Costa Mesa, CA Radon Levels

Q: What is the average radon level in Costa Mesa, CA?

Based on 1 user-submitted tests, the average radon level is 4.00 pCi/L.

Q: What EPA Radon Zone is Costa Mesa in?

Costa Mesa is in Orange County, EPA Zone 3.

Q: How much does radon mitigation cost in Costa Mesa?

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

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

Costa Mesa, CA Radon Facts

EPA Radon Zone Zone 3 — Low Risk < 2.0 pCi/L (Zone 3)

County Orange County, CA

Zip Code 92626

Avg. User Level 4.00 pCi/L

User Tests 1

Located in Orange County as part of the Los Angeles Metro area, Costa Mesa has recorded a radon level of 4.0 pCi/L from testing in the 92626 zip code area. While this reading sits right at the EPA action level threshold, continued monitoring and potential mitigation consideration remain important for homeowners. The city's coastal plain location on marine sediments generally produces lower radon levels than inland mountain areas.

4.00

pCi/L average

Above EPA Action Level

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

4.0 EPA

10+

Costa Mesa, CA Radon Mitigation

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Costa Mesa, CA Radon Levels

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

Radon Level	City	Home Age	Foundation
4 pCi/L	Costa Mesa, CA	51-99 Years	No Basement/All Slab

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Radon FAQ for Costa Mesa, CA

What is the average radon level in Costa Mesa, CA?

Based on 1 user-submitted test, the average radon level in Costa Mesa is 4.00 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 Costa Mesa in?

Costa Mesa and the 92626 zip code are in Orange County, which has an EPA assigned Radon Zone of 3. A zone of 3 predicts an average indoor radon screening level less than 2 pCi/L.

How much does radon mitigation cost in Costa Mesa?

Radon mitigation in Costa Mesa 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 Costa Mesa?

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 California

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

City	Avg User Radon Level	Submissions
Los Angeles	7.83 pCi/L	6
Mammoth Lakes	10.80 pCi/L	5
San Jose	4.20 pCi/L	5
Rancho Palos Verdes	8.00 pCi/L	4
Bishop	6.25 pCi/L	4
Oakland	5.00 pCi/L	4
Woodland Hills	7.67 pCi/L	3
South Lake Tahoe	6.33 pCi/L	3
Palos Verdes Peninsula	6.00 pCi/L	3
Sacramento	4.33 pCi/L	3

Costa Mesa, CA Radon Levels

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

Costa Mesa, CA Radon Facts

Costa Mesa, CA Radon Mitigation

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Costa Mesa, CA Radon Levels

Radon FAQ for Costa Mesa, CA

Most Active Radon Markets in California

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