Reducing Radon Levels in a Home

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 is Active Soil Depressurization. These systems reduce radon by collecting radon prior to entry into the building and discharging it to a safe location.

An active soil depressurization system.

What to look for in your mitigation system

A typical mitigation system.

  • 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 system has a clear warning system.

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

A correctly installed external system.

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).

Crawl space mitigation illustration.

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.

A typical test kit.