INFORMATION RELATIVE TO 
THE DRAFT TITLE V OPERATING PERMIT
June 2, 2026

GENERAL FACILITY INFORMATION
Facility Name:  Columbia Gulf Transmission LLC, Holcomb Compressor Station
Facility Address:  Old Mississippi 7, Holcomb, MS 38940    
County: Grenada
SIC Code(s): 4922
NAICS Code(s): 486210  

APPLICATION SUMMARY 
Permit No.: 0960-00040
Permit Action:  Renewal
Permit Folder: PER20250001
Application Receipt Date: 4/29/2026
Application Deemed Complete: 
CBI Submitted?: No	NSPS (Part 60): A, JJJJ, KKKK, OOOOa
NESHAP (Part 61): N/A
NESHAP (Part 63): A, ZZZZ
112(r) / RMP: N/A
Other: N/A	

FACILITY DESCRIPTION
Columbia Gulf Transmission LLC owns and operates its Holcomb Compressor Station located on Old Highway 7 in Holcomb, Mississippi, for the purpose of transporting natural gas through its pipeline distribution system (SIC 4922 – I Natural Gas Transmission; NAICS 486210).  Natural gas compression at the Holcomb Compressor Station is accomplished through two (2) natural gas-fired turbines rated at 15,845 horsepower (HP)-each. The compressor station also operates one (1) 880-hp natural gas-fired emergency backup power generator engine. All combustion equipment fires only pipeline quality natural gas. The station also has facility blowdowns, fugitive emissions, as well as insignificant activities, including but not limited to one (1) 1.94 MMBTU/hr process heater, and forty (40) 0.072 MMBTU/hr-each catalytic heaters.

The Holcomb Compressor Station was issued a Permit to Construct on May 08, 2017, and was issued its initial Air Title V Operating Permit on December 1, 2020. This permitting action is to renew the Air Title V Operating Permit. 

TITLE V SOURCE APPLICABILITY 
The Holcomb Compressor Station is a major Title V source because the facility’s potential-to-emit exceeds the Title V threshold of 100 tons per year of Carbon Monoxide (CO) emissions.  The facility’s potential-to-emit Hazardous Air Pollutants (HAPs) does not exceed the Title V threshold of 25 tons per year for total HAPs or 10 tons per year for any individual HAP.  

Facility-Wide Potential-to-Emit Summary1
Pollutant	PTE Emissions (tons/yr)	
Particulate Matter (TSP)	2.26	
PM10	7.84	
PM2.5	7.84	
Sulfur Dioxide (SO2)	0.84	
Nitrogen Oxides (NOx)	65.83	
Carbon Monoxide (CO)	158.05	
Volatile Organic Compounds (VOC)	14.91	
Total Reduced Sulfur (TRS)	0.00	
Lead	0.00	
CFC/HCFC	0.00	
Total HAP 	1.43	
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)(c)(iii); therefore, the PSD threshold for a major source is 250 tpy.  The potential emissions of CO from the equipment at the compressor station does not exceed 250 tpy and hence the facility is considered a minor source for PSD purposes.  The permit action is to renew Title V permit which will not trigger a Prevention of Significant Deterioration (PSD) Review.

FACILITY MODIFICATIONS AND/OR PERMIT CHANGES
There are no physical facility modifications proposed for the facility that are being addressed in this permit action. However, the natural gas-fired process heater (Emission Point AA-004) and the natural gas-fired catalytic heaters (Emission Point AA-005) have been removed from the Table of Emission Sources since they qualify as Insignificant Activities and have no applicable requirements other than the state standards for PM, SO2, and Opacity.

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.

There is no control equipment associated with any emission units subject to an emission limit or standard at this facility, therefore, Compliance Assurance Monitoring does not apply to the Holcomb Compressor Station.

NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS (NESHAP) APPLICABILITY
The facility is an area source of Hazardous Air Pollutants (HAP) since the facility does not have the potential to emit more than 25 tons per year of total HAPs or 10 tpy of any individual HAP.

40 CFR 63 Subpart ZZZZ
The permittee is subject to Subpart ZZZZ—National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines and shall comply with all applicable requirements.    

Emission Point AA-003 is a new emergency spark ignition stationary RICE with a site rating greater than 500 brake HP located at an area source of HAP emissions.  As such, the emergency engine must meet the requirements of Subpart ZZZZ by meeting the requirements of 40 CFR part 60 Subpart JJJJ, for spark ignition engines. No further requirements apply for such engines under 40 CFR 63 Subparts ZZZZ or A.

40 CFR 63 Subpart YYYY
The NESHAP for Stationary Combustion Turbines establishes national emission limitations and operating limitations for HAP emissions from stationary combustion turbines located at major sources of HAP emissions, and requirements to demonstrate initial and continuous compliance with the emission and operating limitations.  The Holcomb Compressor Station operates two (2) stationary combustion turbines; however, the facility is an area source and not a major source of HAP emissions.  Therefore, the facility is not subject to the provisions of NESHAP YYYY.  

40 CFR 63 Subpart DDDDD 
MACT Subpart DDDDD - National Emission Standards for Hazardous Air Pollutants for Industrial for Institutional, Commercial, and Industrial Boilers and Process Heaters, 40 CFR Part 63, Subpart DDDDD, establishes emission and operating limitations for HAP emissions from industrial, commercial, or institutional boilers and process heaters that are located at, or is part of, a major source of HAP.  Since the facility is an area source and not a major source of HAP emissions, the facility is not subject to the provisions of NESHAP DDDDD.  

40 CFR 63 Subpart JJJJJJ
MACT Subpart JJJJJJ - National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers Area Sources, 40 CFR Part 63, Subpart JJJJJJ, establishes emission and operating limitations for HAP emissions from industrial, commercial, or institutional boilers that are located at an area source of HAPs.  Since the facility is an area source of HAP emissions, the facility is potentially subject to 40 CFR 63, Subpart JJJJJJ. However, the facility’s process heater and catalytic heaters are gas-fired and do not qualify as boilers and are not covered sources under NESHAP JJJJJJ.  Therefore, none of the facility’s external combustion sources are subject to NESHAP JJJJJJ or to any requirements in NESHAP JJJJJJ.

NEW SOURCE PERFORMANCE STANDARDS (NSPS) APPLICABILITY

40 CFR 60 Subpart Kb
The provisions of 40 CFR 60, Subpart Kb - Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced after July 23, 1984, and On or Before October 4, 2023, are standards applicable to vessels used for storing volatile organic liquids.  The facility’s 2,056-gallon condensate storage tank and 1,500-gallon wastewater storage tank are each below 75 cubic meters; therefore, the facility’s liquids storage tanks are not subject to NSPS Kb.

40 CFR 60 Subpart Kc
The provisions of 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, 2023, are standards applicable to vessels used for storing volatile organic liquids.  The facility’s liquids storage tanks are each  below 20,000 gallons; therefore, the facility’s liquids storage tanks are not subject to NSPS Kc.

40 CFR 60 SUBPART GG
The provisions of 40 CFR 60 Subpart GG - New Source Performance Standards for Stationary Gas Turbines (NSPS GG) are applicable to stationary gas turbines with a heat input at peak load equal to or greater than 10 MMBTUH, which commenced construction, modification, or reconstruction after October 3, 1977.  The Holcomb Compressor Station operates two (2) stationary combustion turbines (Emission Points AA-001 and AA-002).  Each turbine has a heat input of 135.48 MMBTUH and was constructed in 2017; therefore, each turbine is subject to the provisions of NSPS KKKK and is not subject to NSPS GG.  

40 CFR 60 SUBPART KKKK
The provisions of 40 CFR 60 Subpart KKKK - New Source Performance Standards for Stationary Combustion Turbines (NSPS KKKK) 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 February 18, 2005.  Since Emission Points AA-001 and AA-002 each have a heat input of 135.48 MMBTUH and were constructed after 2005, the turbines are subject to NSPS KKKK and are limited to 25 ppm of NOx and 0.06 lb SO2/MMBTU.  The facility is required to conduct annual stack testing to demonstrate compliance with the NOx emissions limitation.  The facility is exempt from monitoring the total sulfur content of the fuels since the natural gas fuel is obligated under tariff to maintain sulfur content to less than 20 grains/scf per 100 standard cubic feet. 

40 CFR 60 SUBPART IIII
The provisions of 40 CFR 60 Subpart IIII - New Source Performance Standards for Stationary Compression Ignition Internal Combustion Engines (NSPS IIII) are applicable to stationary compression ignition internal combustion engines that commenced construction, modification, or reconstruction after June 12, 2006.  Emission Point AA-003 is a stationary spark ignition internal combustion engine.  Therefore, NSPS IIII is not applicable to the engine.  

40 CFR 60 SUBPART JJJJ
The provisions of 40 CFR 60 Subpart JJJJ - New Source Performance Standards for Stationary Spark Ignition Internal Combustion Engines are applicable to stationary spark ignition internal combustion engines that commenced construction, modification, or reconstruction after June 12, 2006. Emission Point AA-003 is a new stationary spark ignition internal combustion engine with a construction date after the June 12, 2006, effective date.  Therefore, Emission Point AA-003 is subject to the requirements of NSPS JJJJ. The engine operates as a non-EPA certified emergency engine.

40 CFR 60 SUBPART OOOO
The provisions of 40 CFR 60 Subpart OOOO - Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution for which Construction, Modification or Reconstruction Commenced After August 23, 2011, and on or before September 18, 2015 are potentially applicable to various sources at an affected compressor station.  All sources at the compressor station were installed after the September 18, 2015, effective date, therefore, the sources are not subject to any requirements of NSPS OOOO.  

40 CFR 60 SUBPART OOOOa
The provisions of 40 CFR 60 Subpart OOOOa - Standards of Performance for Crude Oil and Natural Gas Facilities for which Construction, Modification or Reconstruction Commenced After September 18, 2015 are applicable to the collection of fugitive emissions components at an affected compressor station.  Since, the facility was constructed after the September 18, 2015, affected date, the Holcomb Compressor Station is subject to the provisions of NSPS OOOOa.  Specifically, the collection of facility-wide fugitive emission sources (Emission Point AA-007) are subject to the quarterly LDAR requirements of NSPS OOOOa.  No other requirements of NSPS OOOOa apply to the Holcomb Compressor Station.
40 CFR 60 Subpart OOOOb
The provisions of 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 (NSPS OOOOb) are potentially applicable to new and modified sources in the oil and gas industry after December 6, 2022. 

The Holcomb Compressor Station is considered a natural gas compression facility and is potentially subject to the provisions of NSPS OOOOb. However, all equipment and processes potentially subject to NSPS OOOOb commenced construction prior to the applicability date and have not been modified or reconstructed. Therefore, NSPS OOOOb does not apply to the facility.

SPECIFIC APPLICABLE REQUIREMENTS
Emission Points AA-001, AA-002, and AA-003, are subject to state standards for PM and Opacity. Emission Point AA-003 has a rated heat input less than 10 MMBTU/hr and thus is subject to a PM limit of 0.6 lb/MMBTU.  Emission Points AA-001 and AA-002 each have a rated heat input greater than 10 MMBTU/hr and thus are subject to a PM limit of E=0.8808 * I-0.1667 where E is the emission rate in pounds per million BTU per hour heat input and I is the heat input in millions of BTU per hour.  

The only fuel that is being used at the facility is natural gas.  Since natural gas is a clean burning fuel, the units should have a large margin of compliance with the PM and Opacity standards. The only monitoring proposed for compliance demonstration for PM and Opacity for these units is recording the fuel type. 

The CO, NOx, and VOC emissions at the facility are variable depending on the operating load of the turbines.  The facility intends to operate the units at full load (>50 % load) and the potential to emit for these pollutants have been estimated using normal load emission factors with minimal operation in low load, low temperature and startup/shutdown operations which have higher short term emissions. When considering the worst case lb/hr emission for CO, which is operating at low load, the facility has the potential to be above the PSD thresholds of 250 tpy.  Therefore, the draft permit contains both lb/hr emission limits for each operating mode and an annual CO emissions limitation of 78.83 tons/yr per turbine.  Since the annual tpy limit will only allow for minimal time in operational modes other than normal operation, the permit only requires the facility demonstrate compliance with the normal mode lb/hr limit.  The facility will use the manufacturer’s information for other modes to use in calculating monthly and annual emissions.  

The NOx emissions are also variable; however, even when considering the worst case lb/hr operational mode for the turbines, the NOx emissions are below the PSD threshold.  The turbines are subject to NSPS KKKK, which limits NOx emissions.  Since no limitation on NOx in needed to avoid PSD, there is no lb/hr or tpy limitations for NOx; however, the permit does require the facility to monitor and report NOx emissions.

Thermocouple requirements to continuously monitor the combustion zone temperature to document normal turbine operation have been included in the operating permit.  Each thermocouple is required to alarm if the combustion zone temperature exceeds the design level by >10 °F for 10 seconds and an automatic shutdown of the turbine if the combustion zone temperature exceeds design level by >20 °F for 20 seconds.  Recordkeeping requirements have also been included.  Annual thermocouple calibrations are also required, as well as, corresponding recordkeeping requirements.

The facility’s small process heater and catalytic heaters qualify as insignificant activities.  These activities are subject to the state standards for PM, SO2 and Opacity.  Since these units combust natural gas and the size of the units are small, no monitoring is proposed for the units.  There are no other applicable requirements for the facility’s other insignificant activities listed in their Title V application.

Requirements are tabularized below.

Emission Point(s)	Pollutant / Parameter	Limit/Standard	Monitoring	
AA-003	PM	0.6 lbs/MMBTUH	Record type and quantity of fuel	
AA-001
and
AA-002	PM	E=0.8808*I-0.1667	Record type and quantity of fuel	
	SO2	0.060 lb SO2 /MMBTU (20 grains S/100scf	Record type of fuel	
	NOx	25 ppm at 15 % O2 or 150 ng/J of useful output (1.2 lb/MWh) at ≥ 75% load and ≥ 0 °F	Conduct performance stack tests	
		150 ppm at 15 % O2 or 1,100 ng/J of useful output (8.7 lb/MWh) at <50% load and < 0 °F	Conduct performance stack tests	
	NOx and CO	Minimizing Emissions	Monitoring of operations	
	CO	Normal Operation (≥50 % load) 7.43 lb/hr	Monitoring of operations	
		Low Load (< 50 %); 653.41 lb/hr	Monitoring of operations	
		Low Ambient Temp. (< 0 °F) 31.41 lb/hr	Monitoring of operations	
		Startup & Shutdown 272.70 lb/event	Monitoring of operations	
		78.83 tpy	Monitoring of operations	
AA-003	NOx, CO, and VOC	2.0 g/bhp/hr NOx or 160 ppmvd @ 15% O2,
4.0 g/bhp/hr CO or 540 ppmvd @ 15% O2,
1.0 g/bhp/hr VOC or 86 ppmvd @ 15% O2,	Conduct performance stack tests	
	Operational Restriction	Operational Requirement	Monitoring of operations	
AA-007	GHG/VOC	Continuous Compliance	Monitoring of operations	
		Operational Requirements	Conduct quarterly LDAR	

OTHER REQUIREMENTS:
None.