PUBLIC NOTICE COPY

PERMIT RATIONALE FOR REISSUANCE
Denbury Onshore LLC, Brandon Pump Station
Water NPDES No. MS0061263
May 2026
Samar Patel, Water I Branch 

I.	FACILITY INFORMATION

Facility Address:  	197 Carbonic Drive, Brandon, MS  39042
Facility County:	Rankin County
EPA ID: 		110038110843
SIC:  			1311

II.	NATURE OF BUSINESS

Denbury, Brandon Pump Station (BPS) boosts the pressure of the CO2 traveling down the pipeline. CO2 from the Barksdale pipeline is also combined at the station, upstream of the pumps. The combined CO2 stream from both pipelines is pumped to high pressure and discharged down the pipeline. Four (4) cooling units are on the CO2 discharge from the pumps. These units cool the CO2 pump discharge and increase the density of the fluid leaving the station, overall increasing the pipeline capacity. Water is continually sprayed on to heat transfer tubes, and air is drawn past the wet tubes. The majority of the water is fed to the Wet Surface Air Coolers (WSAC) units is evaporated, but a continuous blow-down of water is required in order to prevent the accumulation of salt in the recirculating water. The facility is classified as an NPDES minor source.

III.	EFFLUENT AND RECEIVING STREAM FLOW DATA

Outfall 001 (External Outfall):	This discharge consists of cooling tower blowdown and has a maximum monthly discharge flow of 0.0276 MGD and discharges into an unnamed tributary of Richland Creek (7Q10=0). 

The receiving stream is classified as “fish and wildlife” and is located in the Pearl River Basin.

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

There are no 303(d) issues with Richland Creek. An Organic Enrichment/Low DO TMDL (ID# 36913) has been issued for Richland Creek (MS158E) in the Pearl River Basin. The facility’s discharge should not contribute to the pollutant loading in the stream, and this permit complies with the following TMDLs:

•	Total Nitrogen and Total Phosphorus - Pearl River - Pearl River Basin - Neshoba, Leake, Copiah, Madison, Lawrence, Simpson, Marion, Pearl River, Hancock Counties - June 2009 - ID# 36886, 36885
•	Legacy Pesticides - Pearl River, South Independent Streams, and Lower Mississippi River Basins - January 2007 - ID# 31700
•	Fecal Coliform -  Pearl River, The Strong River, Halls Creek, Pretty Branch - Pearl River Basin - Copiah, Pearl River, Simpson, and Lawrence Counties - December 20011 - ID# 41449
•	Fecal Coliform -  Pearl River - Pearl River Basin - Hinds County - December 1999 - ID# 913
•	Fecal Coliform -  Pearl River - Pearl River Basin - Marion County - December 2000 - ID# 1609
•	Low pH - Pearl River - Pearl River Basin - Neshoba, Leake, Hinds, Rankin, Hancock Counties - ID# 1607

V.	TYPE OF WASTEWATER TREATMENT:

Disinfection, Neutralization

VI.	EPA APPLICABLE CATEGORICAL GUIDELINES

None.

VII.	DATA FROM APPLICATION FORM (Form 2C)

	1Values for Temperature, flow, and pH were estimated using data from the previous permit renewal application. 

VIII. 	WATER QUALITY LIMITATIONS BASED ON WASTELOAD ALLOCATION 

	None.

CATEGORICAL GUIDELINE LIMITATIONS CALCULATIONS

Not Applicable.

VIII.	TOXICITY SCREENING

QW	 =	max 30-day average wastewater flow; Renewal application 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
XW	 =	historical effluent data; Renewal application data used (use max concentration for acute screening and LTA concentration for chronic and human health screening) 
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
AWQC =	Acute Water Quality Criteria
CWQC =	Chronic Water Quality Criteria

Xt = (Qr*Xr) + (Qw* XW) / (Qr+QW)		When Qr = 0, then Xt =XW

Since IWC > 1%, both acute and chronic screening are developed.  

Outfall 001 Toxicity Screen:

PROPOSED FINAL LIMITATIONS 

1.	Average Permit Limitations

Outfall	Parameter	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Monitoring Frequency	Sample Type	DMR Reporting Frequency	1Basis	
001	Flow (MGD)	---	Report	Report	Twice per Month 	Totalizer	Monthly	PPL	
001	pH (min)	6.0 SU	6.0 SU	6.0 SU	Twice per Month	Grab Sampling	Monthly	MSWQS	
001	Chlorine, TR	0.011 mg/L	---	0.011 mg/L	Twice per Month	Grab Sampling	Monthly	MSWQS	

2.	Maximum Permit Limitations

Outfall	Parameter	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Monitoring Frequency	Sample Type	DMR Reporting Frequency	1Basis	
001	Flow (MGD)	---	Report	Report	Twice per Month 	Totalizer	Monthly	PPL	
001	pH (max)	9.0 SU	9.0 SU	9.0 SU	Monthly 	Grab Sampling	Monthly	MSWQS	
001	Chlorine, TR	0.019 mg/L	---	0.019 mg/L	Twice per Month	Grab Sampling	Monthly	MSWQS	

1Basis: MSWQS = Mississippi Water Quality Standards, PPL=Previous Permit Limits. TR = Total Residual

XII.	BPJ STATEMENT: 

It is our judgment that the foregoing limitations represent Technical Judgment (TJ), and 11 Miss. Admin. Code Pt.6, Ch. 1 and 2 (MSWQS).