Eurofins Microbiology Laboratories
Homeowner samples · Mail-in kits
- Arsenic
- Coliform Bacteria
- Lead
- Nitrate / Nitrite
About 8,433 households in Milwaukee County, 2% of the county, rely on a private well. Nobody tests that water unless the owner does.
Most of Milwaukee County is on public water, but an estimated 8,433 households still rely on a private well. This page covers the rules, labs and licensed contractors that serve them.
Wisconsin’s well code (NR 812) applies in Milwaukee 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.
7 certified labs within 40 miles serve Milwaukee County, starting with Eurofins Microbiology Laboratories in New Berlin (about 9 miles from the county center). Each card below shows whether the lab takes homeowner samples and which tests it is certified for.
7 certified labs within 40 miles
Homeowner samples · Mail-in kits
Homeowner samples · Walk-in
Homeowner samples · Mail-in kits
Homeowner samples · Walk-in
Homeowner samples · Walk-in
Homeowner samples · Walk-in
47 licensed contractors serve Milwaukee 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.
48 licensed contractors
License 6377, 7824, 8157, 9306 Active
License 6371, 6898 Active
License 6261 Active
License 0427 Active
License 4437, 4493, 7564, 8842, 9047, 9199, 9200 Active
License 7524 Active
License 4413 Active
License 4148 Active
License 7998, 8005 Active
License 8680 Active
License 3744 Active
License 9296 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: Waukesha County, Ozaukee County, Racine County, Washington County.
National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.
About 8,433, or 2% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.
Eurofins Microbiology Laboratories in New Berlin, about 9 miles away. 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.