Radon in Water

The soil and water supply are the two main sources for the radon in your home’s indoor air.  Compared to radon coming into the home through water, radon entering your home through soil is usually a much larger risk. 
The radon that can come in through your water supply poses an inhalation risk and an ingestion risk.  Research shows that your risk of lung cancer from breathing in radon air is much larger than your risk of contracting stomach cancer from swallowing water with radon in it.  Most of the risk from radon being in water comes from the radon released into the air when water is used for showering and other household purposes.
When its source is surface water, radon in your home’s water is not usually a problem.  A radon in water problem is more likely to occur when its source is ground water, for example: a private well or a public water supply system that uses ground water.  If you are concerned that radon might be coming into your home through the water, and your water comes from a public water supplier, you should contact your water supplier.
If you have tested your private well and do have a radon problem in your water, it can be fixed.  There are two ways that your home’s water supply can be treated.  The point-of-entry treatment can effectively remove radon from the water before it can enter your home.  The point-of-use treatment devices can remove radon from your water at the tap, but only treat a small portion of the water you use and are not effective in reducing the risk from breathing radon released into the air from all water used in the home.