PERMIT RATIONALE FOR MODIFCATION
Ergon Refining Inc
Warren County
Vicksburg, Mississippi
Water NPDES No. MS0034711
July 2026

I.	FACILITY INFORMATION

Facility Name:		Ergon Refining Inc (ERI)
Facility Address:	2125 Haining Road 
                                       	Vicksburg, MS  39183    
Vicksburg, 
Permit No.:      	MS0034711
SIC:			2911
Permit Writer:		Samar Patel
EPD Branch:		Water I Branch

II.	NATURE OF BUSINESS

This industrial point source produces finished oil products from naphthenic heavy crude oil. Primary finished products include naphthenic lubrication oil and asphalt. Minor products of the refinery include naphtha, diesel, and sodium hydrosulfide. The applicable SIC Code is 2911. 

III.	 NATURE OF MODIFICATION 

The facility submitted a request for permit modification to incorporate a new storm water Outfall 016 to their existing NPDES permit. The refinery currently has fifteen (15) Outfalls and is proposing one new storm water outfall which will drain the former biofuels tank farm including hydrostatic test water. The proposed outfall will discharge into an open ditch that flows into the Vicksburg Harbor Channel. The facility has submitted the anti-degradation analysis report for Outfall 016, as part of their modification application package. 

Also, with this modification, we are incorporating the monitoring and limitation requirements for discharge of their hydrostatic test water that are currently being permitted through the storm water outfalls. As a result, the outfall description for all including storm water outfalls have been revisited and revised except Outfall 017 (please see Section IV for each outfall description). 

IV.	EFFLUENT AND RECEIVING STREAM FLOW DATA

The refinery currently has fifteen (15) outfalls that include one process wastewater outfall (001) and fourteen (14) storm water outfalls. Also, the facility is proposing one (1) new storm water outfall 016. The discharge from each outfall is described below.

A.	Outfall 001 (MS0034711 001) – The treated wastewater includes process wastewater, tank drawdown water, slab wash down, boiler blowdown, heat exchanger wash, laboratory wastewater, hydrostatic test water (intermittent) and storm water from process areas. 

The long-term average (LTA) flow and daily maximum flow as reported in the application are 0.2808 MGD and 0.5127 MGD (from last permit renewal application). 

B.	Outfall 002 (MS0034711 002) – Storm water runoff from roadways in the process areas and hydrostatic test water from internal outfalls 201 and 202 (intermittent).

C.	Outfall 003 (MS0034711 003) – Storm water runoff from roadways in the process areas and hydrostatic test water from internal outfalls 301 and 302 (intermittent).

D.	Outfall 004 (MS0034711 004) – Storm water runoff from the tank farm area that stores primarily the polymerized asphalt and emulsions and hydrostatic test water from internal outfalls 401 and 402 (intermittent).

E.	Outfall 005 (MS0034711 005) - Storm water runoff from the refinery tank farm and hydrostatic test water from internal outfalls 501 and 502 (intermittent).

F.	Outfall 006 (MS0034711 006) – Storm water runoff from the refinery tank farm and hydrostatic test water from internal outfalls 601 and 602 (intermittent).

G.	Outfall 007 (MS0034711 007) - Storm water runoff from the refinery tank farm and hydrostatic test water from internal outfalls 701 and 702 (intermittent).

H.	Outfall 009 (MS0034711 009) – Storm water runoff from a tank farm associated with the Propane De-Asphalting Unit (PDA), area outside the curbed area formerly included in Outfall 008 and hydrostatic test water from internal outfalls 901 and 902 (intermittent).

I.	Outfall 010 (MS0034711 010) – Storm water runoff from outside of the curbed process areas associated with the Propane De-Asphalting Unit (PDA) and hydrostatic test water from internal outfalls 1001 and 1002 (intermittent).

J.	Outfall 011 (MS0034711 011) – Storm water runoff from outside of the curbed process areas, waste storage and handling areas and hydrostatic test water from internal outfalls 1101 and 1102 (intermittent).

K.	Outfall 012 (MS0034711 012) – Storm water collected along the rail loading rack, roadways and traffic areas between the ERI Terminal and administrative buildings  and hydrostatic test water from internal outfalls 1201 and 1201 (intermittent).

L.	Outfall 013 (MS0034711 013) – Storm water collected along the rail loading rack and various paved roadways at the ERI Terminal and hydrostatic test water from internal outfalls 1301 and 1302 (intermittent).

M.	Outfall 014 (MS0034711 014) – Storm water collected from the ERI Terminal tank farm and hydrostatic test water from internal outfalls 1401 and 1402 (intermittent).

N.	Outfall 015 (MS0034711 015) – Storm water collected from the ERI Terminal tank farm and hydrostatic test water from internal outfalls 1501 and 1502 (intermittent).

O.	Outfall 017 (MS0034711 017) – Storm water collected from a 6.13-acre site near the firewater system. 

P.	Proposed Outfall 016 (MS0034711 016) – Storm water will be collected from the former biofuels tank farm area located at their old Ethanol Plant (operation ceased in 2018) and hydrostatic test water from internal outfalls 1601 and 1602 (intermittent).

	RECEIVING WATERS

All outfalls (except outfalls 012-015): Yazoo River Diversion Canal 

Outfalls 012-015 and new proposed Outfall 016: Vicksburg Harbor Channel 

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

The receiving stream is in the Yazoo River Basin and is classified as fish and wildlife. The section of the receiving stream segment, where Outfall 016 discharges into the Vicksburg Harbor Channel, does not appear on the updated State of Mississippi 303(d) List of Impaired Water bodies. However, this site is listed in a State of Mississippi Yazoo River Basin TMDL for Total Nitrogen (TN) and Total Phosphorous (TP) for selected Large Rivers in the Delta, which was completed in June of 2008. This modification proposes no changes to the effluent limitations and reporting requirements for TN and TP consistent with the TMDL for Outfall 001. 

VI.	      TYPE OF WASTEWATER TREATMENT

A.	Outfall 016(MS0034711 016) – None.

VII.	EPA APPLICABLE CATEGORICAL GUIDELINES
 
	40 CFR 419 (Petroleum Refining Point Source Category), Subpart D (Lube Oil
Subcategory). 

VIII.	XI.	PROPOSED FINAL LIMITATIONS 

1.	Average Permit Limitations 
Outfall	Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Basis	

MS0034711-016	-TOC
-Oil & Grease
-pH (Min.)	Report
Report
-	-
-
6.0 (S.U.)	Report, mg/l
Report, mg/l
6.0 (S.U.)	Report, mg/l
Report, mg/l
6.0 (S.U.)	Categorical
Categorical
MSWQS	

2.	Maximum Permit Limitations 

Outfall	Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Basis	
MS0034711-016	-TOC
-Oil &Grease
-pH (Max.)	110 mg/l
15 mg/l
-	-
-
9.0 (S.U.)	110 mg/l
15 mg/l
9.0 (S.U.)	110 mg/l
15 mg/l
9.0 (S.U.)	Categorical
Categorical
MSWQS	
MSWQS = Mississippi Water Quality Standards 

Outfall 016: 

The flow at this outfall is based upon actual rainfall (i.e., Stormwater runoff) and shall be     monitored at least once per month. Oil & Grease, pH, and TOC (Total Organic Carbon) shall be monitored monthly with grab samples and reported on a monthly DMR, including flow estimates at this new outfall. Mention that there are storm water conditions starting on page 20 of 79 of the permit.

Within one (1) year of commencing of discharge from Outfall 016, the permittee shall complete and submit item no. VII of NPDES application Form 2F [40 CFR 122.26(c)(1)(i)(G)].

ANTIDEGRADATION EVALUATION

MDEQ has no comments on the antidegradation report and subsequent correspondence submitted as part of the modification request.