Well Water Nerd

Well water in Oxford County, Maine

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Testing recommended

private wells tested in Oxford County had uranium above the Maine guideline (30 ug/L), according to Maine CDC.

The strongest signal is arsenic: 16% of 31 local samples were above the limit, too few samples to carry the headline but first on the test list below.

1,468 private wells tested in state summaries; 1,484 test results across 17 contaminants from at least 142 wells, 1953 to 2026; nitrate has the most at 289. Data refreshed September 15, 2026.

Compiled by Nick at Well Water Nerd from public records. How these pages are built

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.

An estimated 38,444 people in Oxford County get their drinking water from a private well, per USGS 2015 county water use. That is about 67% of residents.

Separately, the USGS national arsenic model estimates that 16% of the 38,444 people on private wells in Oxford County draw water above 10 ug/L (the model's range is 12% to 21%), from geology and well depth rather than local tests.

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.

ContaminantAbove state levelWells testedMedian95th pctHighestState level
Uranium95330 ug/L
Arsenic1,10810 ug/L
Fluoride1,4682 mg/L
Manganese1,076300 ug/L
Nitrate1,34710 mg/L
Nitrite1,3441 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.

ContaminantAbove limitSamplesDetectedMedianHighestLimit
Arsenic
1977 to 2019
3174%0.133010 ug/L
EPA limit
Uranium
1979 to 2019
1593%4.5843.230 ug/L
EPA limit
PFOS
2019 to 2026
7325%05.284 ng/L
EPA limit
Nitrate
1953 to 2019
28983%0.3211010 mg/L
EPA limit
PFOA
2019 to 2026
7333%035.54 ng/L
EPA limit
PFHxS
2022 to 2026
7218%01210 ng/L
EPA limit
Fluoride
1953 to 2019
12666%0.13.184 mg/L
EPA limit
PFNA
2022 to 2026
724%00.90510 ng/L
EPA limit
Lead
1977 to 2019
3789%02.215 ug/L
EPA limit
Copper
1953 to 2019
33100%00.631.3 mg/L
EPA limit
Radium (226 + 228)
1979 to 2019
1587%035 pCi/L
EPA limit
Manganese
1953 to 2019
no limit21485%3534,000300 ug/L
health guideline
Iron
1953 to 2019
no limit20986%120350,000300 ug/L
nuisance level
Chloride
1953 to 2019
no limit20696%6.9380250 mg/L
nuisance level
Sodium
1964 to 1985
no limit11100%4.710020 mg/L
health guideline

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

Over time

Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.

Contaminantbefore 20002000s2010s2020s
Nitrate3%265 samples5%20 samplesn/an/a
Fluoride0%114 samples0%10 samplesn/an/a
Lead0%25 samples0%10 samplesn/an/a
Arsenic17%18 samples18%11 samplesn/an/a

Nitrate has held within a few points between the two most recent periods with enough samples.

Closer than the county

See the sampled wells near your address

The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.

Check my address

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

  1. 1
    Arsenic
    16% of 31 local samples were above the limit.
  2. 2
    Uranium
    9% of 953 local wells tested were above the Maine guideline.
  3. 3
    Fluoride
    4% of 1,468 local wells tested were above the Maine guideline.
  4. 4
    PFOS
    4% of 73 local samples were above the limit.
  5. 5
    Nitrate
    3% of 289 local samples were above the limit.
  6. 6
    PFOA
    3% of 73 local samples were above the limit.
  7. 7
    PFHxS
    1% of 72 local samples were above the limit.
  8. 8
    Coliform bacteria
    Recommended for every private well, every year.
  9. 9
    Volatile organic compounds (VOCs)
    17 leaking underground storage tank sites on record locally.
  10. 10
    PFAS
    37 unlined landfills on record locally.
  11. 11
    Metals panel
    24 hazardous waste sites on record locally.

Test your Oxford County well for arsenic, uranium and fluoride

Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.

Order the Tap Score well water test kit, from $209Already tested? Upload the report

Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.

Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.

Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.

Where to get a well tested in Maine: certified labs, state programs and prices.

Already have results back? Get your lab report read against the Oxford County numbers, $29. Every line explained, ranked by what matters, with the fix for each.

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

The rock under Oxford County

Not a principal aquifer

The USGS map places this area outside any principal aquifer, which usually means wells here draw from fractured bedrock or thin local deposits rather than a large regional aquifer. Bedrock wells of that kind are where arsenic, radon and uranium turn up, and yields vary from well to well.

Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the county centroid. A single well can sit in a different unit, especially near a boundary.

Official help in Maine

Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.

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

PFOS

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

Nitrate

Point-of-use reverse osmosis; Anion exchange; Distillation

PFOA

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

Systems we would look at first

Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.

For uranium

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For uranium

Whole-house arsenic and uranium filter

whole-house, at the point of entry, about $2,500

Adsorptive iron-based media; sized to your well yield.

For arsenic

Aquasana SmartFlow reverse osmosis

under-sink or countertop, about $225

Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.

For PFOS

Aquasana Claryum 3-Stage under-sink filter

under-sink or countertop, about $175

Certified to NSF/ANSI 53 to reduce 99% of lead and 99.7% of PFOA and PFOS at the tap. Not a fix for arsenic, nitrate or bacteria.

For PFOS

Whole-house PFAS carbon system

whole-house, at the point of entry, about $3,000

Granular activated carbon certified to NSF/ANSI 53 for PFOA and PFOS; replace media on schedule.

For PFOS

Aquasana HealthShield whole-house filter

whole-house, at the point of entry, about $2,099

Whole-house carbon system the maker certifies to reduce PFAS (PFOA and PFOS) and VOCs at every tap; a UV option adds bacteria protection.

Free, no obligation

Get on the list for a free in-home water test in Oxford County

No water treatment company serves Oxford County through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Oxford County, and you get an email naming it first.

What are you worried about?

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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 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.

Counties near Oxford County

Closest first. Groundwater does not stop at a line on a map, so the next county over is a fair second opinion.

Want the numbers themselves? Download the Maine dataset as CSV, every county and town, with the sources named.

Sources

  • USGS Water Quality Portal: 1,196 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.
  • USGS national arsenic model (Ayotte 2017): estimated share of 38,444 people on private wells in Oxford County above 10 ug/L of arsenic, from geology, well depth and land use. County estimates of domestic well users with arsenic above 10 ug/L from the USGS national logistic regression model (Ayotte, Medalie and Qi, 2017), with private well population from the USGS 2015 county water-use compilation (Dieter and others, 2018). Retrieved September 15, 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.