PERMIT RATIONALE FOR MODIFICATION
Gloster POTW
Amite County
Gloster, Mississippi
Water NPDES No. MS0020818
May 2024

I.	FACILITY INFORMATION
Facility Name:  Gloster POTW
Facility Address:  1070 East Pearl Street 
 Gloster, MS  39638    Glo
Permit No.:  MS0020818
SIC:  4952
Permit Writer:  Christiana Boren
EPD Branch:  Municipal and Private Facilities
 
II.	PURPOSE FOR MODIFICATION-
Gloster POTW sent a formal letter requesting the Office to modify its current permit. An antidegradation was submitted with the letter, mentioning the facility’s incapability to comply with the limitations for the existing outfall. The antidegradation report was approved. The facility will install a new lift station and force main to relocate the outfall to Beaver Creek. The permit was reopened to include limitations for the new outfall under construction. 

III.	CLASSIFICATION – NPDES Municipal Minor

IV.	DESCRIPTION OF WASTEWATER – Domestic

V.	DESCRIPTION OF WASTEWATER TREATMENT – Domestic wastewater is collected and treated via an aerated lagoon followed by chlorine disinfection prior to discharge. Only one discharge to surface waters is described within the application with an increase in treated effluent flow proposed. pH adjustments, flow equalization, DO system, and aerators are needed to treat the excess wastewater. 

 OUTFALL 001 (existing outfall)

VI.	RECEIVING WATERS – Unnamed tributary thence Beaver Creek. The receiving waters are located in the South Independent Streams drainage basin and are classified as Fish and Wildlife. At the point of discharge, the receiving stream does 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).

At the point of discharge, the 7Q10 for the receiving stream is 0.08 cfs.  The instream wastewater concentration at the point of discharge can be determined by the following calculation:
IWC = {(Qw)/(Qw + Qr)}*100

	Where, Qw = Design flow of the wastewater treatment facility, 0.19 MGD or 0.29 cfs
		 Qr = Receiving stream 7Q10, 0.08 cfs.
IWC = {(0.29 cfs)/(0.29 cfs + 0.08 cfs)}*100 = 78 %

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

VIII.	SUMMARY OF DISCHARGE LIMITATIONS – 

Parameter		Value				Basis
Flow			0.19 MGD		Design
BOD			25 mg/l 			WLA
NH3-N			2 mg/l				WLA
Dissolved Oxygen	≥ 6.0 mg/l		WLA
TSS 			45 mg/l 			Technology
E. coli			126 Col./100mL 	MSWQS
pH			6.0 to 9.0 S.U.	MSWQS
Chlorine		0.014 mg/l		MSWQS, IWC
Total Nitrogen		Report lbs/day	WLA
Total Phosphorus	Report lbs/day	WLA

OUTFALL 002 (new outfall)

IX.	RECEIVING WATERS –Beaver Creek. The receiving waters are located in the South Independent Streams drainage basin and are classified as Fish and Wildlife. At the point of discharge, the receiving stream does 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).

At the point of discharge, the 7Q10 for the receiving stream is 1.67 cfs.  The instream wastewater concentration at the point of discharge can be determined by the following calculation:
IWC = {(Qw)/(Qw + Qr)}*100

	Where, Qw = Design flow of the wastewater treatment facility, 0.3 MGD or 0.46 cfs
		 Qr = Receiving stream 7Q10, 1.67 cfs.

IWC = {(0.46 cfs)/(0.46 cfs + 1.67 cfs)}*100 = 22 %

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

XI.	SUMMARY OF DISCHARGE LIMITATIONS – 

Parameter		Value				Basis
Flow			0.3 MGD		Design
BOD			21 mg/l 			WLA
NH3-N			2 mg/l				WLA
Dissolved Oxygen	≥ 6.0 mg/l		WLA
TSS 			45 mg/l 			Technology
E. coli			126 Col./100mL 	MSWQS
pH			6.0 to 9.0 S.U.	MSWQS
Chlorine		0.051 mg/l		MSWQS, IWC
Total Nitrogen		Report lbs/day	WLA
Total Phosphorus	Report lbs/day	WLA

CHANGES FROM PREVIOUS PERMIT – Outfall 002 permit limitations and receiving stream have been added to the proposed draft permit. Outfall 001 permit limitations will be removed upon completion of Outfall 002.

Facility will comply with Condition T-62 of the permit:

“The permittee shall achieve compliance with the effluent limitations specified for discharge in accordance with the following schedule: Upon Permit Issuance. The permittee shall comply with limitations designated as Outfall 001 until existing outfall is decommissioned. After Outfall 001 is decommissioned, permittee shall comply with limitations designated as Outfall 002.”