PERMIT RATIONALE FOR REISSUANCE
Newton POTW
Newton County
Newton, Mississippi
Water NPDES No. MS0036323
November 2023

I.	CLASSIFICATION – Municipal Minor 

II.	DESCRIPTION OF WASTEWATER – Municipal/ Domestic Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Wastewater is collected and treated biologically by means of a multi-celled lagoon followed by a trickling filter. No increase in flow is proposed within the application.

IV.	RECEIVING WATER – Richardson Mill Creek. The receiving water is located within the Pascagoula River Basin, and is classified as Fish and Wildlife.  Richardson Mill Creek does not appear on the updated State of Mississippi 303(d) list of impaired waterbodies. The facility is listed in a TMDL for Pathogens. Limitations for Fecal Coliform are included in the permit in order to comply with the conditions of the TMDL. The facility is also listed in a TMDL for Organic Enrichment and Ammonia Toxicity in Richardson Mill Creek. The limitations included in the permit comply with the load requirements given in the TMDL. 

The instream wastewater concentration 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, 1.19 cfs.
	Qr = Receiving stream 7Q10, 0.8 cfs.

IWC = {(1.19 cfs) / (1.19 cfs + 0.8 cfs)}*100 = 60 %

V.	APPLICABLE GUIDELINES – 11 MS Admin Code pt. 6, Municipal Facility Guidelines (Technology), Wasteload Allocation (WLA), Total Maximum Daily Load (TMDL)

VI.	SUMMARY OF LIMITATIONS –
	Parameter					Value					Basis
	Flow					0.77  MGD				Design
	CBOD5 						     
		May – Oct				8 mg/l (Max Monthly Avg.)			TMDL
		Nov – Apr				12 mg/l (Max Monthly Avg.)			TMDL		
	CBOD5 (Percent Removal)		85% Minimum				Technology
	TSS					30 mg/l (Max Monthly Avg.)			Technology
	TSS (Percent Removal)			85% Minimum				Technology
	NH3-N					2 mg/l (Max Monthly Avg.)			TMDL
	Dissolved Oxygen				6.0 mg/l (Minimum)				WLA
	E. Coli    				   126 #col/100ml (Max Monthly Avg.)		TMDL	
	pH					6.0 – 9.0 SU				MSWQC
	Chlorine, Total Residual		0.018 / 0.031 mg/l				MSWQC, IWC
	Total Phosphorus				Report mg/L				WLA
	Total Nitrogen					Report mg/L				WLA