Columbia, IL Radon Levels

Q: What is the average radon level in Columbia, IL?

Based on 4 user-submitted tests, the average radon level is 8.00 pCi/L.

Q: What EPA Radon Zone is Columbia in?

Columbia is in Monroe County, EPA Zone 2.

Q: How much does radon mitigation cost in Columbia?

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

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

Columbia, IL Radon Facts

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

County Monroe County, IL

Zip Code 62236

Avg. User Level 8.00 pCi/L

User Tests 4

Located in Monroe County on the Illinois side of the St. Louis metropolitan area, Columbia sits on Mississippi River bluff deposits and underlying limestone that contribute to elevated radon levels. Testing data shows an average reading of 8.0 pCi/L, well above the EPA action threshold and reflecting the area's geological complexity. The 62236 zip code features many homes with full basements typical of Midwest construction, creating enclosed spaces where radon accumulates most readily.

8.00

pCi/L average

Above EPA Action Level

Based on 4 user-submitted radon tests for homes in Columbia, IL. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Columbia, IL Radon Mitigation

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

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Columbia, Illinois Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
4 pCi/L	Columbia, IL	21-50 Years	Partial Basement	Jul 2024
10 pCi/L	Columbia, IL	0-20 Years	Full Basement	Dec 2020
9 pCi/L	Columbia, IL	—	—	Mar 2020

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

Monroe County Radon Profile

EPA mapping assigns Monroe 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 2 cities in Monroe County average 8.67 pCi/L across 9 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 Monroe County home regardless of zone or a neighbor's results.

Radon FAQ for Columbia, IL

What is the average radon level in Columbia, IL?

Based on 4 user-submitted tests, the average radon level in Columbia is 8.00 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 Columbia in?

Columbia and the 62236 zip code are in Monroe 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.

How much does radon mitigation cost in Columbia?

Radon mitigation in Columbia 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 Columbia?

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.

Radon Levels Near Columbia, IL

User-submitted radon levels from the cities closest to Columbia with recorded test data. Explore nearby communities to compare local readings.

City	Distance	Avg User Level	Submissions
Waterloo	8.2 mi	9.20 pCi/L	5
Belleville	13.2 mi	7.33 pCi/L	3
Fairview Heights	15.5 mi	9.00 pCi/L	1
Caseyville	17.3 mi	7.50 pCi/L	2
O Fallon	19.2 mi	6.00 pCi/L	1
Granite City	20.9 mi	8.00 pCi/L	1
Collinsville	20.9 mi	5.00 pCi/L	1
Mascoutah	22.6 mi	6.50 pCi/L	2