California, MD Radon Levels

Q: What is the average radon level in California, MD?

Based on 2 user-submitted tests, the average radon level is 5.00 pCi/L.

Q: What EPA Radon Zone is California in?

California is in St Mary's County, EPA Zone Unknown.

Q: How much does radon mitigation cost in California?

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

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

California, MD Radon Facts

EPA Radon Zone Unknown Unknown

County St Mary's County, MD

Zip Code 20619

Avg. User Level 5.00 pCi/L

User Tests 2

Based in St Mary's County on Maryland's Western Shore, California has recorded an average radon level of 5.0 pCi/L, which exceeds the EPA action level and indicates the need for mitigation consideration. The area's Coastal Plain geology, featuring sand, clay, and gravel deposits over deeper formations, creates conditions that can concentrate radon in homes throughout zip code 20619. Properties near the Patuxent River Naval Air Station should particularly prioritize testing and mitigation.

5.00

pCi/L average

Above EPA Action Level

Based on 2 user-submitted radon tests for homes in California, MD. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

California, MD Radon Mitigation

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California, MD Radon Levels

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

Radon Level	City	Home Age	Foundation
5 pCi/L	California, MD	0-20 Years	—

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

Radon FAQ for California, MD

What is the average radon level in California, MD?

Based on 2 user-submitted tests, the average radon level in California 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 California in?

California and the 20619 zip code are in St Mary's 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 California?

Radon mitigation in California 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 California?

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 Maryland

Cities in Maryland with the most user-submitted radon test data, ranked by number of submissions.

City	Avg User Radon Level	Submissions
Frederick	8.29 pCi/L	7
Potomac	9.00 pCi/L	6
Hagerstown	8.67 pCi/L	6
Westminster	14.50 pCi/L	4
Baltimore	7.00 pCi/L	4
Annapolis	4.25 pCi/L	4
Upper Marlboro	15.00 pCi/L	3
Edgewater	12.67 pCi/L	3
Bowie	9.00 pCi/L	3
Frostburg	8.67 pCi/L	3

California, MD Radon Levels

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

California, MD Radon Facts

California, MD Radon Mitigation

Need Radon Mitigation or Testing in California?

California, MD Radon Levels

Radon FAQ for California, MD

Most Active Radon Markets in Maryland

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