Radon is a naturally occurring cancer-causing gas. It is found in the soil under many homes, and can seep into a structure from below; it can also come into a home through well water, in some cases. Radon abatement refers to the process of reducing radon levels in a structure, such as a home. Appropriate abatement methods are dependent on the severity of the radon contamination, source classification, type of foundation on which the home rests, and the cost of set-up and operation.
Ventilation can be employed as a radon abatement method regardless of the type of foundation. Natural ventilation — opening windows and doors to the outside air — should only be used as a temporary solution. The ventilation method is sometimes used for radon abatement in crawlspaces either with or without the use of a fan. Another ventilation method utilizes an air-to-air heat exchanger that is installed to enhance a home's air circulation by introducing outdoor air as it uses exhausted air for the purposes of heating and cooling the indoor air.
Soil suction involves drawing the radon gas from the soil beneath the foundation and expelling it away from the home through a pipe. The four soil suction radon abatement methods are sub-slab suction, block wall suction, and perforated pipe or sump hole suction. These methods are sometimes used in combination or with other methods of radon abatement.
Active sub-slab suction is the most common and reliable form of soil suction system. Depending on severity, one or more pipes may be interposed through the foundation into the soil beneath a home. A fan is used to extract the radon gas and discharge it to the outdoors. Though not as reliable, a passive form of this radon abatement process utilizes natural pressure to create the vacuum as opposed to a fan.
Block wall suction is used in basements where the walls are constructed from hollow blocks. This process works by depressurizing the wall by a means similar to that used in the sub-slab technique with the creation of a vacuum. It is generally used in combination with the sub-slab method.
Perforated pipe and sump hole suction methods use the existing drainage system as a vehicle for reducing radon levels. Both the pipe and pump serve their intended functions of draining water while shuttling radon gas away from the home. Both methods are effective approaches to reducing radon levels and require little to no structural changes to a home.
Sealing cracks and openings found in, and around, the foundation is a basic approach used to augment other radon abatement methods. Heavy sheets of plastic can be used as a boundary between the soil and the foundation. The plastic acts as a barrier, trapping the radon gas and blocking it from entering the home. Vents and a fan are generally employed to help dissipate the trapped gas to the outdoors.
House pressurization involves the introduction of outdoor air into a home via a fan and vent system. Pressurization works to adjust a home's air pressure to prevent the further introduction of radon gas; once established, the pressure must be maintained to be effective. Pressurization is usually only considered when other methods fail to reduce radon levels.
Radon contaminated water can be treated one of two ways. Point-of-entry treatment effectively removes radon from the water supply before it enters the home by employing either an aeration system or filters made with granular activated carbon. A second method called point-of-use utilizes a device installed on the tap to treat the water as it is used.