Whether in a real estate transaction, or reducing your radon levels as a homeowner, the advice is similar.
Mitigation is the act of repairing or altering a building or building design for the purpose of reducing the concentration of radon in the indoor atmosphere. A professional licensed by the Illinois Emergency Management Agency’s Radon Program can mitigate your radon levels. The average cost of a mitigation system is between $800 to $1200.
The most common type of mitigation systems are Active Soil Depressurization. These systems reduce radon by collecting radon prior to entry into the building and discharging it to a safe location.

Effective radon reduction
Unobtrusive and permanent installation
Quiet operation
Energy efficient operation and maintenance
A system function indicator
A primary suction point independent of the sump pit
Sump covers with observation ports
Exhaust above the highest eave and as close to the roof ridge line as
possible
All parts of the mitigation system are labeled and have a warning system such as the manometer below to let you know the system is working.

This mitigation system is correctly installed. Notice that the system discharges above the highest eave and as close to the roof ridgeline as possible.

Crawl Spaces must be part of the mitigation plan because they can be sources of radon. A crawl space mitigation system is called Sub-Membrane Depressurization (SMD).

Once your mitigation system is installed, be sure to test for radon to ensure the system reduced your radon levels below the USEPA Action Level of 4 pCi/L.

© University of Illinois Board of Trustees. http://www.takeactiononradon.uiuc.edu