Radon In Well Water? Radon’S Common And Dangerous!

How do we remove radon from my well water?  It’s a common question, especially in Maine. In short, the answer is radon water mitigation.

Geology and radon

Radon is a colorless, odorless, tasteless, and chemically inert radioactive gas. The natural radioactive decay of uranium forms radon in rock, soil, and water. Radon is present in all 50 states. Testing for it is the only way of telling how much is present.

radon water mitigation

The most common way radon can get into a home is through the soil into the groundwater, through well water, and then into the air from typical water usage. When the ground produces radon, and groundwater water naturally flows through the soil, the radon can dissolve and accumulate in the water. The soil will emit gas entering the basement (radon air) and well water (radon water). 

“How do I know if I need radon water mitigation?”

Measuring radon in well water and air uses the same units, but the threshold guidelines are different. Unlike contaminants such as arsenic which have a maximum contamination level (MCL). The limits for radon are described as the maximum exposure guidelines (MEG). The MEG can vary from state to state.

In Maine, the radon thresholds in air MEG are 4.0 pCi/l, and the radon threshold in water is 4,000 pCi/l. So the unit pCi/l is a unit meaning picocuries per liter. A liter of air or water, depending on if radon in the air versus water. (Phonetically its sounds like (Pee-Ko-Curry).

Levels of radon in well water measured below 4,000 pCi/L are considered “acceptable,” and suggests retesting in three to five years. If your well water radon level is between 4,000 and 10,000, call us to discuss your options for a radon water mitigation solution. Historically, FONTUS has found that future home buyers request a mitigation system when the concentration exceeds 4,000 pCi/l. In addition, it makes sense to enjoy the health benefits of having radon mitigation in place for your use. However, if your well water number is 10,000 or higher, it’s time to consider a treatment system.

Everything you forgot about Chemistry Class: radon water mitigation

Here comes the confusing part: radon itself isn’t likely to cause cancer. WHAAATTT??!! Technically, radium “decays” into radon. After 3.8 days, half of the radon turns into polonium 218. After about 3 minutes, it turns into lead 214, 30 minutes later it turns into bismuth 214, 20 minutes later it changes to polonium 214, etc. Radon is the only one of these elements that are a GAS. Each other step is a solid particle which is important to remember.

This is the important part; when radon “decays,” the radiation it gives off is an “ALPHA” particle. Think of the “Alpha” particle as a bowling ball of nuclear radiation; it can easily be stopped by your skin or a piece of paper. This particle is not likely to cause a disruption in DNA and result in cancer. To clarify, all the other products give off beta or gamma radiation, the pea-size, fast-moving radiation and is MORE likely to cause cancer. In short, if radon stayed as radon, it wouldn’t have nearly as significant an effect on us. 

Hold on…almost done. All these other things like polonium, bismuth, and lead are now tiny particles floating around your home. These particles like to stick to other particles floating around like wood smoke from a wood-burning stove, cigarette smoke, and dust. As a result, now you have the makings for something you can breathe in, which gets stuck in your esophagus and lungs. And remember these particles give off the “bad” type of radiation.

“Why is radon in our well water dangerous?”

So what does radon do? Technically, it can cause cancer. Not just in the lungs but also in the esophagus. Just like everything radioactive, radon has a “half-life.” Half-life is the amount of time it takes for 50% less radon—about 3.8 DAYS. For example, if you had one liter of water with 10,000 pCi/l of radon in it and then measured it four days later, the radon would be around 5,000 pCi/l. The pCi/l number is the primary reason we recommend testing a new well after being used for a while under typical usage patterns. Some people rush to perform the radon water test with a new well and get a false negative result. It may be low after drilling but could become more elevated under normal usage. 

The result, regardless of where the radon came from, is the same. Radon in well water will get released from the water and get into the air. Some home appliances are more efficient than others in this process. Showers, laundry, and dishwashers are pretty good at dispersing radon from the water and into the air. Think of it the same way that carbon dioxide releases from a can of soda. If you gently pour the soda into a glass, you can see the carbon dioxide bubble off the surface. But, not as much as if you shook the soda and then opened the top. The carbon dioxide in a soda can is a good analogy for explaining how radon gets into the air from the water.

Radon is a serious health risk

Natural levels of radon are high in Maine. However, radon water mitigation technology can reduce radon air levels below 2 and lower water levels to below 4,000— the safest levels.

You can trust FONTUS for Radon water mitigation

FONTUS Water Treatment is a Maine Registered Radon Reduction Expert. Reducing radon in your home or well water is a job for an expert. A Maine contractor who installs radon treatment systems is called a ‘mitigator’ and must be registered. A registered contractor has had training, passed an exam, and performs work according to State standards. FONTUS is a licensed and permitted Radon water mitigation contractor. Certified by the Department of Health & Human Services Division of Environmental Health.

Fontus radon water mitigation


The FONTUS experts will provide a free immediate-response water test onsite for minerals. We can also correctly collect any state-certified samples needed for health-related contaminants. Then we send them to a state-certified Maine Lab for a TSFHA water test. The TSFHA Water Test will test for Coliform Bacteria & E. coli (pos/neg), Nitrate, Nitrite, Fluoride, Chloride, Hardness, Copper, Iron, pH, Manganese, Sodium, Uranium, Lead, Arsenic, and Magnesium in your water. This test is an additional charge determined by the lab and paid to the lab.

In short, taking control of your water supply is easy. Schedule your free immediate-response water test today. Call (207) 856-0066 or email to speak with the water treatment specialists at FONTUS Water Treatment.


An immediate-response water test is a test done onsite, getting your results immediately. This test allows us to determine if and what iron levels, manganese, hardness, total dissolved solids (TDS), pH, and salinity are present in your water. By the end of our appointment, you’ll have all your questions answered. And, most importantly, you’ll have a plan in hand to make sure your water is clean and pure.

In short, taking control of your water supply is easy. Schedule your free immediate-response water test today. Call (207) 856-0066 or email to speak with the water treatment specialists at FONTUS Water Treatment.


At FONTUS, we’re passionate about water purity. We pride ourselves on being reliable, hassle-free, and always available. For example, as the environment and your water change, we’re here to help evaluate your water. Through testing, installation, and maintenance, you can trust FONTUS to ensure clean, pure water for your home or office.

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