What EPA's radon map says about Sherman County

Sherman County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Rank it against the rest of the country and Sherman County lands in the 72nd percentile for radon potential.

Where Sherman County sits nationally

About 5,796 people live in Sherman County, Kansas, spread over 1,056.064 square miles. Population density there runs about 5 people per square mile. Among counties sharing Sherman County's EPA zone, it outranks 16% of them by population. Geologically, Sherman County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

What this actually means for a house in Sherman County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Sherman County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Sherman County specifically.

Next steps for a home in Sherman County

Mitigation cost doesn't depend on Sherman County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Kansas's state radon program

Sherman County's test kit answers today; a Airthings radon monitor keeps answering for Sherman County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

Sherman 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.