PERMIT RATIONALE FOR MODIFICATION
Mississippi Department of Corrections, Quitman County Residential Treatment Facility
Quitman County
Lambert, Mississippi
Water NPDES No. MS0043281
May 2024

I.	CLASSIFICATION – NPDES Commercial

II.	DESCRIPTION OF WASTEWATER – Domestic 

III.	PURPOSE OF MODIFICATION—

The current treatment system collects domestic wastewater and treats it through a septic tank/rock reed system followed by chlorine disinfection prior to discharge. The system has a design flow 0.001 MGD and discharges to an Ephemeral Stream thence Muddy Bayou. The Antidegradation Report submitted by the permittee provided an evaluation of the facility’s existing sewer flow. With an inmate count of ~ 100 and a staff of ~ 15, the average sewer flow and peak hourly flow were calculated to be 0.0057 and 0.0085 MGD, respectively. Based on these numbers, it is apparent that the existing WWTP is undersized to meet current demands. A new WWTF is proposed, which involves constructing a duplex pump station/ force main to collect and direct the QCCWC raw sewage to the new treatment system which would consist of a two-cell (primary aerated lagoon followed by a lined, covered tertiary lagoon) followed by a chlorine contact chamber/de-chlorination basin/post-aeration process. The effluent flow would then be measured prior to gravity discharge to a rip rapped outfall directly into the Muddy Bayou. The design flow of the new WWTF will be 0.009 MGD to accommodate the estimated flow.

IV.	RECEIVING WATERS – Ephemeral Stream thence into Muddy Bayou. The receiving water is in the Yazoo River drainage basin and is classified as Fish and Wildlife.  At the point of discharge, the receiving water does not appear on the current State of Mississippi 303(d) List of Impaired Waterbodies. The discharge is denoted on the 2008 Nutrient TMDL for Opposum Bayou, which the facility complies with via monitoring for Total Nitrogen and Total Phospohorus.

V.	APPLICABLE GUIDELINES – 11 Mississippi Admin Code pt. 6, Commercial Facility Guidelines (Technology), 2024 Wasteload Allocation (WLA), TMDL

VI.	SUMMARY OF LIMITATIONS – 

Parameter				Value				Basis
Flow	(Phase I)			0.001 MGD			Design
Flow	(Phase II)			0.009 MGD			Design
BOD5					30 mg/l 			Technology
Ammonia Nitrogen			Report mg/l			WLA
TSS					30 mg/l 			Technology
E. coli					126 Col./100mL 		Admin Code
pH					6.0 to 9.0 S.U.			Admin Code
Chlorine				0.011 mg/l			WLA
Dissolved Oxygen			6.0 minimum mg/l		WLA
Nitrogen, Total			Report lbs/day			WLA
Phosphorus, Total			Report lbs/day			WLA

VII.	CHANGES TO PREVIOUS PERMIT – 

The following language has been added to the permit:

"The permittee shall achieve compliance with the effluent limitations specified for discharge in accordance with the following schedule:   Upon issuance of this permit, the permittee shall achieve compliance with the effluent limitations specified for the parameters noted as Phase I; Phase II limitations shall not apply at this time. 

Beginning upon completion and start-up of the new wastewater treatment facility,  the permittee shall achieve compliance with the effluent limitations specified for the parameters noted as Phase II; Phase I limitations shall not apply at this time. The permittee shall notify our office orally at least 48 hours prior to start-up and in writing no later than 5 days after start-up.  
Effluent limits have been developed such that the waste treatment system should protect water quality.”

Total Nitrogen and Total Phosphorus have been updated to “Report Only” to comply with the Opposum Bayou TMDL for Nutrients.