PERMIT RATIONALE FOR REISSUANCE
Hilldale Water District Inc, Hilldale Water Treatment Plant, South Plant
Warren County
Vicksburg, Mississippi
Water NPDES No. MS0052949
March 2018

I.	CLASSIFICATION – NPDES Industrial Minor

II.	DESCRIPTION OF WASTEWATER – Industrial

III.	DESCRIPTION OF WASTEWATER TREATMENT – Industrial wastewater is generated from the pressure filter backwash water, which is treated by sand bed filter to remove iron. The water from the sand filter enters HWD Lake, where mixing is allowed to occur, prior to discharge to surface waters. The facility was previously permitted to include wastewater generated by the Electrodialysis Reversal (EDR) SYSTEM, which has since been taken out of service and is no longer a part of the plant’s water treatment process. 

IV.	RECEIVING WATERS – An Unnamed Ditch thence into Hatcher bayou thence into Hennessey’s Bayou thence into the Mississippi River.  The receiving waters are located in the South Independent Streams Basin and are classified as Fish and Wildlife. At the point of discharge, the receiving stream does not appear on the most recent State of Mississippi 303(d) list of evaluated or impaired waterbodies on any completed Total Maximum Daily Loads (TMDLs). Only one discharge to surface waters is described in the application, with no increase in flow proposed.  

V.	APPLICABLE WATERS - 11 Mississippi Admin Code pt. 6, Commercial Facility Guidelines (Technology), State of Mississippi Water Quality Standards

VI.	SUMMARY OF LIMITATIONS - 

Parameters		Value		Basis
Flow				Report				Design
TSS				30 mg/l			Technology
pH				6.0 to 9.0 S.U.			MSWQS
	Iron 				1.0 mg/l	 		MSWQS
TDS				750 mg/l 	 		MSWQS
Chlorine		0.011 mg/l	 	MSWQS

VII.	CHANGES FROM PREVIOUS PERMIT – 

The specific conductance limitation has been removed from the permit due to the removal of the EDR system from the plant’s water treatment process.