Radioactive Elements in Drinking Water

alpha radiation

Alpha radiation is a type of energy released when certain radioactive elements decay or break down. For example, uranium and thorium are two radioactive elements found naturally in the earth’s crust. Over billions of years, these two elements slowly change form and produce “decay products” such as radium and radon. During this change process, energy is released. One form of this energy is alpha radiation. As a result, alpha radiation can be found in your private drinking water.

The Health Department recommends testing your private water source for gross alpha radiation and other contaminants. Find out what you should test

If gross alpha radiation results are equal to or greater than 5 picocuries per liter (pCi/L), additional testing is needed to determine the source.

  • If the gross alpha result is less than 5 pCi/L, no further testing or treatment is necessary.
  • If the gross alpha result is 5 –15 pCi/L, test for uranium. Once you receive your uranium results, call the Health Department to discuss whether further testing is necessary.
  • If the gross alpha result is greater than 15 pCi/L, test for radium 226, radium 228 and uranium.

Contact the Drinking Water Program if you have questions about your gross alpha radiation results at (802) 863-7220 or (800) 439-8550 (toll-free in Vermont).

Health Effects of Alpha Radiation in Drinking Water

Because alpha radiation loses energy rapidly, it doesn’t pass through skin. It’s not a hazard outside of the body. However, if an individual eats or drinks something containing alpha radiation or breathes it in, the radiation can be harmful. Over a long period of time—and at elevated levels—radium increases the risk of bone cancer and uranium increases the risk of kidney damage.

Well water that contains elevated levels of radioactive minerals sometimes increases the level of radon gas in a home. Activities like taking showers, doing laundry, or running a dishwasher can release the radon into the air. Breathing air with too much radon over a lifetime increases the risk of lung cancer.

The Vermont Department of Environmental Conservation’s uranium standard is 20 µg/L (micrograms per liter). This standard is used for public community water systems. For your private water supply you may want to consider treatment when test results show uranium at greater than or equal to 20 µg/L.

Solving an alpha radiation problem can be complex. See treatment options for each radioactive element below.


Uranium is a radioactive element found in nature. It can be present in soil, air, water, rocks, plants, and food. Uranium breaks down (decays) very slowly into other elements including radium and radon gas.

Health Effects of Uranium in Drinking Water

The body gets rid of most uranium that is swallowed. However, a small amount is absorbed and carried through the bloodstream into the kidneys. Studies show that high levels of uranium in drinking water can increase the risk of kidney damage.

Over time, drinking water that contains uranium can increase lifetime risk of cancer. The amount of increased risk depends on the concentration of radioactivity found in the drinking water, the amount of water consumed daily, and the length of time the you have consumed the water.

Treatment Options for Uranium in Drinking Water

Anion exchange is a treatment like water softening except that in this case uranium is removed and exchanged for chloride. Reverse osmosis also removes uranium. Public systems have additional treatment options not available to homeowners such as lime softening (to reduce radium and uranium) and coagulation and filtration (to reduce uranium).


Radium is a metal that is found in nature. It is radioactive and can exist in several forms (called isotopes). Radium can be found at varying levels throughout Vermont and the entire earth—in soil, water, rocks, plants and food.

Health Effects of Radium in Drinking Water

There are no immediate health risks or symptoms from drinking water that contains radium. However, it may cause health problems over time. Radium is radioactive and decays very slowly. During this process, radiation is released. The health effects of exposure to radiation vary depending on how long a you are exposed and how much radium or radiation you are exposed to. Over decades, exposure to radium can increase the risk of bone cancer.

Treatment Options for Radium in Drinking Water

A water softener (also called a cation exchanger) can be used to remove radium from drinking water. Radium is exchanged for sodium or potassium. When the softener is cleaned, the radium is flushed away with the wastewater into a leach field or municipal sewer.

Another type of treatment called reverse osmosis can also remove most radium from drinking water. Water is forced under pressure through a membrane leaving the radium behind. The radium is then flushed away. The process is relatively slow and may be more suitable for a household rather than a public water system.


Radon is a naturally occurring radioactive gas. Radon has no color, smell, or taste. Radon comes from the decay of uranium, which is a radioactive element found naturally in the earth’s crust. Over billions of years, uranium decays into radium, and eventually, radon.

The Health Department has set an advisory level for radon in water of 4,000 pCi/L. If the result of the radon in water test is less than 4,000 pCi/L, you do not need to treat your water, but test your water again in five years. If your radon in water result is at or above 4,000 pCi/L, consider treating your water. In addition, if you have tested for radon in water, but have not yet tested your home for radon in air, test for radon in air. Breathing radon in air poses more of a health risk than drinking radon in water. Learn more about radon in your home.

Health Effects of Radon in Drinking Water

There are no known health effects connected with brief exposure to radon. However, over longer periods of time, breathing air with too much radon increases the risk of lung cancer.

If you smoke and your home has high levels of radon, your risk of getting lung cancer is especially high. The Environmental Protection Agency (EPA) estimates that 86% of radon-related lung-cancer deaths occur among current or former smokers. Learn more about radon, smoking, and lung cancer.

Over a lifetime, swallowing 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 escapes from the water and is breathed in. 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.

Treatment Options for Radon in Drinking Water

Aeration removes radon from water. Large volumes of air are blown through the water or the water is sprayed so that it is exposed to the air. In this way, the radon gas leaves the water and enters the air. The air is vented outside, and the treated water is repressurized and piped to faucets.

Activated charcoal filtration systems can also remove radon from water. The Health Department discourages the use of these systems because the radon collected on the filter can pose a radiological hazard to both the homeowner and the technicians who service the system.

Learn more about radon in drinking water.