Chemical Change


The Kaukauna Utilities (KU) Water Department will implement a new and improved water treatment method by changing the chemical used in the water treatment process from sodium silicate to a polyphosphate ortho blend. The process of this chemical switchover will begin on Monday, May 16th, 2022.

The benefits of this chemical change will positively impact customers and will help improve the overall quality of KU water. Over time, noticeable changes should include:

  • Reduced calcium buildup on plumbing faucets and fixtures
  • Less iron staining
  • Improved disinfection resulting in a reduction of chlorine introduced to the water distribution system

Throughout the last year, KU staff has researched this chemical change extensively to evaluate the effectiveness of increased water quality and benefit to our customers. This chemical change has also been vetted and approved by the Wisconsin Department of Natural Resources (DNR).

Phosphates are a very common chemical used in the water treatment process, most effectively as a corrosion inhibitor. This chemical blend helps clean, maintain, and extend the life of system infrastructure including mains, service lines, valves, meters, and household plumbing.

Nationwide, more than 50% of the entire US population is served by utilities treating their water with phosphates. They have been utilized in drinking water for over 100 years at levels less than 5 parts per million (ppm).  These are the same phosphates utilized in food at much higher levels.  For example, cola drinks can have over 1,000 ppm and cheese can contain 30,000 ppm.

As mentioned, the process of this chemical switchover will begin on Monday, May 16th, 2022. This will happen in conjunction with spring hydrant flushing. See details below for information on potential water discoloration during hydrant flushing.

Listed below are further resources on this chemical switchover. With comments or concerns, please call our Water Department Superintendent, Andy Vanden Heuvel, at 920-858-9180.


Join us on Tuesday, June 7th from 2pm-6pm for an open house at KU Well No 8 – 311 Delanglade St., Kaukauna (corner of Delanglade St and Blackwell St, across from Kaukauna Meats). Learn about water quality, the filtration process, water conservation, and more! KU water department staff, along with General Manager, Michael Avanzi, will be available to answer any questions or address any concerns you may have with your water service. FREE water conservation kits, prizes, and snacks at the event! Save the date and stay tuned for more details!

More info here.


Kaukauna Utilities customers are advised to check for discoloration prior to washing any clothes.  If employees from the Water Department are seen working in the area, please use as little, or if possible, no water for 45 minutes to ensure that the water has settled down and that the discoloration is not drawn into the home’s water softener or hot water heater.  Ideally wait until after 4:00 p.m. before washing clothes to minimize potential discoloration.  Under certain circumstances, a hydrant being flushed 6-8 blocks away can cause water discoloration.

If discoloration continues, customers are advised to wait another 30 to 45 minutes, then draw off the discolored water through the cold water faucet only.  Flushing will remove most of the sediment of natural minerals such as iron and sulfur that are harmless but still discolor water.