Florissant, MO Radon Levels

Q: What EPA Radon Zone is Florissant in?

Florissant is in St Louis County, EPA Zone Unknown.

Q: How much does radon mitigation cost in Florissant?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Check local Florissant radon levels and find certified testing and mitigation professionals to keep your home safe

Florissant, MO Radon Facts

EPA Radon Zone Unknown Unknown

County St Louis County, MO

Zip Code 63031

This established community in St. Louis County features predominantly mid-century housing with full basements typical of the St. Louis Metro region. While comprehensive radon testing data is limited across the multiple zip codes (63031, 63033, 63034) serving Florissant, Missouri's limestone geology warrants testing. The area's mix of older and newer homes, combined with underlying bedrock formations, can produce varying radon levels.

12.20

pCi/L area average

Above EPA Action Level

St Louis County average: 12.20 pCi/L, based on 5 user-submitted tests across 4 cities in the county. No homeowner readings have been submitted for Florissant itself yet, so this county figure is the closest available benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Florissant, MO Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Radon Readings Near Florissant, MO

No homeowner tests have been submitted for Florissant yet. The closest cities with user-submitted radon data are shown below — explore them to gauge local conditions. Radon varies by home, so testing is the only way to know your level.

City	Distance	Avg User Level	Readings
Hazelwood	3.9 mi	20.00 pCi/L	1
Saint Charles	14.0 mi	5.00 pCi/L	1
Saint Peters	17.2 mi	7.00 pCi/L	1
Chesterfield	18.7 mi	5.00 pCi/L	1
Ballwin	19.8 mi	4.00 pCi/L	1
Fenton	23.2 mi	16.00 pCi/L	2
O Fallon	23.2 mi	7.75 pCi/L	4
Lake Saint Louis	25.9 mi	5.00 pCi/L	2

St Louis County Radon Profile

St Louis County has not been assigned a definitive EPA radon zone, so the agency recommends that every home be tested regardless of predicted risk. Homeowner-submitted tests from 4 cities in St Louis County average 12.20 pCi/L across 5 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. Radon is the second leading cause of lung cancer in the United States, and a short-term test is the only way to confirm a specific home's level in St Louis County.

Radon FAQ for Florissant, MO

What EPA Radon Zone is Florissant in?

Florissant and the 63031 zip code are in St Louis County, which has an EPA assigned Radon Zone of Unknown. A zone of Unknown does not have sufficient data for classification.

Why are radon readings shown from areas near Florissant?

No homeowner radon tests have been submitted for Florissant yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the St Louis County average—are the best available indicator of local conditions until Florissant homeowners submit their own results. The EPA still recommends testing every individual home, since levels can vary significantly from house to house.

How much does radon mitigation cost in Florissant?

Radon mitigation in Florissant typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.

Should I test for radon if I'm buying a home in Florissant?

Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.