Well Water Nerd

Well water in Oxford County, Maine

In Oxford County, 9% of 953 private wells tested had uranium above the Maine guideline (30 ug/L), according to Maine CDC.

1,468 private wells tested in state summaries; 206 individual samples from 141 wells, 1953 to 2026. 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, 4% of 73 PFOS results in Oxford County were above the EPA limit of 4 ng/L. In that targeted sampling, 3% of 73 PFOA results in Oxford County 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. County and state figures combine the town summaries, weighted by wells tested; medians are not combined.

ContaminantWells testedAbove state levelMedian95th pctHighestState level
Uranium9539%30 ug/L
Arsenic1,1085%10 ug/L
Fluoride1,4684%2 mg/L
Manganese1,0764%300 ug/L
Nitrate1,347<1%10 mg/L
Nitrite1,3440%1 mg/L

What individual samples found

Each row summarizes every public sample for that contaminant inside Oxford County. 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
Arsenic
1977 to 2019
3174%16%0.133010 ug/L
EPA limit
Uranium
1979 to 2019
1593%7%4.5843.230 ug/L
EPA limit
Nitrate
1953 to 2019
12686%6%0.44511010 mg/L
EPA limit
PFOS
2019 to 2026
7325%4%05.284 ng/L
EPA limit
PFOA
2019 to 2026
7333%3%035.54 ng/L
EPA limit
PFHxS
2022 to 2026
7218%1%01210 ng/L
EPA limit
PFNA
2022 to 2026
724%0%00.90510 ng/L
EPA limit
Copper
1953 to 2019
33100%0%00.631.3 mg/L
EPA limit
Radium (226 + 228)
1979 to 2019
1587%0%035 pCi/L
EPA limit
Chloride
1953 to 2019
20696%no limit6.9380250 mg/L
nuisance level
Iron
1979 to 2005
1894%no limit11553,000300 ug/L
nuisance level
Manganese
1964 to 1989
18100%no limit50990300 ug/L
health guideline
Sodium
1964 to 1985
11100%no limit4.710020 mg/L
health guideline

Sampled fewer than 10 times, too few to summarize: Lead (9), Fluoride (7), E. coli (2), Radon (6).

Get the free Oxford County well report

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

What this means

Among homeowners in Oxford County who sent a sample to the state lab, the health-based limits most often exceeded were uranium (9% of 953 wells), arsenic (5% of 1,108 wells), and fluoride (4% of 1,468 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 Oxford County

  • Volatile organic compounds (VOCs)17 leaking underground storage tank sites on record locally.
  • PFAS37 unlined landfills on record locally.
  • Metals panel24 hazardous waste sites on record locally.
  • Fluoride4% of 1,468 local wells tested were above the Maine guideline.
  • PFOS4% of 73 local samples were above the limit.
  • Manganese4% of 1,076 local wells tested were above the Maine guideline.
  • PFOA3% of 73 local samples were above the limit.
  • PFHxS1% of 72 local samples were above the limit.
  • Coliform bacteriaRecommended for every private well, every year.

Wells in Oxford County

5,817 domestic wells in Oxford County are on record with the state since 1970. 98% are drilled into bedrock, and the typical well is 340 feet deep (one in ten goes past 600 feet).

In a typical Oxford County well, bedrock starts about 23 feet down, the median yield is 5 gallons per minute, 29% 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.

24
1970s
421
1980s
493
1990s
1,627
2000s
1,304
2010s
1,907
2020s

Contamination sources on record in Oxford County

Maine DEP records 17 leaking underground storage tank sites, 37 unlined landfills, and 24 hazardous waste sites in Oxford County, among 173 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.

17
leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
37
unlined landfillsOlder unlined landfills are a leading source of PFAS, VOCs and metals in nearby wells.
24
hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
95
other remediation projects

Treatment that fits the local profile

Uranium
Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
PFOS
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
PFOA
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange

Book a free water test in Oxford County

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 Oxford County?

The typical domestic well in Oxford County is 340 feet deep, based on 5,817 wells reported to the state since 1970. One in ten is deeper than 600 feet. 98% are drilled into bedrock.

Is there arsenic in well water in Oxford County?

Arsenic was detected in 74% of 31 public well samples in Oxford County, and 16% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.

How high is radon in well water in Oxford County?

The median radon level across 6 public samples in Oxford County was 3,590 pCi/L, with a high of 102,000 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Oxford County?

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.

Towns in Oxford County

15 towns have fewer than 30 public samples and are included in the Oxford County totals above rather than shown separately: Andover, Byron, Gilead, Greenwood, Hanover, Lincoln plantation, Milton UT, North Oxford UT, Roxbury, South Oxford UT, Stoneham, Stow, Sweden, Upton, West Paris.

Sources

  • USGS Water Quality Portal: 499 samples in Oxford County. 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 DEP PFAS investigation: 288 samples in Oxford County. 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 Oxford County, up to 1,468 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: 5,935 well records in Oxford County, 5,817 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: 173 regulated sites located in Oxford County. 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.