Tested Water

Manganese in Wyoming well water, by county

Manganese is widespread, over the limit in 15% or more of tested wells, in 4 of the 16 Wyoming counties with 10 or more tested wells. 2 more look high, but those results likely overstate it. 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 Wyoming compares with the rest of the country

Across Wyoming, about 1 in 10 tested wells had manganese over the EPA health advisory of 0.3 mg/L (44 of 432). 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
Fremont County 11
55%* 6 of 11
Widespread
Teton County 13
54%* 7 of 13
Widespread
Park County 14
21% 3 of 14
Widespread
Washakie County 10
20% 2 of 10
Widespread
Campbell County 26
19% 5 of 26
Widespread
Sweetwater County 38
16% 6 of 38
Widespread
Carbon County 60
12% 7 of 60
Worth checking
Converse County 23
9% 2 of 23
Worth checking
Albany County 25
8% 2 of 25
Worth checking
Crook County 17
6% 1 of 17
Worth checking
Sheridan County 34
3% 1 of 34
Rare
Laramie County 34
0% 0 of 34
Rare
Platte County 28
0% 0 of 28
Rare
Sublette County 27
0% 0 of 27
Rare
Goshen County 25
0% 0 of 25
Rare
Niobrara County 24
0% 0 of 24
Rare

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

  • Fremont County: All of these tests come from the US Geological Survey in one small part of the county, so this likely overstates it.
  • Teton County: All of these tests come from the US Geological Survey in one small part of the county, so this likely overstates it.

4 more Wyoming counties have 1 to 9 tested wells for manganese, too few to rate.

Download this table (CSV) ยท Free to reuse under CC BY 4.0

Where to get your well tested for manganese in Wyoming

1

Your county health department

Wyoming 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.

Wyoming's private well page
2

A lab Wyoming certifies

Ask for manganese by name. Results from a certified lab count for a home sale or a loan.

Labs certified by Wyoming
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 Wyoming

Questions people ask about manganese in Wyoming

Is there manganese in Wyoming well water?

Manganese is widespread, over the limit in 15% or more of tested wells, in 4 of the 16 Wyoming counties with 10 or more tested wells. 2 more look high, but those results likely overstate it. Across Wyoming, about 1 in 10 tested wells had manganese over the EPA health advisory of 0.3 mg/L (44 of 432). 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 Wyoming?

Use a lab certified by Wyoming 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 Wyoming'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 Environmental Quality (DEQ), Know Your Well program.