Since there is no known safe level of radon, there can always be some risk. But the risk can be reduced by lowering the radon level in your home.

A variety of methods are used to reduce radon in your home. In some cases, sealing cracks in floors and walls may help to reduce radon. In other cases, simple systems using pipes and fans may be used to reduce radon. Such systems are called "sub-slab de pressurization," and do not required major changes to your home. These systems remove radon gas from below the concrete floor and the foundation before it can enter the home. Similar systems can also be installed in houses with crawl spaces. Radon contractors use other methods that may also work in your home. The right system depends on the design of your home and other factors. Ways to reduce radon in your home are discussed in EPA's "Consumers guide to Radon Reduction." You can get a copy from your state radon office.

The cost of making repairs to reduce radon depends on how your home was built and the extent of the radon problem. Most homes can be fixed for about the same cost as other common home repairs like painting or having a new hot water heater installed. The average house costs about $1,200 for a contractor to fix, although this can range from about $500 to about $2,500.

If you plan to fix the problem in your home yourself, you should first contact your state radon office for EPA's technical guide, "Radon Reduction Techniques for Detached Houses." You should also test your home again after it is fixed to be sure that radon levels have been reduced. Most radon reduction systems include a monitor that will alert you if the system needs servicing. In addition, it's a good idea to retest your home sometime in the future to be sure radon levels remain low.

Illinois Emergency Management Agency, Radon Division
Guide to Mitigation

Your radon level is 4 picocuries per liter (pCi/L) or higher. What are your options?

• Contact a mitigation professional licensed by IEMA to reduce the radon levels in your home.

• Request two or three price estimates from licensed mitigation professionals.  The cost of a radon reduction system generally ranges from $800 to $2500, depending on characteristics of the house and choice of radon reduction methods.

• Talk to your mitigator and be sure you understand the mitigation design.

• Residents of a dwelling may install a mitigation system in their own dwelling; however without proper equipment or technical knowledge, you could actually increase your radon level or create other potential hazards.

IEMA Assures Consumer Protection

• IEMA-licensed mitigation professionals have passed the radon qualification course and exam approved by the department.
• IEMA-licensed radon professionals work to a Quality Assurance Program and a Worker Protection Plan approved by the department.
• IEMA investigates and resolves complaints and non-compliance reports
• IEMA performs performance audits on a regular basis to evaluate individual professional compliance.
• IEMA radon regulations ensure that radon measurements and mitigations performed by licensed professionals are standardized throughout the state.

• Collecting radon prior to entry into the building and discharging it to a safe location.
• Modifying building pressure differentials.
• Diluting radon concentrations with increased ventilation.

Mitigation Systems in Illinois Must Include:

• Under a specified polyethylene or equivalent flexible material (plastic sheet) permanently installed over exposed soil or rock

• By a fan drawing radon from beneath the plastic sheet and exhausting the radon outdoors above the highest eave.

Discharging Above the Highest Eave

Discharge above the highest eave ensures that there is significant dilution of exhaust by outdoor air to minimize re-entry into the house and minimize exposure to persons in the yard and neighboring areas.  To ensure public health and safety, IEMA requires that the point of discharge from fan powered soil depressurization systems be located:

• Above the highest eave of the roof.

• As close to the roof ridge line as possible.

• 10 feet from any window, door or opening (into the building) that is less than 2 feet below the exhaust point.

• 10 feet or more from any opening to adjacent building

Sealing

Sealing the sump pump and sealing cracks are not effective techniques for reducing radon by themselves.

Sealing enhances radon reduction techniques, such as SSD, SMD and Heat Recovery Ventilation.  Reducing the loss of conditioned air increases radon reduction system effectiveness and cost efficiency.  IEMA does not recommend the use of sealing alone to reduce radon concentrations. Sealing alone has not been shown to lower radon levels significantly or consistently.

New Construction Systems

The Awareness Program encourages residents of McLean County to install radon reduction systems in new home constructions.

Passive New Construction

Passive new construction systems rely solely on the convective flow of air upward in the vent pipe for sub-slab depressurization. The system consists of a vertical vent pipe routed through conditioned space from the suction pit to 12 inches above the roof.

A skeletal system is a system that is designed for the installation of a vent fan that may consist of multiple vent pipes.  This includes vertical and angled runs that are not necessarily routed through living space that may be joined to a single termination above the roof or may terminate separately above the roof

Always Perform a Post-Mitigation Test!

Post-mitigation tests are important evaluators of actual system function.  Professional post-mitigation measurements must be performed to the applicable IEMA measurement protocol.  The Adopted Rule, 32 Illinois Administrative Code, Part 422, prohibits mitigation professionals from performing radon measurements at a residence where they have installed a mitigation system.