Manganese is widespread in Campbell County wells.
1 widespread, 6 rare out of 7 health checks.
From 47 wells tested in Campbell County since 2001; your own well needs its own test. How to read this
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
1 in 5 people 8,920 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Deep wells: fewer surface germs, more minerals from the rock.
Well depths: US Groundwater Well Database
Radon risk (a gas from rock)
Likely here. Test your home's air first.
Radon zones: EPA map
Here's how Campbell County compares with Wyoming and the counties around it.
Each result puts Campbell County next to the 6 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Campbell County wells.
Manganese5 of 26 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Johnson, Weston.
These 6 are rare in Campbell County.
Nitrate2 of 47 wells over
Too few tested to show: Powder River, MT, Weston.
Arsenic1 of 26 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Johnson, Weston.
Uranium0 of 26 wells over
Too few tested to show: Johnson, Powder River, MT, Weston.
Radon in water0 of 11 wells over
Too few tested to show: Converse, Crook, Johnson, Powder River, MT, Weston.
Fluoride0 of 26 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Johnson, Weston.
Lead0 of 26 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Johnson, Weston.
Coliform bacteria turned up in 11 of 21 tested Campbell County wells, so test for it every year.
Coliform bacteria11 of 21 wells had it
Too few tested to show: Johnson, Powder River, MT, Weston.
E. coli0 of 21 wells had it
Too few tested to show: Johnson, Powder River, MT, Weston.
E. coli means human or animal waste is getting in, so if a test of your Campbell County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 7 of 26 tested wells, and it isn't a health risk.
Iron stains7 of 26 wells had it
Too few tested to show: Johnson, Weston.
Campbell County has 47 tested wells, and the busiest decade for testing was the 2010s.
Only 1 of the 47 wells have a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Campbell County wells in these records were tested for research or because someone suspected a problem, which can push the shares above what a typical home well would show (how we read the numbers).
One mail-in lab test covers the 4 things to check in Campbell County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What Wyoming offers well owners
- Free testingWe didn't find a free program for all of Wyoming. Wyoming's private well page
- Certified labsWyoming's list of certified labs
- Well recordsWyoming's well record search
Half the household wells here are shallower than 450 feet.
That comes from 1,115 household wells in Wyoming's drilling records. Most wells of every kind here are 440 to 1,140 feet deep. Wells as deep as Campbell County's are usually better protected from fertilizer and bacteria at the surface, but they can pick up more of what's in the rock, like arsenic and uranium. That's the deepest typical depth for household wells among the 23 Wyoming counties with enough drilling records.
Look up your own well's depth in Wyoming's well record search, or see how to find it.
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Campbell County.
Campbell County is in the EPA's highest radon zone. Radon from well water adds to the radon in your indoor air, so test your air first, and your water too if the air is high. Radon guide
Between 2023 and 2025 the EPA had 2 town water systems in Campbell County test for PFAS. None found any. No well in Campbell County has public PFAS results, so the town systems are the best clue to what's in the groundwater nearby. PFAS guide
Radon zones: EPA Map of Radon Zones. PFAS: EPA tests of town water systems, 2023 to 2025
Questions people ask about well water in Campbell County
Is well water in Campbell County safe to drink?
5 of 26 wells tested in Campbell County had manganese over the limit, about 2 in 10. Across Wyoming it's about 1 in 10. That's a bigger share than in 11 of the 13 other Wyoming counties with 10 or more tested wells, leaving out 2 counties whose results are likely overstated. So test your own well for manganese before you count on it.
Where can I get my well tested in Campbell County?
Use a lab Wyoming has certified for drinking water. Wyoming's list is linked above, in the box about testing. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Campbell County.
How deep are wells in Campbell County?
Half the household wells here are shallower than 450 feet. That's the deepest typical depth for household wells among the 23 Wyoming counties with enough drilling records.
How does Campbell County compare with the counties around it?
For manganese, the share of tested wells over the limit: 1 of the 4 neighboring counties with data had a higher share than Campbell County, at 19%. Powder River, MT had the most, at 41%. Groundwater doesn't stop at county lines, so Powder River, MT's 41% is worth knowing about if you live near it.
How often should I test my well in Campbell County?
In Campbell County, 11 of 21 tested wells had coliform bacteria, so the CDC's advice matters here: test for bacteria and nitrate every year, and right away after a flood, a repair, or any change in taste or smell.
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Where the Campbell County numbers come from
- People on wells: 8,920 in Campbell County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 262 well water samples from 47 wells in the Water Quality Portal, run by the USGS and EPA, 2001 to 2021.
- Well depths: 1,115 Wyoming drilling records for Campbell County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 6 counties that share a border with Campbell County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 2 town water systems in Campbell County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Campbell County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Department of Environmental Quality (DEQ), Know Your Well program, checked November 1, 2026.