Municipal water system disinfection

The vast majority of Wisconsin’s municipal water systems currently disinfect the water they deliver to consumers, killing viruses and bacteria that can unexpectedly occur.

Learn if your municipal water system disinfects its water

Here's how you can learn if your municipal water supplier disinfects:

1. Check the Municipal water disinfection list [PDF], based on DNR records as of April 2022, to see if the system disinfects its water.
2. Contact your water system directly.
3. Go to the Public Drinking Water System Data page, click the “Find Public Water Systems” button, type in your water system's name, click on "Search", then on your system and scroll down and click on "Treatment Processes." If there is no notation of disinfection under the "Objectives" heading, the system does not disinfect.

DNR recommends that all municipal water systems disinfect the water they supply to consumers. A Wisconsin study [exit DNR] shows that viruses can be found in drinking water in communities that use groundwater and do not disinfect it before supplying it to consumers.