Public Health Madison & Dane County
Homeowner samples · Walk-in
- Coliform Bacteria
About 29,946 households in Dane County, 14% of the county, rely on a private well. Nobody tests that water unless the owner does.
Roughly 14% of Dane County households, about 29,946, get their water from a private well rather than a utility. They are concentrated in the rural parts of the county, and they are on their own for testing.
Wisconsin’s well code (NR 812) applies in Dane County: a licensed well driller files a notification with the DNR before drilling, and the driller must sample the new well for bacteria and nitrate before it goes into service. There is no required test at sale, but any paid well inspection for a real-estate deal must be done by a licensed driller or pump installer and must include bacteria, nitrate and arsenic.
Under NR 812 the well driller must collect a bacteria (coliform) and nitrate sample from every new well and report the results to DNR; the pump installer collects a bacteria sample after installing or replacing a pump. A well notification form and fee are filed with DNR before drilling.
No statewide requirement at sale. If a well is inspected for a real-estate transaction, only a licensed well driller or pump installer may perform the paid inspection, and the inspection must include bacteria, nitrate and arsenic tests.
DNR and DHS recommend testing for coliform bacteria and nitrate every year, arsenic and lead at least every 5 years (arsenic yearly in known areas of the Fox River Valley), fluoride once, and manganese, PFAS or radium where local conditions warrant. Test any time taste, color or odor changes or after flooding.
Some county health departments and UW Extension programs run subsidized nitrate and bacteria screening clinics; check the county health department. The DNR-certified lab list shows which labs accept homeowner samples.
11 certified labs within 40 miles serve Dane County, starting with Public Health Madison & Dane County in Madison (in the county). Each card below shows whether the lab takes homeowner samples and which tests it is certified for.
11 certified labs within 40 miles
Homeowner samples · Walk-in
Homeowner samples · Mail-in kits · Walk-in
Homeowner samples · Mail-in kits · Walk-in
Homeowner samples · Mail-in kits
Homeowner samples · Mail-in kits
Homeowner samples · Walk-in
66 licensed contractors serve Dane County, including 4-D Water Well & Pump Service LLC and Absolute Pump & Well Service LLC. Each profile carries the state license number and the date we checked it, and the filters below sort them by drilling, pump work or treatment.
69 licensed contractors
License 6377, 7824, 8157, 9306 Active
License 6371, 6898 Active
License 8623 Active
License 0427 Active
License 4437, 4493, 7564, 8842, 9047, 9199, 9200 Active
License 7524 Active
License 4260, 7881 Active
License 8647 Active
License 6916 Active
License 6639, 0087 Active
License 6136 Active
License 6359 Active
What comes up with the water depends on the aquifer. A first full panel tells you which of them apply to your well.
Varies by location. Check the state well record search for logs of nearby wells.
Neighboring counties: Columbia County, Green County, Jefferson County, Rock County.
National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.
About 29,946, or 14% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.
Public Health Madison & Dane County in Madison, inside the county. It accepts homeowner samples.
A well notification and fee must be filed with the Wisconsin DNR before drilling, and only a DNR-licensed well driller may drill it. Some counties add their own permit or setback review, so check with the county land conservation or zoning office.
A bacteria and nitrate test runs $25 to $75 at most certified labs; a full panel with metals is $150 to $400. Several county health departments and the state lab of hygiene sell homeowner kits for bacteria and nitrate at low cost; ask the county about screening clinics.