Steele County, MN: EPA's radon zone, explained

EPA places Steele 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. Rank it against the rest of the country and Steele County lands in the 87th percentile for radon potential.

Where Steele County sits nationally

Steele County, Minnesota is home to about 37,434 people across 429.588 square miles. That works out to roughly 87 people per square mile. By population, Steele County is the 403rd largest of every county sharing its EPA zone — the 62nd percentile by population within that zone. EPA's geology-based Region 5 groups Steele County with 523 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Where the national indoor average runs about 1.3 pCi/L, Steele County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. Being in Zone 1 raises the odds Steele County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Testing and mitigation in Steele County

For a Steele 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 Minnesota's state radon program

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

Where Steele County's figures come from

Steele County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.