PERMIT REVIEW SUMMARY

Permit Writer:	Brad Luke 	Date:	August 12, 2026
Company Name:	Sun Air Products Inc dba Yellow Creek Coating Service
Facility Location:	9 County Road 370
Iuka, MS 388852
Source Number:	2580-00041
County: 		Tishomingo

FACILITY DESCRIPTION

Sun Air Products, Inc. (d.b.a. Yellow Creek Coating Service) (“Yellow Creek”) is an industrial manufacturer of fabricated metal products. The facility operations fall within SIC Codes 3479 (Coating, Engraving, and Allied Services, Not Elsewhere Classified) and 3449 (Miscellaneous Structural Metal Work). Yellow Creek receives fabricated steel pipes, fittings, and other miscellaneous metal components that are cleaned via abrasive blasting and coated based on design requirements or product specifications. Other operations on-site include metal fabrication (such as cutting, grinding, and welding). The facility’s maximum uncontrolled emissions of particulate matter (PM), PM less than 10 microns in diameter (PM10), PM less than 2.5 microns in diameter (PM2.5), volatile organic compounds (VOCs), individual hazardous air pollutants (HAPs), and total combined HAPs would all exceed the respective thresholds for a Title V major source, Prevention of Significant Deterioration (PSD) major source, and HAPs major source. However, the facility has taken emission limitations on PM, PM10, PM2.5, VOCs, individual HAPs, and combined HAPs to avoid major status for Title V, PSD, and HAPs.

PROJECT/PERMIT ACTION DESCRIPTION

Yellow Creek Coating is requesting a renewal of the Synthetic Minor Operating Permit (SMOP) issued on October 19, 2021. The facility has already made additions of new equipment to the facility including adding a polyurea coating machine to Surface Coating Operations (Emission Point AA-001) and adding an additional metal inert gas (MIG) welding operations to existing welding operations (Emission Point AA-003), both in March of 2023. Prior permitting authorization was not sought for the addition of new equipment and notification was not given when the pieces of equipment entered service, and Yellow Creek is now requesting they be included in the permit. Beyond including this equipment in the permit, Yellow Creek Coating has not proposed any new additions to their facility or modifications of their permitting status.

Emission Point	Description	
AA-001	Surface Coating Operations [indoor and outdoor including four (4) available spray guns with only two (2) are used at a given time and one (1) polyurea machine used to coat various products with polyurea.]	
AA-002	Abrasive Blasting Operations [indoor blasting uses steel shot, is totally enclosed, and possesses a dust collection system; outdoor blasting uses “Black Beauty” and emissions are controlled by blast curtains]	
AA-003	Metal Working Operations [includes cutting, grinding, and welding]	
AA-004	One (1) 550-Gallon Diesel Storage Tank	
AA-005	Seven (7) Diesel-Fired Space Heaters [total rated capacity: 1.33 MMBTU / hour]	

EMISSION SUMMARY

	PM	PM10	PM2.5	NOX	CO	VOCs	Ind. HAP1	Total HAPs	
Uncontrolled Potential Emissions (tpy)	18,663.04
	18,663.04
	18,663.04
	0.11
	0.03
	2,278.50
	3,932.93
	3,549.27
	
Emission Limitations (tpy)	99.0	99.0	99.0	---	---	99.0	9.00	24.0	
1Based on the emission of xylene, the largest single HAP pollutant.

The maximum emissions for Yellow Creek Coating are significantly larger than presented in previous permitting actions, this does not represent an increase in emissions from the facility of that scale. Instead, the increase in maximum uncontrolled emissions represents more accurate calculation of maximum uncontrolled emissions.

APPLICABLE/PROPOSED PERMIT LIMITATIONS

The facility will maintain the following limitations in order to remain below applicable Title V major source thresholds:
•	Particulate Matter (PM) – 99.0 tons per year (tpy)
•	PM less than 10 microns in diameter (PM10) – 99.0 tpy
•	PM less than 2.5 microns in diameter (PM2.5) – 99.0 tpy
•	Volatile Organic Compounds (VOCs) – 99.0 tpy 
•	Hazardous Air Pollutants (HAPs) – 9.00 tpy for any individual HAP and 24.0 tpy for total combined HAPs 
In the 2021 permit renewal, PM was given an emission limitation of 249.0 tpy as PSD major source avoidance limit. However, the facility has requested that PM, PM2.5, and PM10 each receive a 99.0 tpy emission limitation to avoid PSD major status for PM. The emission limitations on HAPs were previously 9.90 tpy for individual HAPs and 24.90 for total HAPs, however these limitations were determined to be too close to the HAP major source thresholds of 10.0 tpy for individual HAPs and 25.0 tpy for total HAPs. If the limitations of 9.90 tpy and 24.90 tpy were ever exceeded, there would be only a 0.10 tpy buffer against HAP major status. For the reason of providing buffer against reaching HAP major status if permit limitations are exceeded, emission limits of 9.0 tpy for individual HAPs and 24.0 tpy for total HAPs were deemed more appropriate.

NSPS APPLICABILITY

40 CFR Part 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: Subpart Kb applies to facilities that that operate storage vessels with a capacity greater than or equal to 19,812.9 gallons (or 75 cubic meters) that are used to store volatile organic liquids for which construction, reconstruction, or modification commenced after July 23, 1984, and on or before October 4, 2023. Yellow Creek Coating operates a 550-gallon diesel storage tank. The storage tank has a capacity well below 20,000 gallons, so Yellow Creek Coating is not subject to the requirements of Subpart Kb.

MACT APPLICABILITY

40 CFR Part 63, Subpart MMMM – National Emission Standards for Hazardous Air Pollutants for Surface Coating of Miscellaneous Metal Parts and Products: Subpart MMMM applies to facilities that operate surface coating operations of miscellaneous metal parts and products at major sources of HAPs. The facility takes federally enforceable limits to remain below the HAP major source threshold of 10 tons per year (tpy) of any individual HAP and 25 tpy for total HAPs, so Yellow Creek Coating is not subject to the requirements of Subpart MMMM.

40 CFR Part 63, Subpart XXXXXX – National Emission Standards for Hazardous Air Pollutants Area Source Standards for Nine Metal fabrication and Finishing Source Categories: Subpart XXXXXX applies to area sources including dry abrasive blasting, machining, dry grinding and polishing, spray painting, and welding that are primarily engaged in operations in one of the nine source categories listed in the subpart. According to an EPA guidance document ‘Nine Metal Fabrication and Finishing Area Source Categories 40 CFR Part 63 Subpart XXXXXX (6X) NESHAP Questions & Answers’, SIC Codes 3479 and 3449 are not part of the affected categories. Therefore, the facility is not subject to the requirements of Subpart XXXXXX.

40 CFR Part 63, Subpart HHHHHH – National Emission Standards for Hazardous Air Pollutants: Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources: Subpart HHHHHH applies to facilities that operate miscellaneous paint stripping and surface coating operations at area sources of HAPs. However, this subpart is only applicable to facilities, which use chemical strippers containing methylene chloride and spray coatings containing various “target HAPs”. Yellow Creek does not use materials containing either methylene chloride or any of the “target HAPs”. As such, Yellow Creek is not subject to the requirements of Subpart HHHHHH.

PUBLIC PARTICIPATION

The 30-day public notice period began on August 12, 2026, when the notice was posted on MDEQ’s website and ends September 14, 2026.