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§ 4.1 — California

Radon mitigation in California

This page lists 12 people and firms with a current radon mitigation credential whose official record names California. Each row shows the credential number, the issuing body, and its own verification date. The latest record check on this page was October 13, 2026; other records may have been checked earlier. Source: CA CDPH. Verify the number before you hire.

Latest credential check October 13, 2026. Methodology Individual record dates may be earlier. CA CDPH.

Radon testingRadon mitigation

Testing listings are people credentialed to measure radon. Mitigation listings are people credentialed to install a reduction system. Some people appear on both lists when the official file says they hold both. The list is ordered by the city or county on each record. That place is where the record is filed, not a promise about where the person works.

12 listings. Type to narrow the list.

  1. Cole, Scott

    current CA CDPH № 115293

    mitigation

    844-852-2858October 13, 2026cite ↗

  2. Denny, Norman

    current CA CDPH № 106142

    mitigation

    775-691-7101October 13, 2026cite ↗

  3. Dopke, Cameron

    current CA CDPH № 112346

    mitigation

    530-544-1862October 13, 2026cite ↗

  4. Ellrott, Fred

    current CA CDPH № 101023

    mitigation

    805-732-2476October 13, 2026cite ↗

  5. Frayman, Daniel

    current CA CDPH № 114455

    mitigation

    818-749-8576October 13, 2026cite ↗

  6. Gregory, Jason

    current CA CDPH № 107970

    mitigation

    805-244-6687October 13, 2026cite ↗

  7. Heichman, Jordan

    current CA CDPH № 106156

    mitigation

    530-621-4052October 13, 2026cite ↗

  8. Henderson, John

    current CA CDPH № 108871

    mitigation

    805-280-6616October 13, 2026cite ↗

  9. Huchingson, Eddie

    current CA CDPH № 107621

    mitigation

    805-908-9274October 13, 2026cite ↗

  10. Mandel, Peter

    current CA CDPH № 104696

    mitigation

    510-300-7500October 13, 2026cite ↗

  11. Riley, Edward

    current CA CDPH № 106415

    mitigation

    530-583-6653October 13, 2026cite ↗

  12. Zharkov, Iurii

    current CA CDPH № 115915

    mitigation

    951-712-4722October 13, 2026cite ↗

Appendix A

Questions before you hire

How do I verify a radon credential listed for California?

Open the source link on this page and match the name and credential number to CA CDPH. Status can change after a record’s verification date. The latest record check on this page was October 13, 2026; check each record’s date. If the official page disagrees with this directory, trust the official page. We do not invent credential numbers.

Does EPA certify radon contractors?

The U.S. EPA does not certify radon contractors. EPA publishes guidance on finding a qualified radon service provider and points to state programs and national certifications. This directory is not affiliated with EPA. We do not display EPA-certified badges.

What does last verified mean on this page?

Last verified on an individual record is the date we checked its official source. The latest credential check on this page was October 13, 2026; other records may have earlier dates. We refresh the roster monthly. Current means the person appeared as currently credentialed on the source at that record’s verification date. Credentials can expire between refreshes, so follow the source link.

Appendix A.2

Before you hire

  1. Ask who holds the credential printed on this page, and ask them to show the same number. Some firms employ several credentialed people. The listing is the person or firm on the official file, not whoever answers the phone.
  2. Ask what test method or mitigation system they will use for this building. A credential is not a work plan. Testing and mitigation are separate services here, and a person appears on both lists only when the official file says they hold both.
  3. Ask how they will document test results or the finished mitigation system. Keep that document with the credential number you verified. This directory does not score jobs, publish reviews, or collect quotes.

The full checklist: How to choose a radon mitigation company: 6 checks before you sign

California CDPH lists radon testers and mitigators certified to operate in California. The people below appear with a current expiration date on that file. CDPH does not publish city or county, so this site does not invent city pages. Read the methodology. Credential status can change.