Well water testing in Fairfield County, Connecticut (2026)
Fairfield County has an estimated 73,000 households on private wells by EPA’s 2020 model, more than any other county in Connecticut. Connecticut has no county health departments. Your town health department or health district handles wells, and the state doesn’t make you test an existing well, so it’s up to you. Here are the state-certified labs inside the county, what they charge, and the extra tests western Connecticut’s bedrock calls for.
The short version
- Test the “basic indicators” every year. Test arsenic, uranium, and radon at least once, and ideally every 5 years. Test lead at least once too. That’s the CT DPH private-well guidance (updated May 2026).
- The cheapest posted local price is in Stamford. The city’s certified lab charges $40 for bacteria (total coliform and E. coli) and $80 for its Full Test. Drop-off is Monday to Thursday.
- Greenwich residents have their own town lab. Its 2026–27 fees are $62 for coliform, $47 for routine physicals, $45 for routine chemicals, and $86 for radon in water. You request a test online, and samples are taken Monday to Wednesday mornings.
- For arsenic, uranium, and organics in one place, ALS Environmental in Newtown is on DPH’s list for every private-well column. It doesn’t post prices, so call for a quote.
- Building a new well? State law sets the test list, including arsenic and uranium, and you can’t use the well until your local health department approves the results.
- Selling? No test is required. You must tell the buyer about DPH’s well-testing material. Buyers should test anyway.
Who to call: town health departments and three districts
Connecticut runs local public health through 59 local health agencies, either town departments or regional districts. In Fairfield County:
- Aspetuck Health District covers Easton, Weston, and Westport.
- Newtown Health District covers Newtown (plus Bridgewater and Roxbury next door).
- Naugatuck Valley Health District covers Shelton, along with towns outside the county.
- Everywhere else, it’s your town or city health department. Ridgefield’s, for example, approves well siting and construction, requires a water analysis on every new well before final approval, and recommends testing every year and before you buy a house (66 Prospect St, 203-431-2745).
Not sure which agency is yours? DPH’s Find Your LHD map lists them. Statewide questions go to the DPH Private Well Program at 860-509-8401.
State-certified labs in Fairfield County
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| Lab | What it’s certified for (private wells) | Posted prices | Practical details |
|---|---|---|---|
| Stamford Health Department Laboratory 888 Washington Blvd, 8th floor · 203-977-4378 |
Bacteria and inorganics (PH-0710). Not arsenic or uranium. | Potability (total coliform + E. coli) $40. Full Test $80: basic indicators plus alkalinity, calcium hardness, zinc, conductivity, flushed lead, copper, sodium, calcium, potassium, and magnesium. | Drop-off Mon–Thu, 8 am–3 pm. Use the lab’s containers. Pay by check or money order to the City of Stamford. The lab recommends testing at least bacteria every year. |
| Greenwich Health Department Laboratory Town Hall, 101 Field Point Rd · 203-622-7843 |
Bacteria, inorganics, arsenic, and radiological (PH-0703). Uranium isn’t marked. | Total coliform $62 · routine physicals $47 · routine chemicals $45 · nitrate or nitrite $46 · lead or arsenic $53 · lead profile $79 · radon in water $86 · bottle deposit $20 (2026–27 fees). | For Greenwich residents. Request a test with the online form. Samples are collected Monday to Wednesday, usually at 9 or 9:30 am, and chlorine has to be out of the system first. Results take about a week, and urgent 24-hour testing is available. |
| ALS Environmental – Newtown 56 Church Hill Rd #2, Newtown · 203-270-9973 |
Bacteria, inorganics, arsenic, uranium, radiological, and organics (PH-0843), the full private-well row. | No posted prices. Call for a quote. | ALS says it offers private test kits for homeowners and testing for real estate transfers. Town lists may still show this lab under its old name, Aqua Environmental Lab (same phone number). |
Short drives just outside the county: Aquatek Laboratories in Woodbridge (PH-0466) is marked for every private-well column, and Northwest Environmental Water Labs in Waterbury (PH-0537) also takes private-well samples. These Fairfield County labs aren’t marked for private-well samples on the October 2026 list, though they hold other drinking-water certifications: Complete Environmental Testing and ALS in Stratford, and the South Norwalk Electric & Water lab in Wilton. Brooks Laboratories (Norwalk) and Hydro-Technologies (New Milford) still appear on some town handouts but aren’t on DPH’s current drinking-water list. We leave out any lab that sells water treatment or belongs to a pump or treatment company.
Not certified, but useful: UConn Extension’s well-testing program runs a broad panel for $235. UConn says those results can’t be used for official purposes, such as real estate transactions or town-mandated tests.
What’s in Fairfield County groundwater
- Uranium and arsenic from bedrock. A USGS and CT DPH study of private-well samples from 2013–18 (2,433 tested for arsenic and 2,191 for uranium) estimated that 4.7% of the state is over the uranium limit of 30 µg/L and 3.9% is over the arsenic limit of 10 µg/L. Uranium of at least 1 µg/L turned up across about 45% of the state. When USGS released it, DPH urged all well owners to test for both, because routine tests usually don’t include them. Brookfield’s health department says “elevated uranium levels are not uncommon in western Connecticut.” It also says DPH testing puts Brookfield at higher risk because of its bedrock, and it recommends a uranium test on every new well.
- Radon in water. DPH’s recommended action level is 5,000 pCi/L, based on the average of two samples drawn at the same time (fact sheet, revised Feb 2025). Greenwich’s lab tests radon in water for $86.
- Sodium and chloride. Both are on DPH’s yearly basic-indicator list and in Stamford’s $80 Full Test. They’re worth watching if your well is close to a salted road or driveway.
- PFAS. Connecticut’s private-well action levels are 16 ppt for PFOA, 10 ppt for PFOS, 12 ppt for PFNA, and 49 ppt for PFHxS. PFAS isn’t in any routine panel. DPH and UConn Extension offer free PFAS testing for private wells at primary residences in select towns. Check UConn’s eligibility map for your address before you pay for a test. See our PFAS Method 533 / 537.1 guide.
New wells and home sales
New wells. Under CGS §19a-37(c), a private well built on or after October 1, 2022 must be tested for total coliform, nitrate, nitrite, sodium, chloride, iron, manganese, hardness, turbidity, pH, sulfate, apparent color, odor, arsenic, and uranium, plus first-draw lead for an existing building. You can’t use the well until your local health authority approves the results. In Greenwich, a town inspector collects the new-well sample and the town issues a Permit to Use after it passes (Greenwich well permit steps). The well permit itself is $693.
Sales and rentals. Connecticut doesn’t require a water test when you sell. Under §19a-37(d), before a sale, exchange, or rental of a property with a private well, the owner must tell the buyer or tenant about DPH’s educational material on well testing. Ridgefield and DPH both recommend testing before you buy. A law that took effect October 1, 2026 (Public Act 26-13, §31, summarized by the Office of Legislative Research) lets local health authorities share private-well test results with eligible people without the DPH commissioner’s sign-off, and adds certain nearby property owners to that list. It still doesn’t require a test at sale. More detail is on our home purchase / lender page.
Mail-in kits that email a PDF
If you can’t get to Stamford or Newtown on a weekday, independent mail-in labs ship to Fairfield County. Listed prices checked October 24, 2026:
- Tap Score / SimpleLab Essential Well: $209.
- National Testing Laboratories WaterCheck Basic: $220. Next-day return shipping isn’t included, so budget for it on the bacteria bottle. NTL is on DPH’s list of approved out-of-state labs.
These cost more than Stamford’s $80 Full Test. They make sense when you want bacteria, metals, and minerals in one readable report. Tap Score’s Essential Well (54 analytes) includes arsenic and uranium. NTL’s Basic covers 22 metals and minerals, but its uranium test is a separate radiological kit. Neither covers VOCs, radon in water, or PFAS; those need bigger or separate kits. Ask your lender or health department before using one for a sale or a new-well approval.
Side by side for a Fairfield County well
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| Stamford city lab | Greenwich town lab | ALS Newtown | Mail-in (Tap Score / NTL) | |
|---|---|---|---|---|
| Yearly bacteria | $40 | $62 (residents) | Call | Included in $209–$220 panel |
| Yearly chemistry panel | $80 Full Test (includes bacteria) | $47 physicals + $45 chemicals | Call | Included |
| Arsenic | Not certified | $53 | Call | Included |
| Uranium | Not certified | Not certified | Call | Included in Tap Score; separate NTL kit |
| Radon in water | No | $86 | Call | Separate kit |
| Sales visit? | No | No | No | No |
Remind me to test my well every year
CDC and EPA say to test a private well at least once a year. We’ll send one email a year, about when your test is due, with your state’s lab options.
Thanks, you’re on the list. We’ll email you once a year when it’s time to test your well. Nothing else.
What to do in Fairfield County
- Every year, test the basic indicators. Stamford’s $80 Full Test covers them, and Greenwich residents can use the town lab.
- Test arsenic, uranium, and radon at least once if you never have, especially in the western and northern towns. ALS Newtown is certified for all three. Or use Tap Score’s Essential Well for arsenic and uranium, plus a separate radon-in-water test (Greenwich residents: $86 at the town lab).
- Check the free PFAS program on UConn’s map before paying for PFAS.
- Got a result over a limit? Retest to confirm, then call your town health department or the DPH Private Well Program (860-509-8401) before you buy treatment.
- Want a PDF without driving? Use Tap Score / SimpleLab or National Testing Laboratories.
Not this if…
- You’re on public water. Your water system tests it and publishes a yearly report.
- You’re getting a new well approved. Use a Connecticut-certified lab, or your health department’s own sampler, and the state test list. Don’t use a mail-in kit.
- A lender named a lab and a chain-of-custody form. Use that lab.
- Someone offered a free in-home “test” that ends in a softener pitch. See the Home Depot free kit comparison.
Related: Connecticut well testing · Rockingham County, NH · Chester County, PA · Oakland County, MI · How to read a well water report · PFAS 533 / 537.1 · Home purchase / lender · back to the directory.