PERMIT RATIONALE FOR REISSUANCE
Shady Grove Utility District, Hoy and Green Acres Subdivision
Jones County
Laurel, Mississippi
Water NPDES No. MS0029599
July 2017

I.	CLASSIFICATION – NPDES Commercial 

II.	DESCRIPTION OF WASTEWATER – Domestic 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 within the application with no increase in treated effluent flow proposed.  

IV.	RECEIVING STREAM – Brushy Branch.  The receiving waters are located within the Pascagoula 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 or on any completed Total Maximum Daily Loads (TMDLs). Only one discharge to surface waters is described within the application with no increase in treated effluent flow proposed.  

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

VI.	SUMMARY OF LIMITATIONS – 
	Parameter			Value				Basis
	Flow				0.07 MGD			Design 
	BOD5				30 mg/l 			WLA
	TSS				60 mg/l 			Technology
	E. coli				126 Col./100 ml		Admin Code
pH				 6.0 – 9.0 SU			Admin Code
	Chlorine, total residual -
            	          Phase I		0.1 – 1.0 mg/l			Admin Code
		          Phase II		0.023 mg/l			WLA
	Dissolved Oxygen -	  
		       Phase I	            Report minimum mg/l		WLA
		       Phase II	  	   ≥6.0 mg/l			WLA	
	Ammonia Nitrogen -		   
		       Phase I		   Report mg/l			WLA
		       Phase II	   	   4 mg/l			WLA	

VII.	CHANGES FROM PREVIOUS PERMIT – 

E. coli has replaced fecal coliform as the bacterial indicator for all freshwaters in MS designated as Recreation, Fish and Wildlife Support, and/or Public Water supply. 

The draft permit contains phase limits for total residual Chlorine, listed in the table above.

The draft permit contains phase limits for minimum Dissolved Oxygen, listed in the table above.

The draft permit contains phase limits for Ammonia Nitrogen, listed in the table above.	

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 improvements needed to comply with Phase II limitations or three (3) years after the issuance of the permit, whichever comes first, 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.