Manganese is worth checking in Hartford County wells.
1 worth checking, 5 rare out of 6 health checks.
From 31 wells tested in Hartford County since 2002; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: radon (4).
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 21 people 43,263 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 Hartford County compares with Connecticut and the counties around it.
Each result puts Hartford County next to the 6 counties that border it, on the chart's 0 to 50% scale.
This one is worth checking in Hartford County.
Manganese3 of 23 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Middlesex, New Haven, Tolland.
These 5 are rare in Hartford County.
Nitrate0 of 26 wells over
Too few tested to show: Middlesex, New Haven.
Arsenic0 of 23 wells over
Too few tested to show: Middlesex, New Haven, Tolland.
Uranium0 of 23 wells over
Too few tested to show: Middlesex, New Haven, New London, Tolland.
Lead0 of 23 wells over
Too few tested to show: Middlesex, New Haven, New London, Tolland.
Fluoride0 of 23 wells over
Too few tested to show: Middlesex, New Haven, Tolland.
Too few Hartford County wells were tested for this one.
Radon in water4 wells tested
Coliform bacteria turned up in 2 of 10 tested Hartford County wells, so test for it every year.
Coliform bacteria2 of 10 wells had it
E. coli0 of 10 wells had it
E. coli means human or animal waste is getting in, so if a test of your Hartford County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 6 of 23 tested wells, and it isn't a health risk.
Iron stains6 of 23 wells had it
Too few tested to show: Middlesex, New Haven, Tolland.
Hartford County has 31 tested wells, and the busiest decade for testing was the 2000s.
None of the 31 wells has a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Hartford 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 Hartford County.
- Bacteria
- Nitrate
- Manganese
- 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 Hartford County.
Hartford 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 14 town water systems in Hartford County test for PFAS. 10 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 16 ng/L of PFOS. No well in Hartford 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 Hartford County
Is well water in Hartford County safe to drink?
3 of 23 wells tested in Hartford County had manganese over the limit, about 1 in 8. Across Connecticut it's about 2 in 10. So test your own well for manganese before you count on it.
Where can I get my well tested in Hartford 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 and arsenic, the tests that matter most in Hartford County.
How does Hartford County compare with the counties around it?
For manganese, the share of tested wells over the limit: 3 of the 3 neighboring counties with data had a higher share than Hartford County, at 13%. New London had the most, at 31%. Groundwater doesn't stop at county lines, so New London's 31% is worth knowing about if you live near it.
How often should I test my well in Hartford County?
In Hartford County, 2 of 10 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 Hartford County numbers come from
- People on wells: 43,263 in Hartford County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 491 well water samples from 31 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 Hartford County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 14 town water systems in Hartford County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Hartford County is zone 3 on the EPA Map of Radon Zones.
- State programs and links: Department of Public Health, checked November 1, 2026.