Leslie, MO Radon Levels

Q: What EPA Radon Zone is Leslie in?

Leslie is in Franklin County, EPA Zone 2.

Q: Why are radon readings shown from areas near Leslie?

No homeowner radon tests have been submitted for Leslie yet, so readings from the closest cities and the Franklin County average are used as the best available indicator of local conditions. The EPA recommends testing every individual home.

Q: How much does radon mitigation cost in Leslie?

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

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

Leslie, MO Radon Facts

EPA Radon Zone Zone 2 — Moderate Risk 2–4 pCi/L (Zone 2)

County Franklin County, MO

Zip Code 63056

Situated in Franklin County within the St. Louis Metro region, Leslie occupies EPA Zone 2 where Missouri River valley geology influences radon levels. With limited testing data available for zip code 63056, residents should prioritize home radon testing to establish baseline readings. The community's varied housing ages and foundation types may result in different radon entry patterns.

7.33

pCi/L area average

Above EPA Action Level

Franklin County average: 7.33 pCi/L, based on 3 user-submitted tests across 3 cities in the county. No homeowner readings have been submitted for Leslie 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+

Leslie, MO Radon Mitigation

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

Need Radon Mitigation or Testing in Leslie?

100% Free, No-Obligation Quotes
Matches You with State-Licensed Franklin County Pros

1-800-299-3578 636-205-4618 (local) Toll-free · Mon–Fri 8am–6pm ET

Radon Readings Near Leslie, MO

No homeowner tests have been submitted for Leslie 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
New Haven	8.2 mi	5.00 pCi/L	1
Union	11.5 mi	13.00 pCi/L	1
Bourbon	19.6 mi	6.00 pCi/L	1
Labadie	19.8 mi	4.00 pCi/L	1
Leasburg	25.4 mi	4.00 pCi/L	1
Cuba	26.8 mi	5.00 pCi/L	1
Lake Saint Louis	33.6 mi	5.00 pCi/L	2
O Fallon	35.3 mi	7.75 pCi/L	4

Franklin County Radon Profile

EPA mapping assigns Franklin County to Radon Zone 2, indicating moderate predicted indoor screening levels in the 2 to 4 pCi/L range based on regional geology. Homeowner-submitted tests from 3 cities in Franklin County average 7.33 pCi/L across 3 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. As the second leading cause of lung cancer in the U.S., radon warrants testing in every Franklin County home regardless of zone or a neighbor's results.

Radon FAQ for Leslie, MO

What EPA Radon Zone is Leslie in?

Leslie and the 63056 zip code are in Franklin County, which has an EPA assigned Radon Zone of 2. A zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L.

Why are radon readings shown from areas near Leslie?

No homeowner radon tests have been submitted for Leslie yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Franklin County average—are the best available indicator of local conditions until Leslie 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 Leslie?

Radon mitigation in Leslie 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 Leslie?

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.