If mitigation is chosen as the option, consider working with a contractor in the National Radon Safety Board (NRSB) or the American Association of Radon Scientists and Technologists (AARST) National Radon Proficiency Program (NRPP). 

Use the following guidelines in selecting a mitigating contractor, or consult the "Consumer's Guide to Radon Reduction."

How to Select a Contractor

Get Estimates! Choose a contractor to fix a radon problem just as you would choose someone to do other home repairs. It is wise to get more than one estimate, to ask for references, and to contact some of those references to ask if they are satisfied with the contractors' work. Also, ask your county or state consumer protection office for information about the contractors. Use the following checklist when evaluating and comparing contractors and ask the following questions:

Compare the contractors' proposed costs and consider what you will get for your money. Take into account the following: a system that is less expensive to install may have higher operating and maintenance costs than a system that is more expensive to install; the best system for your house may be the more expensive option; and the quality of the building material will effect how long the system lasts.

Do the contractors' proposals and estimates include:

The Contract

Ask the contractor to prepare a contract before any work starts. Carefully read the contract before you sign it. Make sure everything in the contract matches the original proposal. The contract should describe exactly what work will be done prior to and during the installation of the system, what the system consists of, and how the system will operate. Carefully consider optional additions to your contract that may add to the initial cost of the system, but may be worth the extra expense. Typical options might include a guarantee that the contractor will adjust or modify the system to reach the promised radon level, or, an extended warranty and/or a service plan.