Groundwater and Private Well Information

Private Well Owner Tips

As a private well owner, you are responsible for the quality of drinking water supplied to your home. On average, only 10% of well owners sample drinking water wells annually. At a minimum, a well should be sampled for bacteria and nitrate every 15 months. In karst areas of Calumet County, more frequent sampling is recommended.

October 2021 Calumet County Well Water Webinar

A webinar was held to go over well test results from the 2021 private well testing program that occurred in September 2021.  The webinar provides general information about groundwater and private wells, discussed unique characteristics of groundwater in Calumet County, and water quality data and maps from the 190 samples collected on September 13, 2021.  

Calumet Co. Groundwater Series

During the early part of 2019, the Calumet County Land Conservation Committee hosted a series of presentations. Below are links to those presentations.

Groundwater, Private Wells, and Calumet County Well Data (PDF)
Presentation given on February 13, 2019 at the Engler Center for Performing Arts by Dani Santry, Calumet County Water Resource Specialist

Cows or People? Fecal Sources and Risk Factors Associated with Private Well Contamination in Northeast Wisconsin (PDF)
Presentation given on February 27, 2019 at the Engler Center for Performing Arts by Mark Borchardt, USDA-Agricultural Research Services

Results from the March 25 Group Testing Program (PDF)
Presentation given on April 30, 2019 by Kevin Masarik, UW Extension

What to know if you are located in the Groundwater Protection Area? Use the groundwater layer in the Calumet County Online Map.

Well Water Test Kits

Test kits are available in the Land & Water Conservation Department. The bottles can be used to test for coliform bacteria, E. coli, Nitrates, pH, conductivity, hardness, and chlorides. Test range from $30 - $60 depending on the type of test(s).

Kits may be picked up at the Land & Water Conservation Office in room 227 at the Calumet County Courthouse.

How to Sample Your Well

Here is a quick 5 minute video on how to sample your well for 3 common analyses: homeowners' package (includes the bacteria and nitrate test), metal's package, and the DACT screen.  The video was created by the UWSP Water & Environmental Analysis Lab.

Video: How to collect a Water Sample

Online Private Well Class

Want to learn more about private wells? This free online class is a short series of weekly programming for homeowners on private wells. Visit the Private Well Class website to sign up and get started. This is highly recommended for residents that are new to owning a private well.
2019 Groundwater Report

The Land & Water Conservation Department collects private good data from program volunteers to determine the current condition of groundwater resources and trends in water quality. The most recent report was released in December 2020. The report highlights the 2020 Group Testing Event held in September (2020) as well as the current average water quality in private wells (2005-2020).

The report and updated maps are available:

County-Wide Map of Nitrate Levels (collected 2020)

Map of Nitrate Levels found in private wells in Calumet County in 2020

Groundwater in Karst Areas 

The karst areas of Calumet County are sensitive to groundwater contamination. The unique geology and soils present extreme challenges in protecting groundwater from surface contamination. The upper layer of bedrock is a type of rock that is easily dissolved by water. Sinkholes, disappearing streams, and caves are visible examples of places where bedrock is dissolved. Vertical and horizontal fractures (or cracks) that for from dissolution act similar to a network of pipes underground and can rapidly move water (in some cases, water can move 100 feet or more per day) from the surface to the underlying aquifer.

In some areas, the soil can be very shallow (0 to 40 inches thick) and/or can consist of light textured materials. Soil is important for protecting water quality because it naturally filters contaminants picked up by rainwaters and snowmelt before they reach groundwater. Where there is little soil or light textured soil, there is little to no natural filtering of contaminants. Pollution on the surface of the land can directly and quickly impact water underground, creating significant health concerns if the contaminants reach wells.

Calumet County's private well testing program is a voluntary program that has sampled over 1800 wells since 2005. With over 4000 samples to date, the results indicate that over 1/3 of wells do not meet safe drinking water standard requirements for bacteria and/or nitrate.

Susceptibility Map of the Silurian Aquifer
Aquifer Susceptibility.jpg

Helpful Links

Wisconsin Well Water Quality Viewer

Wisconsin Well Water 101 (PDF)

What's Wrong with my Well Water - resources to help identify problems based on symptoms

Water Health Series: Filtration Facts (PDF) - in-depth information on different treatment systems available.

Wisconsin DNR Groundwater Collaboration Workgroup – links to the workgroup commissions out of the Kewaunee County events

Final Report of the Workgroup (PDF)