#1
David A. Holt
Longmont, CO
Google rating: 5.0 (34 reviews)
Reviews: 34
Certifications: 1
Certifications
NRPP Measurement Professional
Services
TestingMeasurement
Best Radon Contractors in Longmont, Colorado (2026)
Ranked using real Google ratings, review counts, and certification data only.
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#2
Brian Cornwell
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 2
Certifications
NRSB CertifiedNRSB:RMS:25MS053
Services
TestingNew ConstructionCommercialwater treatment
#3
Darren Corso
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 1
Certifications
NRPP Mitigation Specialist
Services
MitigationTestingCrawlspacePost-Mitigation Testing
#4
Mark B Pepin
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 1
Certifications
NRPP Measurement Professional
Services
Testing
How We Rank
- Google rating: higher average ratings rank higher.
- Review count: more reviews break ties between similar ratings.
- Certification count: more certifications break ties after rating and review metrics.
- Verified data only: rankings are based on stored profile data, not manual edits or paid placement.
FAQ
Who is the best radon contractor in Longmont?
David A. Holt is currently ranked #1 in Longmont based on Google rating, review volume, and certification count from our verified data sources.
How many radon contractors are in Longmont?
We currently list 4 radon contractors in Longmont, Colorado.
What should I look for?
Focus on strong ratings with meaningful review volume, current professional certifications, and clear service coverage for your home type.