Radon in Drinking Water | Vermont Department of Health

What You Need to Know About Radon in Drinking Water

Radon is a naturally occurring radioactive gas. Radon may be present in both soil and water. Soil is the most common source of radon in your home. Well water that contains radon may increase the level of radon in a home. Activities — like taking showers, doing laundry, or running the dishwasher — can release radon into the air.

Health concerns: Is radon harmful to my health?

Everyone is exposed to some radon in indoor and outdoor air. Breathing in radon increases your risk of getting lung cancer over the course of your lifetime. Your risk of getting lung cancer from radon depends on the level of radon in the air you breathe, how long you are exposed to radon, and whether you smoke.

Over a lifetime, consuming radon in water also poses a risk of stomach cancer. However, the major danger posed by radon in water is the risk of lung cancer when radon from the water is released into the air and you breathe it in.

Source: How does radon get into my water?

Radon comes from the decay of uranium, which is naturally found in the Earth’s crust. Radon can get into your drinking water if your well is drilled into or near natural rock formations that contain uranium.

Testing: How do I know if radon is in my water?

You cannot see, smell or taste radon. Testing is the only way to know if radon is in your drinking water. You can order a radon in water test kit for $25 from the Health Department Laboratory, or you can use another certified drinking water lab to test for radon.

Because radon concentrations in well water can vary throughout the year, it can be beneficial to test more than once at different times of the year.

Test results: Is my result a problem?

To fully understand your radon risk, it is important to know your home’s radon in air result too. If the air in your home has not been tested, test your home for radon in air before considering how to reduce radon levels. Order a free radon in air test kit

The Health Department has set an advisory level for radon in water of 4,000 pCi/L (picocuries per liter). If your radon in water test result is:

Less than 4,000 pCi/L, you do not need to treat your water. Test your water again in five years.
At or above 4,000 pCi/L, take action to reduce radon levels in your home. Use the radon contribution calculator to help you determine the best fix for your home. If you decide to treat your water, contact a certified water treatment specialist.

Need help understanding your drinking water test results? Find out how to read your results

Treatment options: Can I remove or lower the levels of radon in my water?

Radon levels can be lowered or removed from drinking water. There are two types of water treatment systems that can be installed.

Aeration system: An aeration system uses a fan to reduce radon in water. This system mixes your water with air inside a tank and then vents the air and radon outdoors away from the house.
Granular activated carbon (GAC): This filtration system uses a charcoal filter to remove the radon from the water. Install a carbon filtration system with an NSF/ANSI Standard 53 Certification. Note: The Health Department discourages the use of GAC systems to remove radon because the radon collected on the filter could create a radiation hazard.

Re-test your drinking water for radon after any treatment system is installed to make sure levels are below the health advisory level.

Financial assistance: Is there funding available to help me pay for water system or treatment?

Funding is available to help you pay for water treatment or to fix your water system. Learn more about financial assistance programs and eligibility.