Source of Radon in Water: Radon (Rn) is a colorless, odorless, tasteless radioactive gas naturally formed by the decay of uranium. Radon can slip out of the soil and into homes through cracks in the foundation, gaps around pipes, and even into basements. This is the largest source of radon. However, radon can also get into homes through water supplies. When water containing radon is sprayed, heated or exposed to air, the radon gas escapes, increasing the concentration of the radon gas in one’s home. These can be caused by common household activities and appliances, including taking showers, using dishwashers and washing machines, and filling bath tubs. Those with private and community wells are usually at higher risk for radon in their drinking water than those with municipal water.
Symptoms of Radon in Water: Radon kills more people every year from lung cancer than those who die in drunk driving accidents. Radon exposure generally comes from inhalation, and radon in water can increase that exposure while adding a risk of ingestion. This can also add the risk of internal organ cancer as well, including stomach cancer.
Filtration Solutions for Radon: Radon is easily removed from water by aeration, since it is a gas. Granular activated carbon systems and filters can also reduce radon levels when the levels are below 20,000 pCi/L. If radon in your drinking water is a concern, it is important to have a point of entry system, eliminating the exposure of radon in showers and baths.
Radon in Drinking Water Frequently Asked Questions:
• How do I know if I have radon in my water? All states and territories have homes with various levels of radon; some homes may even have hazardous levels. Testing your water is the only way to determine if your home has radon. For municipal water, contact your local company for testing results. For well water, contact the EPA for radon testing professionals in your area.
• How can I treat or remove radon from my water? Two treatments are commonly accepted for radon in the water: aeration and carbon filtration. Both should be used as whole house filtration systems. Aeration is the most effective method, but systems can be costly. Carbon filtration is also effective but not recommended for levels above 20,000 pCi/L.
• Will aeration or carbon systems cause a pressure drop? A carbon system will see a drop in pressure by a few psi. The pressure leaving an aeration system may be higher or lower than the incoming pressure, depending on the type of pump utilized by the aeration system to re-pressurize the water after treatment.
• How do aeration systems work? An aeration system is usually a large tank where air is injected into the water, causing the radon to escape from the water. The water is then pressurized by a pump and sent to the house. The air containing the radon is vented through an exhaust on the tank before being routed to the roof line.
• Do aeration systems become radioactive? No. An aeration system causes the radon gas to escape from the water without leaving a long term radioactive footprint.
• How will an aeration system affect my water? Typically, an aerator can raise the pH up to 1.0 point and cause the oxidation of common contaminants such as hydrogen sulfide, ferrous iron, and manganese.
• How does a carbon system work? A carbon system used for treating radon in water is typically a large tank containing granular activated carbon (GAC) media. As the water passes through the tank, radon is adsorbed by the carbon granules, trapping the radon atoms as they decay. The GAC media will accumulate these atoms until capacity is reached. Carbon systems remove other contaminants which may reduce the life/capacity of the GAC media.
• Can carbon filters become radioactive? Carbon media accumulates radon atoms. These atoms remain radioactive as they decay. In addition to the accumulation of radon, carbon will also accumulate a byproduct of radon—Lead-210. The carbon media should be replaced before reaching its capacity for Lead-210. A typical GAC system for a house of four people with a radon in water level of 20,000pCi/L will reach capacity for Lead-210 in approximately 5 years. Don't install a carbon filtration system near a high traffic area, due to the accumulation of radon atoms. Further consideration should be given to handling and disposal of carbon filters or carbon media after being used for radon treatment.
• Does aeration or do carbon systems need pre-treatment? Yes. Both systems need sediment pre-filtration. Water should also be tested for iron, pH, hardness, and other known contaminants in the area.
• Do high levels of radon in air mean I have levels of radon in my well? No. The two are not directly linked. The best way to know the radon content of your water is to have the water tested.
• Does the depth of my well affect how much radon is in the water? No. Radon levels do not depend on the depth of your well.