Kenosha Membrane Filtration Plant

"Building World’s Largest Membrane Filtration Plant"

How can a mid-sized membrane microfiltration plant be built cost-effectively? Is it possible to use this new technology to treat cold lake water?

These were the challenges MWH faced when designing and building the Kenosha Membrane Filtration Plant in Kenosha, Wisconsin (USA). Previously, membrane microfiltration had never been tested on cold Lake Michigan waters and had been considered too costly for a mid-sized facility.

Membrane microfiltration technology filters water through microscopic membrane pores. This removes bacteria and other pollutants more efficiently than conventional sand filters. The result is water of extremely high clarity and purity. A pilot study indicated a microfiltration plant would be one-half the size of a conventional treatment plant. It also would cost less to construct. And it would ultimately produce water that exceeded current and anticipated state and federal regulatory requirements with minimal operating complexity and cost.

The final result — the largest membrane microfiltration plant in the United States — was awarded a merit award from the American Consulting Engineers Council of Wisconsin.

Project Details

MWH designed and managed the construction of the state-of-the-art microfiltration facility. This included the demolition of several structures, as well as significant modifications to the raw water pump station and other facilities. Additionally, MWH constructed a 40 mgd treated water pump station; a 2.5 million-gallon chlorine contact tank and clearwell; and a Visitor’s Center.

The $24.2 million plant began operation on time and on budget at a cost of nearly 40 percent less than original estimates.

It currently produces an average of 14 million gallons daily (mgd) with a peak flow capacity of 16 mgd. Each day, the facility provides 40 million gallons of potable water to approximately 120 thousand residential and industrial customers. The plant achieves this by integrating microfiltration membrane technology with an existing conventional water treatment process facility. To-date the plant has welcomed more than two thousand visitors from around the world.

The Kenosha membrane system consists of two microfiltration trains, with additional space provided for a third train. Each train consists of eight Memcor 90 M10C Memcor Continuous Microfiltration (CMF) membrane units. Each unit consists of 90 membrane modules that contain 20 thousand hollow fibers each with a nominal pore size of 0.2 microns. The total number of fibers for the sixteen microfiltration units is 28.8 million.

MWH worked closely with the staff to complete the new construction without shutdowns of ongoing conventional plant operations. It continues to provide start-up services for the Kenosha plant.

The new facility has put Kenosha ahead of the expected regulatory requirements concerning surface water and disinfection byproducts without the use of pretreatment chemicals.