Well water in Portland, Maine
1in9
Testing recommended
private wells tested in Portland had arsenic above the Maine guideline (10 ug/L), according to Maine CDC.
66 private wells tested in state summaries; 20 test results across 4 contaminants from at least 5 wells, 2023 to 2025; PFOA has the most at 5. Data refreshed September 3, 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.
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.
Closer than the town
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 addressWhat this means
Among homeowners in Portland who sent a sample to the state lab, the health-based limits most often exceeded were arsenic (11% of 63 wells) and uranium (2% of 48 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.
Manganese exceeds the state's advisory level in a sizable share of wells; this is mostly a taste, staining or diet issue rather than a toxicity one.
What to test for in Portland
- 1Arsenic11% of 63 local wells tested were above the Maine guideline.
- 2Uranium2% of 48 local wells tested were above the Maine guideline.
- 3Coliform bacteriaRecommended for every private well, every year.
- 4NitrateRecommended for every private well, especially near farms or septic systems.
- 5Manganese17% of 60 local wells tested were above the Maine guideline.
- 6PFOAAbove the limit in 1 of 5 local samples; too few to quote a rate.
- 7PFOSAbove the limit in 1 of 5 local samples; too few to quote a rate.
- 8Volatile organic compounds (VOCs)25 leaking underground storage tank sites on record locally.
- 9PFAS4 unlined landfills on record locally.
- 10Metals panel26 hazardous waste sites on record locally.
Test your Portland well for arsenic, uranium and coliform bacteria
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 Portland numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Portland
79 domestic wells in Portland are on record with the state since 1985. 100% are drilled into bedrock, and the typical well is 200 feet deep (one in ten goes past 344 feet).
In a typical Portland well, bedrock starts about 10 feet down, the median yield is 7 gallons per minute, 22% 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.
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.
- Private Well Water, Maine CDC
- Laboratory Accreditation, Maine CDC
Contamination sources on record in Portland
Maine DEP records 25 leaking underground storage tank sites, 4 unlined landfills, and 26 hazardous waste sites in Portland, among 285 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.
- 25
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 4
- unlined landfillsOlder unlined landfills are a leading source of PFAS, VOCs and metals in nearby wells.
- 26
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 230
- other remediation projects
Treatment that fits the local profile
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Manganese
Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Systems we would look at first
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For arsenic
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For arsenic
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 manganese
Iron and manganese oxidizing filter
whole-house, at the point of entry, about $1,800
Air-injection or greensand media; fixes staining at the source.
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Common questions
How deep are wells in Portland?
The typical domestic well in Portland is 200 feet deep, based on 79 wells reported to the state since 1985. One in ten is deeper than 344 feet. 100% are drilled into bedrock.
How often should I test a private well in Portland?
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 near Portland
Closest first. Groundwater does not stop at a line on a map, so the next town 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
- Maine DEP PFAS investigation: 20 samples in Portland. 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 Portland, up to 66 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: 93 well records in Portland, 79 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: 285 regulated sites located in Portland. 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.