spark Ignition Internal Combustion Engines
40 CFR 60, Subpart JJJJ applies to owners and operators of stationary SI ICE that commence construction after June 12, 2006, where the stationary SI ICE is manufactured on or after January 1, 2009, for emergency engines with a maximum engine power greater than 19 KW. The facility proposes to have two (2) 966 hp emergency SI ICE. Therefore, the facility is subject to Subpart JJJJ. 

40 CFR 60, Subpart KKKK—Standards of Performance for Stationary Combustion Turbines
40 CFR 60, Subpart KKKK applies to stationary turbines with a heat input at peak load equal to or greater than 10.7 gigajoules (10 MMBTU) per hour, based on the higher heating value of the fuel, which commenced construction, modification, or reconstruction after February 18, 2005. The facility plans to operate three (3) natural gas-fired stationary compressor turbines with a maximum heat input of 83.17, 121.35, and 209.49 MMBTU/hr that will be constructed after December 13, 2024. However, engines subject to 40 CFR 60, Subpart KKKKa are exempt from the requirements of Subpart KKKK. Therefore, the facility is NOT subject to the requirements of Subpart KKKK. 

Emission Point	Maximum Heat Input MMBTU/hr	
AA-001	83.17	
AA-002	121.35	
AA-003	209.49	

40 CFR 60 Subpart KKKKa - New Source Performance Standards for Stationary Combustion Turbines
The provisions of 40 CFR 60 Subpart KKKKa - New Source Performance Standards for Stationary Combustion Turbines are applicable to stationary combustion turbines with a heat input at peak load equal to or greater than 10.7 gigajoules (10 MMBtu) per hour, based on the higher heating value of the fuel, which commenced construction, modification, or reconstruction after December 13, 2024.

Emission Points AA-001, AA-002, and AA-003 are stationary combustion turbines with heat inputs at peak load equal to or greater than 10 MMBTU per hour which commenced construction, modification, or reconstruction after December 13, 2024. Therefore, NSPS KKKKa applies to Emission Points AA-001, AA-002, and AA-003.

40 CFR 60, Subpart OOOO—Standards of Performance for Crude Oil and Natural Gas Production, Transmission, and Distribution
40 CFR 60, Subpart OOOO establishes emission standards and compliance schedules for the control of volatile organic compounds (VOCs) and sulfur dioxide (SO2) emissions from affected facilities that commence construction, modification, or reconstruction after August 23, 2011, and on or before September 18, 2015. All equipment at the facility will be installed after September 18, 2015. Therefore, Subpart OOOO will NOT be applicable.

40 CFR 60, Subpart OOOOa—Standards of Performance for Crude Oil and Natural Gas Production, Transmission, and Distribution
40 CFR 60, Subpart OOOOa establishes emission standards and compliance schedules for the control of methane, VOCs, and SO2 emissions from affected facilities that commence construction, modification, or reconstruction after September 18, 2015, and on or before December 6, 2022. All equipment at the facility will be installed after December 6, 2022. Therefore, Subpart OOOOa will NOT be applicable.

40 CFR 60, Subpart OOOOb—Standards of Performance for Crude Oil and Natural Gas Facilities for Which Construction, Modification, or Reconstruction Commenced After December 6, 2022
40 CFR 60, Subpart OOOOb applies to affected facilities located within the Crude Oil and Natural Gas Source Category which commences construction, modification, or reconstruction after December 6, 2022. The facility is classified as a natural gas compression facility (SIC 4922) and will commence construction after December 6, 2022. The facility operates three (3) natural gas fired turbines (AA-001 through AA-003) with centrifugal compressors (AA-016 through AA-018) and has fugitive emissions. Therefore, the facility is subject to Subpart OOOOb for the compressors and fugitive emissions. 
For Emission Points AA-009 and AA-010, the permittee is NOT subject to requirements of 40 CFR 60, Subpart OOOOb other than recordkeeping due to the potential VOC emissions of the tanks being less than 6 tpy and the potential methane emissions being less than 20 tpy.

40 CFR 60, Subpart OOOOc—Emissions Guidelines for Greenhouse Gas Emissions from Existing Crude Oil and Natural Gas Facilities
40 CFR 60, Subpart OOOOc regulates greenhouse gases (GHG). The greenhouse gas standards in this subpart are in the form of a limitation on emissions of methane from designated facilities in the crude oil and natural gas source category that commenced construction, modification, or reconstruction on or before December 6, 2022. The facility will be constructed after December 6, 2022. Therefore, Subpart OOOOc will NOT apply.

40 CFR 60, Subpart TTTTa--Standards of Performance for Greenhouse Gas Emissions for Modified Coal-Fired Steam Electric Generating Units and New Construction and Reconstruction Stationary Combustion Turbine Electric Generating Units
40 CFR 60, Subpart TTTTa establishes emission standards and compliance schedules for the control of greenhouse gas (GHG) emissions from a coal-fired steam generating unit or integrated gasification combined cycle facility (IGCC) that commences modification after May 23, 2023. The standards in this subpart apply to any stationary combustion turbine that commences construction or reconstruction after May 23, 2023, that has a base load rating greater than 250 MMBtu/hr of fossil fuel and serves a generator or generators capable of selling greater than 25 MW of electricity to a utility power distribution system. Kosciusko Compressor Station will have three (3) stationary combustion turbines that have a maximum heat input of 83.17, 121.35, and 209.49  MMBTU/hr. Therefore, Subpart TTTTa does NOT apply.

MACT APPLICABILITY

40 CFR 63, Subpart A—General Provisions
40 CFR 63, Subpart A contains general provisions that are applicable to affected sources. The facility is subject to and will comply with NESHAP regulations.

40 CFR 63, Subpart HH—National Emissions Standards for Hazardous Air Pollutants from Oil and Natural Gas Production Facilities Service
40 CFR 63, Subpart HH applies to emissions points that are located at oil and natural gas production facilities. Kosciusko Compressor Station is a transmission facility, not a production facility. Therefore, Subpart HH does NOT apply.

40 CFR 63, Subpart HHH—National Emission Standards for Hazardous Air Pollutants from Natural Gas Transmission and Storage Facilities
40 CFR 63 Subpart HHH applies to natural gas transmission and storage facilities that transport or store natural gas prior to entering the pipeline to a local distribution company or to final end users and that are major sources of HAP emissions. The affected source is each new and existing glycol dehydration unit. If the facility does not contain an affected source (a glycol dehydration unit), Subpart HHH is not applicable to the facility. Kosciusko Compressor Station is a natural gas transmission facility but will not operate a glycol dehydration unit, therefore the facility is NOT subject to the provisions of Subpart HHH.

40 CFR 63, Subpart YYYY—National Emission Standards for Hazardous Air Pollutants for Stationary Combustion Turbines
40 CFR 63, Subpart YYYY establishes national emission limitations and operating limitations for HAP emissions from stationary combustion turbines located at major sources of HAP emissions. Kosciusko Compressor Station is an area source of HAPs. Therefore, Subpart YYYY is NOT applicable.

40 CFR 63, Subpart ZZZZ—National Emissions Standards for Hazardous Air pollutants for Stationary Reciprocating Internal Combustion Engines
40 CFR 63, Subpart ZZZZ establishes national emission limitations and operating limitations for HAPs emitted from stationary reciprocating internal combustion engines (RICE) located at major and area sources of HAP Emissions. Kosciusko Compressor Station is an area source of HAPs and will have two (2) RICE at the facility. However, the requirements of Subpart ZZZZ are met by complying with 40 CFR 60 Subpart JJJJ. Therefore, the facility is subject to and will comply with Subpart ZZZZ by complying with Subpart JJJJ. No further requirements under Subpart ZZZZ will be applicable. 

40 CFR 63, Subpart JJJJJJ—National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers Area Sources
40 CFR 63, Subpart JJJJJJ applies to industrial, commercial, or institutional boilers located at an area source of HAPs. The proposed catalytic converter does not meet the definition of boiler as stated in the rule. Therefore, Subpart JJJJJJ does NOT apply.

PUBLIC PARTICIPATION

The 30-day public notice period began on June 17, 2026 when the notice was posted on MDEQ’s website and ends July 17, 2026.