The Marathon County Public Health Laboratory provides convenient, reliable, and reasonably priced water testing services to the citizens of Marathon County and surrounding counties, with the goal of safer water supplies. The lab is involved in monitoring public drinking water supplies which include municipal community water systems and those involved in our Department of Natural Resources (DNR) transient non-community water (TNC) systems program.

Clean, safe drinking water is one of the most important elements of good health. Testing well water on an annual basis is one of the easiest things a private well owner can do to take care of their health and the health of their loved ones. It’s estimated that 20-25% of Wisconsin wells have bacterial contamination, so Marathon County Health Department advises all private well owners to have their well water tested for coliform bacteria and nitrates. If there are infants under six months of age or women of childbearing age drinking the water, it should also be tested for fluoride.

• The Wisconsin Department of Health Services provides guidance about drinking water and private wells. Go to their website to learn about tests for private wells, contaminants with fact sheets, and what to do if you have a contamination.
• Frequently Asked Questions
• Sampling Instructions
• Identify Your Water’s Symptoms
• Water Treatment Devices for Private Well Contaminants Guide - This guide describes how treatment devices work and includes a table indicating which treatment devices are best for which common contaminant. The guide is available in English, Spanish, and Hmong.

Water Testing Fees 

Prices effective January 1, 2024.

Click the "Order a Water Test Kit" button above to order any of the following test kits.

How Often Do I Need to Test my Private Well?

Every private well should be tested annually and whenever there are changes in taste, color, odor, or appearance.  Contact the Marathon County Health Department to find more information by calling 715-261-1900.

Additional Information:

• Drinking Water Concerns
• Tests for Drinking Water from Private Wells
• Frequently Asked Questions
• Drinking Water
• Sampling Instructions 
• Water Quality Issues
• Well Chlorination Procedures

Qualifying families or business owners may be eligible through the DNR to receive funding to replace, reconstruct, or treat a contaminated private well. More information about how to apply can be found here

Test Result Information:

• Arsenic
• Bacteria
• Copper
• Fluoride
• Hardness, pH, Alkalinity
• Iron
• Lead
• Nitrate