PERMIT RATIONALE FOR ISSUANCE
Gulf to Sea Inc
Harrison County
Biloxi, Mississippi
Water NPDES No. MS0062961
May 27, 2026

I.	FACILITY INFORMATION

Facility Name: Gulf to Sea Inc
Facility Address: 364 Bayview Ave 
Biloxi, MS  39530    
Biloxi, 
Permit No.: MS0062961
SIC: 2092
Permit Writer: Tracy Tomkins
EPD Branch: Water I Branch

II.	NATURE OF BUSINESS

	Shrimp processing and packaging

III.	EFFLUENT AND RECEIVING STREAM FLOW DATA

The facility proposes to discharge approximately 0.034 MGD of process wastewater into the Back Bay of Biloxi.

IV.	303(d) and TMDL ISSUES

	Back Bay of Biloxi has a TMDL for pathogens.
  
V.	TYPE OF WASTEWATER TREATMENT:

Screening

VI.	EPA APPLICABLE CATEGORICAL GUIDELINES

40 CFR 408 Subpart L – Southern Non-Breaded Shrimp Processing in the Contiguous States Subcategory (408.125 NSPS).  Gulf to Sea proposes to process 15,000 pounds per day.

VII.	DATA FROM APPLICATION FORM 2C

Parameter	Maximum Daily Value	
BOD5	973.9 mg/L	
TSS	149.23 mg/L	
NH3-N	3.93 mg/L	
Flow	0.014 MGD	
pH	8.57 S.U. (min) – 8.69 (max) S.U.	
Oil & Grease	5.52 mg/L	

VIII. 	WATER QUALITY LIMITATIONS BASED ON WASTELOAD ALLOCATION 

Parameter	Maximum	
CBOD5 /BOD5	945 lbs/day	
NH3-N	3.93 mg/L	
Minimum Dissolved Oxygen	6 mg/L	
pH	6.0 S.U. (min) – 9.0 S.U. (max)	
Flow	Varies	
Total Nitrogen	Report, lbs/day	
Total Phosphorus	Report, lbs/day	

IX.	CATEGORICAL GUIDELINE LIMITATIONS CALCULATIONS

Subpart L - Southern Non-Breaded Shrimp Processing in the Contiguous States Subcategory: (Shrimp 15,000 pounds live weight) 408.125 - NSPS

a.	Average Limitations:

Production
Parameter		Limitation		Rate			lbs/day
BOD5			25		x	15		=	375
TSS			10		x	15		=	150
Oil & Grease		1.6		x 	15		=	24
pH			6.0 S.U. (Min)

b.	Maximum Limitations:

Production
Parameter		Limitation		Rate			lbs/day
BOD5			63		x	15		=	945	
TSS			25		x	15		=	375
Oil & Grease		4.0		x 	15		=	60
pH			9.0 S.U. (Max)

X.	TOXICITY SCREENING

Not applicable.

XI.	PROPOSED FINAL LIMITATIONS 

1.	Average Permit Limitations: lbs/day (mg/L)
Parameter	Categorical Limitation	Water Quality Limitation	Proposed Permit Limitation	Basis	
BOD5	375 lbs/day	375 lbs/day	375 (3,211)	Categorical	
TSS	150 lbs/day	N/A	150 (1,284)	Categorical	
Oil & Grease	24 lbs/day	N/A	24 (205)	Categorical	
NH3-N	N/A	0.31 lbs/day	0.31 (2.63)	WLA	
D.O. (min.)	N/A	6.0 mg/L	6.0 mg/L	WLA	
pH (min.)	6.0 S.U.	6.0 S.U.	6.0 S.U.	Categorical	
Total Nitrogen	N/A	Report mg/L	Report mg/L	WLA	
Total Phosphorus	N/A	Report mg/L	Report mg/L	WLA	
Production	N/A	N/A	Report lbs/day	1/	

2.	Maximum Permit Limitations lbs/day (mg/L)
Parameter	Categorical Limitation	Water Quality Limitation	Proposed Permit Limitation	Basis	
BOD5	945 lbs/day	945 lbs/day	945 (8,093)	Categorical	
TSS	35 lbs/day	N/A	375 (3,211)	Categorical	
Oil & Grease	60 lbs/day	N/A	60 (513)	Categorical	
NH3-N	N/A	N/A	0.5(3.93)	WLA	
pH	9.0 S.U.	9.0 S.U.	9.0 S.U.	Categorical	
Total Nitrogen	N/A	Report mg/L	Report mg/L	WLA	
Total Phosphorus	N/A	Report mg/L	Report mg/L	WLA	
Production	N/A	N/A	Report lbs/day	1/	

TSS, BOD5 and Ammonia (as N) shall be monitored twice per month utilizing a 24-hour composite sample.  Composite samples shall be timed and/or flow proportioned throughout the production day. Oil & Grease, D.O., and pH shall be monitored twice per month with a grab sample of the effluent.   Flow shall be measured daily instantaneously.  

1/ Production will be measured daily and reported because the federal effluent guideline (ELG) is production based.

The concentration (mg/L) limitations were calculated using the flow of 0.014 MGD provided in the application. 

The Discharge Monitoring Reports are to be submitted monthly because the federal regulations    require monthly average limitations.

XII.	NSPS TATEMENT

It is our judgment that the foregoing limitations represent NSPS. New Source Performance Standards (NSPS) are being applied to the facility because of the reconstruction of the building.