PERMIT RATIONALE FOR REISSUANCE
Pearl River County Utility Authority, Round Rock Subdivision
Pearl River County
Picayune, Mississippi
Water NPDES No. MS0059510
May 2024

I.	FACILITY INFORMATION

Facility Name:  Pearl River County Utility Authority, Round Rock Subdivision
Facility Address:  412 Moeller Road 
Picayune, MS  39466    
Picayune, 
Permit No.:  MS0059510
SIC:  6552
Permit Writer:  Christiana Boren
EPD Branch:  Municipal and Private Facilities

II.	CLASSIFICATION – NPDES Commercial

III.	DESCRIPTION OF WASTEWATER – Domestic

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

V.	RECEIVING WATERS – Unnamed Creek thence into Blacksnake Creek. The receiving waters are located in the Pearl River drainage 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 Impaired Waterbodies, nor does the discharge appear on a completed Total Maximum Daily Load (TMDL).

The 7-day, 10-year minimum flow (7Q10) of the receiving stream is 0.15 cfs. The Instream Wastewater Concentration (IWC) at the point of the discharge is determined by the following calculation:

IWC = {(Qw)/(Qw + QR)} * 100 
	Where:
	Qw = Design flow of the wastewater treatment facility 0.138 MGD or 0.21 cfs.  
	QR = Receiving stream 7Q10, 0.15 cfs.

IWC = {(0.21 cfs)/(0.21 cfs + 0.15 cfs)} * 100 = 58.3 %

VI.	APPLICABLE GUIDELINES – 11 Mississippi Admin Code pt. 6, Commercial Facility Guidelines (Technology), Wasteload Allocation (WLA), State of Mississippi Water Quality Standards (MSWQS)

VII.	CHANGES FROM PREVIOUS PERMIT – None.

VIII.	SUMMARY OF DISCHARGE LIMITATIONS – 

	Parameter		Value			Basis
	Flow			0.138 MGD		Design
	BOD			10 mg/l 			WLA
	Ammonia		2 mg/l			WLA
	Dissolved Oxygen	6.0 mg/l minimum		WLA
	TSS 			30 mg/l 			Technology
	E. coli			126 Col./100mL 		MSWQS
	pH			6.0 to 9.0 S.U.		MSWQS
	Chlorine			0.019 mg/l		MSWQS, IWC