Health problems are rare in tested Clinton County wells.
All 5 health checks came back rare here.
From 24 wells tested in Clinton County since 2000; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: uranium (4), 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 13,313 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 Clinton County compares with Iowa and the counties around it.
Each result puts Clinton County next to the 7 counties that border it, on the chart's 0 to 50% scale.
All 5 health checks are rare in Clinton County.
Manganese1 of 23 wells over
Too few tested to show: Carroll, IL, Cedar, Rock Island, IL, Whiteside, IL.
Nitrate0 of 11 wells over
Too few tested to show: Carroll, IL, Cedar, Jones, Rock Island, IL, Scott, Whiteside, IL.
Arsenic0 of 23 wells over
Too few tested to show: Carroll, IL, Cedar, Rock Island, IL, Whiteside, IL.
Fluoride0 of 23 wells over
Too few tested to show: Carroll, IL, Cedar, Rock Island, IL, Whiteside, IL.
Lead0 of 23 wells over
Too few tested to show: Carroll, IL, Cedar, Rock Island, IL, Whiteside, IL.
Too few Clinton County wells were tested for these 2.
Uranium4 wells tested
Radon in water1 well tested
None of the 7 Clinton County wells tested for bacteria had it, but every well needs a yearly test.
Coliform bacteria0 of 7 wells had it
E. coli0 of 7 wells had it
E. coli means human or animal waste is getting in, so if a test of your Clinton County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 11 of 23 tested wells, and it isn't a health risk.
Iron stains11 of 23 wells had it
Too few tested to show: Carroll, IL, Cedar, Rock Island, IL, Whiteside, IL.
Most of the 24 wells tested in Clinton County were last tested before 2010.
An old result shows the water as it was then, so treat these 24 wells as a starting point and test your own.
Most Clinton 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 Clinton County.
- Bacteria
- Nitrate
- Arsenic
What Iowa offers well owners
- Free testingIowa's Private Well Grants program provides free testing for bacteria, nitrate, arsenic, and manganese through participating county environmental health offices. See the program
- Certified labsIowa's list of certified labs
- Well recordsIowa's well record search
Half the household wells here are shallower than 195 feet.
That comes from 1,278 household wells in Iowa's drilling records. Most wells of every kind here are 100 to 215 feet deep. Wells as deep as Clinton 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 57 of the 92 other Iowa counties with enough drilling records.
Look up your own well's depth in Iowa'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 Clinton County.
Clinton 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 Clinton County test for PFAS. 1 found some PFAS, all below the new limits. No well in Clinton 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 Clinton County
Is well water in Clinton County safe to drink?
Most tested wells in Clinton County came in under the limits. Of 5 health checks with enough tests, manganese came closest, at 1 of 23 wells over. Every well is different, so test yours for bacteria, nitrate and arsenic.
Can I get my well tested for free in Clinton County?
Iowa's Private Well Grants program provides free testing for bacteria, nitrate, arsenic, and manganese through participating county environmental health offices. If not, use a lab Iowa has certified for drinking water. Ask for bacteria, nitrate and arsenic, the tests that matter most in Clinton County.
How deep are wells in Clinton County?
Half the household wells here are shallower than 195 feet. Typical household wells here go deeper than in 57 of the 92 other Iowa counties with enough drilling records.
How does Clinton County compare with the counties around it?
For manganese, the share of tested wells over the limit: Clinton County, at 4%, had a higher share than all 3 neighboring counties with data. Groundwater doesn't stop at county lines, so Jackson's 0% is worth knowing about if you live near it.
How often should I test my well in Clinton County?
None of the 7 wells tested for bacteria in Clinton 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 Clinton County numbers come from
- People on wells: 13,313 in Clinton County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 215 well water samples from 24 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2017.
- Well depths: 1,278 Iowa drilling records for Clinton County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 7 counties that share a border with Clinton County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 3 town water systems in Clinton County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Clinton County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Iowa Department of Natural Resources, checked November 1, 2026.