Fixing Radon: Mitigation

The Environmental Protection Agency (EPA) recommends taking action to reduce radon in homes that have an airborne radon level of 4 picocuries per liter (pCi/L) or higher.

Radon in Air Reduction

The best way to reduce radon is to have a system put in that removes the radon from under the home before it enters into your living space. To do this a trained radon professional will install a pipe into the basement or crawlspace floor and route the pipe to the outside of the home. This pipe is then connected to a radon fan that exhausts the air. This type of system is very good at reducing radon levels year round to below the EPA Action Level of 4.0 pCi/L. It is not possible to reduce radon levels to zero as even outdoor air has an average radon level of 0.4 pCi/L in the United States.

Just sealing cracks and other openings in homes is not a good way to lower radon in a home by itself but is often done to improve the efficiency of the radon reduction system. In fact, the EPA tried many types of sealing to stop radon from getting into a home and they found it did very little to reduce the radon levels. Spending money on expensive “radon barriers” or “radon sealant paints” is not considered a good idea as this money would be better spent on the installation of a radon removal system.

In New Hampshire, contractors that install systems to reduce radon in air are called “radon mitigators” and are required to be nationally certified. A list of nationally certified radon professionals can be found at the American Association of Radon Scientists and Technologists National Radon Proficiency Program and the National Radon Safety Board.

Radon in Water Reduction

Although the major health concern for radon is in air, it is a good idea to reduce any Radon that you find in your water as it can migrate into the air. For every 10,000 pCi/L of Radon that you have in your water, an estimated 1 pCi/L can get into your air through faucets, toilets and showers. The current recommendation in New Hampshire is to consider reducing radon in water when the level is between 2,000 - 10,000 pCi/L and the airborne radon level in the home is 4pCi/L or more.

Radon in water is most often reduced by a system that is installed where the water line from the well enters the home. These types of systems aerate or bubble the water to release the radon from the water into the air. The airborne radon released by the system is then vented to the outside of the home with piping. Charcoal filters can also be used to reduce radon in water but are not very effective for levels of radon in water greater than 2,000 pCi/L. A filter also requires more maintenance and radiation can build up in the filter, which can pose a health risk to home residents. Filters used to reduce radon in water can also result in a low-level radioactive material that has to be disposed of properly. There is no requirement for radon in water mitigators to be certified in New Hampshire but those installing these systems may require licensing as a plumber.

Maintenance of Radon Mitigation Systems

Radon reduction systems for radon in air require little maintenance with only the fan being a possible source of failure. Fans used in radon reduction systems are designed for long-term use and are usually good for 10 - 15 years before needing to be replaced. Radon in water treatment systems are often maintained by the companies that install them who can provide maintenance contracts to keep the system running well. If a filter system is used to reduce radon in water it is a good idea to have a maintenance contract so that the filter is changed out on a regular schedule to keep the system filtering out the radon effectively.