Well Water Nerd

Arsenic in Vermont well water

In Vermont, 3% of 22,062 private wells tested had arsenic above the Vermont limit (10 ug/L), according to the Vermont Department of Health.

Arsenic occurs naturally in New England bedrock and dissolves into well water. Long-term exposure raises the risk of bladder, lung and skin cancers, and is linked to heart disease and lower IQ in children. It has no taste or smell, so testing is the only way to know.

By county, from homeowner tests

Share of private wells above the state guidance level (10 ug/L) in tests homeowners sent to the state lab, to .

CountyWells testedAbove state levelHighest
Rutland1,55113%173 ug/L
Chittenden4,4754%194 ug/L
Orleans1,0504%103 ug/L
Lamoille1,6253%434 ug/L
Orange1,2183%135 ug/L
Franklin2,0173%116 ug/L
Bennington8563%43 ug/L
Addison1,8352%72 ug/L
Windham1,1841%262 ug/L
Caledonia1,0611%26 ug/L
Washington2,7601%344 ug/L
Windsor1,9611%103 ug/L
Grand Isle3490%9 ug/L
Essex1200%6 ug/L

Towns with the highest share above the state level

Sources

  • Vermont Tracking private well summaries: Town summaries of private well tests reported to the Vermont Department of Health, published through Vermont Environmental Public Health Tracking. Shares are against the limit Vermont applies to each analyte: arsenic 10 ug/L, uranium 20 ug/L (stricter than EPA), fluoride 4 mg/L, nitrate 10 mg/L, gross alpha 15 pCi/L, radon 4,000 pCi/L advisory. Only towns with 20 or more results are published; statistics below the reporting limit show as *. Retrieved September 3, 2026.
  • Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. arsenic counts and shares are listed on each county and town page with their sources.