San Marino, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is San Marino in?

San Marino is in Los Angeles County, EPA Zone 2.

Q: How much does radon mitigation cost in San Marino?

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

Los Angeles County

EPA Zone 2

Nestled in Los Angeles County within the San Gabriel Valley, San Marino sits on alluvial fan deposits from the nearby San Gabriel Mountains. Testing data for zip code 91108 is currently insufficient to determine community radon averages. This affluent community's housing stock, featuring many large homes built throughout the 20th century with varied foundation types, may experience different radon levels depending on construction details and proximity to mountain-derived sediments.

San Marino, CA Radon Mitigation

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

San Marino, CA Radon Testing

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

San Marino Radon Facts

Key details about the radon risk profile for San Marino and the 91108 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Los Angeles County, CA

Zip Code

91108

Predicted Screening Level

2–4 pCi/L (Zone 2)

San Marino and the 91108 zip code are located in Los Angeles County, which has an EPA assigned Radon Zone of 2. A radon zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for San Marino, CA

What EPA Radon Zone is San Marino in?

San Marino and the 91108 zip code are in Los Angeles 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 San Marino?

Radon mitigation in San Marino 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 San Marino?

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