Certified radon testers & mitigatorsNorth Dakota — mitigation — verified 29 Aug 2026

§ 4.1 — Bismarck, ND

Certified radon mitigation in Bismarck, ND

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

Last verified August 29, 2026. Methodology NRPP.

Certified radon testingCertified radon mitigation

  1. Daniel Gietzen

    Gray Ghost Construction

    current NRPP № 107257

    mitigation

    (701) 471-4544August 29, 2026cite ↗
Fig. 4 — Bismarck, ND, approximate. Pin is the city 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?

North Dakota pages here use current NRPP or NRSB certifications. City pages use the city printed on that record, not a ZIP-radius search. A national certification is not a North Dakota license. Some states require a separate state credential to work legally. Read the methodology. Credential status can change.