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      Fontana, CA Radon Levels

      Check local Fontana radon levels and find certified testing and mitigation professionals to keep your home safe

      Fontana, CA Radon Facts

      EPA Radon Zone Zone 2 — Moderate Risk 2–4 pCi/L (Zone 2)
      County San Bernardino County, CA
      Zip Code 92335
      Avg. User Level 6.00 pCi/L
      User Tests 1

      Located in San Bernardino County within the Riverside metropolitan area, Fontana shows an elevated average radon level of 6.0 pCi/L, significantly above the EPA's 4.0 pCi/L action threshold. The region's alluvial soils and nearby mountain geology create variable radon conditions across zip codes 92335, 92336, and 92337. Despite California's generally moderate radon reputation, these readings demonstrate why testing remains crucial for Inland Empire residents.

      6.00
      pCi/L average
      Above EPA Action Level

      Based on 1 user-submitted radon test for homes in Fontana, CA. The EPA recommends taking action at or above 4.0 pCi/L.

      0
      4.0 EPA
      10+

      Fontana, CA Radon Mitigation

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

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      Fontana, CA Radon Levels

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

      Radon LevelCityHome AgeFoundation
      6 pCi/L Fontana, CA 21-50 Years —

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

      Radon FAQ for Fontana, CA

      What is the average radon level in Fontana, CA?
      Based on 1 user-submitted test, the average radon level in Fontana is 6.00 pCi/L. This exceeds the EPA's recommended action level of 4.0 pCi/L, and radon testing is recommended for all homes in the area.
      What EPA Radon Zone is Fontana in?
      Fontana and the 92335 zip code are in San Bernardino 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 Fontana?
      Radon mitigation in Fontana 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 Fontana?
      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.

      CityAvg User Radon LevelSubmissions
      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

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      Free Radon Mitigation Quote

      Or call for a free quote: 1-800-299-3578

      A licensed contractor will contact you immediately.

      * Required