Water Quality
We monitor and communicate ground and surface water conditions so that appropriate regulation and control efforts are followed.
Water Quality in Dane County
Access to quality drinking water is vital to the public health and well-being of Dane County residents. We expect our tap water to be clean and safe, and in Dane County it almost always is.
The biggest threats to safe drinking water in Dane County are:
- Nitrates: Private wells are sometimes contaminated by fertilizers and other agricultural or industrial chemicals. Nitrates are particularly harmful to infants and pregnant women. Wells can be contaminated with nitrate from over-fertilization of crops or lawns, animal waste run-off and failing septic systems.
- Lead: Lead and other metals can be released into the drinking water from old plumbing pipes and fixtures.
- Chloride & Sodium: As a result of six decades of road salt application, surface and ground water monitoring shows increasing trends in chloride and sodium levels, although the levels are not yet a human health hazard. See the animation below to see how chloride levels have changed over time:
Recently, drinking water contaminated with perfluoroalkyl and polyfluoroalkyl substances (PFAS), has been getting a lot of attention. The Madison Water Utility has information about PFAS found in Madison wells. Our Environmental Hazards website section has general PFAS information.
If you are concerned about the quality of your drinking water:
- All community water systems (utilities) are required to provide customers with a Consumer Confidence Report by July 1 of each year. If you did not get a report, contact your water system or generate your own on the Department of Natural Resources website.
- Get information on how to get your water tested.
Water Quality Reports
- Water Quality in Dane County: Overview, Current Challenges, Recommendations, July 2017
- Madison and Dane County Water Quality Report Card - 2014
- Road Salt and Impact on Lake and Ground Water Quality Reports
- For more Madison water quality data, go to Madison Water Utility.