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Marseilles, IL Radon Levels

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


Marseilles, IL Radon Facts

EPA Radon Zone Zone 1 — High Risk > 4.0 pCi/L (Zone 1)
County La Salle County, IL
Zip Code 61341
Avg. User Level 9.00 pCi/L
User Tests 1

Situated along the Illinois River in La Salle County, Marseilles has recorded an average radon level of 9.0 pCi/L, significantly exceeding the EPA action level. The community sits where Illinois River valley alluvial soils meet underlying Ordovician limestone, creating conditions highly favorable for radon gas production and migration. Residents should prioritize radon testing and mitigation given these consistently elevated readings.

9.00
pCi/L average
Above EPA Action Level

Based on 1 user-submitted radon test for homes in Marseilles, IL. The EPA recommends taking action at or above 4.0 pCi/L.

0
4.0 EPA
10+

Marseilles, IL Radon Mitigation

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Marseilles, IL Radon Levels

User-submitted radon test readings from homes in the Marseilles area.

Radon LevelCityHome AgeFoundation
9 pCi/L Marseilles, IL 21-50 Years Partial Basement

Have a radon test result for Marseilles? Submit your reading to help other homeowners.

Radon Readings Near Marseilles, IL

Compare radon levels in Marseilles with the closest nearby cities that have user-submitted test data.

CityDistanceAvg User LevelReadings
Streator 16.0 mi 7.00 pCi/L 1
Newark 16.1 mi 11.00 pCi/L 1
Earlville 20.9 mi 11.00 pCi/L 1
Ancona 21.7 mi 20.00 pCi/L 1
Dwight 22.1 mi 7.00 pCi/L 1
Peru 22.4 mi 6.50 pCi/L 2
Minooka 23.4 mi 11.00 pCi/L 1
Plano 24.6 mi 10.00 pCi/L 1

La Salle County Radon Profile

The bedrock and soils beneath La Salle County are classified by the EPA as Radon Zone 1, the highest-risk tier, with predicted average indoor screening levels above 4 pCi/L. Homeowner-submitted tests from 4 cities in La Salle County average 8.00 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 La Salle County.

Radon FAQ for Marseilles, IL

What is the average radon level in Marseilles, IL?
Based on 1 user-submitted test, the average radon level in Marseilles is 9.00 pCi/L. This exceeds the EPA's recommended action level of 4.0 pCi/L, and radon testing is recommended for all homes in the area.
What EPA Radon Zone is Marseilles in?
Marseilles and the 61341 zip code are in La Salle County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.
How much does radon mitigation cost in Marseilles?
Radon mitigation in Marseilles 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 Marseilles?
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.