Radon is a naturally occurring radioactive gas that forms from the decay of uranium in soil, rock, and water. It's colorless, odorless, and tasteless — which means you can't detect it without proper testing. In Maine, radon is a particularly significant concern due to the state's unique geology.
Why Maine Has High Radon Levels
Maine sits atop granite bedrock that contains elevated levels of naturally occurring uranium. As uranium breaks down over time, it produces radon gas that seeps upward through the soil and can enter homes through foundation cracks, gaps around pipes, sump pits, and other openings.
According to the Maine CDC, approximately one in three Maine homes has radon levels above the EPA's recommended action level of 4 picocuries per liter (pCi/L). Some areas of the state — particularly central and southern Maine — have even higher rates of elevated radon.
Health Risks of Radon Exposure
Radon is the second leading cause of lung cancer in the United States, responsible for an estimated 21,000 deaths each year. The risk increases with higher radon concentrations and longer exposure times. Even non-smokers are at risk — though the combination of radon exposure and smoking significantly multiplies the danger.
The EPA compares radon exposure at 4 pCi/L to smoking approximately half a pack of cigarettes per day. At 8 pCi/L, the equivalent jumps to a full pack. These numbers underscore why testing and mitigation are so important.
Radon in Maine's Water
Unlike many other states, Maine homeowners who rely on well water face an additional radon risk: radon dissolved in groundwater. When water containing radon is used for showering, washing dishes, or other household activities, the gas is released into indoor air.
The EPA estimates that radon in water contributes approximately 1 pCi/L to indoor air for every 10,000 pCi/L in the water supply. Maine wells can contain radon levels well above this threshold, making water treatment an important part of a comprehensive radon strategy.
Which Maine Counties Are Most Affected?
While radon can be found anywhere in Maine, certain areas tend to have higher concentrations:
- Kennebec County — The Augusta area and surrounding towns frequently test above 4 pCi/L
- Androscoggin County — Lewiston, Auburn, and nearby communities show elevated levels
- Cumberland County — Portland and the surrounding region have significant radon presence
- Oxford County — Rural areas with granite bedrock often test high
- York County — Southern Maine communities regularly report elevated radon
However, high radon has been found in every Maine county. The only way to know your home's radon level is to test.
How to Protect Your Maine Home
The good news is that radon mitigation is highly effective. A professionally installed radon mitigation system can reduce radon levels by up to 99%. Here's what you should do:
- Test your home — Short-term test kits are available from the Maine CDC, or you can hire a professional for more accurate results
- Test your water — If you have a private well, have your water tested for radon as well
- Take action at 4 pCi/L or above — The EPA recommends mitigation when indoor radon reaches 4 pCi/L, though you may want to consider action at 2 pCi/L
- Hire a certified professional — Proper installation is critical for effective radon reduction
What Does Radon Mitigation Involve?
The most common mitigation approach for Maine homes is an active soil depressurization (ASD) system. This involves:
- Installing a suction point through the foundation slab or crawlspace
- Running PVC piping from the suction point to above the roofline
- Attaching an inline fan that creates negative pressure beneath the foundation
- Sealing major cracks and openings in the foundation
For radon in water, an aeration system is typically installed at the point of entry to remove radon before it enters the home's plumbing.
Most installations are completed in a single day, and homeowners notice no impact on their daily routine. The systems are quiet, energy-efficient, and require minimal maintenance.
Don't Wait — Test Your Home Today
With Maine's high-risk geology and the serious health consequences of prolonged radon exposure, testing your home is one of the most important steps you can take to protect your family. If your results come back elevated, professional mitigation provides a reliable, long-term solution.
Central Maine Radon & Water Mitigation serves homeowners throughout Maine with professional radon testing, air mitigation systems, and water treatment solutions. Contact us for a free quote or call (207) 483-5637 to schedule a consultation.