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Nitrate 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

Nitrate is widespread, over the limit in 15% or more of tested wells, in 1 of the 52 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 a nitrate test See every county

How New York compares with the rest of the country

Across New York, about 1 in 35 tested wells had nitrate over the EPA limit of 10 mg/L (44 of 1,544). Across all tested wells in the US it's about 1 in 12. That's less often than in the country as a whole. Counties still differ, so check yours below.

Why it matters: It's dangerous for babies under 6 months, because it keeps their blood from carrying enough oxygen.

Nitrate soaks down into groundwater from fertilizer, manure and septic systems.

Nitrate in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA limit of 10 mg/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
Kings County 35
29% 10 of 35
 Widespread
Queens County 104
12% 13 of 104
 Worth checking
Richmond County 23
9% 2 of 23
 Worth checking
Suffolk County 220
6% 14 of 220
 Worth checking
Washington County 17
6% 1 of 17
 Worth checking
Cortland County 19
5% 1 of 19
 Worth checking
New York County 25
4% 1 of 25
 Rare
Saratoga County 40
2% 1 of 40
 Rare
St. Lawrence County 43
2% 1 of 43
 Rare
Tompkins County 63
0% 0 of 63
 Rare
Ulster County 61
0% 0 of 61
 Rare
Westchester County 44
0% 0 of 44
 Rare
Nassau County 37
0% 0 of 37
 Rare
Essex County 33
0% 0 of 33
 Rare
Steuben County 33
0% 0 of 33
 Rare
Broome County 30
0% 0 of 30
 Rare
Delaware County 27
0% 0 of 27
 Rare
Allegany County 26
0% 0 of 26
 Rare
Cattaraugus County 26
0% 0 of 26
 Rare
Chautauqua County 25
0% 0 of 25
 Rare
Jefferson County 25
0% 0 of 25
 Rare
Oneida County 25
0% 0 of 25
 Rare
Warren County 24
0% 0 of 24
 Rare
Herkimer County 23
0% 0 of 23
 Rare
Monroe County 23
0% 0 of 23
 Rare
Erie County 22
0% 0 of 22
 Rare
Lewis County 22
0% 0 of 22
 Rare
Oswego County 22
0% 0 of 22
 Rare
Clinton County 21
0% 0 of 21
 Rare
Onondaga County 20
0% 0 of 20
 Rare
Chemung County 19
0% 0 of 19
 Rare
Chenango County 19
0% 0 of 19
 Rare
Madison County 19
0% 0 of 19
 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
Livingston County 17
0% 0 of 17
 Rare
Sullivan County 17
0% 0 of 17
 Rare
Otsego County 16
0% 0 of 16
 Rare
Tioga County 16
0% 0 of 16
 Rare
Wyoming County 16
0% 0 of 16
 Rare
Ontario County 15
0% 0 of 15
 Rare
Rensselaer County 14
0% 0 of 14
 Rare
Cayuga County 13
0% 0 of 13
 Rare
Fulton County 13
0% 0 of 13
 Rare
Albany County 12
0% 0 of 12
 Rare
Orange County 12
0% 0 of 12
 Rare
Schenectady County 12
0% 0 of 12
 Rare
Wayne County 11
0% 0 of 11
 Rare
Genesee County 10
0% 0 of 10
 Rare
Greene County 10
0% 0 of 10
 Rare
Schuyler County 10
0% 0 of 10
 Rare

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

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Where to get your well tested for nitrate 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 nitrate.

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 nitrate.

Compare kits

Keep reading about wells in New York

Questions people ask about nitrate in New York

Is there nitrate in New York well water?

Nitrate is widespread, over the limit in 15% or more of tested wells, in 1 of the 52 New York counties with 10 or more tested wells. Across New York, about 1 in 35 tested wells had nitrate over the EPA limit of 10 mg/L (44 of 1,544). Across all tested wells in the US it's about 1 in 12. 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 nitrate 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 nitrate 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 mg/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.