Saint Helena, CA Radon Levels

Q: What is the average radon level in Saint Helena, CA?

Based on 1 user-submitted tests, the average radon level is 3.00 pCi/L.

Q: What EPA Radon Zone is Saint Helena in?

Saint Helena is in Napa County, EPA Zone 3.

Q: How much does radon mitigation cost in Saint Helena?

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

Check local Saint Helena radon levels and find certified testing and mitigation professionals to keep your home safe

Saint Helena, CA Radon Facts

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

County Napa County, CA

Zip Code 94574

Avg. User Level 3.00 pCi/L

User Tests 1

Saint Helena in Napa County has measured an average radon level of 3.0 pCi/L, which falls within the EPA's acceptable range but still warrants attention from homeowners. This Napa Valley community sits atop volcanic soils and sedimentary formations that create variable radon conditions throughout the wine region. Properties in zip code 94574 should undergo testing, as local geology and construction methods can influence radon accumulation in individual homes.

3.00

pCi/L average

Below EPA Action Level

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

4.0 EPA

10+

Saint Helena, CA Radon Mitigation

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Saint Helena, CA Radon Levels

User-submitted radon test readings from homes in the Saint Helena area.

Radon Level	City	Home Age	Foundation
3 pCi/L	Saint Helena, CA	21-50 Years	No Basement/All Slab

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Radon FAQ for Saint Helena, CA

What is the average radon level in Saint Helena, CA?

Based on 1 user-submitted test, the average radon level in Saint Helena is 3.00 pCi/L. This is below the EPA's recommended action level of 4.0 pCi/L. However, we recommend all homes be tested regardless of your neighbor's results.

What EPA Radon Zone is Saint Helena in?

Saint Helena and the 94574 zip code are in Napa 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 Saint Helena?

Radon mitigation in Saint Helena 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 Saint Helena?

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

Saint Helena, CA Radon Levels

Check local Saint Helena radon levels and find certified testing and mitigation professionals to keep your home safe

Saint Helena, CA Radon Facts

Saint Helena, CA Radon Mitigation

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Saint Helena, CA Radon Levels

Radon FAQ for Saint Helena, CA

Most Active Radon Markets in California

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