Arsenic is worth checking in Clay County wells.
1 worth checking, 4 rare out of 5 health checks.
From 76 wells tested in Clay County since 2002; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: uranium (1), 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 3 people 67,217 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
Radon risk (a gas from rock)
Less likely, but the EPA still says test your air.
Radon zones: EPA map
Here's how Clay County compares with Florida and the counties around it.
Each result puts Clay County next to the 5 counties that border it, on the chart's 0 to 50% scale.
This one is worth checking in Clay County.
Arsenic6 of 74 wells over
These 4 are rare in Clay County.
Lead1 of 73 wells over
Manganese1 of 75 wells over
Nitrate0 of 48 wells over
Too few Clay County wells were tested for these 2.
Uranium1 well tested
Radon in water1 well tested
Coliform bacteria turned up in 9 of 31 tested Clay County wells, so test for it every year.
Coliform bacteria9 of 31 wells had it
Too few tested to show: Bradford.
Most of Florida's bacteria results come from shallow monitoring-network wells, so they aren't a guide to household wells.
E. coli0 of 13 wells had it
Too few tested to show: Baker, Bradford, Duval, Putnam.
E. coli means human or animal waste is getting in, so if a test of your Clay County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 38 of 75 tested wells, and it isn't a health risk.
Iron stains38 of 75 wells had it
About 5 in 10 of the 76 wells tested in Clay County have a test from 2020 or later.
With 39 wells tested since 2020, age matters less here than who did the testing and why.
Most Clay 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 3 things to check in Clay County.
- Bacteria
- Nitrate
- Arsenic
What Florida offers well owners
- Free testingSome county health departments may test for certain toxic substances free of charge. See the program
- Certified labsFlorida's list of certified labs
- Well recordsWe didn't find an online search.
- New wellsNo statewide rule. We didn't find a local rule for Clay County, so ask its health department.
Here's what we know about radon and PFAS in Clay County.
Clay County is in the EPA's lowest radon zone, so radon from well water is unlikely to be a problem. Radon guide
Between 2023 and 2025 the EPA had 7 town water systems in Clay County test for PFAS. None found any. No well in Clay 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 Clay County
Is well water in Clay County safe to drink?
6 of 74 wells tested in Clay County had arsenic over the limit, about 1 in 12. Across Florida it's about 1 in 9. That's a bigger share than in 43 of the 63 other Florida counties with 10 or more tested wells. So test your own well for arsenic before you count on it.
Can I get my well tested for free in Clay County?
Some county health departments may test for certain toxic substances free of charge. If not, use a lab Florida has certified for drinking water. Ask for bacteria, nitrate and arsenic, the tests that matter most in Clay County.
How does Clay County compare with the counties around it?
For arsenic, the share of tested wells over the limit: 1 of the 5 neighboring counties with data had a higher share than Clay County, at 8%. Bradford had the most, at 46%. Groundwater doesn't stop at county lines, so Bradford's 46% is worth knowing about if you live near it.
How often should I test my well in Clay County?
In Clay County, 9 of 31 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 Clay County numbers come from
- People on wells: 67,217 in Clay County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 1,330 well water samples from 76 wells in the Water Quality Portal, run by the USGS and EPA, 2002 to 2025.
- Neighboring counties: the 5 counties that share a border with Clay County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 7 town water systems in Clay County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Clay County is zone 3 on the EPA Map of Radon Zones.
- State programs and links: Department of Health, checked November 1, 2026.