Downey, CA Radon Levels
Check local Downey radon levels and find certified testing and mitigation professionals to keep your home safe
Downey, CA Radon Facts
EPA Radon Zone
Zone 2 — Moderate Risk
2–4 pCi/L (Zone 2)
County
Los Angeles County, CA
Zip Code
90240
Situated in Los Angeles County within the greater Los Angeles basin, Downey occupies alluvial plains and coastal sediments that generally produce lower radon concentrations than found in mountainous or granitic regions. While testing data for zip codes 90240, 90241, and 90242 remains limited, the EPA Zone 2 classification suggests moderate radon potential. Homeowners should consider radon testing, particularly in properties with enclosed spaces below ground level or those built on fill material.
Downey, 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 Downey, CA
What EPA Radon Zone is Downey in?
Downey and the 90240 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 Downey?
Radon mitigation in Downey 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 Downey?
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 |