PERMIT REVIEW SUMMARY

Permit Writer:	Jeffrey Bland 		Date:	February 17, 2025

Company Name:	Southeast Supply Header LLC, Dentville Compressor Station

Facility Location:	13171 Dentville Road, Hazlehurst, MS 39083

Source Number:	0600-00073

County: 		Copiah

FACILITY DESCRIPTION

Southeast Supply Header, LLC (SESH) is a natural gas transmission compression station responsible for the compression of natural gas into a pipeline.  The Dentville Compressor Station operates one (1) natural gas-fired reciprocating compressor engine, one (1) natural gas-fired emergency generator engine, two (2) natural gas-fired catalytic heaters, one (1) parts washer, four (4) storage tanks, condensate truck loading equipment, fugitive equipment leaks, and natural gas venting. The standard industrial code (SIC) for the facility is 4922 for Natural Gas Transmission. The following table contains the emission points at the facility.

Emission 
Point	Description	
AA-001a	8,000 HP Cooper Bessemer Model 16W330-C3 two stroke lean burn (2SLB) spark ignition (SI) natural gas-fired non-emergency compressor engine (Facility Ref. No. 1353) equipped with an oxidation catalyst utilized for driving Emission Point AA-001b	
AA-001b	Reciprocating compressor driven by Emission Point AA-001a	
AA-002	760 HP Caterpillar Model G3412C four stroke lean burn (4SLB) SI natural gas-fired emergency backup power generating engine (Facility Ref. No. 5069)	
AA-003	Natural Gas In-line Catalytic Instrument Heater (Facility Ref. No. H01)	
AA-004	Natural Gas In-line Catalytic Instrument Heater (Facility Ref. No. H02)	
AA-005	Parts Washer (Facility Ref. No. PW01)	
AA-006	8,000 Gallon Horizontal Vertical Fixed Roof Coolant Storage Tank (Facility Ref. No. TK01)	
AA-008	2,000 Gallon Vertical Fixed Roof Used Oil Storage Tank (Facility Ref. No. TK03)	
AA-009	2,000 Gallon Vertical Fixed Roof Used Oil Storage Tank (Facility Ref. No. TK03a)	
AA-010	2,000 Gallon Vertical Fixed Roof Produced Water Storage Tank (Facility Ref. No. TK04)	
AA-013	Truck Loading Area (Facility Ref. No. TL01-TL03)	
AA-014	Piping Components (Facility Ref. No. PC)	
AA-015	Natural Gas Releases (Facility Ref. No. GR)	

PROJECT/PERMIT ACTION DESCRIPTION

SESH 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) and the individual hazardous air pollutant (HAP) formaldehyde as well as total, combined HAPs; however, SESH requested limitations on Emission Point AA-001a consistent with 11 Miss. Admin. Code, Pt. 2, Ch. 6 to reduce the site-wide emissions below Title V thresholds. SESH utilizes an oxidation catalyst on the compressor engine to restrict CO emissions below the Title V threshold of 100 tpy and to restrict Total HAP and formaldehyde emissions below the Title V thresholds of 25 tpy and 10 tpy, respectively.

EMISSION SUMMARY

Facility-Wide Potential-to-Emit Summary1
Pollutant	PTE Emissions (tons/yr)	
Particulate Matter (TSP)	10.06	
PM10	10.06	
PM2.5	10.06	
Sulfur Dioxide (SO2)	0.15	
Nitrogen Oxides (NOx)	77.95	
Carbon Monoxide (CO)	95.0	
Volatile Organic Compounds (VOC)	41.50	
Formaldehyde	9.0	
Total HAP 	13.24	
1 The PTE emissions reflect any emission limits or enforceable restrictions included in the proposed permit.

APPLICABLE PERMIT LIMITATIONS

The compressor engine (Emission Point AA-001a) operates under a federally enforceable restriction in which the engine must be operated with an oxidation catalyst to control CO and formaldehyde below Title V major source thresholds.   

The compressor engine (Emission Point AA-001a) is also limited to 1.0 g/HP-hr NOx emissions, 2.0 g/HP-hr CO emissions, and 0.7 g/HP-hr VOC emissions in order to comply with 40 CFR 60, Subpart JJJJ emission limitations. The facility is required to conduct performance stack testing every 8,760 hours of operation, or 3 years, whichever comes first.

The emergency back generator engine (Emission Point AA-002) is 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. Since the engine is a certified engine, the facility is required to operate and maintain the engine according to the manufacturer's emission-related written instructions and keep records of conducted maintenance.

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 compressor engine (Emission Point AA-001a) was reconstructed in 2014, and the emergency generator engine (Emission Point AA-002) was 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 Engine Manufactured after 7/1/10 (Emission Point AA-001a)	
Pollutant	Emission Standard	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	
Emergency Engine Manufactured after 1/1/09 (Emission Point AA-002)	
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 a non-certified engine for Emission Point AA-001a. Therefore, an initial performance test was required to be conducted followed by subsequent testing to demonstrate compliance with the standards. A maintenance plan was also developed 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-002.

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 Dentville Compressor Station is not located at an onshore natural gas processing plant, as defined in 40 CFR 60.631, the Dentville 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.  The facility’s compressor is subject to the rod packing requirements of NSPS OOOO.  No other sources at the compressor station are 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 (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 Dentville Compressor Station are the facility’s compressor engine 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 Dentville 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 storage tanks are each below 19,800 gallons; therefore, the facility’s oil storage tanks are 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 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 - 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-001a is considered a new, spark ignition, 4-stroke lean-burn, non-emergency engine, with a site rating greater 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.

Emission Point AA-002 is considered a new, spark ignition, 4-stroke lean-burn, emergency engine with a site rating greater than 500 HP that is located at an area source of HAP emissions. As such, the engine must also 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 Dentville Compressor Station is an “Area” source of Hazardous Air Pollutant (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.