PERMIT RATIONALE FOR REISSUANCE
Ellisville POTW, North
Jones County
Ellisville, Mississippi
Water NPDES No. MS0026018
February 2017

I.	CLASSIFICATION – NPDES Minor Municipal

II.	DESCRIPTION OF WASTEWATER – Domestic/Municipal Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Domestic wastewater is collected and treated biologically by means of an aerated lagoon followed by chlorine disinfection prior to discharge.  Only one discharge to surface waters is described in the application with no increase in treated effluent flow proposed.

IV.	RECEIVING WATERS – Tallahoma Creek thence into Tallahala Creek.  The receiving stream is located within the Pascagoula River Basin and is classified as Fish and Wildlife.  At the point of discharge, the receiving stream appears on the most recent State of Mississippi 303(d) list of evaluated or impaired waterbodies.  Specifically, waterbody ID 412911 is listed for biological impairment from the confluence with Horse Creek to the confluence with Tallahala Creek.  The discharge also appears on a completed Total Maximum Daily Load (TMDL) for fecal coliform (1999).  The facility utilizes chlorine disinfection, which complies with the conditions of the TMDL.  At the point of discharge, the 7Q10 of the receiving stream is 3.61 cfs.  The instream wastewater concentration (IWC) at the point of discharge is determined by the following calculation:

IWC = {(QW)/(QW + QR)} * 100
Where:
	QW = Design flow of the wastewater treatment facility 0.29 MGD or 0.45 cfs.
	QR = Receiving stream 7Q10, 3.61 cfs

IWC = {(0.45 cfs)/(0.45 cfs + 3.61 cfs)} * 100 = 11.1 %

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

VI.	SUMMARY OF LIMITATIONS –
	Parameters							 Value			Basis
Flow					0.29 MGD			Design
BOD5 (PHASE I)			45 mg/L			WLA
BOD5 (PHASE II)			20 mg/L			WLA
Ammonia Nitrogen (as N) PHASE I	Report mg/L                                WLA
Ammonia Nitrogen (as N) PHASE II	10 mg/L			WLA
TSS					90 mg/L			Technology
Dissolved Oxygen			6.0 mg/L minimum		Admin Code
E. coli   				126 Col./100 mL		Admin Code
Chlorine, Total Residual			0.1 mg/L 			WLA
pH					6.0 – 9.0 SU			Admin Code
Nitrogen (Total)				Report lbs/day			WLA
Phosphorus (Total)			Report lbs/day			WLA

VII.	CHANGES FROM PREVIOUS PERMIT – 

1.	E. coli standards have been adopted in place of fecal coliform standards.

2.	The Ammonia Nitrogen limits listed above will be phased in on a 5-year schedule in accordance with Condition T-15 of the permit.  Ammonia Nitrogen influent loading and concentration will also be reported. 

3.	The existing BOD5 limit of 45 mg/L will be reduced to 20 mg/L on a 5-year schedule in accordance with Condition T-15 of the permit.