PERMIT REVIEW SUMMARY

Permit Writer:	Jeffrey Bland 	Date:	February 20, 2025

Company Name:	Gulf South Pipeline Company LLC, Moss Point Compressor Station

Facility Location:	14451 Highway 63, Moss Point, MS 39562

Source Number:	1280-00143

County: 		Jackson

FACILITY DESCRIPTION

Gulf South Pipeline Company LP owns and operates its Moss Point Compressor Station located near Moss Point, Mississippi, for the purpose of transporting natural gas through its pipeline distribution system. The Moss Point Compressor Station operates two (2) natural gas-fired reciprocating compressor engines, one (1) natural gas-fired emergency generator engine, one (1) natural gas-fired catalytic heater, and five (5) liquid product storage tanks. The facility also has emissions from a condensate truck loading operation, fugitive equipment leaks, and natural gas venting. The standard industrial code (SIC) for the facility is 4922 for Natural Gas Transmission. 

PROJECT/PERMIT ACTION DESCRIPTION

The Moss Point Compressor Station is classified as a synthetic minor source with respect to Title V of the Federal Clean Air Act. The facility has the uncontrolled potential to emit more than 100 tons per year (tpy) of the criteria pollutant, Carbon Monoxide (CO); however, the facility has requested limitations on Emission Points AA-001 and AA-002 consistent with 11 Miss. Admin. Code, Pt. 2, Ch. 6 to reduce the site-wide emissions below the Title V thresholds. Emission Points AA-001 and AA-002 utilize catalytic converters to restrict CO emissions below the Title V threshold of 100 tpy.

The facility also has the uncontrolled potential to emit more than 10 tpy of the individual hazardous air pollutant (HAP), Formaldehyde; however, since Emission Points AA-001 and AA-002 operate oxidation catalysts, Formaldehyde emissions are restricted below the Title V threshold of 10 tpy. With operation of the catalytic converters, the facility does not have the potential to emit more than 100 tpy of any other criteria pollutant or more than 25 tpy of total HAPs or more than 10 tpy of any other individual HAP. The following table includes the emission points at the facility.

Emission 
Point	Description	
AA-001	1,035 HP Caterpillar Model G3512BLE four stroke lean burn (4SLB) spark ignition (SI) natural gas-fired non-emergency compressor engine equipped with a catalytic converter (Facility Ref. No. RC01)	
AA-002	1,380 HP Caterpillar Model G3516BLE 4SLB SI natural gas-fired non-emergency compressor engine equipped with a catalytic converter (Facility Ref. No. RC02)	
AA-003	477 HP Generac Model SG300 4SLB SI natural gas-fired emergency backup power generating engine (Facility Ref. No. AX01)	
AA-005	1,100 gallon above ground fixed roof condensate storage tank (Facility Ref. No. TK01)	
AA-006	1,000 gallon above ground fixed roof oily water storage tank (Facility Ref. No. TK02)	
AA-007	1,100 gallon above ground fixed roof lubricating oil storage tank (Facility Ref. No. TK03)	
AA-008	Natural Gas Venting from Compressor Startup and Compressor Blowdown	
AA-009	Condensate Truck Loading	
AA-010	Fugitive Equipment Leaks	
AA-011	1,100 gallon above ground fixed roof ethylene glycol storage tank (Facility Ref. No. TK04)	
AA-012	550 gallon above ground fixed roof ethylene glycol storage tank (Facility Ref. No. TK05)	
AA-013	0.0576 MMBTU/hr natural gas fired Catalytic Heater	

EMISSION SUMMARY

Facility-Wide Potential-to-Emit Summary1
Pollutant	PTE Emissions (tons/yr)	
Particulate Matter (TSP)	0.01	
PM10	0.79	
PM2.5	0.79	
Sulfur Dioxide (SO2)	0.05	
Nitrogen Oxides (NOx)	12.19	
Carbon Monoxide (CO)	95.0	
Volatile Organic Compounds (VOC)	15.74	
Total HAP 	24.0	
1 The PTE emissions reflect any emission limits or enforceable restrictions included in the proposed permit.

APPLICABLE/PROPOSED PERMIT LIMITATIONS

Gulf South has requested a federally enforceable restriction in which the two compressor engines must be operated with catalytic converters to control formaldehyde below Title V major source thresholds.   

Emission Points AA-001 and AA-002 are also each limited to 2.0 g/HP-hr NOx emissions, 4.0 g/HP-hr CO emissions, and 1.0 g/HP-hr VOC emissions in order to comply with 40 CFR 60, Subpart JJJJ emission limitations.

A facility-wide CO emission limit of 95 tpy has been included in the permit and a total combined HAP emission limit of 24.0 tpy and individual HAP emission limit of 9.0 tpy has been included in the draft permit.

PERMIT MODIFICATIONS

The capacity of Emission Point AA-006 (Facility Ref. No. TK02) was corrected from 850 gallons to 1,000 gallons according to updated information in the renewal application.  Also, facility-wide limitations for CO, Total HAPs, and formaldehyde have been included in the draft renewal permit, as well as recordkeeping and reporting requirements.
 
NSPS APPLICABILITY

40 CFR 60 Subpart IIII
The provisions of 40 CFR 60 Subpart IIII - New Source Performance Standards for Compression Ignition Internal Combustion Engines (NSPS IIII) are applicable to stationary compression ignition internal combustion engines that commenced construction, modification, or reconstruction after April 1, 2006.  None of the compressor station’s engines are compression ignition internal combustion engines, therefore, none of the compressor station’s engines are subject to any requirements of NSPS IIII.  

40 CFR 60 Subpart JJJJ
The provisions of 40 CFR 60 Subpart JJJJ - New Source Performance Standards for Stationary Spark Ignition Internal Combustion Engines (NSPS JJJJ) are applicable to stationary spark ignition internal combustion engines that commenced construction, modification, or reconstruction after June 12, 2006.  The two compressor engines and the emergency generator engine were manufactured in 2014.  Therefore, each engine is subject to emission standards for NOx, CO and VOC. The standards applicable to the engines from Table 1 of NSPS Subpart JJJJ are shown in the table below.

Non-Emergency SI Lean Burn Natural Gas and LPG Manufactured after 7/1/10, 500≤HP<1,350 (Emission Point AA-001)	
Pollutant	Emission Standard	
NOx	1.0 g/BHP-HR	82 ppmvd @ 15% O2	
CO	2.0 g/BHP-HR	270 ppmvd@15% O2	
VOC	0.7 g/BHP-HR	60 ppmvd@15% O2	
Non-Emergency SI Natural Gas and Non-Emergency SI Lean Burn LPG (except lean burn 500≤HP<1,350) Manufactured after 7/1/10, HP≥500 (Emission Point AA-002)	
NOx	1.0 g/BHP-HR	82 ppmvd @ 15% O2	
CO	2.0 g/BHP-HR	270 ppmvd@15% O2	
VOC	0.7 g/BHP-HR	60 ppmvd@15% O2	
Emergency Engine Manufactured after 1/1/09 (Emission Point AA-003)	
NOx	2.0 g/BHP-HR	160 ppmvd@15% O2	
CO	4.0 g/BHP-HR	540 ppmvd@15% O2	
VOC	1.0 g/BHP-HR	86 ppmvd@15% O2	

To demonstrate compliance with the emission standards in NSPS Subpart JJJJ, the facility purchased non-certified engines for Emission Points AA-001 and AA-002.  Therefore, initial performance tests were required to be conducted followed by subsequent testing to demonstrate compliance with the standards. A maintenance plan must also be followed and records kept demonstrating proper maintenance procedures are followed.

To demonstrate compliance with the emission standards in NSPS Subpart JJJJ, the facility purchased a certified engine for Emission Point AA-003, therefore, the permittee is required to operate the emergency engine according to the manufacturer’s specifications.

40 CFR 60 Subpart KKK
The provisions of 40 CFR 60, Subpart KKK - Standards of Performance for Equipment Leaks of VOC from Onshore Natural Gas Processing Plants (NSPS KKK) apply to affected facilities in onshore natural gas processing plants that commences construction, reconstruction, or modification after January 20, 1984, and on or before August 23, 2011.  Since the Moss Point Compressor Station is not located at an onshore natural gas processing plant, as defined in 40 CFR 60.631, the Moss Point Compressor Station is not subject to NSPS KKK.

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 (NSPS OOOO) are potentially applicable to owners and operators of onshore affected facilities that commence construction, modification, or reconstruction after August 23, 2011.  While the oil condensate storage vessel was installed after the August 23, 2011, effective date, the tank does not have the potential to emit greater than or equal to 6 tpy of VOC emissions, therefore, the tank is not subject to any requirements of NSPS OOOO.  The facility’s compressor engines are not subject to the rod packing requirements of NSPS OOOO since each compressor is located between the wellhead and the point of custody transfer to the natural gas transmission and storage segment, and is therefore, not an affected facility under this Subpart 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 (NSPS OOOOa) are potentially applicable to new and modified sources in the oil and gas industry after August 18, 2015.  The only potentially affected sources at the Compressor Station are the facility’s compressor engines and fugitive components with respect to Leak Detection and Repair (LDAR).  However, there have been no new compressors installed at the facility resulting in increased compression, nor has the facility modified any existing compressor engines; consequently, NSPS OOOOa does not apply to the Moss Point Compressor Station.

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, are standards applicable to vessels used for storing volatile organic liquids.  The facility’s oil condensate storage tank is a 1,100-gallon tank. NSPS Kb is applicable to tanks with a storage capacity greater than 19,800 gallons; therefore, the facility’s oil condensate storage tank is not subject to NSPS Kb.

MACT APPLICABILITY

NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS (NESHAP) APPLICABILITY
The facility is an area source of Hazardous Air Pollutants (HAP) since upon permit issuance the facility will 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 - National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines
The Reciprocating Internal Combustion Engines (RICE) NESHAP, Subpart ZZZZ, regulates HAP emissions from RICE.

Emission Points AA-001 and AA-002 are considered new, spark ignition, 4-stroke lean-burn, non-emergency engines, each with a site rating greater than 500 HP that are located at an area source of HAP emissions. As such, each engine must meet the requirements of Subpart ZZZZ by meeting the requirements of 40 CFR 60, subpart JJJJ, for spark ignition engines. No further requirements apply for such engines under 40 CFR 63 Subpart ZZZZ or the General Provisions of Subpart A.

Emission Point AA-003 is considered a new, spark ignition, 4-stroke lean-burn, emergency engine with a site rating less than 500 HP that is located at an area source of HAP emissions. As such, the engine must meet the requirements of Subpart ZZZZ by meeting the requirements of 40 CFR 60, subpart JJJJ, for spark ignition engines. No further requirements apply for such engines under 40 CFR 63 Subpart ZZZZ or the General Provisions of Subpart A.

40 CFR 63 Subpart JJJJJJ - National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers Area Sources
Since the Moss Point Compressor Station is an area source of HAP emissions, the facility is potentially subject to 40 CFR 63, Subpart JJJJJJ However,  since the Compressor Station does not operate any boilers, and since process heaters are not covered emission points  under Subpart JJJJJJ, none of the facility’s external combustion sources are subject to Subpart JJJJJJ or to any requirements in Subpart JJJJJJ.

40 CFR 63 Subpart HHH - National Emission Standards for Hazardous Air Pollutants From Oil and Natural Gas Production Facilities
NESHAP HHH does not apply to this facility because it is not a major source of HAPs, and there are no glycol dehydration units at the facility. 

PUBLIC PARTICIPATION

The 30-day public notice period began on , with the publication of a notice MDEQ website and ends .
RECOMMENDATION

The staff has preliminarily decided to recommend issuance of the permit to the Mississippi Environmental Quality Permit Board as shown in the draft permit.  However, the staff recommendation to the Board will be made only after a thorough consideration of all public comments.