Radon Mitigation in St. Louis, MO

Air Sense Environmental installs and tests radon mitigation systems across St. Louis, MO, St. Louis County and St. Charles County, from historic brick homes in South City and Webster Groves to newer subdivisions in Chesterfield and Florissant. Every system is designed for the house it goes into, installed by an NRPP-certified crew (IEMA license #RNM20232346), and verified with a post-mitigation test against the EPA action level of 4.0 pCi/L.

If a test has already come back high, our radon mitigation service page explains the systems we install, the readings they reach and the guarantee behind them, and our St. Louis radon mitigation cost guide covers what to budget. If you have not tested yet, radon testing in St. Louis is the first step, and it is the only way to know your number.

How We Mitigate Radon in St. Louis Homes

Most St. Louis homes get an active sub-slab depressurization system: a suction pit cored through the basement floor, a sealed riser, and a continuously running fan that exhausts soil gas above the roofline. Block-wall foundations common in older city neighborhoods may need wall suction as well, and crawl space homes are encapsulated first so the fan has something to pull against. A pressure field test during the free estimate tells us how many suction points the slab needs, which is what sets the price.

Every install ends with a post-mitigation radon test. If that reading is not below 4.0 pCi/L, we adjust the system at no charge: a bigger fan, a second suction point, or more sealing, whatever the house needs.

St. Louis Radon Mitigation Results

Each project below is a real St. Louis area home, with the radon reading before the system went in and the reading from the post-install test. The EPA action level is 4.0 pCi/L.

• High-level basement mitigation. Before: 12 to 14 pCi/L, three to four times the EPA action level. After: 0.1 to 0.4 pCi/L. Sub-slab depressurization with a monitored exhaust fan.
• Severe reduction from 30+ pCi/L. Before: more than 30 pCi/L. After: under 1 pCi/L. Engineered sub-slab depressurization with sealed entry points and a high-flow fan.
• Two-zone whole-home mitigation. Before: 4 pCi/L upstairs and 10 pCi/L in the basement. After: both zones below 2 pCi/L. Multi-point depressurization with balanced exhaust.
• Sump-pump-integrated mitigation. Sump pump replacement combined with the radon system tie-in, with the reduction confirmed by post-install testing.

All six documented projects are on our reviews and project results page.

Where We Work in St. Louis

Our crews are on the Missouri side every week. In St. Louis City that means South City, Tower Grove, Soulard and the Central West End. In St. Louis County it includes Kirkwood, Webster Groves, Clayton, University City, Maplewood, Brentwood, Richmond Heights, Des Peres, Creve Coeur, Chesterfield, Ballwin, Ellisville, Wildwood, Maryland Heights, Hazelwood, Florissant, Affton, Oakville and Fenton. In St. Charles County we cover St. Charles, St. Peters, O’Fallon, Wentzville and Weldon Spring, and in Jefferson County, Arnold and Festus. Each community has its own page under our service area, and the Illinois side of the metro is covered from our Edwardsville headquarters.

Other Areas We Serve

Air Sense Environmental is committed to protecting communities through thorough radon testing and reliable mitigation solutions. We proudly serve the following areas:

• St. Charles, MO
• St. Peters, MO
• Florissant, MO
• University City, MO
• Wildwood, MO
• Maryland Heights, MO
• Kirkwood, MO

From Our Work