PERMIT RATIONALE FOR REISSUANCE
Moss Point Reverse Osmosis Water Plant
Jackson County
Moss Point,, Mississippi
Water NPDES No. MS0060305
3/3/2026

I.	CLASSIFICATION – Industrial NPDES

II.	DESCRIPTION OF WASTEWATER – Minor Industrial

III.	DESCRIPTION OF WASTEWATER TREATMENT – Reject water from a Reverse Osmosis Water Treatment Plant will be discharged into the receiving waters. As part of the Reverse Osmosis process a pressure gradient must be established over the filter system. Due to this process 20%, on average, of the influent water is rejected from the filter. This facility will have an influent flow of 2.5 MGD, producing, on average, 2 MGD of drinking water to the distribution system, and 0.5 MGD of reject water to discharge to the receiving waters. The backwash water used to clean the filter system will be discharged to the sewer system.

IV.	RECEIVING WATERS – Ditch to an Unnamed Tributary of the Escatawpa River. The receiving waters do not appear on the current 303(d) List of Impaired Waterbodies. The permit will not add to or contribute to any listed TMDL on the Escatawpa River.  These waterbodies are in the Pascagoula River drainage basin, and are classified as Fish and Wildlife. 

V.	APPLICABLE GUIDELINES – State of Mississippi Wastewater Regulations (11 MS admin code part 6),  State of Mississippi Water Quality Criteria (11 MS admin code part 6), Industrial Facility Guidelines, Best Professional Judgment (BPJ)

VI.	SUMMARY OF DISCHARGE LIMITATIONS – 

Parameter		Value					Basis
Flow			Report					BPJ
TSS			30 mg/l (Monthly Average)		BPJ
TDS			Report					BPJ
pH			6.0 – 9.0 SU				WPC-2