Last checked: October 22, 2026

Licensed well drillers, pump installers and certified water labs in Wisconsin

Every licensed water well driller and pump installer on the Wisconsin DNR's service directories, grouped by county, plus the labs certified to test drinking water for coliform bacteria. Filter by county or search by name.

How Wisconsin licenses well contractors and certifies labs

• DNR directories: the Wisconsin DNR publishes directories of well drilling, pump installing, heat exchange drilling, filling and sealing, and property transfer well inspection services. DNR says the people and businesses listed "are authorized by the Wisconsin DNR to engage in activities designated by the directory."¹
• Individuals and businesses are both listed. Many entries are licensed individuals, shown by name the way DNR lists them. If a person holds both a driller and a pump installer license under the same number, we show one row with both.
• Labs: DNR recommends testing every well for bacteria once a year, nitrate once a year, and arsenic every five years for most well users (every year in Outagamie, Winnebago and Brown counties or after a previous arsenic detection), using a certified lab.² Bacteria samples must reach the lab within 48 hours.²

Check a license yourself

• Drillers and pump installers: download DNR's current well drilling and pump installing directories (spreadsheets).¹
• Bacteria labs: DNR's list of labs certified for coliform bacteria testing.
• Labs for nitrate, arsenic and other tests: DNR's certified lab lists, including a list of drinking water labs for homeowners.³

The list

We loaded the bacteria lab list. Labs certified for nitrate, arsenic and other chemistry are on DNR's spreadsheets (link above) and aren't loaded here yet. Many bacteria-certified labs are city water or wastewater plant labs, so call to ask whether they take private well samples.