Customer: Town of Hinesburg
Location: Hinesburg, Vermont, USA
Capacity: 350,000 USGPD (1326 m3/d), expandable to 700,000 USGPD (2,652 m3/d)
Description: 1X 350,000 USGPD Nanofiltration system, expandable to two systems. Includes well intake, bag filters, cartridge filters, chemical dosing and product pump systems.
Commissioning Date: May 20th, 2016
ISI Water was contracted to build a nanofiltration system for the town of Hinesburg to remove excess hardness from the groundwater. The original intent was for a conventional water softening system to be installed but ISI Water was able to convince the town to use nanofiltration. This is the first plant in the Northeast United States to use nanofiltration for municipal water supply.
The Nanofiltration System
The water from the wells in Hinesburg was measured at 422 mg/l as CaCO3. The target hardness for the final product is 125 mg/l, so nanofiltration is used to treat part of the well water stream, and the rest bypasses the nanofiltration system and blends together with the nanofiltration permeate to form 125 mg/l as a blended product.
The skid itself features a 316SS bag filter by Fil-Trek, a 316SS cartridge filter by Fil-Trek, a Grundfos vertical multistage centrifugal high pressure pump, 7 Protec 300 psi pressure vessels (4 into 2 into 1), and Dow Filmtec nanofiltration membrane elements. The whole plant is fully automated with OPTO22 control hardware and software and UL listed control cabinets designed and programmed by ISI Water engineers.