Arsenic is widespread in Scott County wells.
1 widespread, 3 rare out of 4 health checks.
From 20 wells tested in Scott County since 2001; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: nitrate (8).
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 9 people 18,981 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 Scott County compares with Iowa and the counties around it.
Each result puts Scott County next to the 4 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Scott County wells.
Arsenic4 of 17 wells over
Too few tested to show: Cedar, Rock Island, IL.
These 3 are rare in Scott County.
Manganese0 of 17 wells over
Too few tested to show: Cedar, Rock Island, IL.
Fluoride0 of 19 wells over
Too few tested to show: Cedar, Rock Island, IL.
Lead0 of 17 wells over
Too few tested to show: Cedar, Rock Island, IL.
Too few Scott County wells were tested for this one.
Nitrate8 wells tested
None of the 1 Scott 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 Scott County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 5 of 17 tested wells, and it isn't a health risk.
Iron stains5 of 17 wells had it
Too few tested to show: Cedar, Rock Island, IL.
Most of the 20 wells tested in Scott County were last tested before 2010.
An old result shows the water as it was then, so treat these 20 wells as a starting point and test your own.
Most Scott 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 Scott 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 232 feet.
That comes from 763 household wells in Iowa's drilling records. Most wells of every kind here are 96 to 265 feet deep. Wells as deep as Scott 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 73 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 Scott County.
Scott 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 Scott 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 4.1 ng/L of PFOA. No well in Scott 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 Scott County
Is well water in Scott County safe to drink?
4 of 17 wells tested in Scott County had arsenic over the limit, about 1 in 4. Across Iowa it's about 1 in 14. That's a bigger share than in 61 of the 68 other Iowa 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 Scott 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 Scott County.
How deep are wells in Scott County?
Half the household wells here are shallower than 232 feet. Typical household wells here go deeper than in 73 of the 92 other Iowa counties with enough drilling records.
How does Scott County compare with the counties around it?
For arsenic, the share of tested wells over the limit: Scott County, at 24%, had a higher share than all 2 neighboring counties with data. Groundwater doesn't stop at county lines, so Clinton's 0% is worth knowing about if you live near it.
How often should I test my well in Scott County?
None of the 1 wells tested for bacteria in Scott 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 Scott County numbers come from
- People on wells: 18,981 in Scott County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 144 well water samples from 20 wells in the Water Quality Portal, run by the USGS and EPA, 2001 to 2016.
- Well depths: 763 Iowa drilling records for Scott County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 4 counties that share a border with Scott County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 2 town water systems in Scott County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Scott County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Iowa Department of Natural Resources, checked November 1, 2026.