Well Water Testing

Information on getting your well tested:


Well water quality viewer: Private well data for Wisconsin:


November 13, 2014

FOCUS ARTICLE BY:  Jay Dampier, Extension Educator
Community, Natural Resources and Economic Development
Green Lake County, UW-Extension

How well is your well water?

Most private wells provide safe and clean water. However, it is important to annually check your well to ensure safety and reduce potential health risks caused by contaminated water. The most important test to perform regularly on your well is the one for coliform bacteria detection. Bacteria in well water can cause flu-like symptoms such as nausea, vomiting, fever and diarrhea – and in some instances the symptoms can be much more severe.

Another important well water test looks for nitrate. According to the UW Water and Environmental Analysis Lab, nitrate is the most common chemical contaminant in Wisconsin groundwater. Nitrate contamination can come from fertilizers, septic systems or manure. Some researchers suspect that nitrates in water can cause a number of health problems, and can be particularly dangerous for pregnant women and infants.

The UW Center for Watershed Science and Education has an interactive map that shows well water quality throughout the entire state, including Green Lake County. The website’s maps provide test results such as bacteria and nitrates (among other measures such as hardness and pH), but it does warn. “Do not extrapolate this information to a specific well, but rather use the maps to visualize regional trends and as a basis for laboratory testing of your well water to ensure a safe water supply.” You can check out how Green Lake County compares to other counties by clicking on the link above.

If this article has got you curious about your own well’s water, you can pick up a water test kit from the Green Lake County Health Unit. For more information and test fees, contact the Green Lake County Health Unit at 920-294-4070.

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