Radon in Water Testing Labs in Connecticut (4 state-certified labs)
Labs on Connecticut's official certification list that test drinking water for radon in water, with the ones that take homeowner samples first.
0 named for radon in water itself on the list.
Per the state list or a state web page. Call to confirm.
Located outside Connecticut but on its list.
USGS estimate for Connecticut.
How many labs test for radon in water in Connecticut
4 labs on Connecticut's official drinking-water lab list are certified to test for radon in water. Of these, 4 hold a group certification that includes it. 4 of them are marked as taking samples from the public. They are listed first.
The list is published by the Connecticut Department of Public Health - Environmental Laboratory Certification Program. List version on file: 10/09/2026. Fetched 2026-10-29 (UTC).
Connecticut labs certified for radon in water
Marked as taking public samples (4)
| Lab | Location | Radon in water certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| ALS Environmental - Newtown | Newtown, CT | Certified for a group that includes radon in water: confirm with the lab | Public samples: yes (per state) | Not on the list |
| Aquatek Labs, Inc. | Woodbridge, CT | Certified for a group that includes radon in water: confirm with the lab | Public samples: yes (per state) | Not on the list |
| Envirotech Laboratory | Windsor, CT | Certified for a group that includes radon in water: confirm with the lab | Public samples: yes (per state) | Not on the list |
| Greenwich Health Department Laboratory | Greenwich, CT | Certified for a group that includes radon in water: confirm with the lab | Public samples: yes (per state) | Not on the list |
How the Connecticut list marks public samples (whole list). Explicit 'Private Well Testing' column.
Before you send a sample, call the lab to confirm it is currently certified for the exact test and method, that it accepts samples from homeowners, and how to collect and ship them. Status can change between list updates.
Why test for radon in water in Connecticut
Most of the risk from radon in a well comes from breathing the gas the water releases indoors, not from drinking it. Read our radon in water explainer.
Connecticut guidance that mentions radon in water:
- Connecticut's health department guidance, as summarized by the state legislature's research office in 2019: basic indicators every year; lead at least once; arsenic, uranium and radon at least once and ideally every five years; VOCs at least once. [1]
- The local director of health may require testing for arsenic, radium, uranium, radon or gross alpha where there are reasonable grounds to suspect them, such as known local geology. [2]
EPA's radon zone map puts 4 of Connecticut's 8 historic counties in Zone 1 (highest potential), 3 in Zone 2 and 1 in Zone 3. [3] That map is about radon in indoor air, and EPA says it should not be used to decide whether an individual home needs testing. If radon is found in your air and you have a well, EPA suggests testing the water too.
About 861,472 people in Connecticut used private wells in 2015, by the USGS estimate of people on domestic self-supplied water. [4] Federal limits are written for public water systems, not private wells, so testing is up to the owner.
For tests that depend on your home (farms nearby, old plumbing, a new baby), use the which-tests checklist. When results arrive, check your numbers against EPA's limits. State guidance, county data and every lab: Connecticut.
Other tests in Connecticut
- Connecticut General Assembly OLR Research Report 2019-R-0246, Private well testing (Oct 16, 2019)
- Connecticut General Statutes ยง 19a-37 (current, chapter 368a)
- U.S. EPA, Map of Radon Zones, county list (EPA 402/A-16/001, spreadsheet Sep 2025)
- USGS, Estimated use of water in the United States, county-level data for 2015 (Dieter et al., ver. 2.0, 2018)
- CT DPH In-State Approved Commercial Laboratories Certified to Test Drinking Water (official list)
CT DPH In-State Approved Commercial Laboratories Certified to Test Drinking Water.
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