Glendora, CA Radon Levels
Check local Glendora radon levels and find certified testing and mitigation professionals to keep your home safe
Glendora, CA Radon Facts
EPA Radon Zone
Zone 2 — Moderate Risk
2–4 pCi/L (Zone 2)
County
Los Angeles County, CA
Zip Code
91740
Situated in the San Gabriel Valley foothills of Los Angeles County, Glendora's location on alluvial fan deposits typically results in lower radon levels than areas with granite bedrock. Testing data for zip codes 91740 and 91741 within the Los Angeles metro remains limited, though California's Mediterranean climate and slab-on-grade construction styles generally reduce radon accumulation risks. Homeowners should still consider testing, particularly in properties with basements or below-grade spaces.
Glendora, CA Radon Mitigation
Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.
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Radon FAQ for Glendora, CA
What EPA Radon Zone is Glendora in?
Glendora and the 91740 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 Glendora?
Radon mitigation in Glendora 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 Glendora?
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 |