How it gets in
Groundwater moving through rock can pick up radon. When that water runs from a shower, a washing machine, or a tap, some of the radon escapes into the air. The Department of Health notes that elevated radon in water adds to the radon in a home's air.
Homes on a public water system that draws from reservoirs or other surface water generally don't have this concern. It's mainly a question for private wells.
What Rhode Island says
There is no federal or state standard for radon in private well water. That means no required limit and no required test. It's the owner's decision.
A sensible order of steps
- Test the air first. It's the simpler test and, in most homes, soil gas is the larger source. See radon testing.
- If the air result is high and you have a well, ask about a water test too. Knowing both numbers helps a contractor decide what to fix.
- If the air is being mitigated and levels stay high, water is one of the things worth checking.
How it's treated
The Department of Health points to water aeration systems as a way to address radon in well water. An aeration unit strips radon out of the water where it enters the house and vents it outside. Treating water is a separate job from an air mitigation system, and some homes need both.
Mention on the request form that you have a private well, and include any water or air results you already have.