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State-certified water testing labs in Wisconsin

129 state-accredited labs for drinking and well water testing in Wisconsin.

52 cities & counties129 certified labs

Source: Wisconsin DNR list of labs certified for coliform bacteria testing, list dated Oct 28, 2026. Find a Water Test is independent and not affiliated with the Wisconsin Department of Natural Resources. Certification covers specific tests, so confirm the lab is certified for the ones you need: Verify a certification.

Major cities

Milwaukee 6Green Bay 5Madison 3Oshkosh 3Port Washington 3Stevens Point 3Superior 3Antigo 2Appleton 2Ashland 2Crandon 2Eau Claire 2

Counties in Wisconsin A–Z

Smaller counties in Wisconsin

Counties with only a few listings so far, grouped by county.

Buffalo County 1

Chippewa County 1

Clark County 1

Dodge County 1

Florence County 1

Fond du Lac County 1

Grant County 1

Green County 1

Iowa County 1

Iron County 1

Jackson County 1

Jefferson County 1

Lafayette County 1

Lincoln County 1

Marquette County 1

Monroe County 1

Oneida County 1

Pierce County 1

RF

River Falls Wastewater Treatment Plant

432 Apollo Rd, River Falls, WI

State-accredited labDrinking waterBacteria testingPublic or utility lab

Public water system lab. Many don't accept private well samples, so call first.

(715) 222-7090Directions
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Polk County 1

Rusk County 1

Sawyer County 1

Sheboygan County 1

SW

Sheboygan Water Utility

72 Park Ave, Sheboygan, WI

State-accredited labDrinking waterBacteria testingPublic or utility lab

Public water system lab. Many don't accept private well samples, so call first.

(920) 459-3812Directions
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Taylor County 1

CM

City of Medford Wastewater Treatment Plant

603 S Whelen Ave, Medford, WI

State-accredited labDrinking waterBacteria testingPublic or utility lab

Public water system lab. Many don't accept private well samples, so call first.

(715) 748-4122Directions
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Vilas County 1

Waupaca County 1

Mail-in labs that ship to Wisconsin

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Just need a lab? Every certified lab is listed above with directions.