PERMIT RATIONALE FOR REISSUANCE
Glen Allan Utility District
Washington County
Glen Allan,, Mississippi
Water NPDES No. MS0047601
March 30,2026

I.	CLASSIFICATION –Municipal NPDES Minor 

II.	DESCRIPTION OF WASTEWATER – Municipal Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Municipal wastewater is collected and treated by means of a conventional lagoon followed by a rock reed filter.  No increase in flow is proposed within the application.  

IV.	RECEIVING WATERS – Unnamed Tributary of Steele Bayou.  The receiving waters are located within the Yazoo River Basin and are classified as Fish and Wildlife.  Steele Bayou does not appear on the current State of Mississippi 303(d) list of evaluated or impaired waterbodies, but it currently appears on updated State of Mississippi 303(d) list as an impaired waterbody without monitoring data. 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, 0.1 MGD or 0.155 cfs
		 Qr = Receiving stream 7Q10, 0.0 cfs.

IWC = {(0.155 cfs)/(0.155 cfs + 0.0 cfs)}*100 = 100 %

V.	APPLICABLE GUIDELINES – 11 MS Admin Code pt. 6, 2019 Wasteload Allocation, Municipal Guidelines

VI.	SUMMARY OF LIMITATIONS –
Parameter			Flow				Basis
Flow				0.1 MGD			Design
BOD5				15 mg/l 			Modeled
NH3-N				4.0 mg/l			TMDL
BOD (Percent Removal)		85% Minimum			Technology
Minimum DO			6 mg/l				Modeled
TSS				30 mg/l 			Technology
TSS (Percent Removal)		85% Minimum			Technology
E Coli				126 Col./100 ml			Admin Code
Chlorine, Total Residual		0.011 mg/l / 0.019 mg/l		Admin Code, IWC
pH				6.0 – 9.0 SU			Admin Code