Manganese is worth checking in Champaign County wells.
1 worth checking, 2 rare out of 3 health checks.
From 10 wells tested in Champaign County since 2002; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: arsenic (9), uranium (9), radon (1), lead (9).
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
About 1 in 14 people 14,975 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Middle depth: some shelter from the surface, not complete.
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 Champaign County compares with Illinois and the counties around it.
Each result puts Champaign County next to the 6 counties that border it, on the chart's 0 to 50% scale.
This one is worth checking in Champaign County.
Manganese1 of 10 wells over
Too few tested to show: Douglas, Edgar, Ford, Piatt, Vermilion.
These 2 are rare in Champaign County.
Nitrate0 of 10 wells over
Too few tested to show: Douglas, Edgar, Ford, Piatt, Vermilion.
Fluoride0 of 10 wells over
Too few tested to show: Douglas, Edgar, Ford, Piatt, Vermilion.
Too few Champaign County wells were tested for these 4.
Arsenic9 wells tested
Uranium9 wells tested
Radon in water1 well tested
Lead9 wells tested
Coliform bacteria turned up in 1 of 6 tested Champaign County wells, so test for it every year.
Coliform bacteria1 of 6 wells had it
E. coli0 of 6 wells had it
E. coli means human or animal waste is getting in, so if a test of your Champaign County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 9 of 10 tested wells, and it isn't a health risk.
Iron stains9 of 10 wells had it
Too few tested to show: Douglas, Edgar, Ford, Piatt, Vermilion.
Champaign County has 10 tested wells, and the busiest decade for testing was the 2000s.
None of the 10 wells has a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Champaign 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 Champaign County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What Illinois offers well owners
- Free testingWe didn't find a free program for all of Illinois. Illinois's private well page
- Certified labsIllinois's list of certified labs
- Well recordsIllinois's well record search
Half the household wells here are shallower than 119 feet.
That comes from 2,780 household wells in Illinois's drilling records. Most wells of every kind here are 90 to 201 feet deep. Wells as deep as Champaign 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 are shallower than in 55 of the 101 other Illinois counties with enough drilling records.
Look up your own well's depth in Illinois'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 Champaign County.
Champaign 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 5 town water systems in Champaign County test for PFAS. None found any. No well in Champaign 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 Champaign County
Is well water in Champaign County safe to drink?
1 of 10 wells tested in Champaign County had manganese over the limit, about 1 in 10. Across Illinois it's about 1 in 8. That's a bigger share than in 4 of the 6 other Illinois counties with 10 or more tested wells. So test your own well for manganese before you count on it.
Where can I get my well tested in Champaign County?
Use a lab Illinois has certified for drinking water. Illinois's list is linked above, in the box about testing. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Champaign County.
How deep are wells in Champaign County?
Half the household wells here are shallower than 119 feet. Typical household wells here are shallower than in 55 of the 101 other Illinois counties with enough drilling records.
How does Champaign County compare with the counties around it?
For manganese, the share of tested wells over the limit: McLean, the one neighbor with data, came in lower than Champaign County, at 8% against 10%. Groundwater doesn't stop at county lines, so McLean's 8% is worth knowing about if you live near it.
How often should I test my well in Champaign County?
In Champaign County, 1 of 6 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 Champaign County numbers come from
- People on wells: 14,975 in Champaign County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 150 well water samples from 10 wells in the Water Quality Portal, run by the USGS and EPA, 2002 to 2018.
- Well depths: 2,780 Illinois drilling records for Champaign County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 6 counties that share a border with Champaign County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 5 town water systems in Champaign County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Champaign County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Illinois Department of Public Health, checked November 1, 2026.