Mariposa, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is Mariposa in?

Mariposa is in Mariposa County, EPA Zone 2.

Q: How much does radon mitigation cost in Mariposa?

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

Mariposa County

EPA Zone 2

Nestled in Mariposa County in California's Sierra Nevada foothills, Mariposa sits among granite formations that can produce variable radon levels throughout the region. While testing data remains limited for this community, the mountainous geology suggests radon potential may vary significantly by location. Homeowners should consider testing, especially in properties with basement or crawl space foundations less common in California construction.

Mariposa, CA Radon Mitigation

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

Mariposa, CA Radon Testing

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

Mariposa Radon Facts

Key details about the radon risk profile for Mariposa and the 95338 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Mariposa County, CA

Zip Code

95338

Predicted Screening Level

2–4 pCi/L (Zone 2)

Mariposa and the 95338 zip code are located in Mariposa 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 Mariposa, CA

What EPA Radon Zone is Mariposa in?

Mariposa and the 95338 zip code are in Mariposa 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 Mariposa?

Radon mitigation in Mariposa 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 Mariposa?

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