Tested Water

Manganese in Wisconsin well water, by county

Manganese has turned up often in 1 of the 8 Wisconsin counties with 10 or more tested wells, but those results likely overstate it, because of who tested the wells, when or where. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

How Wisconsin compares with the rest of the country

Across Wisconsin, about 1 in 15 tested wells had manganese over the EPA health advisory of 0.3 mg/L (17 of 249). Across all tested wells in the US it's about 1 in 7. That's less often than in the country as a whole. Counties still differ, so check yours below.

Why it matters: High levels over many years may affect the nervous system, and babies are more sensitive to it. It also leaves black stains.

Manganese dissolves out of rock and soil, especially in water with little oxygen.

Manganese in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA health advisory of 0.3 mg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Dane County 19
32%* 6 of 19
Widespread
Shawano County 13
8% 1 of 13
Worth checking
Waushara County 28
7% 2 of 28
Worth checking
Waukesha County 18
6% 1 of 18
Worth checking
Portage County 34
3% 1 of 34
Rare
Waupaca County 15
0% 0 of 15
Rare
Marquette County 12
0% 0 of 12
Rare
Vilas County 11
0% 0 of 11
Rare

* Likely overstated. These shares come from a narrow set of wells, so they probably run high for the county as a whole:

  • Dane County: All of these tests come from the US Geological Survey in one small part of the county, so it may not match the rest of the county.

35 more Wisconsin counties have 1 to 9 tested wells for manganese, too few to rate.

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Where to get your well tested for manganese in Wisconsin

1

Your county health department

Wisconsin doesn't run a statewide free testing program that we know of. Some county health departments test wells or sell kits, so call yours first.

Wisconsin's private well page
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include manganese.

Compare kits

Keep reading about wells in Wisconsin

Questions people ask about manganese in Wisconsin

Is there manganese in Wisconsin well water?

Manganese has turned up often in 1 of the 8 Wisconsin counties with 10 or more tested wells, but those results likely overstate it, because of who tested the wells, when or where. Across Wisconsin, about 1 in 15 tested wells had manganese over the EPA health advisory of 0.3 mg/L (17 of 249). Across all tested wells in the US it's about 1 in 7. That's less often than in the country as a whole. Counties still differ, so check yours below.

Where can I get my well tested for manganese in Wisconsin?

Use a lab certified by Wisconsin for drinking water, or a mail-in kit that includes manganese from a certified lab. Some county health departments test wells too, so call yours first.

See Wisconsin's list of certified labs, or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA health advisory of 0.3 mg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Department of Natural Resources (DNR).