Manganese and lead are widespread in Westchester County wells.
2 widespread, 1 worth checking, 2 rare out of 5 health checks.
From 44 wells tested in Westchester County since 2006; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: uranium (9), radon (7).
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 22 people 45,497 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)
Less likely, but the EPA still says test your air.
Radon zones: EPA map
Here's how Westchester County compares with New York and the counties around it.
Each result puts Westchester County next to the 6 counties that border it, on the chart's 0 to 50% scale.
These 2 are widespread in Westchester County wells.
Manganese25 of 44 wells over
Too few tested to show: Bronx, Fairfield, CT, Putnam, Rockland.
Lead15 of 44 wells over
Too few tested to show: Bergen, NJ, Bronx, Fairfield, CT, Putnam, Rockland.
This one is worth checking in Westchester County.
Arsenic3 of 44 wells over
Too few tested to show: Bronx, Fairfield, CT, Putnam, Rockland.
These 2 are rare in Westchester County.
Nitrate0 of 44 wells over
Too few tested to show: Bronx, Fairfield, CT, Putnam, Rockland.
Fluoride0 of 44 wells over
Too few tested to show: Bronx, Fairfield, CT, Putnam, Rockland.
Too few Westchester County wells were tested for these 2.
Uranium9 wells tested
Radon in water7 wells tested
Coliform bacteria turned up in 1 of 7 tested Westchester County wells, so test for it every year.
Coliform bacteria1 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 Westchester County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 36 of 44 tested wells, and it isn't a health risk.
Iron stains36 of 44 wells had it
Too few tested to show: Bronx, Fairfield, CT, Putnam, Rockland.
Westchester County has 44 tested wells, and the busiest decade for testing was the 2010s.
None of the 44 wells has a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Westchester 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 Westchester County.
- Bacteria
- Nitrate
- Manganese
- Lead
- Arsenic
What New York offers well owners
- Free testingThe Private Well PFAS Testing and Mitigation Rebate Pilot Program offers limited free PFAS testing and treatment rebates in Dutchess, Orange, Putnam, Suffolk, Ulster and Westchester counties. See the program
- Certified labsNew York's list of certified labs
- Well recordsNew York's well record search
Half the household wells here are shallower than 465 feet.
That comes from 1,472 household wells in New York's drilling records. Most wells of every kind here are 325 to 630 feet deep. Wells as deep as Westchester 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. That's the deepest typical depth for household wells among the 57 New York counties with enough drilling records.
Look up your own well's depth in New York'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 Westchester County.
Westchester 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 29 town water systems in Westchester County test for PFAS. 8 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 112 ng/L of PFOA. No well in Westchester 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 Westchester County
Is well water in Westchester County safe to drink?
25 of 44 wells tested in Westchester County had manganese over the limit, about 6 in 10. Across New York it's about 1 in 7. That's the highest share among the 51 New York counties with 10 or more tested wells, leaving out 1 county whose results are likely overstated. So test your own well for manganese before you count on it.
Can I get my well tested for free in Westchester County?
The Private Well PFAS Testing and Mitigation Rebate Pilot Program offers limited free PFAS testing and treatment rebates in Dutchess, Orange, Putnam, Suffolk, Ulster and Westchester counties. If not, use a lab New York has certified for drinking water. Ask for bacteria, nitrate, manganese, lead and arsenic, the tests that matter most in Westchester County.
How deep are wells in Westchester County?
Half the household wells here are shallower than 465 feet. That's the deepest typical depth for household wells among the 57 New York counties with enough drilling records.
How does Westchester County compare with the counties around it?
For manganese, the share of tested wells over the limit: Westchester County, at 57%, had a higher share than all 2 neighboring counties with data. Groundwater doesn't stop at county lines, so Bergen, NJ's 17% is worth knowing about if you live near it.
How often should I test my well in Westchester County?
In Westchester County, 1 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 Westchester County numbers come from
- People on wells: 45,497 in Westchester County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 378 well water samples from 44 wells in the Water Quality Portal, run by the USGS and EPA, 2006 to 2018.
- Well depths: 1,472 New York drilling records for Westchester County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 6 counties that share a border with Westchester County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 29 town water systems in Westchester County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Westchester County is zone 3 on the EPA Map of Radon Zones.
- State programs and links: Department of Health, checked November 1, 2026.