CH
TestingCommercial
Radon Pros in California
42 contractorsEPA zone context: California has a mix of all three zones. The northern Sierra Nevada foothills and some southern inland areas are Zone 1. Coastal regions are mostly Zone 2-3.
WI
TestingNew ConstructionCommercialPost-Test
MR
MG Remediation, Inc.
4.9 (96 Google reviews)
Certified Professional
Licensed Provider: Ryan J Mandel
Full Service•San Leandro, CA
MitigationTestingCommercial
Certified RMS/RMPFree Estimates
SO
MitigationCommercial
WE
Wood Environmental Services
5.0 (2 Google reviews)
Certified Professional
Licensed Provider: Judith H Wood
Santa Barbara, CA
TestingCommercial
Certified RMP
PE
TestingCommercial
AI
TestingCommercialWater Treatment
RC
Radon California
5.0 (13 Google reviews)
Certified Professional
Licensed Provider: Jason Wayne Gregory
Full Service•Thousand Oaks, CA
MitigationTestingCrawlspaceCommercial
Certified RMS/RMP
Radon California is a dedicated radon services company serving Thousand Oaks, CA. Services include radon mitigation system installation, mitigation system design, radon testing, radon measurement. Works with crawlspaces. Methods include heat recovery ventilation. Holds Certified Radon Mitigation Specialist and Certified Radon Measurement Professional certifications. Rated 5.0/5 on Google based on 13 reviews. Offers real estate transaction testing.
GC
TestingCrawlspaceCommercial
Free Estimates
Data provided by Google Maps
State Info
Radon levels vary house-to-house even in the same city. Testing your own home is the only reliable way to know your risk.
Popular Cities for Radon Mitigation in California
Radon mitigation in Santa Barbara, California4 local contractors listedRadon mitigation in Irvine, California3 local contractors listedRadon mitigation in Los Angeles, California3 local contractors listedRadon mitigation in Glendale, California2 local contractors listedRadon mitigation in Oakland, California2 local contractors listedRadon mitigation in San Luis Obispo, California2 local contractors listedRadon mitigation in Santa Monica, California2 local contractors listedRadon mitigation in Thousand Oaks, California2 local contractors listedRadon mitigation in Altadena, California1 local contractors listedRadon mitigation in Auburn, California1 local contractors listedRadon mitigation in Burlingame, California1 local contractors listedRadon mitigation in Chico, California1 local contractors listedRadon mitigation in Clayton, California1 local contractors listedRadon mitigation in Cudahy, California1 local contractors listedRadon mitigation in El Dorado Hills, California1 local contractors listedRadon mitigation in Hayward, California1 local contractors listedRadon mitigation in Heritage Ranch, California1 local contractors listedRadon mitigation in La Jolla, California1 local contractors listedRadon mitigation in Long Beach, California1 local contractors listedRadon mitigation in Marina, California1 local contractors listedRadon mitigation in Monterey, California1 local contractors listedRadon mitigation in North Hollywood, California1 local contractors listedRadon mitigation in Pasadena, California1 local contractors listedRadon mitigation in San Leandro, California1 local contractors listed
FAQ: Radon Mitigation in California
Is radon a problem in California?
It depends on location. Coastal areas are generally low risk, but the foothill communities, parts of Santa Barbara County, and the inland valleys can test above the EPA action level.
How much does radon mitigation cost in California?
Most homeowners in California see mitigation quotes in the low-thousands, but the final cost depends on foundation type, fan location, and pipe routing complexity. A cost calculator can help you benchmark estimates before requesting bids.
Do I need radon testing in California before hiring a contractor?
Yes. A valid short-term or long-term test is the fastest way to confirm if mitigation is needed and to scope the right system design.
What radon level is dangerous in California?
EPA recommends action at 4.0 pCi/L, and many homeowners choose to reduce levels even below that threshold. California has a mix of all three zones. The northern Sierra Nevada foothills and some southern inland areas are Zone 1. Coastal regions are mostly Zone 2-3. ZIP-level lookup tools are useful for local context, but home testing is still required.
How do I choose a certified radon contractor in California?
Look for current NRPP or NRSB credentials, ask for post-mitigation test expectations, and confirm local compliance details. California doesn't have state-specific radon certification requirements, but NRPP/NRSB certification is recommended.
State Resources for California
Radon mitigation cost in California
Estimate likely project pricing by foundation type and system complexity.
Radon testing guide for California homes
Learn when and how to test, plus how to interpret pCi/L results.
Radon levels and EPA zones in California
See how state-level risk varies and what zone maps can and cannot tell you.
ZIP-level radon risk in California
Check projected local risk by ZIP code before you request quotes.