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Find out the average radon testing cost in St. Louis, MO. Learn what you can expect to pay for local testing services and keep your home safe from harmful gas.
How Much Does a Radon Mitigation System Cost in St. Louis? [2026 Data]
Radon detection and reduction costs depend on your project and location. Check with a local pro for your specific job.
Get quotes from radon detection and reduction specialists near you
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Get quotes from radon detection and reduction specialists near you
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Cost Insights
Active depressurization radon mitigation costs $694 to $2,083 in St. Louis.
Other radon mitigation approaches include passive depressurization and ventilation.
Larger homes often require additional equipment and more labor.
Hiring a qualified radon mitigation pro ensures safe, effective results.
The average radon mitigation system cost in St. Louis is $716, but it commonly ranges from $660 to $790. The factors that influence your overall cost include the mitigation method, the size and age of your house, and whether you need any additional work (like foundation repairs). Based on these factors, here’s how much you can expect to pay for radon reduction in St. Louis.
Radon Mitigation Cost Factors
Here’s what to expect in terms of price when installing a radon mitigation system in St. Louis, MO.
Cost by Method
The cost of a radon mitigation system depends on the chosen approach, which might be sealing the basement, depressurization, or lower-level pressurization. The depressurization method happens in one of two types: active suction (soil depressurization) or passive depressurization.
Here’s what to expect for pricing by radon mitigation method:
| Method | Cost Range in St. Louis, MO | Description |
|---|---|---|
| Sealing the basement | $278–$3,194 | Half as effective; may require repeated resealing |
| Active suction soil depressurization | $694–$2,083 | Most common method; PVC pipe suctions gas from beneath foundation |
| Passive depressurization | $347–$1,736 | Vents radon through PVC piping using pressure differences; low efficiency at high levels |
| Wall-based systems | $347–$2,083 | Cinder block wall creates vented cavity to exhaust radon |
| Ventilation systems | $903–$1,736 | Two fans remove radon and vent it outside |
| Water mitigation | $833–$3,472 | Uses carbon and aeration to remove radon from water |
Cost by Home Size
If you have a larger home, prepare to pay more for radon mitigation. To reduce radon in a bigger property, your pro may need to use extra materials and spend more time setting up the system, which can add $347 to $1,042 to your project costs.
Cost by Home Age
Your home’s age is another cost factor for this project. Over time, a house’s foundation can crack, making it more likely for radon to leak in. In cases like these, there may be additional costs for the extra equipment, materials, or labor needed for repairs.
Radon Mitigation Pro Costs
The cost of radon mitigation also depends on which permits you need and how much your contractor charges for labor.
Permits
Permits can also increase the cost of installing a radon mitigation system in St. Louis. Permit requirements depend on your specific project, but in many cases, you’ll need at least an electrical permit for the system’s electrical components. A radon detection and reduction specialist in St. Louis, MO, can let you know how much these permits cost and pull the right ones for your project.
Labor
Labor is another big expense when installing a radon mitigation system in St. Louis. These costs vary by contractor, but you should find your pro’s rates listed in your project estimate.
Angi Tip
Exposure to radon over a long period of time can cause serious health problems, including lung cancer. Lowering radon in your home requires professional knowledge and skills only available by hiring a radon mitigation pro.
Licensing and Certification
Even though Missouri doesn’t have a licensing requirement for radon mitigation contractors, the state’s Department of Health and Senior Services (MDHSS) advises residents to hire a pro who’s certified by the National Radon Safety Board (NRSB) or National Radon Proficiency Program (NRPP).
Additional Pros to Consider Hiring
Sometimes, radon reduction will require multiple pros to handle different aspects of the project. Aside from a radon mitigation contractor, you might also need:
Electrical work: An electrician can add wiring, replace a radon fan, or handle other electrical work. For straightforward jobs like these, St. Louis electricians charge between $148 and $466.
Foundation repair: A solid, damage-free foundation can prevent radon from coming into your home. If yours needs fixing, the average cost of foundation repair in St. Louis ranges from $1,079 to $6,470.
Encapsulation: Sealing your crawl space—also called encapsulation—is another common part of the radon mitigation process. Encapsulation costs vary but run between $2 and $10 per square foot.
Does a Radon Mitigation System Increase Home Value?
According to data from the MDHSS, one in three homes tested in Missouri has radon levels that exceed 4 pCi/L (picocuries per liter), the “action level” set by the Environmental Protection Agency (EPA). By adding a radon mitigation system to your St. Louis home, you’ll get the peace of mind of knowing that your family is protected against this dangerous gas. In addition, you could see a lift in your home’s value, since radon reduction systems are an attractive feature for homebuyers.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
Radon detection and reduction services reviews from real Angi homeowners in Saint Louis, MO
Last update on August 28, 2026
- James M.
I contacted CL Contracting and Renovation through Angi for work involving a downspout that had disconnected and been blown free by high winds. I dealt entirely with Chance, who was prompt, courteous, and helpful at every turn. I was quite satisfied with all aspects of my dealings with...
CL Contracting and Renovation - Bruce T.
Michael SalazarII did anexcellant job of checking my roof and explaining what needed to be done. He showed me drone pictures of the condition of the roof and what was on top of it. 3938 Labadie Ave. St. louis, Mo. 63107-2115
ECI: A Missouri Exterior Co. - David H.
The work was done promptly and very competently. I had an old wood fence removed and replaced with a black metal fence to match the other fencing around the yard. I was very pleased with the result. It was a perfect match and the crew completed the job in one day as promised.
St. Louis Fence & Gate - Matthew C.
This company trimmed 4 large Oak trees at my property in Ballwin. They went above and beyond. My trees look spectacular.
Accutree LLC - Mark H.
We hired Swenson Electric to connect a Hitachi HVAC split system. The work was performed onetime, quickly and in professional manner.
Swenson Electric - Carine D.
I highly recommend Impact Wood Refinishing. A professional operation with clear communication, beautiful work product and a reasonable price. You wonâ t be disappointed if you use their services.
- Ryan N.
I had 2 large stumps and about 5 little ones and Grumpy Stumpyâ s came right over and took care of all of my stumps that were sticking out of the ground. They were very professional and easy to work with, I would definitely recommend to anyone who has stumps.
Grumpy Stumpy's LLC - Marie V.
Provided inspection of property quickly.
Scapular Engineering Firm - Dennis P.
Ace Fireplace Services did an exceptional job with my chimney sweep. They left no stone unturned, ensuring a thorough cleaning. My chimney is cleaner and safer than ever, thanks to their dedication.
Ace Fireplace Services - Jorge H.
The work was exceptionally done, not a detail was missed and completed as requested. Will continue to use Hayes Painting for future projects.
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