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Manganese in Nevada well water, by county

By the Tested Water teamLab data from the USGS and EPA Water Quality Portal, 2000 to 2025Updated November 8, 2026

Manganese is widespread, over the limit in 15% or more of tested wells, in 2 of the 11 Nevada counties with 10 or more tested wells. 1 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.

Find a manganese test See every county

How Nevada compares with the rest of the country

Across Nevada, about 1 in 8 tested wells had manganese over the EPA health advisory of 0.3 mg/L (70 of 547). Across all tested wells in the US it's about 1 in 7. Nevada is about average, so the county you live in tells you more than the state does.

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
Humboldt County 13
31% 4 of 13
 Widespread
Churchill County 179
23% 42 of 179
 Widespread
Mineral County 23
22%* 5 of 23
 Widespread
Carson City 36
11% 4 of 36
 Worth checking
Lyon County 36
8% 3 of 36
 Worth checking
Douglas County 25
8% 2 of 25
 Worth checking
Washoe County 103
8% 8 of 103
 Worth checking
Clark County 28
4% 1 of 28
 Rare
Nye County 43
2% 1 of 43
 Rare
White Pine County 23
0% 0 of 23
 Rare
Elko County 12
0% 0 of 12
 Rare

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

  • Mineral County: All of these tests come from the US Geological Survey, mostly before 2013 in one small part of the county, so this likely overstates it.

6 more Nevada 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 Nevada

1

Your county health department

Nevada 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.

Nevada's private well page
2

A lab Nevada certifies

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

Labs certified by Nevada
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 Nevada

Questions people ask about manganese in Nevada

Is there manganese in Nevada well water?

Manganese is widespread, over the limit in 15% or more of tested wells, in 2 of the 11 Nevada counties with 10 or more tested wells. 1 more look high, but those results likely overstate it. Across Nevada, about 1 in 8 tested wells had manganese over the EPA health advisory of 0.3 mg/L (70 of 547). Across all tested wells in the US it's about 1 in 7. Nevada is about average, so the county you live in tells you more than the state does.

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

Use a lab certified by Nevada 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 Nevada'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: Division of Environmental Protection.