What EPA's radon map says about Sheridan County

EPA's own radon map rates Sheridan County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Sheridan County sits at the 68th percentile nationally for radon potential — above 68 of every 100 rated counties.

Sheridan County by the numbers

About 2,397 people live in Sheridan County, Kansas, spread over 895.957 square miles. Population density there runs about 3 people per square mile. Among counties sharing Sheridan County's EPA zone, it outranks 5% of them by population. EPA's geology-based Region 7 groups Sheridan County with 411 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Sheridan County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Sheridan County will test well under the action level, and EPA's guidance is to test regardless of zone.

Next steps for a home in Sheridan County

Mitigation cost doesn't depend on Sheridan 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

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

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.