PERMIT RATIONALE FOR REISSUANCE
Belmont POTW, East
Tishomingo County
Belmont, Mississippi
Water NPDES No. MS0059692
July 2025

I.	CLASSIFICATION – NPDES Minor Municipal

II.	DESCRIPTION OF WASTEWATER – Municipal Wastewater

III.	DESCRIPTION OF WASTEWATER TREATMENT – Municipal wastewater is collected and treated by means of a conventional lagoon followed by chlorine disinfection. No increase in flow is proposed within the application.  

IV.	RECEIVING WATERS – Bear Creek.  The receiving water is located within the Tennessee River Basin and is classified as Fish and Wildlife.  Bear Creek is listed in the updated 2025 Section 303(d) List of Impaired Water Bodies for aquatic use life support due to pH. A Total Maximum Daily Load (TMDL) has not been developed for this water body. 

The 7-day, 10-year minimum flow (7Q10) of the receiving stream is 15.76 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 0.8 MGD or 1.24 cfs.  
            QR = Receiving stream 7Q10, 15.76 cfs.

IWC = {(1.24 cfs)/(15.76 cfs + 1.24 cfs)} * 100 = 7.29 %

V.	APPLICABLE GUIDELINES – 11 MS Admin Code Pt 6, Municipal Facility Guidelines (Technology), MS Water Quality Standards, Wasteload Allocation (WLA)

VI.	CHANGES FROM PREVIOUS PERMIT – 2025 Waste load allocation provided new ammonia limit of 1.45 mg/L leading to a new phase rationale. The following conditions are added to the permit:

The permittee shall achieve compliance with the effluent limitations specified for discharge in accordance with the following schedule:
Upon issuance of this permit, the permittee shall achieve compliance with the effluent limitations specified for the parameters without a phase designation and 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 without a phase designation and for the parameters noted as Phase II; Phase I limitations shall no longer apply at this time. Phase II limitations shall apply as soon as the treatment system has demonstrated compliance with the Phase II limitations, but no longer than three (3) years after the issuance of the permit.
The permittee shall notify our office orally at least 24 hours prior to start-up and in writing no later than 48 hours after start-up. [11 Miss. Admin. Code Pt. 6, R. 1.1.4.A(9).]

VII.	SUMMARY OF LIMITATIONS –

Parameter			Value				Basis
(Phase 1) Ammonia                2.87 mg/L			WLA
(Phase 2) Ammonia	            1.45 mg/L			WLA
Chlorine, Total Residual	0.013 mg/L			WLA/MS WQS 
E. coli				126 (#Col/100mL)		MS WQS 
Flow				0.80 MGD			Design
BOD5				30 mg/L			WLA/MS WQS
Oxygen, Dissolved		6.0 mg/L, Minimum		WLA
TSS				90 mg/L			Technology
pH				6.0 – 9.0 SU			MS WQS