How do I fix it when I find a problem?

The cost of a radon reduction system by a certified radon mitigator can generally range from $800 to $2500, depending on the characteristics of the house and choice of radon reduction methods. The average cost of a radon reduction system is about $1200. 

Your State Radon Contact (click on your state for contacts) may provide information about your state's requirements or recommendations for a successful mitigation.

 Read a Consumer's Guide to Radon Reduction