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Arsenic in New York well water, by county

By the Tested Water teamLab data from the USGS and EPA Water Quality Portal, 2000 to 2023Updated November 8, 2026

Arsenic is widespread, over the limit in 15% or more of tested wells, in 2 of the 50 New York counties with 10 or more tested wells. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

Find an arsenic test See every county

How New York compares with the rest of the country

Across New York, about 1 in 28 tested wells had arsenic over the EPA limit of 10 µg/L (47 of 1,322). Across all tested wells in the US it's about 1 in 9. That's less often than in the country as a whole. Counties still differ, so check yours below.

Why it matters: Drinking it for years raises the risk of skin, bladder and lung cancer.

Arsenic dissolves out of certain rocks and old sediments, so it can be high even where nobody has polluted anything.

Arsenic in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA limit of 10 µg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Monroe County 16
31% 5 of 16
 Widespread
Tioga County 16
19% 3 of 16
 Widespread
Greene County 10
10% 1 of 10
 Worth checking
Broome County 31
10% 3 of 31
 Worth checking
Wayne County 11
9% 1 of 11
 Worth checking
Oneida County 25
8% 2 of 25
 Worth checking
Allegany County 26
8% 2 of 26
 Worth checking
Rensselaer County 13
8% 1 of 13
 Worth checking
Westchester County 44
7% 3 of 44
 Worth checking
Ulster County 62
6% 4 of 62
 Worth checking
Onondaga County 16
6% 1 of 16
 Worth checking
Steuben County 16
6% 1 of 16
 Worth checking
Livingston County 17
6% 1 of 17
 Worth checking
Sullivan County 17
6% 1 of 17
 Worth checking
Chenango County 19
5% 1 of 19
 Worth checking
Saratoga County 40
5% 2 of 40
 Worth checking
Tompkins County 62
5% 3 of 62
 Rare
Nassau County 22
5% 1 of 22
 Rare
Oswego County 22
5% 1 of 22
 Rare
Richmond County 23
4% 1 of 23
 Rare
Chautauqua County 25
4% 1 of 25
 Rare
Queens County 103
4% 4 of 103
 Rare
Suffolk County 69
3% 2 of 69
 Rare
St. Lawrence County 43
0% 0 of 43
 Rare
Kings County 35
0% 0 of 35
 Rare
Essex County 33
0% 0 of 33
 Rare
Delaware County 27
0% 0 of 27
 Rare
Cattaraugus County 26
0% 0 of 26
 Rare
Jefferson County 25
0% 0 of 25
 Rare
New York County 25
0% 0 of 25
 Rare
Warren County 24
0% 0 of 24
 Rare
Herkimer County 23
0% 0 of 23
 Rare
Erie County 22
0% 0 of 22
 Rare
Lewis County 22
0% 0 of 22
 Rare
Clinton County 21
0% 0 of 21
 Rare
Schoharie County 18
0% 0 of 18
 Rare
Franklin County 17
0% 0 of 17
 Rare
Hamilton County 17
0% 0 of 17
 Rare
Washington County 17
0% 0 of 17
 Rare
Madison County 16
0% 0 of 16
 Rare
Wyoming County 16
0% 0 of 16
 Rare
Ontario County 15
0% 0 of 15
 Rare
Otsego County 15
0% 0 of 15
 Rare
Cortland County 13
0% 0 of 13
 Rare
Fulton County 13
0% 0 of 13
 Rare
Albany County 12
0% 0 of 12
 Rare
Cayuga County 12
0% 0 of 12
 Rare
Orange County 12
0% 0 of 12
 Rare
Schenectady County 12
0% 0 of 12
 Rare
Genesee County 10
0% 0 of 10
 Rare

12 more New York counties have 1 to 9 tested wells for arsenic, too few to rate.

Download this table (CSV) · Free to reuse under CC BY 4.0

Where to get your well tested for arsenic in New York

1

Free testing, with limits

Free PFAS testing in New York is limited to a pilot in 6 counties. Check which tests it includes before you count on it for arsenic.

New York's private well page
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include arsenic.

Compare kits

Keep reading about wells in New York

Questions people ask about arsenic in New York

Is there arsenic in New York well water?

Arsenic is widespread, over the limit in 15% or more of tested wells, in 2 of the 50 New York counties with 10 or more tested wells. Across New York, about 1 in 28 tested wells had arsenic over the EPA limit of 10 µg/L (47 of 1,322). Across all tested wells in the US it's about 1 in 9. That's less often than in the country as a whole. Counties still differ, so check yours below.

Where can I get my well tested for arsenic in New York?

Free PFAS testing in New York is limited to a pilot in 6 counties. If that doesn't cover you, use a lab certified by New York for drinking water, or a mail-in kit that includes arsenic from a certified lab.

See New York's list of certified labs, or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA limit of 10 µg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Department of Health.