PERMIT RATIONALE FOR REISSUANCE
Maben POTW
Webster County
Maben, Mississippi
Water NPDES No. MS0020966
May 23, 2022

I.	CLASSIFICATION – Municipal NPDES Minor

II.	DESCRIPTION OF WASTEWATER – Domestic Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Domestic wastewater is collected and treated by means of a two cell lagoon followed by sand filtration beds and cascade aeration.  No increase in flow is proposed within the application.  

IV.	RECEIVING WATERS – Unnamed stream thence Pigeon Roost.  The receiving waters are located within the Big Black River Basin and are classified as Fish and Wildlife.  At the point of discharge the receiving stream does not appear on the current State of Mississippi 303(d) list of evaluated or impaired waterbodies.  The 7Q10 of the receiving stream, at the point of discharge, is 0.0 cfs.  Only one discharge to surface waters is described within the application with no increase in flow proposed.  

V.	APPLICABLE GUIDELINES – 11 MS admin code part 6 

VI.	SUMMARY OF LIMITATIONS – 
	Parameters				Value		Basis
	Flow				0.141 MGD		Design
	BOD5				10 mg/l 		Model
	TSS				30 mg/l 		Technology Based
	Dissolved Oxygen			> 6.0 mg/l 		MSWQS
	E. Coli				126 Col./100 ml		MSWQS
	Chlorine, Total Residual 	0.011 mg/l 		MSWQS
	pH				6.0 – 9.0 SU		MSWQS
	Ammonia (Phase I)			2.0 mg/l		Model
	Ammonia (Phase II)			1.37 mg/l		WLA
	Total Nitrogen 			Report (lbs/day)		WLA
	Total Phosphorus			Report (lbs/day)		WLA

II.	CHANGES FROM PREVIOUS PERMIT – 

The proposed draft permit contains Phase I and Phase II Ammonia Nitrogen effluent requirements.  The Phase I requirements are Ammonia Nitrogen limitations same as the previous permit.  The Phase II requirement reflects limitations proposed in the Nutrient TMDL for this permit. 

Upon issuance of this permit, the permittee shall achieve compliance with the effluent limitations specified for the parameters noted as Phase I.  Beginning upon the completions and start-up of the improvements needed to comply with Phase II limitations, but no longer than the expiration date of the permit, the permittee shall achieve compliance with the effluent limitations specified for the parameter noted as Phase II.

The permittee shall submit an engineering report that describes how the facility will come into compliance with the Phase II limitations.