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

§ 4.1 — Downers Grove, IL

Certified radon testing in Downers Grove, IL

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

Last verified August 29, 2026. Methodology IL IEMA.

Certified radon testingCertified radon mitigation

  1. Olson, Jeff

    Gallagher Bassett Technical Services

    current IL IEMA № RNI20232098

    testing

    630-879-3006August 29, 2026cite ↗

  2. Rossignuolo, Tony

    Alta Inspection Services

    current IL IEMA № RNI2001215

    testing

    630-852-0993August 29, 2026cite ↗
Fig. 4 — Downers Grove, IL, 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?

§ 4.3

Nearby places in Illinois

Illinois IEMA licenses radon measurement and mitigation professionals and technicians. The people below appear on the active licensee listing we imported. Read the methodology. Credential status can change.