Certified radon testers & mitigatorsWisconsin — mitigation — verified 29 Aug 2026

§ 4.1 — Appleton, WI

Certified radon mitigation in Appleton, WI

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

Last verified August 29, 2026. Methodology NRPP. NRSB.

Certified radon testingCertified radon mitigation

  1. Adam Olinski

    A-1 Radon & Vacuum

    current NRPP № 104254

    mitigation, testing

    (920) 639-6542August 29, 2026cite ↗

  2. Dustin Welch

    Swat Environmental

    current NRPP № 113935

    mitigation

    (262) 754-2211August 29, 2026cite ↗
Fig. 4 — Appleton, WI, 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 Wisconsin

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