Well Water Nerd

Well water in Durham, Maine

In Durham, 3% of 130 private wells tested had uranium above the Maine guideline (30 ug/L), according to Maine CDC.

286 private wells tested in state summaries; 27 individual samples from 27 wells, 1964 to 2025. 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, 7% of 27 PFOS results in Durham were above the EPA limit of 4 ng/L. In that targeted sampling, 0% of 27 PFOA results in Durham 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.

ContaminantWells testedAbove state levelMedian95th pctHighestState level
Uranium1303%30 ug/L
Fluoride2862%2 mg/L
Manganese2311%300 ug/L
Arsenic233<1%10 ug/L
Nitrate256<1%10 mg/L
Nitrite2550%1 mg/L

What individual samples found

Each row summarizes every public sample for that contaminant inside Durham. 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.

ContaminantSamplesDetectedAbove limitMedianHighestLimit
PFOS
2022 to 2025
2711%7%06.854 ng/L
EPA limit
PFOA
2022 to 2025
2741%0%01.364 ng/L
EPA limit
PFNA
2022 to 2025
270%0%0010 ng/L
EPA limit
PFHxS
2022 to 2025
270%0%0010 ng/L
EPA limit

Sampled fewer than 10 times, too few to summarize: Nitrate (3), Chloride (3).

Get the free Durham well report

One email with the numbers above, what they mean for a home in Durham, exactly which tests to order, and what treatment fits the local profile. No spam, unsubscribe in one click.

What this means

Among homeowners in Durham who sent a sample to the state lab, the health-based limits most often exceeded were uranium (3% of 130 wells), fluoride (2% of 286 wells), and arsenic (<1% of 233 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 Durham

  • Volatile organic compounds (VOCs)3 leaking underground storage tank sites on record locally.
  • PFAS1 unlined landfill on record locally.
  • PFOS7% of 27 local samples were above the limit.
  • Uranium3% of 130 local wells tested were above the Maine guideline.
  • Fluoride2% of 286 local wells tested were above the Maine guideline.
  • Manganese1% of 231 local wells tested were above the Maine guideline.
  • Arsenic<1% of 233 local wells tested were above the Maine guideline.
  • Nitrate<1% of 256 local wells tested were above the Maine guideline.
  • Coliform bacteriaRecommended for every private well, every year.
  • ChlorideDetected in 100% of local samples.

Wells in Durham

486 domestic wells in Durham are on record with the state since 1970. 93% are drilled into bedrock, and the typical well is 305 feet deep (one in ten goes past 530 feet).

In a typical Durham well, bedrock starts about 21 feet down, the median yield is 7 gallons per minute, 25% 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.

41
1970s
32
1980s
88
1990s
99
2000s
95
2010s
103
2020s

Contamination sources on record in Durham

Maine DEP records 3 leaking underground storage tank sites and 1 unlined landfill in Durham, among 5 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.
1
other remediation project

Treatment that fits the local profile

PFOS
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
Chloride
Point-of-use reverse osmosis; Distillation

Book a free water test in Durham

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.

What are you worried about?

The test is free and there is no obligation. Your details go only to the company named above, and we log the time and address of this request.

Common questions

How deep are wells in Durham?

The typical domestic well in Durham is 305 feet deep, based on 486 wells reported to the state since 1970. One in ten is deeper than 530 feet. 93% are drilled into bedrock.

How often should I test a private well in Durham?

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: 108 samples in Durham. PFAS results for private wells sampled by the Maine Department of Environmental Protection. Retrieved September 3, 2026.
  • USGS Water Quality Portal: 6 samples in Durham. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
  • Maine Tracking Network private well summaries: summaries for 6 contaminants in Durham, up to 286 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: 510 well records in Durham, 486 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: 5 regulated sites located in Durham. 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.