Free testing, with limits
Colorado tests private wells for PFAS for free, but not for anything else. Check which tests it includes before you count on it for manganese.
Colorado's private well pageManganese in Colorado well water, by county
Manganese is widespread, over the limit in 15% or more of tested wells, in 6 of the 21 Colorado 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.
How Colorado compares with the rest of the country
Across Colorado, about 2 in 10 tested wells had manganese over the EPA health advisory of 0.3 mg/L (165 of 855). Across all tested wells in the US it's about 1 in 7. So manganese turns up somewhat more often in Colorado than in the country as a whole. Check your county 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%.
| County | Wells tested | Wells over the limit | Level |
|---|---|---|---|
| Montrose County | 56 | Widespread | |
| Pueblo County | 18 | Widespread | |
| Lake County | 73 | Widespread | |
| Grand County | 12 | Widespread | |
| Eagle County | 87 | Widespread | |
| Arapahoe County | 67 | Widespread | |
| Elbert County | 30 | Widespread | |
| Adams County | 36 | Worth checking | |
| Weld County | 22 | Worth checking | |
| Montezuma County | 16 | Worth checking | |
| Douglas County | 31 | Worth checking | |
| El Paso County | 86 | Worth checking | |
| Park County | 35 | Worth checking | |
| Otero County | 19 | Worth checking | |
| Rio Blanco County | 28 | Rare | |
| Chaffee County | 31 | Rare | |
| Alamosa County | 26 | Rare | |
| Saguache County | 24 | Rare | |
| Garfield County | 20 | Rare | |
| Rio Grande County | 20 | Rare | |
| La Plata County | 13 | Rare |
* Likely overstated. These shares come from a narrow set of wells, so they probably run high for the county as a whole:
- Grand 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.
25 more Colorado 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 Colorado
A lab Colorado certifies
Ask for manganese by name. Results from a certified lab count for a home sale or a loan.
Labs certified by ColoradoA mail-in kit
Fill the bottles at your kitchen tap and mail them back. We mark the kits that include manganese.
Compare kitsKeep reading about wells in Colorado
- Well water testing in Colorado: how to get tested and what turns up statewide
- Manganese in well water: where it comes from, what it does and how to remove it
- Nitrate in Colorado wells, by county
- Arsenic in Colorado wells, by county
- Uranium in Colorado wells, by county
- Lead in Colorado wells, by county
Questions people ask about manganese in Colorado
Is there manganese in Colorado well water?
Manganese is widespread, over the limit in 15% or more of tested wells, in 6 of the 21 Colorado counties with 10 or more tested wells. 1 more look high, but those results likely overstate it. Across Colorado, about 2 in 10 tested wells had manganese over the EPA health advisory of 0.3 mg/L (165 of 855). Across all tested wells in the US it's about 1 in 7. So manganese turns up somewhat more often in Colorado than in the country as a whole. Check your county below.
Where can I get my well tested for manganese in Colorado?
Colorado tests private wells for PFAS for free, but not for anything else. If that doesn't cover you, use a lab certified by Colorado for drinking water, or a mail-in kit that includes manganese from a certified lab.
See Colorado'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 Public Health and Environment.