Radon Testing & Mitigation in Festus, MO

Festus, MO homeowners call Air Sense Environmental for four things: radon testing, radon mitigation, indoor air quality testing and crawl space encapsulation. The NRPP-certified, IEMA-licensed (#RNM20232346) team serves Jefferson County from Edwardsville, Illinois, and designs every radon system to bring the home below the EPA action level of 4.0 pCi/L.

Is radon a problem in Festus, MO?

Yes. Jefferson County is in EPA Radon Zone 2, where the predicted average indoor radon level is 2 to 4 pCi/L, and individual Festus homes routinely test well above the 4.0 pCi/L action level. Missouri’s Department of Health and Senior Services reports that roughly one in three homes tested through its statewide program between 2003 and 2023 came back at or above 4.0 pCi/L. Festus and its twin city Crystal City sit in the Mississippi River hills of Jefferson County, with an older downtown and hillside subdivisions on rocky ground.

Because radon depends on the ground under a single lot and the openings in a single foundation, Festus results change from address to address. Testing the specific house is the only way to know where it stands.

Radon testing in Festus, MO

For radon testing in Festus, Air Sense Environmental places a continuous monitor on the lowest livable level for 48 hours and delivers a documented report against the 4.0 pCi/L action level. The St. Louis radon testing page covers how the test works, and the radon testing cost guide holds current pricing.

Radon mitigation in Festus, MO

A Festus radon mitigation system pulls soil gas from beneath the slab or crawl space membrane and vents it above the roofline; every install ends with a verification test. See radon mitigation in Festus for the process, documented results and warranty.

Indoor air quality testing in Festus, MO

For indoor air quality in Festus, a continuous monitor tracks particulates, VOCs, carbon dioxide, carbon monoxide and humidity, and the report shows which readings sit outside healthy ranges. Details are on the St. Louis indoor air quality testing page.

Crawl space encapsulation in Festus, MO

A sealed, conditioned crawl space keeps ground moisture and soil gas from rising into a Festus home; Air Sense Environmental installs the barrier, seals the vents and sizes the dehumidifier. Read more on the St. Louis crawl space encapsulation page.

Which Festus homes does Air Sense Environmental work on?

The Festus homes the team sees most often:

• Early 1900s homes near downtown Festus with older basements and cellars
• Hillside subdivision homes with walkout basements
• Ranch homes with crawl spaces
• Newer homes on poured basements along Highway A and Highway 61

What should Festus homeowners expect?

1. Test first. A 48-hour continuous monitor test gives the number everything else depends on.
2. Read the report together. You get the hourly data and a plain explanation of what it means for the house.
3. Design the fix. If the reading is at or above 4.0 pCi/L, the system is designed around your foundation during a free in-home estimate.
4. Install and verify. Most systems go in within a single day, and a post-mitigation test confirms the result.

Festus neighborhoods and nearby communities

Air Sense Environmental works across Festus, MO, including downtown Festus, the Crystal City line and the subdivisions along Highway A, in ZIP code 63028. Nearby communities with their own service pages:

• Radon testing and mitigation in Arnold, MO
• Radon testing and mitigation in Fenton, MO
• Radon testing and mitigation in Oakville, MO
• Radon testing and mitigation in Pacific, MO
• All Air Sense Environmental service areas

From Our Work