lPERMIT RATIONALE FOR REISSUANCE
Denbury Onshore LLC, Jackson Dome Facility
Rankin County
Brandon, Mississippi
Water NPDES No. MS0057941
March 16, 2020

I.	FACILITY INFORMATION

Facility Name:  Denbury Onshore LLC, Jackson Dome Facility
Facility Address:  1919 Holly Bush Road 
Pelahatchie, MS 39145    
Permit No.:  MS0057941
SIC:  1321
Permit Writer:  Thomas Kelly
EPD Branch:  Water I Branch

II.	NATURE OF BUSINESS

Carbon dioxide is extracted from underground reserves. Produced water and carbon dioxide are processed at the surface facility. Produced water is disposed of into an underground disposal well, and carbon dioxide is sold via pipeline. The cooling tower blowdown is discharged at the facility. This facility is classified as an NPDES Minor Source.

III.	EFFLUENT AND RECEIVING STREAM FLOW DATA

Outfall 001:  Cooling tower blowdown. This outfall has a maximum 30-day flow of 0.0152 MGD and discharges to an unnamed tributary (7Q10=0 MGD) of Hollybush Creek. 

Hollybush Creek is classified as “fish and wildlife” and is located in the Pearl River Basin. 

IV.	303(d) and TMDL ISSUES

Hollybush Creek is on the 2018 303(d) list of Waterbodies listed or biological impairment. The applicant is an existing source discharging cooling tower blowdown. It is not expected that this waste water will contribute to the impairment of the stream. The permit complies with the following applicable TMDLs:

Pollutant		Drainage Area	Basin	Waterbody ID	TMDL ID
Fecal Coliform		Segments of Pearl River, the 	Pearl River	Multiple	41449
Fecal Coliform		Strong River, Halls Creek, and	Pearl River 	Multiple	41449
Fecal Coliform		Pretty Branch	Pearl River		Multiple	41449
Sediment		Pearl River Basin	  	Pearl River	Multiple	36886
Nitrogen		Pearl River	Pearl River	Multiple	36885
Phosphorus		Pearl River	Pearl River	Multiple 	36885
DDT and Toxaphene		Pearl River Basin	Pearl River	Multiple	31700
Pollutant		Drainage Area	Basin	Waterbody ID	TMDL ID
Fecal Coliform		Pearl River Basin-Hancock Co.	Pearl River	Multiple	1495	
Low pH		Pearl River Basin-Neshoba, Leake Co.	Pearl River	Multiple	1607
Low pH		Pearl River Basin-Hinds and Rankin Co.	Pearl River	Multiple	1607
Low pH		Pearl River Basin-Hancock Co.	Pearl River	Multiple	1607
Fecal Coliform	  Pearl River, Segment 5 (Marion Co.)	Pearl River	MSLPRLRM5	1609
Fecal Coliform		Pearl River Basin -Hinds Co.	Pearl River	Multiple	  913

V.	TYPE OF WASTEWATER TREATMENT:

Evaporation.

VI.	EPA APPLICABLE CATEGORICAL GUIDELINES

Not applicable.

VII.	DATA FROM APPLICATION FORM (2C):

Parameter	1Max. 	2LTA	3# 						
BOD5, mg/L	6.0 	--	 1						
COD, mg/L	15.0 	--	 1						
TOC, mg/L	5.96	--	 1						
TSS, mg/L	3.0 	--	 1						
Ammonia, mg/L	0.101 	--	 1						
Flow, MGD	0.0166 	--	1						
Temperature (w), ºC	35.4	--	1						
Temperature (s), ºC	29.9	--	1						
pH, SU (max)	9.1	--	1						
Bromide, mg/L	0.100	--	1						
Iron, mg/L	0.246	--	1						
Zinc, mg/L	 0.15	--	1						

VIII. 	WATER QUALITY LIMITATIONS BASED ON WASTELOAD ALLOCATION 

	None.

IX.	CATEGORICAL GUIDELINE LIMITATIONS CALCULATIONS

Not Applicable

X.	TOXICITY SCREENING

Iron and Zinc are the only two applicable parameters, reported on the application, which can be evaluated in the toxicity screen. During the last five (5) years, the facility only discharge during one month. Therefore, due to the lack of discharge monitoring data, and because total recoverable iron and total recoverable zinc are already have numeric discharge limitations in the permit, a toxicity screen will not be performed on these parameters. 

XI.	PROPOSED FINAL LIMITATIONS 

1.	Average Permit Limitations   lb/day (mg/L)

Outfall	Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Monitoring Frequency	Sample Type	DMR Reporting Frequency	1Basis	
001	Flow (MGD)	--	--	Report 	Report	Weekly	Instantaneous Sampling	Monthly	TJ	
001	Bromide	--	--	Report (Report)	Report (Report)	Twice per month	24-hr Composite	Monthly	TJ	
001	Bromine	--	--	Report (Report)	Report (Report)	Twice per month	Grab Sampling	Monthly	TJ	
001	Iron, TR2	--	(1.0)	Report (1.0) 	Report (1.0) 	Twice per month	24-hr Composite	Monthly	NRWQC	
001	Zinc, TR2	--	(0.065)	Report (0.065)	Report (0.065)	Twice per month	24-hr Composite	Monthly	MSWQS	
001	BOD, 5-day	--	--	Report (Report)	Report (Report)	Twice per month	24-hr Composite	Monthly	TJ	
001	Ammonia Nitrogen, Total (as N)	--	--	Report (Report)	Report (Report)	Twice per month	24-hr Composite	Monthly	TJ	
001	TSS	--	--	Report (30)	Report (30)	Twice per month	24-hr Composite	Monthly	TJ	
001	Temperature (°F)	--	--	Report	Report	Twice per month	Grab Sampling	Monthly	TJ	
001	pH	--	6.0 SU	6.0 SU	6.0 SU	Twice per month	Grab Sampling	Monthly	MSWQS	

2.	Maximum Permit Limitations

Outfall	Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Monitoring Frequency	Sample Type	DMR Reporting Frequency	1Basis	
001	Flow (MGD)	--	--	Report 	Report	Weekly	Instantaneous Sampling	Monthly	TJ	
001	Bromide	--	--	Report (Report)	Report (Report)	Twice per month	24-hr Composite	Monthly	TJ	
001	Bromine	--	--	Report (Report)	Report (Report)	Twice per month	Grab Sampling	Monthly	TJ	

Outfall	Parameter	Categorical Limitation	Water Quality Limitation	Present Permit Limitation	Proposed Permit Limitation	Monitoring Frequency	Sample Type	DMR Reporting Frequency	1Basis	
001	Iron, TR2	--	--	Report (1.5) 	Report (1.5) 	Twice per month	24-hr Composite	Monthly	TJ	
001	Zinc, TR2	--	(0.065)	Report (0.065)	Report (0.065)	Twice per month	24-hr Composite	Monthly	MSWQS	
001	BOD, 5-day	--	--	Report (Report)	Report (Report)	Twice per month	24-hr Composite	Monthly	TJ	
001	Ammonia Nitrogen, Total (as N)	--	--	Report (Report)	Report (Report)	Twice per month	24-hr Composite	Monthly	TJ	
001	TSS	--	--	Report (45)	Report (45)	Twice per month	24-hr Composite	Monthly	TJ	
001	Temperature (°F)	--	--	90	90	Twice per month	Grab Sampling	Monthly	TJ	
001	pH	--	9.0 SU	9.0 SU	9.0 SU	Twice per month	Grab Sampling	Monthly	MSWQS	

1Basis: 11 Miss. Pt. 6, Ch.1 = 11 Miss. Admin Code Pt. 6, Ch.2, MSWQS = Mississippi Water Quality Standards, NRWQC = National Recommended Water Quality Criteria, TJ = Technical Judgement.
2TR =Total Recoverable

XII.	STATEMENT OF BASIS: 

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