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:

  • Will the contractor provide references or photographs, as well as test results of 'before' and 'after' radon levels of past radon reduction work?
  • Can the contractor explain what the work will involve, how long it will take to complete, and exactly how the radon reduction system will work?
  • Does the contractor charge a fee for any diagnostic tests? Although many contractors give free estimates, they may charge for diagnostic tests - these tests help determine what radon reduction system should be used, but are not always necessary (see the booklet for more information on diagnostic tests).
  • Did the contractor inspect your home's structure before giving you an estimate?
  • Did the contractor review the quality of your radon measurement results and determine if EPA testing procedures were followed? This is a requirement of the program!

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:

  • Proof of liability insurance and being bonded and licensed?
  • Proof of NRPP or NRSB certification?
  • Diagnostic testing prior to design and installation of a radon reduction system?
  • Installation of a warning device to caution you if the radon reduction system is not working correctly? (A program requirement.)
  • Testing after installation to make sure the radon reduction system works well? (A program requirement.)
  • A guarantee to reduce radon levels to 4 pCi/L or below, and if so, for how long?

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.

  • The total cost of the job, including all taxes and permit fees; how much, if any, is required for a deposit; and when payment is due in full.
  • The time needed to complete the work.
  • An agreement by the contractor to obtain necessary licenses and follow required building codes.
  • A statement that the contractor carries liability insurance and is bonded and insured to protect you in case of injury to persons, or damage to property, while the work is being done.
  • A guarantee that the contractor will be responsible for damage and clean up after the job.
  • Details of warranties, guarantees, or other optional features, including the acceptable resulting radon level.
  • A declaration stating whether any warranties or guarantees are transferable if you sell your home.
  • A description of what the contractor expects the homeowner to do (e.g., make the work area accessible) before work begins.