Coliform Bacteria Water Testing Labs in Connecticut (16 state-certified labs)
Labs on Connecticut's official certification list that test drinking water for coliform bacteria, with the ones that take homeowner samples first.
16 named for coliform bacteria 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 coliform bacteria in Connecticut
16 labs on Connecticut's official drinking-water lab list are certified to test for coliform bacteria. All 16 are named for coliform bacteria on the list. 13 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 coliform bacteria
Marked as taking public samples (13)
| Lab | Location | Bacteria certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| ALS Environmental - Newtown | Newtown, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Aquatek Labs, Inc. | Woodbridge, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Eastern Analytical Laboratory, Inc. | Old Saybrook, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| EMSL Analytical, Inc. - CT | Meriden, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Environmental Consulting Lab | Madison, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Environmental Monitoring Lab | Wallingford, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Envirotech Laboratory | Windsor, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Greenwich Health Department Laboratory | Greenwich, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Microbac Laboratories, INC. - Dayville | Dayville, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Northeast Laboratories, Inc | Rocky Hill, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Northwest Environmental Water Labs | Waterbury, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Regional Water Authority | New Haven, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
| Stamford Health Department Laboratory | Stamford, CT | Named on the official list | Public samples: yes (per state) | Not on the list |
Other labs on the list (3)
| Lab | Location | Bacteria certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| Complete Environmental Testing, Inc. | Stratford, CT | Named on the official list | Not marked as taking public samples | Not on the list |
| Phoenix Environmental Laboratories, Inc. | Manchester, CT | Named on the official list | Not marked as taking public samples | Not on the list |
| South Norwalk Electric & Water Laboratory | Wilton, CT | Named on the official list | Not marked as taking public samples | 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 coliform bacteria in Connecticut
About a third of the 397 domestic wells tested for bacteria in a national USGS study had total coliform. Read our coliform bacteria explainer.
EPA advises private-well owners to test every year for total coliform bacteria, nitrates, total dissolved solids and pH. [1]
Connecticut guidance that mentions coliform bacteria:
- New wells: since October 1, 2022, the owner of every newly built private well must have it tested by a laboratory, including coliform, nitrate, nitrite, sodium, chloride, iron, manganese, hardness, turbidity, pH, sulfate, color, odor, arsenic and uranium (plus a first-draw lead sample if the well serves an existing building), and send the results to the local health authority. A new well may not be used for household purposes until the local health authority finds the results meet the state limits. [2]
About 861,472 people in Connecticut used private wells in 2015, by the USGS estimate of people on domestic self-supplied water. [3] 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
- U.S. EPA, Protect your home's water
- Connecticut General Statutes ยง 19a-37 (current, chapter 368a)
- 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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