Microbac Laboratories, INC. - Dayville
Dayville
Certified for
- Arsenic
- Bacteria
- Minerals and metals (inorganics)
- Fuel and chemical compounds (organics)
- Uranium
Call to request a private well test kit and price.
Well water in Windham County, CT: what to know and what to test for
Bottom line
About5,800people on private wells may have arsenic above the drinking water limit of 10 micrograms per liter (likely 4,200 to 7,900).
In the middle range for Connecticut.
Indoor radon potential: Moderate
Connecticut recommends testing every private well for arsenic, uranium and radon at least once.
Find a certified labHow to read these numbers
USGS estimate based on 2010 population, published 2017.
Connecticut advises well owners to compare their results to this limit.
Larger counties have more well users, so higher counts don't mean any one well is more likely to be affected.
EPA zone for indoor air. It doesn't measure your well water.
What to test for
The Connecticut Department of Public Health recommends these tests for every private well.
| Test | How often |
|---|---|
| Basic indicators (bacteria, nitrate, pH, iron and other common measures) | Every year, and after any repair to your well, pump or pipes, or if your well head floods |
| Arsenic, uranium and radon in water | At least once, ideally every 5 years |
| Lead | At least once; also if you're planning a pregnancy or have a child under 6; every 3 to 5 years if your water is corrosive |
| Volatile organic compounds (VOCs: gasoline, oil, solvents) | At least once; more often if a problem is suspected |
| Fluoride | Every 5 years when a child under 12 lives in the home |
Questions about testing or treatment? Call the CT DPH Private Well Program at (860) 509-8401.
Where to test
Certified labs in Windham County that accept private-well samples.
These are the test groups marked yes for that lab. A yes means the lab is certified for some or all of the tests in that group.
Lab list current as of October 9, 2026, from the Connecticut Department of Public Health.