Manganese has turned up often in Litchfield County wells, mostly in older study samples.
1 likely overstated, 1 worth checking, 5 rare out of 7 health checks.
From 42 wells tested in Litchfield County since 2002; your own well needs its own test. How to read this
*Manganese: All of these tests come from the US Geological Survey, mostly before 2013 in one small part of the county, so this likely overstates it.
*Radon: All of these tests come from the US Geological Survey between 2002 and 2005 in one small part of the county, so this likely overstates it.
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 66,566 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
Radon risk (a gas from rock)
Possible here. A home air test is inexpensive.
Radon zones: EPA map
Here's how Litchfield County compares with Connecticut and the counties around it.
Each result puts Litchfield County next to the 6 counties that border it, on the chart's 0 to 50% scale.
This one has turned up often here, mostly in older study samples.
Manganese8 of 42 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
All of these tests come from the US Geological Survey, mostly before 2013 in one small part of the county, so this likely overstates it.
This one is worth checking in Litchfield County.
Radon in water3 of 33 wells over
All of these tests come from the US Geological Survey between 2002 and 2005 in one small part of the county, so this likely overstates it.
These 5 are rare in Litchfield County.
Nitrate2 of 42 wells over
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
Arsenic0 of 40 wells over
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
Uranium0 of 40 wells over
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
Lead0 of 40 wells over
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
Fluoride0 of 42 wells over
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
Coliform bacteria turned up in 2 of 7 tested Litchfield County wells, so test for it every year.
Coliform bacteria2 of 7 wells had it
E. coli1 of 7 wells had it
E. coli means human or animal waste is getting in, so if a test of your Litchfield County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 5 of 42 tested wells, and it isn't a health risk.
Iron stains5 of 42 wells had it
Too few tested to show: Berkshire, MA, Dutchess, NY, Fairfield, New Haven.
Most of the 42 wells tested in Litchfield County were last tested before 2010.
An old result shows the water as it was then, so treat these 42 wells as a starting point and test your own.
Most Litchfield 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 5 things to check in Litchfield County.
- Bacteria
- Nitrate
- Manganese
- Radon in water
- Arsenic
What Connecticut offers well owners
- Free testingWe didn't find a free program for all of Connecticut. Connecticut's private well page
- Certified labsConnecticut's list of certified labs
- Well recordsWe didn't find an online search.
- New wellsUnder Section 19a-37 of the Connecticut General Statutes, water testing is required for all new private wells, but testing at home sale is not required by law.
Here's what we know about radon and PFAS in Litchfield County.
Litchfield County is in the EPA's middle radon zone. An indoor air test is cheap and tells you whether to look at your water. Radon guide
Between 2023 and 2025 the EPA had 10 town water systems in Litchfield 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 5.3 ng/L of PFOS. No well in Litchfield 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 Litchfield County
Is well water in Litchfield County safe to drink?
8 of 42 wells tested in Litchfield County had manganese over the limit, about 2 in 10. Across Connecticut it's about 2 in 10. We don't rank this against other Connecticut counties, because most of these tests are old study samples. All of these tests come from the US Geological Survey, mostly before 2013 in one small part of the county, so this likely overstates it. So test your own well for manganese before you count on it.
Where can I get my well tested in Litchfield County?
Use a lab Connecticut has certified for drinking water. Connecticut's list is linked above, in the box about testing. Ask for bacteria, nitrate, manganese, radon in water and arsenic, the tests that matter most in Litchfield County.
How does Litchfield County compare with the counties around it?
For manganese, the share of tested wells over the limit: Litchfield County, at 19%, had a higher share than all 2 neighboring counties with data. Groundwater doesn't stop at county lines, so Hampden, MA's 18% is worth knowing about if you live near it.
How often should I test my well in Litchfield County?
In Litchfield County, 2 of 7 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 Litchfield County numbers come from
- People on wells: 66,566 in Litchfield County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 591 well water samples from 42 wells in the Water Quality Portal, run by the USGS and EPA, 2002 to 2017.
- Neighboring counties: the 6 counties that share a border with Litchfield County, from the Census Bureau's county adjacency file.
- Results marked likely overstated: our own check of who tested the wells, when and where.
- PFAS: EPA tests of 10 town water systems in Litchfield County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Litchfield County is zone 2 on the EPA Map of Radon Zones.
- State programs and links: Department of Public Health, checked November 1, 2026.