Radon Testing & Mitigation in Fenton, MO

In Fenton, MO, Air Sense Environmental tests homes for radon, installs radon mitigation systems, tests indoor air quality and encapsulates crawl spaces. Every radon job in St. Louis County is measured against the EPA action level of 4.0 pCi/L, and the team is NRPP-certified and IEMA-licensed (#RNM20232346).

Is radon a problem in Fenton, MO?

Yes. St. Louis County is in EPA Radon Zone 2, where the predicted average indoor radon level is 2 to 4 pCi/L, and individual Fenton 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. Fenton runs from the Meramec River bottoms around Old Town up into the hills toward Jefferson County, so foundation types range from raised and crawl space homes on the flats to walkout basements on the slopes.

A Fenton neighbor’s reading is a signal, not an answer. The soil under one lot, the cracks in one slab and the way one sump pit was sealed decide the number, which is why two similar homes a few doors apart can land on opposite sides of the action level.

Radon testing in Fenton, MO

A Fenton radon test runs 48 hours under closed-house conditions on a calibrated continuous monitor, and the report shows the hourly data as well as the average. The St. Louis radon testing page covers how the test works, and the radon testing cost guide holds current pricing.

Radon mitigation in Fenton, MO

When a Fenton home tests at or above 4.0 pCi/L, the same team designs and installs the radon mitigation system, usually in a single day, and retests to confirm the home is below the action level. See the St. Louis radon mitigation services page for the process, documented results and warranty.

Indoor air quality testing in Fenton, MO

An indoor air quality assessment for a Fenton home logs particulate matter, chemical vapors, CO2, CO and humidity at one-minute intervals for 48 hours or more, so the fix is based on data. Details are on the St. Louis indoor air quality testing page.

Crawl space encapsulation in Fenton, MO

For Fenton homes with a crawl space, encapsulation lays a sealed vapor barrier over the soil and walls and adds humidity control, keeping damp air and soil gas out of the rooms above. Read more on the St. Louis crawl space encapsulation page.

Which Fenton homes does Air Sense Environmental work on?

The Fenton homes the team sees most often:

• Homes in Old Town Fenton near the Meramec River with crawl spaces or raised foundations
• 1970s to 1990s subdivision homes with walkout basements
• Newer homes on poured basements near Gravois Bluffs
• Homes with sump pits, which are common radon entry points near the river

What should Fenton 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.

Fenton neighborhoods and nearby communities

Air Sense Environmental works across Fenton, MO, including Old Town Fenton, the Gravois Bluffs area and the subdivisions along Highway 141, in ZIP code 63026. Nearby communities with their own service pages:

• Radon testing and mitigation in Valley Park, MO
• Radon testing and mitigation in Arnold, MO
• Radon testing and mitigation in Kirkwood, MO
• Radon testing and mitigation in Eureka, MO
• All Air Sense Environmental service areas

From Our Work