Arsenic is widespread in Lyon County wells.
1 widespread, 4 worth checking out of 5 health checks.
From 42 wells tested in Lyon County since 2002; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: radon (4), lead (5).
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 11,849 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 Lyon County compares with Nevada and the counties around it.
Each result puts Lyon County next to the 7 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Lyon County wells.
Arsenic5 of 11 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Mineral, Storey.
These 4 are worth checking in Lyon County.
Manganese3 of 36 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Storey.
Uranium1 of 16 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Storey.
Fluoride2 of 33 wells over
Nitrate1 of 19 wells over
Too few tested to show: Mineral, Storey.
Too few Lyon County wells were tested for these 2.
Radon in water4 wells tested
Lead5 wells tested
None of the 1 Lyon County wells tested for bacteria had it, but every well needs a yearly test.
Coliform bacteria0 of 1 wells had it
E. coli0 of 1 wells had it
E. coli means human or animal waste is getting in, so if a test of your Lyon County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 2 of 34 tested wells, and it isn't a health risk.
Iron stains2 of 34 wells had it
Too few tested to show: Storey.
Lyon County has 42 tested wells, and the busiest decade for testing was the 2000s.
Only 1 of the 42 wells have a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Lyon 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 6 things to check in Lyon County.
- Bacteria
- Nitrate
- Arsenic
- Manganese
- Uranium
- Fluoride
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 160 feet.
That comes from 5,384 household wells in Nevada's drilling records. Most wells of every kind here are 120 to 260 feet deep. Wells as deep as Lyon 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 7 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 Lyon County.
Lyon 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 3 town water systems in Lyon County test for PFAS. 1 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 5.6 ng/L of PFOS. No well in Lyon 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 Lyon County
Is well water in Lyon County safe to drink?
5 of 11 wells tested in Lyon County had arsenic over the limit, about 5 in 10. Across Nevada it's about 6 in 10. That's the highest share among the 7 Nevada counties with 10 or more tested wells, leaving out 2 counties whose results are likely overstated. So test your own well for arsenic before you count on it.
Where can I get my well tested in Lyon 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, manganese, uranium and fluoride, the tests that matter most in Lyon County.
How deep are wells in Lyon County?
Half the household wells here are shallower than 160 feet. Typical household wells here go deeper than in 7 of the 16 other Nevada counties with enough drilling records.
How does Lyon County compare with the counties around it?
For arsenic, the share of tested wells over the limit: 3 of the 5 neighboring counties with data had a higher share than Lyon County, at 45%. Churchill had the most, at 88%. Groundwater doesn't stop at county lines, so Churchill's 88% is worth knowing about if you live near it.
How often should I test my well in Lyon County?
None of the 1 wells tested for bacteria in Lyon County had it, but the CDC still says to 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 Lyon County numbers come from
- People on wells: 11,849 in Lyon County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 340 well water samples from 42 wells in the Water Quality Portal, run by the USGS and EPA, 2002 to 2021.
- Well depths: 5,384 Nevada drilling records for Lyon County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 7 counties that share a border with Lyon County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 3 town water systems in Lyon County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Lyon County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Division of Environmental Protection, checked November 1, 2026.