PERMIT RATIONALE FOR REISSUANCE
US Army COE, Chickasaw Hill Recreation Area
Yalobusha County
Enid, Mississippi
Water NPDES No. MS0040703
November 2023

I.	CLASSIFICATION – NPDES Commercial
II.	DESCRIPTION OF WASTEWATER – Domestic
III.	DESCRIPTION OF WASTEWATER TREATMENT – Domestic wastewater is collected and treated via an activated sludge system followed by chlorine disinfection prior to discharge. Only one discharge to surface waters is described within the application with no increase in treated effluent flow proposed. 
IV.	RECEIVING WATERS – Enid Lake. The receiving waters are located in the Yazoo River drainage basin and are classified as Recreational. At the point of discharge, the receiving stream does not appear on the current State of Mississippi 303(d) List of Impaired Waterbodies. The discharge does appear on a completed Total Maximum Daily Load (TMDL) for Mercury in the Yocona River and Enid Reservoir (January 2003), however, the facility does not meet the 0.05 MGD discharge threshold for mercury monitoring specified in the TMDL.
V.	APPLICABLE GUIDELINES – 11 Mississippi Admin Code pt. 6, Commercial Facility Guidelines (Technology)

VI.	SUMMARY OF DISCHARGE LIMITATIONS – 
Parameter		Value				Basis
Flow			0.007 MGD		Design
BOD			30 mg/l 			Technology
TSS 			30 mg/l 			Technology
E. coli			126 Col./100mL 	Admin Code
pH			6.0 to 9.0 S.U.	Admin Code
Chlorine		0.1 to 1.0 mg/l	Admin Code

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