The Kenosha Water Utility in Kenosha, Wisconsin, could not agree more. The utility embarked on an ambitious, two-part cost reduction project. The first part of the project was a plan to increase the generation of methane gas and the second part focused on disposal costs by turning their unusable sludge into a reusable Class A biosolid product.

From the beginning, KWU realized that to achieve these two goals, it was critical to capture and remove as much debris as possible at the headworks of the plant. The plant’s maximum average daily flow is 28.6 mgd, but it can increase by a factor of five during large rain events.  Although the collection system has separate storm and sanitary sewers, the amount of inflow and infiltration from various sources create problems similar to a combined system especially during the initial rain event surge.

Replacing bar screens

To increase debris capture and handle those debris ladened “sewernamis,” the utility replaced its old 1/2-inch coarse bar screens with two SAVECO FSM perforated plate Filterscreens Model FRSIII 1500 x 70/6 with a verified debris capture of more than 85%. Each screen has 6 mm holes and is rated for a peak flow of 50 mgd. The Filterscreens are equipped with FSM’s proprietary auto adjusting cleaning brushes which require no manual adjustments and guarantee maximum capture efficiency for the life of the brush, according to the manufacturer.

Kenosha almost immediately saw the benefits of the increased debris capture. Since the screens were installed, there have been no primary clarifier failures, no floatables on the clarifiers or the wet wells or the aeration tanks, and no rags in the centrifuge tanks. To reduce the volume of the captured debris going to landfill, Kenosha also installed two FSM washer compactors.

SAVECO North America Inc. is a supplier of custom-engineered headworks screens and grit/solids management equipment for water and wastewater treatment applications.

815-636-8306 | ecsales@savecowaterna.com | www.savecowaterna.com