PERMIT RATIONALE FOR REISSUANCE
Western Line School District, Riverside High School
Washington County
Avon, Mississippi
Water NPDES No. MS0051527
November 2023

I.	CLASSIFICATION – Domestic NPDES

II.	DESCRIPTION OF WASTEWATER – Minor Domestic

III.	DESCRIPTION OF WASTEWATER TREATMENT – Domestic wastewater is collected and treated via an activated sludge system. 

IV.	RECEIVING WATERS – Unnamed Creek thence into Black Bayou. Black Bayou does not appear on the current State of Mississippi 303(d) List of Impaired Waterbodies. The facility is included in a completed TMDL for Organic Enrichment and Nutrients. The TMDL does not require a loading reduction for this facility. This waterbody is in the Yazoo River drainage basin, and is classified as Fish & Wildlife. One discharge to surface waters is described within the application with no increase in proposed flow. The discharge from this facility should not further impair water quality. 

V.	APPLICABLE GUIDELINES – 11 MS Admin Code pt. 6, Commercial Facility Guidelines

VI.	SUMMARY OF DISCHARGE LIMITATIONS – 
Parameter		Value					Basis
Flow			0.05 MGD				Design
BOD			30 mg/l (Monthly Average)		Domestic Guidelines
TSS			30 mg/l (Monthly Average)		Domestic Guidelines
E Coli			126 Col./100mL(Monthly Average)	Domestic Guidelines
Effluent pH		6.0 to 9.0 S.U.				MS WQS
Chlorine		0.1 to 1.0 mg/l				MS WQS

The minimum and maximum values for Influent ph, Dissolved Oxygen in aeration unit, and 30-Minute Sludge Settleability in aeration unit must be reported