San Dimas, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is San Dimas in?

San Dimas is in Los Angeles County, EPA Zone 2.

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

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

Los Angeles County

EPA Zone 2

Nestled in the foothills of Los Angeles County, San Dimas currently has limited radon testing data available for homeowners and prospective buyers. The area's position at the base of the San Gabriel Mountains, with underlying sedimentary and igneous geological formations, suggests variable radon potential throughout different elevations and soil types. Testing is particularly recommended for homes in zip code 91773, especially those built into hillsides or with basement areas.

San Dimas, CA Radon Mitigation

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

San Dimas, CA Radon Testing

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

San Dimas Radon Facts

Key details about the radon risk profile for San Dimas and the 91773 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Los Angeles County, CA

Zip Code

91773

Predicted Screening Level

2–4 pCi/L (Zone 2)

San Dimas and the 91773 zip code are located in Los Angeles 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 San Dimas, CA

What EPA Radon Zone is San Dimas in?

San Dimas and the 91773 zip code are in Los Angeles 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 San Dimas?

Radon mitigation in San Dimas 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 Dimas?

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