Well water testing in Monmouth, Maine
If your Monmouth home is on a private well, testing is up to you. Maine doesn't regulate private wells. Below is what the state lab found when 257 Monmouth well owners tested for arsenic, where to drop off a sample, and a free 60-second checkup.
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What the state lab found in Monmouth wells
Arsenic: 47.5% of 257 tested wells in Monmouth were above Maine's guideline. That is about 1.5 times the Kennebec County rate (28.1%). The middle result was 9 µg/L, and 1 in 20 tested wells came in at 97 µg/L or higher. Comes from bedrock. You can't taste, smell, or see it.
| Tested for | Wells tested | Above Maine's guideline | Maine's guideline |
|---|---|---|---|
| Arsenic | 257 | 47.5% | 10 µg/L |
| Uranium | 205 | 4.4% | 30 µg/L |
| Manganese | 235 | 4.3% | 0.3 mg/L |
| Fluoride | 270 | 3.7% | 2 mg/L |
| Nitrate | 295 | 0.3% | 10 mg/L |
| Chloride | 148 | 0% | 250 mg/L |
Wells whose owners chose to test at Maine's state lab (HETL): a voluntary sample, not a prediction about any one well. Neighbors can test very differently. No rate is shown when fewer than 20 wells were tested. Source: Maine Tracking Network (Maine CDC), data updated 5/2023
Not in this data: bacteria and radon in water. Maine does not publish those results by town or county. Maine CDC still recommends testing every well for bacteria every year and for radon every 3 to 5 years.
PFAS in Monmouth
Maine DEP has sampled 50 private wells tied to PFAS investigation sites in Monmouth. Of those, 30 were above 20 parts per trillion for six PFAS combined, the level DEP reports against. DEP chose these wells because they were near sites it was checking, so the results are not a picture of every well in town.
Source: Maine DEP, PFAS private well results by town (preliminary; DEP is still adding results; read November 2026).
What Maine recommends for every well
Maine CDC says to test every private well each year for bacteria and nitrate, and every 3 to 5 years for a full panel that includes arsenic, uranium, radon, and lead. Retest after flooding, well or pump work, or any change in taste, smell, or color. The Kennebec County page has the full schedule and the rules for home sales and rentals.
Area-level information cannot determine what is in a specific household's well. Only a properly collected laboratory sample can tell you what's in your water. This page is educational; see the disclaimer.
Parts of central Maine are within Maine DEP's PFAS (sludge-spreading) investigation area. Check the DEP map if your property is near historically licensed spreading sites.
Nearest sample drop-off locations to Monmouth
- The Mailing Center — 126 Western Ave., Augusta, ME · Directions
Bacteria samples must reach the lab within about 30 hours of collection. Confirm timing: (207) 747-1815.
Buying or selling in Monmouth?
FHA loans require a water test for coliform, nitrate, nitrite, and lead; VA and USDA follow the local health authority. Maine sellers must disclose the date of the last water test. The checkup has a transaction mode that walks through it.