Arsenic has turned up often in Douglas County wells, mostly in older study samples.
1 likely overstated, 1 worth checking, 4 rare out of 6 health checks.
From 287 wells tested in Douglas County since 2000; your own well needs its own test. How to read this
*Arsenic: All of these tests come from the US Geological Survey, mostly before 2013, so this likely overstates it.
Not charted, because fewer than 10 wells were tested: radon (1).
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 4 people 12,057 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 Douglas County compares with Nevada and the counties around it.
Each result puts Douglas County next to the 6 counties that border it, on the chart's 0 to 50% scale.
This one has turned up often here, mostly in older study samples.
Arsenic12 of 16 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Alpine, CA.
All of these tests come from the US Geological Survey, mostly before 2013, so this likely overstates it.
This one is worth checking in Douglas County.
Manganese2 of 25 wells over
Too few tested to show: Alpine, CA.
These 4 are rare in Douglas County.
Fluoride4 of 96 wells over
Too few tested to show: Alpine, CA.
Nitrate10 of 275 wells over
Too few tested to show: Alpine, CA.
Uranium0 of 16 wells over
Too few tested to show: Alpine, CA.
Lead0 of 14 wells over
Too few tested to show: Alpine, CA, Lyon.
Too few Douglas County wells were tested for this one.
Radon in water1 well tested
Every well needs a bacteria test every year.
No bacteria tests from Douglas County wells are in the public data. Test every year anyway.
Iron reached staining levels in 2 of 36 tested wells, and it isn't a health risk.
Iron stains2 of 36 wells had it
Too few tested to show: Alpine, CA.
Most of the 287 wells tested in Douglas County were last tested before 2010.
An old result shows the water as it was then, so treat these 287 wells as a starting point and test your own.
Most Douglas 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 Douglas County.
- Bacteria
- Nitrate
- Arsenic
- Manganese
What Nevada offers well owners
- Free testingWe didn't find a free program for all of Nevada. Nevada's private well page
- Certified labsNevada's list of certified labs
- Well recordsNevada's well record search
Half the household wells here are shallower than 180 feet.
That comes from 4,955 household wells in Nevada's drilling records. Most wells of every kind here are 121 to 260 feet deep. Wells as deep as Douglas 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. Typical household wells here go deeper than in 10 of the 16 other Nevada counties with enough drilling records.
Look up your own well's depth in Nevada'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 Douglas County.
Douglas 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 7 town water systems in Douglas County test for PFAS. 2 found some PFAS, all below the new limits. No well in Douglas 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 Douglas County
Is well water in Douglas County safe to drink?
12 of 16 wells tested in Douglas County had arsenic over the limit, about 3 in 4. Across Nevada it's about 6 in 10. We don't rank this against other Nevada counties, because most of these tests are old study samples. All of these tests come from the US Geological Survey, mostly before 2013, so this likely overstates it. So test your own well for arsenic before you count on it.
Where can I get my well tested in Douglas County?
Use a lab Nevada has certified for drinking water. Nevada's list is linked above, in the box about testing. Ask for bacteria, nitrate, arsenic and manganese, the tests that matter most in Douglas County.
How deep are wells in Douglas County?
Half the household wells here are shallower than 180 feet. Typical household wells here go deeper than in 10 of the 16 other Nevada counties with enough drilling records.
How does Douglas County compare with the counties around it?
For arsenic, the share of tested wells over the limit: Douglas County, at 75%, had a higher share than all 5 neighboring counties with data. Groundwater doesn't stop at county lines, so Mono, CA's 49% is worth knowing about if you live near it.
How often should I test my well in Douglas County?
Douglas County has no public bacteria results for wells, so follow the CDC's advice: 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 Douglas County numbers come from
- People on wells: 12,057 in Douglas County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 2,086 well water samples from 287 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2023.
- Well depths: 4,955 Nevada drilling records for Douglas County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 6 counties that share a border with Douglas County, from the Census Bureau's county adjacency file.
- Results marked likely overstated: our own check of who tested the wells, when and where.
- PFAS: EPA tests of 7 town water systems in Douglas County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Douglas County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Division of Environmental Protection, checked November 1, 2026.