Radon Levels in Idaho
Idaho is classified as an EPA Zone 1 state with a high risk for radon. Average indoor radon levels range from 2 to 7 pCi/L, and approximately 35% of Idaho homes test above the EPA action level of 4.0 pCi/L.
Idaho Radon Summary
High Radon Risk State
Idaho is among the higher-risk states for residential radon. The Idaho 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 Idaho
- Idaho has significant radon risk, particularly in the northern and eastern regions
- Volcanic basalt and granite geology contribute to elevated uranium content
- Idaho has one of the highest rates of homes testing above the action level in the Northwest
Idaho Testing Requirements & Recommendations
Idaho Division of Health recommends testing all homes. No statewide mandate.
Idaho's soil composition responds well to standard sub-slab depressurization systems.
Major Cities in Idaho
Radon levels can vary significantly within Idaho 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 Idaho 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 Idaho. 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.
Some links are affiliate links. Learn more.
