PERMIT RATIONALE FOR REISSUANCE
Delta City Utility District
Sharkey County
Delta City, Mississippi
Water NPDES No. MS0038164
March 17, 2026

I.	CLASSIFICATION –Municipal NPDES Minor 

II.	DESCRIPTION OF WASTEWATER – Domestic / Municipal Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Wastewater is collected and treated by means of a conventional lagoon.  No increase in flow is proposed within the application.  

IV.	RECEIVING WATERS – Canal Number 12 thence into Big Sunflower River. The receiving waters are located within the Yazoo River Basin, and Canal Number 12 is classified as ephemeral.  The Sunflower River is listed on the current State of Mississippi 303(d) list of impaired waterbodies for pathogens. The effluent must comply with State criteria for pathogens (fecal coliform) before discharging into the receiving stream. The discharge is listed in a TMDL for organic enrichment / low do, nutrients, and sediment. The wasteload allocation in which the permit is based complies with the conditions of the TMDL.

At the point of discharge the 7Q10 for the receiving stream is 0.0 cfs.  The instream wastewater concentration at the point of discharge can be determined by the following calculation:

IWC = {(Qw)/(Qw + Qr)}*100

	Where, Qw = Design flow of the wastewater treatment facility, 0.025 MGD or 0.039 cfs
		 Qr = Receiving stream 7Q10, 0.0 cfs.

IWC = {(0.039 cfs)/(0.039 cfs + 0.0 cfs)}*100 = 100%

V.	APPLICABLE GUIDELINES – State of Mississippi Wastewater Regulations (11 MS admin code part 6),  State of Mississippi Water Quality Criteria (11 MS admin code part 6), Municipal Facility Guidelines (Technology), Wasteload Allocation (WLA), Total Maximum Daily Load (TMDL), Best Professional Judgment (BPJ), Federal Regulations (40 CFR)

VI.	SUMMARY OF LIMITATIONS –
Parameter				Flow					Basis
Flow					0.025 MGD				Design
BOD5					45 mg/l (Max Monthly Avg)		Previous Permit
BOD (Percent Removal)		65% Minimum				Technology
TSS					90 mg/l (Max Monthly Avg)		Technology
TSS (Percent Removal)			65% Minimum				40 CFR
E. coli					126 Col./100 ml			 	Admin code
Chlorine, Total Residual	 	0.011 mg/l / 0.019 mg/l		  	Admin code
pH					6.0 – 9.0 SU		              	Admin code
Total Nitrogen (lbs/day)			          Report				WLA
Total Phosphorus (lbs/day)	             Report				WLA

Limitations based on the Wasteload Allocation (WLA) are modeled for oxygen depletion in the receiving stream. The wasteload allocation limits are based on the Big Sunflower River, due to the ephemeral status of the Canal Number 12. The limitations for Cl2 are determined to meet acute and chronic toxicity.