O Fallon, IL Radon Levels
Check local O Fallon radon levels and find certified testing and mitigation professionals to keep your home safe
O Fallon, IL Radon Facts
Located in St. Clair County on the Illinois side of the St. Louis Metro, O'Fallon shows a concerning average radon level of 6.0 pCi/L, which exceeds the EPA action threshold. This elevated reading reflects the area's geological conditions, including Mississippi River floodplain deposits over limestone bedrock. Homeowners in zip code 62269 should prioritize professional radon testing and consider mitigation systems if levels exceed 4.0 pCi/L.
Based on 1 user-submitted radon test for homes in O Fallon, IL. The EPA recommends taking action at or above 4.0 pCi/L.
O Fallon, IL Radon Mitigation
Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.
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O Fallon, IL Radon Levels
User-submitted radon test readings from homes in the O Fallon area.
| Radon Level | City | Home Age | Foundation |
|---|---|---|---|
| 6 pCi/L | O Fallon, IL | 0-20 Years | Full Basement |
Have a radon test result for O Fallon? Submit your reading to help other homeowners.
Radon Readings Near O Fallon, IL
Compare radon levels in O Fallon with the closest nearby cities that have user-submitted test data.
| City | Distance | Avg User Level | Readings |
|---|---|---|---|
| Lebanon | 5.7 mi | 10.50 pCi/L | 2 |
| Belleville | 6.0 mi | 7.33 pCi/L | 3 |
| Fairview Heights | 6.2 mi | 9.00 pCi/L | 1 |
| Caseyville | 7.7 mi | 7.50 pCi/L | 2 |
| Mascoutah | 8.9 mi | 6.50 pCi/L | 2 |
| Collinsville | 9.1 mi | 5.00 pCi/L | 1 |
| Maryville | 10.5 mi | 11.00 pCi/L | 1 |
| Troy | 10.6 mi | 4.00 pCi/L | 1 |
St Clair County Radon Profile
EPA mapping assigns St Clair 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 7 cities in St Clair County average 7.50 pCi/L across 12 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 St Clair County home regardless of zone or a neighbor's results.