PERMIT RATIONALE FOR REISSUANCE
Hunt Southland Refining Company
Water NPDES No. MS0001686
July 2026
Samar Patel, Water I Branch

I.	FACILITY INFORMATION

Facility Address:	177 Haney Road, Sandersville, MS 39439    Sandersville, 
Facility County:	Jones
SIC:  			2911

II.	NATURE OF BUSINESS

This facility is a petroleum refinery that produces asphalt and other petroleum distillates via atmospheric and vacuum distillation of crude oil.  The facility throughput is 12,500 barrels per day.

III.	EFFLUENT AND RECEIVING STREAM FLOW DATA

Outfall 001: discharges a long term average flow of 0.174 MGD and a daily maximum flow of 0.295 MGD into Old Julie Branch (7Q10= 0.07 MGD). The receiving stream is located in the Pascagoula River Basin and classified as Fish and Wildlife. The facility discharge consists of process wastewater, wash down, storm water from process areas, and wastewater from groundwater remediation wells.  

IV.	TOTAL DAILY MAXIMUM LOAD (TMDL) AND 303(d) ISSUES

Old Julie Branch is not listed on the Mississippi 2024 Section 303(d) List of Impaired Water Bodies. The permit complies with the five (5) following applicable TMDLs:  

•	Nutrients, Organic Enrichment, Low DO – Bogue Homo River – Pascagoula River Basin – Jones County – June 2005- ID#405063001
•	Phase 1 Mercury – West Pascagoula River – Pascagoula River Basin - George and Jackson Counties – March 2005 – ID#405031801
•	Phase 1 Mercury – Pascagoula River – Pascagoula River Basin – George and Jackson Counties – March 2005 – ID#405031801
•	Fecal Coliform – Pascagoula River – Pascagoula River Basin - George, Jackson, Forrest, Perry, and Greene Counties – December 1999 – ID#499121505
•	Fecal Coliform – Leaf River seg 1 and eg 2 – Pascagoula River Basin - Forrest, Perry, and George Counties – May 2007 – ID#400050301

V.	TYPE OF WASTEWATER TREATMENT:

Outfall 001 is treated by an oil-water separator, dissolved air flotation, activated sludge, and two aerated lagoons in series.

VI.	DATA FROM APPLICATION FORM 2C

Parameter	Maximum Daily Value	Long Term Average Value	No. of Analyses	
Biochemical Oxygen Demand, 5-Day (BOD5)	115 mg/L	12.26 mg/L	109	
Chemical Oxygen Demand (COD)	1270 mg/L	114.25 mg/L	108	
Total Suspended Solids (TSS)	205 mg/L	33.1 mg/L	112	
Ammonia (as N)	27.5 mg/L	2.53 mg/L	79	
Flow	0.42 MGD	0.14 MGD	73	
Temperature (winter)	15.16oC	--	106	
Temperature (summer)	31.5oC	--	106	
pH	9.0 SU – 6.8 SU		106	
Oil & Grease	109 mg/L	4.49 mg/L	57	
Sulfide (S)	6.8 mg/L	0.617 mg/L	67	
Aluminum	1.3 mg/L	0.146 mg/L	106	
Arsenic	<0.005 mg/L		1	
Chromium	0.006 mg/L	0.00046	53	
Copper	0.002 mg/L		1	
Lead	0.002 mg/L		1	
Mercury	0.00000077 mg/L		1	
Nickel	0.004 mg/L		1	
Zinc	0.43 mg/L	0.0145 mg/L	105	
Phenols, Total	1.1 mg/L	0.043 mg/L	100	

VII.	WATER QUALITY LIMITATIONS BASED ON WASTELOAD ALLOCATION 

Wasteload Allocation (WLA) received February 17, 2021 (See Appendix A).

Parameter	Average	
Flow	0.125 MGD	
Carbonaceous Biochemical Oxygen Demand, 5-Day (CBOD5)	15.9 mg/L	
Total Ammonia Nitrogen (NH3-N)	1.46 mg/L	
Minimum Dissolved Oxygen (Min. DO)	6.0 mg/L	
Total Nitrogen (TN)	Report lbs/day	
Total Phosphorus (TP)	Report lbs/day	
pH	6.0 SU – 9.0 SU	

I.	
VIII.	EPA APPLICABLE CATEGORICAL GUIDELINE LIMITATIONS CALCULATIONS

40 CFR 419 (Petroleum Refining Point Source Category), Subpart A (Topping Subcategory); Specifically 40 CFR 419.13 (BAT) & 40 CFR 419.14 (BCT)

 (A)	Size Factor [40 CFR Part 419.12(b)(1)]
		Maximum throughput: 12,500 bbls/day
		Stormwater flow: 40,000 gpd
		Size Factors (SF): 1.02

(B)	Calculation of Process Factor [40 CFR Part 419.12(b)(2]
Process Category	Process	Production (bbls/day)	Capacity relative to throughput	Weighting Factor	Process Configuration	
Crude						
	Atmospheric Crude Distillation	12500	1	--		
	Vacuum Crude Distillation	7500	0.6	--		
	Desalting	12500	1	--		
	Subtotal	32500	2.6	1	2.6	
Asphalt						
	Production	6875	0.55	--		
	Oxidation	1095	0.0876	--		
	Emulsifying	0	0	--		
	Subtotal	7970	0.6376	12	7.6512	
Cracking and Coking		0	0	6	0	
Lubes		0	0	13	0	
				Total:	10.2512	
	Process Factor (PF): 2.31
(C) 	Limitation Factor = Throughput * SF * PF
	LF = 12500bbls * 1.02 * 2.31 = 29452.5
Pollutant	BAT Category	Process Rate	BAT Limits	BAT Storm Water Category	BAT Storm Water Limits	Total	
	Daily Max.	Mo. Avg.		Daily Max.	Mo. Avg.	Daily Max.	Mo. Avg.	Daily Max.	Mo. Avg.	Daily Max.	Mo. Avg.	
	(lbs/1000 bbls throughput)	(bbls/day)	(lbs/day)	(lbs/1000 gpd)	(lbs/day)	(lbs/day)	
COD	41.2	21.3		1213.4	627.3	3	1.5	120	60	1333.4	687.3	
Ammonia (as N)	0.99	0.45		29.2	13.3					29.2	13.3	
Sulfide	0.053	0.024		1.56	0.71					1.56	0.71	
Phenolic Compounds							
Crude	0.013	0.003	32500	0.423	0.098							
Asphalt	0.079	0.019	7970	0.630	0.151							
Total			1.053	0.249	0.0029	0.0014	0.116	0.056	1.169	0.305	
Total Chromium							
Crude	0.011	0.004	32500	0.357	0.13				
Asphalt	0.064	0.022	7970	0.510	0.175				
Total			0.867	0.305	0.005	0.0018	0.2	0.072	1.067	0.377	
Hexavalent Chromium							
Crude	0.0007	0.0003	32500	0.0227	0.0097				
Asphalt	0.0041	0.0019	7970	0.0327	0.0151				
Total			0.0554	0.0248	0.00052	0.00023	0.0208	0.009	0.0762	0.0338	
pH	6.0 SU – 9.0 SU					6.0 SU – 9.0 SU	

Pollutant	BCT Category	Process Rate	BCT Limits	BCT Storm Water Category	BCT Storm Water Limits	Total	
	Daily Max.	Mo. Avg.		Daily Max.	Mo. Avg.	Daily Max.	Mo. Avg.	Daily Max.	Mo. Avg.	Daily Max.	Mo. Avg.	
	(lbs/1000 bbls throughput)	(bbls/day)	(lbs/day)	(lbs/1000 gpd)	(lbs/day)	(lbs/day)	
BOD5	8	4.25		235.62	125.17	0.4	0.22	16	8.8	251.62	133.97	
TSS	5.6	3.6		164.93	106.03	0.28	0.18	11.2	7.2	176.13	113.23	
Oil and Grease	2.5	1.3		73.63	38.29	0.13	0.067	5.2	2.68	78.83	40.97	
pH	6.0 SU – 9.0 SU								6.0 SU – 9.0 SU	

IX.	TOXICITY SCREENING

QW	=	max 30-day avg wastewater flow; Jan 2024 – Dec 2025 DMR data used
Qr	=	receiving stream flow (7Q10 flow used for acute and chronic screening and Mean Annual Flow used for Human Health screening)
Xr	=	receiving stream concentration, assume 0 mg/L
XW	=	historical effluent data (use max concentration for acute screening and LTA concentration for chronic and human health screening); less than 12 samples will be multiplied by 10
XWa 	=	permit limits from previous permit or from effluent guidelines
Xta	=	the calculated instream concentration based on existing permit limits or the              			calculated limit based on current effluent guidelines
Xt	=	the calculated instream concentration based on historical effluent data 
IWC 	=	Instream Wastewater Concentration

Xt = (Qr*Xr) + (Qw* XW) / (Qr+QW)	Xr = Assume 0 mg/L	

Qw = 0.295 MGD
Qr = 0.07 MGD- 7Q10, 2.04 MGD – (mean annual flow)

IWC = [Qw / (Qw + Qr)]*100 = [0.295/(0.295 + 0.07)]*100 = 80.82%
IWC (mean annual flow) = [Qw / (Qw + Qr)]*100 = [0.295/(0.295 + 2.04)]*100 = 12.63%
Since IWC > 1%, both acute and chronic screening are developed.  

Total Aluminum
XW = 1.3 mg/L (acute), 0.0.146 mg/L (chronic, human health)
Xt (acute) = (0.295*1.3) / (0.07+0.295) = 1.05 mg/L
Xt (chronic) = (0.295*0.146) / (0.07+0.295) = 0.118 mg/L

Total Arsenic
XW = 0.005 mg/L * 10 = 0.05 mg/L (No. of Samples <12)
Xt (human) = (0.295*0.05) / (2.04+0.295) = 0.0063 mg/L

Total Chromium (III)
XW = 0.006 mg/L (acute), 0.00046 mg/L (chronic, human health)
Xt (acute) = (0.295*0.006) / (0.07+0.295) = 0.00048 mg/L
Xt (chronic) = (0.295*0.00046) / (0.07+0.295) = 0.000037 mg/L
Xt (human) = (0.295*0.00046) / (2.04+0.295) = 0.00006 mg/L

Total Copper
XW = 0.002 mg/L * 10 = 0.02 mg/L (No. of Samples <12)
Xt (acute) = (0.295*0.02) / (0.07+0.295) = 0.0162 mg/L
Xt (chronic) = (0.295*0.02) / (0.07+0.295) = 0.0162 mg/L
Xt (human) = (0.295*0.02) / (2.04+0.295) = 0.0025 mg/L

Total Lead
XW = 0.002 mg/L * 10 = 0.02 mg/L (No. of Samples <12)
Xt (acute) = (0.295*0.02) / (0.07+0.295) = 0.0162 mg/L
Xt (chronic) = (0.295*0.02) / (0.07+0.295) = 0.0162 mg/L

Total Mercury
XW = 0.00000077 mg/L * 10 = 0.0000077 mg/L (No. of Samples <12)
Xt (human) = (0.295*0.0000077) / (2.04+0.28) = 0.00000097 mg/L

Total Nickel
XW = 0.004 mg/L * 10 = 0.04 mg/L (No. of Samples <12)
Xt (acute) = (0.295*0.04) / (0.07+0.295) = 0.0323 mg/L
Xt (chronic) = (0.295*0.04) / (0.07+0.295) = 0.0323 mg/L
Xt (human) = (0.295*0.04) / (2.04+0.295) = 0.005 mg/L

Total Zinc
XW = 0.43 mg/L (acute), 0.0145 mg/L (chronic, human health)
Xt (acute) = (0.295*0.43) / (0.07+0.295) = 0.347 mg/L
Xt (chronic) = (0.295*0.0145) / (0.07+0.295) = 0.012 mg/L
Xt (human) = (0.295*0.0145) / (2.04+0.295) = 0.0018 mg/L

Toxicity Screening Summary

Parameter	Max XT (mg/L)	AWQC (mg/L)	Pass/Fail	Avg XT (mg/L)	CWQC (mg/L)	Pass/Fail	Avg XT (mg/L)	HHC (mg/L)	Pass/Fail	
Aluminum	1.05	2.0	Pass	0.118	0.70	Pass	- -	- -	- -	
Arsenic	- -	 - -	- -	 - -	- -	- -	0.0063	0.024	Pass	
Chromium (Hex)	ND	0.016	Pass	ND	0.011	Pass	ND	1.47	Pass	
Chromium (III)	0.00048	0.323	Pass	0.000037	0.042	Pass	0.00006	140	Pass	
Copper	0.0162	0.007	Fail	0.0162	0.005	Fail	0.0025	1	Pass	
Lead	0.0162	0.03	Pass	0.0162	0.00118	Fail	- -	- -	- -	
Mercury	- -	 - -	- -	- -	- -	- -	0.00000097	0.000153	Pass	
Nickel	0.0323	0.26	Pass	0.0323	0.029	Fail	0.005	4.6	Pass	
Zinc	0.347	0.065	Fail	0.012	0.065	Pass	0.0018	26	Pass	

AWQC = Acute Water Quality Criteria; CWQC = Chronic Water Quality Criteria; HHC = Human Health Criteria

X.	WATER QUALITY LIMITATIONS CALCULATIONS

IWC = [Qw / (Qw + Qr)]*100 = [0.295/(0.295 + 0.07)]*100 = 80.82%
IWC (mean annual flow) = [Qw / (Qw + Qr)]*100 = [0.295/(0.295 + 2.04)]*100 = 12.63%

Water Quality Limitation = Water Quality Criteria / IWC

Zinc (acute) = 0.065 / 0.8676 = 0.080 mg/L
Zinc (chronic) = 0.065 / 0.8676 = 0.080 mg/L

XI.	PROPOSED FINAL LIMITATIONS 

Parameter	Categorical Limit	Water Quality Limit	Current Permit Limit	Proposed Permit Limit	Basis1	
	Load (lbs/day)	Conc. (mg/L)	Load2 (lbs/day)	Conc. (mg/L)	Load (lbs/day)	Conc. (mg/L)	Load (lbs/day)	Conc. (mg/L)		
	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.	Mo. Avg.	D. Max.		
NH3-N	13.25	29.16	12.22	26.89	2.19	4.38	1.46	2.92	1.52	3.04	1.46	2.92	1.52	3.04	1.46	2.92	WLA/ABS	
BOD5	133.97	251.62	123.57	232.08	23.07	46.15	15.9	31.8	16.6	33.2	15.9	28	16.6	33.2	15.9	28	WLA/ABS	
COD3	687.34	1333.44	633.96	1229.89	--	--	--	--	259	500.9	218.7	423	259	500.9	218.7	423	ABS	
Chromium (Hexavalent)	0.03	0.08	0.03	0.07	0.016	0.023	0.011	0.016	0.013	0.019	0.011	0.016	0.013	0.019	0.011	0.016	ABS	
Chromium (Total)4	0.38	1.07	0.35	0.98	0.061	0.469	0.042	0.323	0.044	0.093	0.042	0.089	0.044	0.093	0.042	0.089	WQS/ABS	
Flow	--	--	--	--	--	--	--	--	R	R	--	--	R	R	--	--	ABS	
Oil & Grease3	40.97	78.83	37.79	72.71	--	--	--	--	15.8	30.4	13.5	25.7	15.8	30.4	13.5	25.7	ABS	
Phenolic Compounds	0.30	1.17	0.28	1.08	0.148	0.435	0.102	0.30	0.12	0.30	0.102	0.30	0.12	0.30	0.102	0.30	WQS/ABS	
TSS3	113.23	176.13	104.44	162.46	--	--	--	--	43.8	71.0	42	68.1	43.8	71.0	42	68.1	ABS	
Sulfide	0.71	1.56	0.65	1.44	--	--	--	--	0.71	1.56	0.65	1.44	0.71	1.56	0.65	1.44	CBEL	
Zinc (Total)	--	--	--	--	0.116	0.116	0.08	0.08	0.089	0.089	0.076	0.076	0.116	0.116	0.08	0.08	WQS	
Total Nitrogen (TN)	--	--	--	--	--	--	--	--	--	--	--	--	R	R	--	--	WLA	
Total Phosphorous (TP)	--	--	--	--	--	--	--	--	--	--	--	--	R	R	--	--	WLA	
Aluminum	--	--	--	--	R	R	0.7	2.0	--	--	--	--	R	R	0.7	2.0	ERWQS	
Dissolved Oxygen	--	6.0 mg/L minimum	6.0 mg/L minimum	6.0 mg/L minimum	WLA	
pH	6.0--9.0 S.U.	6.0--9.0 S.U.	6.0--9.0 S.U.	6.0--9.0 S.U.	CBEL/WQS	
Temperature	--	90ºF maximum	90ºF maximum	90ºF maximum	WQS	

1WLA = Wasteload allocation, WQS = water quality standards, ABS = Antibacksliding limit, CBEL = categorical based effluent limitation, EJ = Engineering Judgment, ERWQS = EPA 2018                    
  Recommended Aluminum Aquatic Life Criteria (Based on Site-Specific Study Report from March 2020)
2Limitations on loading were calculated using 0.174 MGD.
3Permit limits established in 1994 reissuance based on categorical standards.  Due to demonstrated compliance and antibacksliding regulations, these will remain the same. 
4Water quality limits based on the standard set by Mississippi for chromium (trivalent).

Parameter	Monitoring Type	Frequency	
NH3-N	24-hr Composite	1/month	
BOD5	24-hr Composite	2/month	
COD	24-hr Composite	2/month	
Chromium (Hexavalent)	24-hr Composite	1/month	
Chromium (Total)	24-hr Composite	1/month	
Flow	Continuous Recorder	Continuously	
Oil & Grease	Grab Sampling	1/month	
Phenolic Compounds	Grab Sampling	2/month	
TSS	24-hr Composite	2/month	
Sulfide	24-hr Composite	1/month	
Zinc (Total as ZN)	24-hr Composite	2/month	
Dissolved Oxygen	Grab Sampling	2/month	
pH	Grab Sampling	2/month	
Temperature	Grab Sampling	2/month	
Aluminum	24-hr Composite	2/month	
           Total Nitrogen (TN)	24-hr Composite	2/month	
     Total Phosphorous (TP)	24-hr Composite	2/month	

Other monitoring requirements: Using data submitted in the application, the facility failed toxicity screenings for zinc, copper, lead and nickel.  While a permit limit was developed for zinc, the permittee will be required to perform additional monitoring for the other three pollutants.  The permittee shall sample for copper, lead and nickel twice per month until 12 samples are obtained and reported to the agency no later than the 28th day of the month following completion of data collection.  

Whole Effluent Toxicity (WET) testing requirement: The issuance of this permit will require the chronic WET testing only four times in the year preceding the deadline for the next renewal application (two of which should include the hot-dry and cold-wet seasons).

APPENDIX A: Wasteload Allocation