Manganese is widespread in Rensselaer County wells.

1 widespread, 1 worth checking, 5 rare out of 7 health checks.

From 14 wells tested in Rensselaer County since 2006; your own well needs its own test. How to read this

Tested wells over the limit RensselaerNew York

Manganese15%2 of 13 Arsenic8%1 of 13 Nitrate0%0 of 14 Lead0%0 of 13 Radon0%0 of 14 Uranium0%0 of 13 Fluoride0%0 of 13

GermsTest every year, whatever the chart says

Coliform bacteria7%1 of 14 E. coli0%0 of 14

StainsNot a health risk

Iron stains23%3 of 13

Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+

Lab results: Water Quality Portal (USGS and EPA)

Show bacteria and iron

Who drinks from a well here

1 in 3 people 47,239 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)

LowMiddleHigh

Likely here. Test your home's air first.

Radon zones: EPA map

Here's how Rensselaer County compares with New York and the counties around it.

Each result puts Rensselaer County next to the 7 counties that border it, on the chart's 0 to 50% scale.

This one is widespread in Rensselaer County wells.

Manganese2 of 13 wells over

2 of 13 wells tested here from 2006 to 2022 were over the EPA health advisory of 0.3 mg/L, against about 1 in 7 across New York. Half the results were under 0.042 mg/L, and the top 1 in 10 were 0.31 mg/L or more. That's a bigger share than in 36 of the 50 other New York counties with 10 or more tested wells, leaving out 1 county whose results are likely overstated.

Rensselaer and its neighbors

Greene20%

Rensselaer15%

Saratoga10%

Albany0%

Washington0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Manganese guide

This one is worth checking in Rensselaer County.

Arsenic1 of 13 wells over

1 of 13 wells tested here from 2006 to 2022 was over the EPA limit of 10 µg/L, against about 1 in 28 across New York. Half the results were under 0.65 µg/L, and the top 1 in 10 were 6.4 µg/L or more. That's a bigger share than in 42 of the 49 other New York counties with 10 or more tested wells.

Rensselaer and its neighbors

Greene10%

Rensselaer8%

Saratoga5%

Albany0%

Washington0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Arsenic guide

These 5 are rare in Rensselaer County.

Nitrate0 of 14 wells over

None of the 14 wells tested here from 2006 to 2022 were over the EPA limit of 10 mg/L, against about 1 in 35 across New York. Half the results were under 0.19 mg/L, and the top 1 in 10 were 2.6 mg/L or more. Rensselaer County had none, while 9 of the 51 other New York counties with 10 or more tested wells had at least one.

Rensselaer and its neighbors

Washington6%

Saratoga2%

Albany0%

Greene0%

Rensselaer0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Nitrate guide

Lead0 of 13 wells over

None of the 13 wells tested here from 2006 to 2022 were over the EPA action level of 15 µg/L, against about 1 in 40 across New York. Half the results were under 0.15 µg/L, and the top 1 in 10 were 1.9 µg/L or more. Rensselaer County had none, while 3 of the 51 other New York counties with 10 or more tested wells had at least one.

Rensselaer and its neighbors

Albany0%

Greene0%

Rensselaer0%

Saratoga0%

Washington0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Lead guide

Radon in water0 of 14 wells over

None of the 14 wells tested here from 2006 to 2022 were over 4,000 pCi/L, a level the EPA proposed, against under 1 in 50 across New York. Half the results were under 570 pCi/L, and the top 1 in 10 were 2,070 pCi/L or more. Rensselaer County had none, while 7 of the 45 other New York counties with 10 or more tested wells had at least one.

Rensselaer and its neighbors

Albany0%

Greene0%

Rensselaer0%

Saratoga0%

Washington0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Radon guide

Uranium0 of 13 wells over

None of the 13 wells tested here from 2006 to 2022 were over the EPA limit of 30 µg/L, against under 1 in 100 across New York. Half the results were under 0.34 µg/L, and the top 1 in 10 were 1.9 µg/L or more. Rensselaer County had none, while 3 of the 46 other New York counties with 10 or more tested wells had at least one.

Rensselaer and its neighbors

Albany0%

Greene0%

Rensselaer0%

Saratoga0%

Washington0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Uranium guide

Fluoride0 of 13 wells over

None of the 13 wells tested here from 2006 to 2022 were over the EPA limit of 4 mg/L, against under 1 in 100 across New York. Half the results were under 0.09 mg/L, and the top 1 in 10 were 0.17 mg/L or more. Rensselaer County had none, while 2 of the 51 other New York counties with 10 or more tested wells had at least one.

Rensselaer and its neighbors

Albany0%

Greene0%

Rensselaer0%

Saratoga0%

Washington0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Coliform bacteria turned up in 1 of 14 tested Rensselaer County wells, so test for it every year.

Coliform bacteria1 of 14 wells had it

1 of 14 wells tested here from 2006 to 2022 had coliform bacteria, against about 1 in 4 across New York.

Rensselaer and its neighbors

Greene20%

Albany17%

Washington12%

Rensselaer7%

Saratoga5%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Bacteria guide

E. coli0 of 14 wells had it

None of the 14 wells tested here from 2006 to 2022 had E. coli, against about 1 in 26 across New York.

Rensselaer and its neighbors

Albany8%

Washington6%

Greene0%

Rensselaer0%

Saratoga0%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

E. coli means human or animal waste is getting in, so if a test of your Rensselaer County well finds it, boil drinking water until the well is fixed.

Bacteria guide

Iron reached staining levels in 3 of 13 tested wells, and it isn't a health risk.

Iron stains3 of 13 wells had it

3 of 13 wells tested here from 2006 to 2022 had enough iron to stain (0.3 mg/L), against about 4 in 10 across New York.

Rensselaer and its neighbors

Albany33%

Saratoga28%

Rensselaer23%

Washington12%

Greene10%

Too few tested to show: Bennington, VT, Berkshire, MA, Columbia.

Iron guide

Rensselaer County has 14 tested wells, and the busiest decade for testing was the 2000s.

7 wells had a test in the 2000s, 7 in the 2010s and 2 since 2020.

Only 2 of the 14 wells have a test from 2020 or later, so a fresh test of your own well tells you more than any of these.

Most Rensselaer 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 Rensselaer County.

Bacteria
Nitrate
Manganese
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 310 feet.

That comes from 4,223 household wells in New York's drilling records. Most wells of every kind here are 220 to 420 feet deep. Wells as deep as Rensselaer 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. Typical household wells here go deeper than in 49 of the 56 other 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 Rensselaer County.

Rensselaer County is in the EPA's highest radon zone. Radon from well water adds to the radon in your indoor air, so test your air first, and your water too if the air is high. Radon guide

Between 2023 and 2025 the EPA had 7 town water systems in Rensselaer County test for PFAS. None found any. No well in Rensselaer 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

Next door to Rensselaer County

Saratoga

Elsewhere in New York

Orange Ulster St. Lawrence Oneida Oswego Steuben Westchester

All of New York

Questions people ask about well water in Rensselaer County

Is well water in Rensselaer County safe to drink?

2 of 13 wells tested in Rensselaer County had manganese over the limit, about 2 in 10. Across New York it's about 1 in 7. That's a bigger share than in 36 of the 50 other 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 Rensselaer 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 and arsenic, the tests that matter most in Rensselaer County.

How deep are wells in Rensselaer County?

Half the household wells here are shallower than 310 feet. Typical household wells here go deeper than in 49 of the 56 other New York counties with enough drilling records.

How does Rensselaer County compare with the counties around it?

For manganese, the share of tested wells over the limit: 1 of the 4 neighboring counties with data had a higher share than Rensselaer County, at 15%. Greene had the most, at 20%. Groundwater doesn't stop at county lines, so Greene's 20% is worth knowing about if you live near it.

How often should I test my well in Rensselaer County?

In Rensselaer County, 1 of 14 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.

By the Tested Water teamData from the USGS, EPA and Department of HealthUpdated November 8, 2026

If you buy something through our links, we may earn a commission. We'd recommend the same thing either way, and we'll tell you when a free option exists. How we make money

Where the Rensselaer County numbers come from

People on wells: 47,239 in Rensselaer County, from EPA estimates built on the 2020 Census (Murray et al.).
Lab tests: 154 well water samples from 14 wells in the Water Quality Portal, run by the USGS and EPA, 2006 to 2022.
Well depths: 4,223 New York drilling records for Rensselaer County, gathered in the US Groundwater Well Database (Lin and others, 2024).
Neighboring counties: the 7 counties that share a border with Rensselaer County, from the Census Bureau's county adjacency file.
PFAS: EPA tests of 7 town water systems in Rensselaer County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
Radon: Rensselaer County is zone 1 on the EPA Map of Radon Zones.
State programs and links: Department of Health, checked November 1, 2026.

Download this county's data (CSV)How we read these numbers Report an error