Arsenic in Maine well water
In Maine, 17% of 27,616 private wells tested had arsenic above the Maine guideline (10 ug/L), according to Maine CDC.
Arsenic occurs naturally in New England bedrock and dissolves into well water. Long-term exposure raises the risk of bladder, lung and skin cancers, and is linked to heart disease and lower IQ in children. It has no taste or smell, so testing is the only way to know.
Check your arsenic number
Type the value from your lab report. It is compared to the Maine guideline and the EPA limit, the same way the full interpretation does it.
Test your Maine well for arsenic
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
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Systems that remove arsenic
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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 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.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where to get a well tested for arsenic in Maine: certified labs, state programs and prices.
By county, from homeowner tests
Share of private wells above the state guidance level (10 ug/L) in tests homeowners sent to the state lab, to .
| County | Above state level | Wells tested | Highest |
|---|---|---|---|
| Kennebec | 4,743 | ||
| York | 2,174 | ||
| Hancock | 2,622 | ||
| Somerset | 952 | ||
| Cumberland | 4,050 | ||
| Washington | 1,210 | ||
| Knox | 798 | ||
| Androscoggin | 1,293 | ||
| Piscataquis | 320 | ||
| Franklin | 778 | ||
| Waldo | 1,434 | ||
| Penobscot | 2,501 | ||
| Sagadahoc | 1,019 | ||
| Oxford | 1,108 | ||
| Lincoln | 1,770 |
Towns with the highest share above the state level
- Manchester, Kennebec County57% of 207 wells
- Sedgwick, Hancock County52% of 81 wells
- Gorham, Cumberland County49% of 508 wells
- Otis, Hancock County49% of 37 wells
- Monmouth, Kennebec County48% of 257 wells
- Eliot, York County46% of 89 wells
- Surry, Hancock County46% of 176 wells
- Winthrop, Kennebec County44% of 371 wells
- Hollis, York County43% of 133 wells
- Buxton, York County42% of 317 wells
- Trenton, Hancock County42% of 112 wells
- Readfield, Kennebec County42% of 334 wells
- Litchfield, Kennebec County41% of 249 wells
- Blue Hill, Hancock County41% of 175 wells
- Orland, Hancock County40% of 99 wells
- Charlotte, Washington County39% of 31 wells
- Hallowell, Kennebec County39% of 57 wells
- Minot, Androscoggin County38% of 76 wells
- Wales, Androscoggin County37% of 49 wells
- Dayton, York County36% of 64 wells
- Saco, York County35% of 230 wells
- Danforth, Washington County34% of 38 wells
- Camden, Knox County34% of 47 wells
- Owls Head, Knox County34% of 80 wells
- Mount Vernon, Kennebec County34% of 175 wells
By county, from individual samples
Public monitoring samples against the EPA limit (10 ug/L); counties with at least 30 samples.
| County | Above EPA limit | Samples | Detected | Median | Highest |
|---|---|---|---|---|---|
| Kennebec | 114 | 99% | 49.4 | 410 ug/L | |
| York | 48 | 98% | 55.5 | 710 ug/L | |
| Cumberland | 73 | 71% | 24 | 450 ug/L | |
| Hancock | 64 | 84% | 10.1 | 720 ug/L | |
| Androscoggin | 33 | 91% | 2.7 | 190 ug/L | |
| Somerset | 31 | 94% | 1.9 | 120 ug/L | |
| Washington | 61 | 98% | 1 | 3,000 ug/L | |
| Oxford | 31 | 74% | 0.1 | 330 ug/L |
Sources
- Maine Tracking Network private well summaries: 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.
- Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. arsenic counts and shares are listed on each county and town page with their sources.
Analysis: Arsenic in private wells, state by state, from the same public records.