Radon Levels in Colorado
Colorado is classified as an EPA Zone 1 state with a high risk for radon. Average indoor radon levels range from 2 to 8 pCi/L, and approximately 45% of Colorado homes test above the EPA action level of 4.0 pCi/L.
Colorado Radon Summary
High Radon Risk State
Colorado is among the higher-risk states for residential radon. The Colorado Department of Health strongly recommends that all residents test their homes. If you have not tested your home, consider ordering a test kit or radon detector today.
Key Facts About Radon in Colorado
- Colorado has some of the highest radon levels in the nation
- Over 50% of Colorado homes test above the EPA action level
- The Rocky Mountain geology is rich in uranium-bearing granite
- Colorado Department of Public Health actively promotes radon testing
Colorado Testing Requirements & Recommendations
No mandate but Colorado state law requires sellers to disclose known radon issues. Testing strongly recommended.
Colorado has a robust network of certified radon mitigators. Mitigation systems cost $800–$2,500 depending on home design.
Major Cities in Colorado
Radon levels can vary significantly within Colorado depending on local geology. All residents — regardless of city — should test their specific home, as neighborhood-level radon varies independently of broader state and county averages.
What Should Colorado Residents Do?
Test Your Home
Use a short-term charcoal test kit ($15–$25) for an initial reading, or a continuous radon detector for ongoing monitoring. Test in your basement or lowest livable area.
Understand Your Result
If your result is below 2.0 pCi/L: monitor periodically. Between 2.0–4.0 pCi/L: consider mitigation. Above 4.0 pCi/L: the EPA recommends mitigation. Above 8.0 pCi/L: take action promptly.
Hire a Certified Contractor if Needed
Look for NRPP or NRSB-certified radon mitigation contractors in Colorado. Mitigation systems typically cost $800–$2,500 and can reduce radon levels by 50–99%.
Verify with a Follow-Up Test
After mitigation, test again to confirm the system is working. Retest every 2 years, or after significant home renovations.
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