Saint Helena, CA Radon Mitigation and Testing

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.

Avg: 3.00 pCi/L

Napa County

EPA Zone 3

1 user test

Saint Helena is located in Napa County, California. With 1 user-submitted readings averaging 3.00 pCi/L, levels are currently 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.

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

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

Saint Helena, CA Radon Testing

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

Saint Helena, California Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
3 pCi/L	Saint Helena, CA	21-50 Years	No Basement/All Slab	Jul 2022

Have a radon test result for Saint Helena? Submit your reading to help other homeowners.

Saint Helena Radon Facts

Key details about the radon risk profile for Saint Helena and the 94574 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Napa County, CA

Zip Code

94574

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

Avg. User Submitted Level

3.00 pCi/L

User Tests Submitted

Saint Helena and the 94574 zip code are located in Napa 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 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 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