Saint Charles, MO Radon Mitigation and Testing

Q: What is the average radon level in Saint Charles, MO?

Based on 1 user-submitted tests, the average radon level is 5.00 pCi/L.

Q: What EPA Radon Zone is Saint Charles in?

Saint Charles is in St Charles County, EPA Zone Unknown.

Q: How much does radon mitigation cost in Saint Charles?

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

Avg: 5.00 pCi/L

St Charles County

EPA Zone Unknown

1 user test

Found in St Charles County as part of the greater St. Louis metropolitan area, Saint Charles encompasses multiple zip codes (63301, 63303, 63304) with varying housing characteristics and geological conditions. While comprehensive radon testing data is currently limited for these areas, Missouri's diverse geology can produce unexpected radon readings. Residents across all Saint Charles zip codes should consider radon testing, particularly in homes with basements or lower-level living spaces.

5.00

pCi/L average

Above EPA Action Level

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

4.0 EPA

10+

Saint Charles, MO Radon Mitigation

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

Saint Charles, MO Radon Testing

Finding qualified radon testing professionals is the first step toward protecting your home.

Saint Charles, Missouri Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
5 pCi/L	Saint Charles, MO	51-99 Years	No Basement/All Slab	Jun 2026

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

Saint Charles Radon Facts

Key details about the radon risk profile for Saint Charles and the 63301 zip code area.

EPA Radon Zone

Unknown

County

St Charles County, MO

Zip Code

63301

Predicted Screening Level

Unknown

Avg. User Submitted Level

5.00 pCi/L

User Tests Submitted

Saint Charles and the 63301 zip code are located in St Charles County, which has an EPA assigned Radon Zone of Unknown. A radon zone of Unknown does not have sufficient data for classification. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for Saint Charles, MO

What is the average radon level in Saint Charles, MO?

Based on 1 user-submitted test, the average radon level in Saint Charles is 5.00 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 Saint Charles in?

Saint Charles and the 63301 zip code are in St Charles County, which has an EPA assigned Radon Zone of Unknown. A zone of Unknown does not have sufficient data for classification.

How much does radon mitigation cost in Saint Charles?

Radon mitigation in Saint Charles 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 Saint Charles?

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.

Most Active Radon Markets in Missouri

Cities with the most user-submitted radon test data in the state.

City	Avg User Radon Level	Submissions
Troy	8.50 pCi/L	4
Lees Summit	7.00 pCi/L	3
Columbia	3.00 pCi/L	2
House Springs	7.00 pCi/L	1
Kansas City	7.00 pCi/L	1
Springfield	7.00 pCi/L	1
Independence	5.00 pCi/L	1
Wentzville	No submissions	0