Maine sits on bedrock that quietly releases uranium and radon into private wells — and neither one shows up on a standard water test.
More than half of Maine households drink from a private well, and almost none of those wells are tested for the two contaminants our geology is most likely to produce. Research on private bedrock wells in the greater Augusta area found roughly 4.8% of samples above the 30 µg/L uranium guideline, and statewide estimates put 5.8% to 7.6% of Maine’s rural population at risk of uranium exposure above that level. Radon in water tracks the same bedrock and is often present in the same wells.
Here is the problem: a standard bacteria-and-nitrate test — the one most homeowners run, and the one required at many closings — does not look for either. A clean result on that panel says nothing about uranium or radon. If you have never specifically ordered those analytes, you have never tested for them.
Why Maine Wells Get Uranium and Radon
Uranium is a naturally occurring element in granite and other bedrock, and Maine has a lot of it underfoot. It is not a spill or a pollution event — it is the rock the well is drilled through. As groundwater moves through fractured bedrock, uranium dissolves into it. The same decay chain produces radium and then radon gas, which dissolves in water and comes back out when the water is agitated.
That last detail is what most people miss. Radon in water is not primarily a drinking problem — it is an inhalation problem. Every shower, dishwasher cycle, and load of laundry releases dissolved radon into the air inside the house. A home can pass an air radon test and still be receiving a steady contribution from the well. And a home with high radon in water will keep re-supplying the air no matter how well the basement is sealed.
Uranium is a different exposure. At elevated levels the concern is kidney toxicity from long-term ingestion, and it has no taste, odor, or color. Neighbors a quarter mile apart can get very different results, because bedrock fractures are not uniform — a neighbor’s clean test is not evidence about your well.
What Maine and New Hampshire Homeowners Should Do
The practical guidance is straightforward:
- Test for uranium and radon at least once, and again after any well work, pump replacement, or new well. These are geologic, not seasonal — but a new fracture or a deepened well can change the result.
- Keep the annual basics on schedule. Maine CDC recommends testing private wells every year for total coliform bacteria, E. coli, nitrate, and nitrite. Summer is the right time — warm-weather bacteria levels run higher than winter levels, so a January clean result does not describe your well in July.
- Do not rely on an air radon test to clear the water. They measure different things. If the well is the source, mitigating the air alone will not fix it.
- Know the reference points. Maine’s guideline value for uranium is 30 µg/L, and the recommended action level for radon in water is 4,000 pCi/L. A number on a report only means something against the guideline it is measured to.
- In a real estate transaction, ask what was actually ordered. A basic safety panel satisfies many lenders but leaves uranium and radon untested. Buyers of bedrock-well homes should decide deliberately whether to add them — before the inspection contingency closes, not after.
What Chanalytical Tests For
Our analyte menu is built around what Maine wells actually contain: arsenic, uranium, radon in water, PFAS (including PFOA and PFOS), lead, nitrate and nitrite, total coliform and E. coli, metals, and hardness. Panels run from the FHA/VA Basic Safety Test up to a 20-analyte Comprehensive panel, with radon and PFAS available as additions or standalone tests.
If you are unsure what to order, the practical starting point for a bedrock well is a comprehensive panel plus radon in water. That single round establishes a baseline across the contaminants most likely to be present, so future tests have something to compare against.
For Home Inspectors
Uranium and radon are an easy add-on conversation at the inspection, and a hard one to have after closing. Working with a local lab means samples do not lose a day in transit — most panels are processed in Gorham and reported the next business day, with report-ready PDF results you can hand straight to your client. Nine drop-off locations across the state (Gorham, Scarborough, Steep Falls, New Gloucester, Auburn, Augusta, Hermon) keep sample handoff on your route instead of on a courier’s schedule.
For Water Treatment Companies
Uranium and radon both respond to treatment, but the paths differ — and neither can be sized without numbers. Independent baseline testing before installation and verification testing after it document that the system is doing what was specified. Third-party results also protect the installer: when the lab has no stake in the equipment sale, the post-installation number is defensible to the customer.
Why Trust Chanalytical
We are an independent water testing laboratory in Gorham, staffed by Maine scientists who have spent their careers on this state’s bedrock wells and know what comes out of them. Samples are handled locally rather than shipped out of state, which is why most panels come back the next business day — fast enough to fit a real estate timeline. Because we sell testing and nothing else, we have no stake in whether a result is high or low; the number you get is the number the sample produced, written up in plain English rather than lab shorthand. If a result raises a question, real people answer the phone at (207) 747-1815.
Test the Water You Already Drink
Uranium and radon do not announce themselves. There is no smell, no color, no stain on the fixtures — just a number you either have or you don’t. You do not need an account, an appointment, or a contractor to find out. Order a kit online, collect the sample yourself, and drop it at any of our seven Maine locations:
- Complete Safety Test — $405. The 20-parameter Comprehensive panel (uranium included) plus radon in water. One kit, one sampling session, one report. This is the right first test for a bedrock well.
- Comprehensive Safety Test — $235. All 20 parameters including uranium, arsenic, lead, manganese, bacteria, and nitrate. Add radon later if you want to stage the cost.
- Radon Water Test — $170. Radon in water only, by liquid scintillation, reported in pCi/L. The one to order if you have already done a metals panel or your air radon came back high.
Not sure which fits your well? Take the free 60-second Well Check, browse the full kit lineup, or call (207) 747-1815 and a person will walk you through it. Most panels are reported the next business day.