Projects

During the process of evaluating alternatives to increase water supply capacity and replace aging treatment equipment at Well #2, the Village received violation notices regarding MCL exceedances of Gross Alpha particulate activity in Well #1 and levels approaching MCL at Well #2. Analysis revealed a high percentage of Uranium 235, suggesting the need for a high removal rate of the Ur 235 isotope. Pilot testing of Reverse Osmosis (RO) Membrane Treatment not only verified the efficacy of Uranium removal as the basis for bringing the Village’s water system into compliance but also verified its ability to provide Radium removal and hardness reduction. Testing also confirmed that there would be no need for either iron or manganese pretreatment if unoxidized iron was delivered to the membranes.

Rather than construct RO treatment systems at both well sites, which are located on opposite sides of the Wolf River, the Well #1 supply was connected to the treatment system at the Well #2 site through the construction of 3,200 ft of 8” transmission watermain. Directional boring for the 1,150-ft Wolf River crossing was required.

The Well #2 pumphouse, which originally housed a cation exchange softening system, was modified for placement of three (3) 2-stage reverse osmosis membrane skids. Each skid contains eight (8) 8-inch diameter, 6-element pressure vessels providing a feed capacity of 250-gpm per skid for a total system capacity of 500-gpm when one stage is out of service or in a cleaning cycle. A clean-in-place and permeate flush skid system was provided.

Chemical feed systems consisting of scale inhibitors, sodium hypochlorite, blended phosphate and pH adjustment as well as chemicals for membrane cleaning were provided. 
The Well #2 project included upgrades to the electrical and control systems and new emergency backup power.

This would be the Third Municipal RO Membrane System Installed in Wisconsin.