Caspar, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is Caspar in?

Caspar is in Mendocino County, EPA Zone 3.

Q: How much does radon mitigation cost in Caspar?

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

Mendocino County

EPA Zone 3

Perched along the rugged Mendocino County coastline, Caspar sits on marine terraces where Franciscan Complex bedrock and coastal geology typically produce lower radon levels. Testing data remains limited for this 95420 community, though the coastal location generally indicates reduced radon risk compared to inland areas.

Caspar, CA Radon Mitigation

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

Caspar, CA Radon Testing

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

Caspar Radon Facts

Key details about the radon risk profile for Caspar and the 95420 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Mendocino County, CA

Zip Code

95420

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

Caspar and the 95420 zip code are located in Mendocino 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 Caspar, CA

What EPA Radon Zone is Caspar in?

Caspar and the 95420 zip code are in Mendocino 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 Caspar?

Radon mitigation in Caspar 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 Caspar?

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