Certified radon testers & mitigatorsDistrict of Columbia — testing — verified 29 Aug 2026

§ 4.1 — Washington, DC

Certified radon testing in Washington, DC

3 current listings from the official file. Verify the credential number before you hire.

Last verified August 29, 2026. Methodology NRSB.

Certified radon testingCertified radon mitigation

  1. Aruna Bandaranayake

    Soil And Land Use Technology, Inc.

    current NRSB № RMS-25MS093

    testing

    August 29, 2026cite ↗

  2. Thomas Howell

    Soil And Land Use Technology, Inc.

    current NRSB № RMS-24MS079

    testing

    August 29, 2026cite ↗

  3. Timothy F. Bills

    Sentry Home Inspections, Llc

    current NRSB № RMS-11SS037

    testing

    August 29, 2026cite ↗
Fig. 4 — Washington, DC, 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?

District of Columbia 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 District of Columbia license. Some states require a separate state credential to work legally. Read the methodology. Credential status can change.