Radon Levels in Wisconsin
Wisconsin is classified as an EPA Zone 1 state with a high risk for radon. Average indoor radon levels range from 3 to 7 pCi/L, and approximately 37% of Wisconsin homes test above the EPA action level of 4.0 pCi/L.
Wisconsin Radon Summary
High Radon Risk State
Wisconsin is among the higher-risk states for residential radon. The Wisconsin 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 Wisconsin
- Wisconsin has widespread high radon levels due to its granite and glacial geology
- The Wisconsin Geological and Natural History Survey has extensively documented radon risk
- Wisconsin DHS operates a comprehensive radon program with low-cost test kit availability
Wisconsin Testing Requirements & Recommendations
Wisconsin requires disclosure of known radon test results in home sales. Testing strongly recommended.
Wisconsin radon contractors are widely available and well-certified.
Major Cities in Wisconsin
Radon levels can vary significantly within Wisconsin 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 Wisconsin 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 Wisconsin. 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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