#1
Darren Corso
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 1
Certifications
NRPP Mitigation Specialist
Services
MitigationTestingCrawlspacePost-Mitigation Testing
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: 1
Certifications
NRSB Mitigation Specialist
Services
TestingNew ConstructionCommercialwater treatment
#3
David A. Holt
Longmont, CO
Google rating: 5.0 (34 reviews)
Reviews: 34
Certifications: 1
Certifications
NRPP Measurement Professional
Services
TestingMeasurement
#4
Mark B Pepin
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 1
Certifications
NRPP Measurement Professional
Services
Testing
#5
OUTLAW RADON LLC
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 1
Certifications
NRSB Reduction Specialist
Services
radon mitigationMitigation
#6
PEACE OF MIND INSPECTIONS, LLC
Longmont, CO
Google rating: No Google rating available
Reviews: 0
Certifications: 2
Certifications
NRSB Measurement TechnicianNRSB Mitigation Specialist
Services
TestingMeasurementradon mitigationMitigation
How We Rank Contractors in Longmont
Our ranking methodology is transparent and data-driven. Sponsored placements are clearly labeled and appear separately — they do not influence organic ranking position.
- Google rating — Higher average ratings rank higher. This reflects real customer satisfaction across verified Google Business profiles.
- Review volume — More reviews break ties between similar ratings. A 4.8 with 50 reviews outranks a 4.8 with 3 reviews because the signal is more reliable.
- Certification count — NRPP and NRSB certifications break remaining ties. More certifications indicate broader competency across mitigation, measurement, and specialized techniques.
- Data integrity — All ranking data comes from verified sources: Google Business API, NRPP/NRSB certification databases, and contractor websites. Template-generated or unverifiable data is excluded.
Read our full methodology for details on data sourcing, verification, and quality thresholds.
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FAQ
Who is the best radon contractor in Longmont?
Darren Corso 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 6 radon contractors in Longmont, Colorado. 6 hold NRPP or NRSB certifications and 1 have Google reviews.
What should I look for when choosing a radon contractor?
Focus on strong ratings with meaningful review volume, current professional certifications (NRPP or NRSB), and clear service coverage for your home type. A good contractor will assess your specific foundation and provide a written scope that includes suction point count, pipe routing, fan specification, and post-mitigation testing.
How are these Longmont contractors ranked?
We rank contractors using a transparent, data-only methodology: Google rating first, review count second, and certification count third. Sponsored placements appear in a separate, clearly labeled section and do not influence organic ranking position. All ranking data comes from verified sources including Google Business profiles and national certification databases.
Should I get multiple quotes in Longmont?
Yes. With 6 contractors in Longmont, getting at least two written quotes is practical and recommended. Compare the number of suction points, fan model, pipe routing plan, warranty length, and whether post-mitigation testing is included. Price alone is not a reliable differentiator — system design matters more for long-term radon reduction.