PERMIT RATIONALE FOR REISSUANCE
Silver City POTW
Humphreys County
Silver City, Mississippi
Water NPDES No. MS0044709
May 15, 2026

I.	CLASSIFICATION – Municipal Minor

II.	DESCRIPTION OF WASTEWATER – Domestic wastewater is generated from the Town of Silver City. 

III.	DESCRIPTION OF WASTEWATER TREATMENT – Wastewater is treated biologically by means of a conventional lagoon followed by disinfection by chlorination prior to discharge. The current design capacity of the facility is 0.06 MGD. 

IV.	RECEIVING WATERS – Yazoo River. At the point of discharge the receiving stream does not appear on the current State of Mississippi 303(d) List of Impaired Waterbodies. The facility is noted in three TMDL’s. The Delta Large Rivers Nutrient TMDL contains nutrient limitations that have been included in this draft permit. There is also a TMDL for the Big Sunflower River for organic enrichment, nutrients, and sediment; this TMDL does not recommend any more stringent limits for this facility. This facility is also included in a TMDL for pathogens. The facility disinfects, which complies with the TMDL. The receiving stream is located in the Yazoo River drainage basin and is classified as Fish & Wildlife. 

V.	APPLICABLE GUIDELINES – 11 MS admin code part 6

VI.	SUMMARY OF DISCHARGE LIMITATIONS – 
Parameter			Value			Basis
Flow				0.06 MGD			Design
BOD5				45 mg/l (Monthly Average)		WLA
TSS				90 mg/l (Monthly Average)		Technology
E. Coli				126 Col./100mL			MSWQS
Chlorine, T.R.			0.011 mg/l			MSWQS
Dissolved Oxygen		6.0 mg/l			WLA
pH				6.0 – 9.0 SU			MSWQS
Total Nitrogen			5.8 lbs/day			TMDL
Total Phosphorus		2.8 lbs/day			TMDL
TSS, % Removal		65%				MSWQS
BOD5, % Removal		65%				MSWQS