Costa Mesa, CA Radon Mitigation and Testing

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.

Avg: 4.00 pCi/L

Orange County

EPA Zone 3

1 user test

Costa Mesa is located in Orange County, California. With 1 user-submitted readings averaging 4.00 pCi/L, the area exceeds the EPA's 4.0 pCi/L action threshold, and testing is strongly recommended for homeowners in the 92626 zip code.

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

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

Costa Mesa, CA Radon Testing

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

Costa Mesa, California Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
4 pCi/L	Costa Mesa, CA	51-99 Years	No Basement/All Slab	Nov 2023

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

Costa Mesa Radon Facts

Key details about the radon risk profile for Costa Mesa and the 92626 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Orange County, CA

Zip Code

92626

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

Avg. User Submitted Level

4.00 pCi/L

User Tests Submitted

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

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

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
Woodland Hills	7.67 pCi/L	3
South Lake Tahoe	6.33 pCi/L	3
Palos Verdes Peninsula	6.00 pCi/L	3
Bishop	5.67 pCi/L	3
Sacramento	4.33 pCi/L	3
Oakland	3.33 pCi/L	3
Fresno	10.00 pCi/L	2
Davis	8.00 pCi/L	2
Palo Alto	6.50 pCi/L	2
Studio City	6.50 pCi/L	2
Menlo Park	5.00 pCi/L	2
Truckee	5.00 pCi/L	2
Walnut Creek	4.00 pCi/L	2
San Diego	3.50 pCi/L	2
San Francisco	3.50 pCi/L	2
Belmont	20.00 pCi/L	1