Especially important to canaries is the level of radon in the proposed building site. Radon is a toxic gas formed from the natural decay of uranium in soil. If allowed to accumulate within a building, the inhalation of the gas by the building’s occupants could result in death. Radon cannot be prevented. It can only be mitigated. When selecting a building site, the soil below and within the foundation footers should be tested for radon levels. Though there is no safe radon level, mitigation is required at or above 4 pCi/l.
Mitigation options include both active and passive methods. Both forms start with penetrating the soil below the basement level with a pipe. If installed during construction, a perforated pipe running the length of the foundation in the middle of the footprint is ideal. The inground pipe connects to a vertical pipe that is vented through the roof, clearing the roof line to prevent back pressure. For the non-EMF sensitive, a 24/7 low level fan can be added to the vertical pipe drawing air from the underground pipe and expelling through the vertical pipe. When a fan is added, it is known as an active mitigation system. If a mitigation system is being installed in an existing building, the soil below the basement is penetrated with a pipe through the basement flooring which is then vented through the roof.