Well water in Stonington, Maine
In Stonington, 3% of 40 private wells tested had uranium above the Maine guideline (30 ug/L), according to Maine CDC.
54 private wells tested in state summaries; 18 individual samples from 18 wells, 2022 to 2023. Data refreshed September 3, 2026.
Maine DEP samples private wells near fields where sludge or septage was spread and near other known PFAS sources, and resamples detections. PFAS shares describe wells that were tested for a reason, not every well in the area. In that targeted sampling, 0% of 18 PFOA results in Stonington were above the EPA limit of 4 ng/L. In that targeted sampling, 0% of 18 PFOS results in Stonington were above the EPA limit of 4 ng/L.
What homeowner tests found
Maine Tracking Network private well summaries: private wells tested and reported to the state. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.
What individual samples found
Each row summarizes every public sample for that contaminant inside Stonington. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
Get the free Stonington well report
One email with the numbers above, what they mean for a home in Stonington, exactly which tests to order, and what treatment fits the local profile. No spam, unsubscribe in one click.
What this means
Among homeowners in Stonington who sent a sample to the state lab, the health-based limits most often exceeded were uranium (3% of 40 wells) and arsenic (2% of 45 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.
What to test for in Stonington
- Volatile organic compounds (VOCs)3 leaking underground storage tank sites on record locally.
- PFAS1 unlined landfill on record locally.
- Manganese9% of 43 local wells tested were above the Maine guideline.
- Uranium3% of 40 local wells tested were above the Maine guideline.
- Arsenic2% of 45 local wells tested were above the Maine guideline.
- Coliform bacteriaRecommended for every private well, every year.
- NitrateRecommended for every private well, especially near farms or septic systems.
Wells in Stonington
178 domestic wells in Stonington are on record with the state since 1971. 100% are drilled into bedrock, and the typical well is 220 feet deep (one in ten goes past 420 feet).
In a typical Stonington well, bedrock starts about 6 feet down, the median yield is 3 gallons per minute, 42% of wells yield under 3 gallons per minute and usually need a storage tank.
Bedrock wells are where arsenic, uranium and radon come from: the water sits in fractures in granite and metamorphic rock and picks up whatever the rock carries. That is why testing for those three matters more here than in a dug or gravel well.
Contamination sources on record in Stonington
Maine DEP records 3 leaking underground storage tank sites and 1 unlined landfill in Stonington, among 11 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 3
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 1
- unlined landfillOlder unlined landfills are a leading source of PFAS, VOCs and metals in nearby wells.
- 7
- other remediation projects
Treatment that fits the local profile
- Manganese
- Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Book a free water test in Stonington
A licensed local water treatment company tests your tap water in your home, walks you through the numbers, and quotes treatment only if something needs fixing. Free, about 30 minutes, no obligation.
Common questions
How deep are wells in Stonington?
The typical domestic well in Stonington is 220 feet deep, based on 178 wells reported to the state since 1971. One in ten is deeper than 420 feet. 100% are drilled into bedrock.
How often should I test a private well in Stonington?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Sources
- Maine DEP PFAS investigation: 72 samples in Stonington. PFAS results for private wells sampled by the Maine Department of Environmental Protection. Retrieved September 3, 2026.
- Maine Tracking Network private well summaries: summaries for 6 contaminants in Stonington, up to 54 wells each. Town summaries of private well tests run by the Maine Health and Environmental Testing Laboratory, published by Maine CDC through the Maine Tracking Network. Shares are against Maine's guideline for each analyte (arsenic 10 ug/L, uranium 30 ug/L, fluoride 2 mg/L, manganese 0.3 mg/L, nitrate 10 mg/L, nitrite 1 mg/L). Towns with too few tests are suppressed (NR). Only the share above the guideline and wells tested are published; no medians. Retrieved September 3, 2026.
- Maine Geological Survey well database: 185 well records in Stonington, 178 domestic. Well construction records reported to the Maine Geological Survey by licensed well drillers. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 3, 2026.
- Maine DEP regulated sites: 11 regulated sites located in Stonington. Remediation sites, leaking underground storage tanks and closed municipal landfills from the Maine Department of Environmental Protection. Retrieved September 3, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.