San Quentin, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is San Quentin in?

San Quentin is in Marin County, EPA Zone 3.

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

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

Marin County

EPA Zone 3

Situated in Marin County along San Francisco Bay, San Quentin sits on marine sedimentary formations that typically result in low radon potential. Testing data for zip code 94974 is currently limited, highlighting the importance of individual radon testing for homeowners. The area's limited residential development features primarily older California architecture adapted to the coastal environment.

San Quentin, CA Radon Mitigation

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

San Quentin, CA Radon Testing

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

San Quentin Radon Facts

Key details about the radon risk profile for San Quentin and the 94974 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Marin County, CA

Zip Code

94974

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

San Quentin and the 94974 zip code are located in Marin 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 San Quentin, CA

What EPA Radon Zone is San Quentin in?

San Quentin and the 94974 zip code are in Marin 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 San Quentin?

Radon mitigation in San Quentin 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 Quentin?

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