Water Treatment

Filter BedThe Milwaukee Water Works treats Lake Michigan water at the Linnwood Water Treatment Plant on the north and the Howard Avenue Water Treatment Plant on the south. The lake water passes through what are called multiple treatment process barriers to protect public health. The barriers destroy and remove illness-causing microorganisms in the lake water.

The primary form of disinfection is ozone gas. As source water enters the first stage of water treatment, ozone is bubbled into the water in large contactor tanks. This highly reactive gas destroys illness-causing microorganisms such as Cryptosporidium and Giardia, and harmful compounds. Ozone also breaks apart compounds that can cause taste and odor. Its use reduces the formation of disinfection byproducts. Following disinfection of the water, particles are removed through coagulation, flocculation, settling, and biologically active filtration. Chlorine is added as a secondary disinfectant. Fluoride is added to reduce dental cavities. A phosphorous compound is added to control pipe corrosion to prevent lead and copper that may be present in pipes from leaching into the water. Finally, chloramine disinfection maintains a residual in the distribution system to protect against bacterial contamination. The Wisconsin Department of Natural Resources (DNR) requires water utilities to maintain a detectable level of disinfectant throughout the distribution system to maintain bacteriological protection. All chemicals that are added are certified food grade, safe for human consumption. The Supervisory Control and Data Acquisition System (SCADA) at both treatment plants provides real-time data from chemical feed systems, including ozone, and all water quality monitoring as well as control of water pumping stations and the distribution system. Pure, fresh water arrives at your taps.

View a printable treatment process diagram (Spanish version)

You can see how the Milwaukee Water Works fits into the Milwaukee freshwater cycle by visiting our exhibit at Discovery World. After we purify the water, we pump it into the distribution system of water mains to your service line pipe, and through the water meter into your home. After you use water, it leaves your home through the sanitary sewer pipe and flows to the Milwaukee Metropolitan Sewerage District treatment facility where it is treated and returned to Lake Michigan.