Certified radon testers & mitigatorsPennsylvania — testing — verified 29 Aug 2026

§ 4.1 — Northumberland County, PA

Certified radon testing in Northumberland County, PA

1 current listing from the official file. Verify the credential number before you hire.

Last verified August 29, 2026. Methodology PA DEP.

Certified radon testingCertified radon mitigation

  1. Barclay, Gary

    current PA DEP № 3501

    testing

    (570) 538-1490August 29, 2026cite ↗
Fig. 4 — Northumberland County, PA, approximate. Pin is the county on the official file, not a street address.

Appendix A — Before you hire

  1. Who holds the credential, and can they show the same number that appears on this page?
  2. What test method or mitigation system will they use for this building?
  3. How will they document results or the finished system?

§ 4.3

Nearby places in Pennsylvania

Pennsylvania DEP certifies individuals and firms that test or mitigate radon. The people below appear as currently certified on the DEP Radon Services Directory we imported. Read the methodology. Credential status can change.