For immediate release, September 14, 2023

Waukesha will begin the switch from groundwater to Lake Michigan water on October 9, officials announced today.

“We have heard from many customers who want to know a firm date for the transition to a Lake Michigan water supply. Moving the timeline back a few weeks allows us to set a date with certainty. That will help our customers plan ahead,” according to Dan Duchniak, the general manager of the Waukesha Water Utility.

“Residential customers are asking when they should turn off softeners or remove filters from kitchen sinks or refrigerators. Many business customers also need to make changes to adjust to the water supply,” he said.

Duchniak said pushing the transition back from next week until October 9 will also allow the utility and contractors to ensure the highest possible water quality during the transition and protect public health and safety throughout the process. The transition had been planned to start between Sept. 14 and 18, but a specific date had not yet been set.

“With a little more time, we can ensure the best product from the start. For example, after testing, we have made the decision to purge our new above-ground reservoirs and refill them to help minimize any potential taste or odor problems during the transition,” he said. “That process alone takes a week to accomplish.”

The utility head also said issues developed with the programming of the new water pumps during startup testing. “The pumps will not need any repairs but it will take time for the manufacturer to send the people to correct the programming and ensure correct operation of the pumps. We apologize for any inconvenience the delay may cause for customers but we want to be sure those kinds of smaller details don’t keep changing the timeline. We are moving the date back to provide certainty.”

The new infrastructure involved to bring the water from Milwaukee and pump it through our system is complex at both ends. “Providing a little more time will allow the needed troubleshooting to be completed properly without rushing. Having a definitive timetable allows residents to plan, which will result in a smoother transition,” he said. “Waukesha residents are telling us they are looking forward to the new water supply. They have waited a long time for this and we want to be sure the change is as trouble-free and predictable as possible.”

Customers can find helpful answers to frequently asked questions about the transition at, in bill inserts and through other communications. The city also posts a weekly electronic newsletter that residents can sign up for through the Connect link at Customers can also call the water utility staff at 262-521-5272 for answers.

An average of 6 million gallons per day will come to Waukesha initially from the Milwaukee Water Works as the city transitions to 100% Great Lakes water. Waukesha’s current groundwater supply is severely depleted and contaminated with naturally occurring radium. The city is under a court order to provide drinking water that complies with radium standards.

Duchniak said the utility will continue provide radium treatment to its current water supply until the transition to radium-free lake water occurs. The water will meet radium standards during that interim period on a weighted average basis, as called for in the court order.

The transition to the new supply of Lake Michigan water will move approximately 50 million gallons of water through more than 300 miles of water mains over the course of several weeks, starting on the east side. “For about 90% of our customers, the transition will start and end sometime within the first five days. But for customers on the edges of our service area or at dead ends and cul-de-sacs, it may take as long as three to four weeks after the starting date for the new water supply to reach them,” Duchniak said.

One permanent difference with the transition is a change in the disinfection process from chlorine that Waukesha had used to chloramines that is used by Milwaukee. Both disinfectants are commonly used by water utilities to ensure public health protection and the change should be generally unnoticeable. However, kidney dialysis patients should contact their dialysis center for guidance on any needed modification to in-home dialysis procedures. Also, owners of fish, reptiles and amphibians should consult local pet stores about required changes in water treatment.

For most customers, the potential issue to be alert for will be discolored water. “Discolored water, if a customer has it at all, should last a couple of days, or less, at individual locations. This is similar to what can occur during the annual flushing of our water mains, as the normal build- up of sediment in pipes is stirred up by water movement,” Duchniak said.

Duchniak said the reddish water is aesthetically unappealing but does not pose a human health risk. “If you have discolored water, avoid doing laundry or making ice until the water runs clear. If you accidentally stain your laundry, avoid drying it. Use Red-B-Gone, Iron Out or other rust removers to remove stains,” Duchniak said.

Flushing pipes is typically the best way to resolve discolored water problems. Remove the screens or aerators from the ends of the indoor faucets to prevent clogging. Then run all of the cold-water faucets wide-open and simultaneously for three to five minutes. During that time, also flush each toilet two or three times. Turn off the water and reinstall the aerators.

The large flow of water through the pipes will generally dislodge any buildup of organic material that is causing discoloration or other issues. For a typical house, the cost of the water used should be less than a dollar.

Duchniak recommended removing or bypassing in-home water filtration systems – like the ones used with some refrigerator water dispensers or attached to kitchen faucets – before the start of the transition. Customers should also bypass any reverse osmosis (RO) system if they have one. Customers can resume using filters again in a normal manner after the transition, or after they’ve flushed your system and the water runs clear.

Users should also bypass water softeners during the transition for the same reasons. Customers should check their user manual or look online for instructions for the softener model. Simply unplugging the softener will not bypass it.

“Most people who use lake water don’t use softeners. Lake water is at least 60% softer than our current supply. We recommend that you continue to bypass softeners for a month or two to see if you are satisfied with the new water without a softener,” Duchniak said. Additional details about softeners are available at

During the transition, some customers may also notice a chlorine-like smell or taste. This is because the disinfectant levels will be temporarily increased to ensure a safe drinking water supply. Once the transition is complete, the disinfectant levels will return to normal. Customers may also notice a subtle permanent change in the taste of water because the new supply has fewer naturally occurring minerals than groundwater.

Duchniak noted that Milwaukee is recognized as a national leader for providing safe, high- quality drinking water. It supplies more than 860,000 people in the region, including customers in more than a dozen area communities that previously switched from groundwater.

The Waukesha Water Utility serves the 72,000 residents of the city, as well as some residents in the City of Pewaukee and the Village of Waukesha.

As the utility provides Lake Michigan water to its customers, it will also be recycling water back to the Great Lakes Basin. Approximately 100% of the volume of water withdrawn from the lake, after use in Waukesha, will be treated and returned to the Root River. From there it will flow to Lake Michigan. The additional clean water will provide a needed improvement to river flow and help the fishery by improving spawning.

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