Lenawee County, MI: EPA's radon zone, explained

EPA places Lenawee County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Lenawee County ranks higher in radon potential than 94% of rated counties (the 94th percentile).

Lenawee County by the numbers

Lenawee County, Michigan is home to about 97,746 people across 749.653 square miles. Population density there runs about 130 people per square mile. By population, Lenawee County is the 202nd largest of every county sharing its EPA zone — the 81st percentile by population within that zone. EPA's geology-based Region 5 groups Lenawee County with 523 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Lenawee County

Lenawee County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. That doesn't mean every Lenawee County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Next steps for a home in Lenawee County

For a Lenawee County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Michigan's state radon program

For Lenawee County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Lenawee County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Lenawee County's figures come from

Lenawee County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.