PERMIT RATIONALE FOR REISSUANCE
Abbeville POTW
Lafayette County
Abbeville, Mississippi
Water NPDES No. MS0061671
September 2022

I.	CLASSIFICATION – NPDES Minor Municipal 

II.	DESCRIPTION OF WASTEWATER – Municipal/Domestic Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Wastewater is collected and treated by means of an Aerated Treatment Unit (ATU) followed by chlorine disinfection prior to discharge. Only one discharge to surface water is described in the application.

IV.	RECEIVING WATER – Unnamed tributary of Sardis Lake. The receiving water is located in the Yazoo River Basin and is classified as Fish and Wildlife.  The receiving water does not appear on the current State of Mississippi 303(d) list of evaluated or impaired waterbodies nor does the discharge appear on a completed Total Maximum Daily Load (TMDL).

The 7-day, 10-year minimum flow (7Q10) of the receiving stream is 0.0 cubic feet per second (cfs). The Instream Wastewater Concentration (IWC) at the point of the discharge is 100%, due to the receiving stream having a 7Q10 of 0.0 cfs.

V.	APPLICABLE GUIDELINES – 11 Mississippi Admin Code pt. 6, Municipal Facility Guidelines (Technology), Wasteload Allocation (WLA)

VI.	SUMMARY OF LIMITATIONS – 
Parameter				Value			Basis
Flow				0.004999 MGD		Design
BOD5				30 mg/l			WLA
Ammonia Nitrogen			1.37 mg/l			WLA
TSS				30 mg/l			Technology
E. coli				126 Col./100ml		Admin Code
Chlorine, Total Residual		0.011 mg/l			Admin Code
pH				6.0 – 9.0 S.U		Admin Code
Total Nitrogen				Report lbs./day		WLA
Total Phosphorus 			Report lbs./day		WLA
	
VII.	CHANGES FROM PREVIOUS PERMIT – 

Ammonia Nitrogen limits of 1.37 mg/l have been added to the draft permit based on the State of Mississippi Water Quality Standard for Ammonia toxicity. The plant has yet to commence discharge, and the limit will be effective upon permit issuance.