Leavenworth County, KS: EPA's radon zone, explained

EPA places Leavenworth 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. That puts Leavenworth County in the 93rd percentile nationally for radon potential — higher than 93% of the counties EPA has rated.

How Leavenworth County compares

Leavenworth County, Kansas is home to about 84,670 people across 463.409 square miles. Population density there runs about 183 people per square mile. By population, Leavenworth County is the 218th largest of every county sharing its EPA zone — the 80th percentile by population within that zone. Leavenworth County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Leavenworth County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. Some Leavenworth County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

Next steps for a home in Leavenworth County

For a Leavenworth 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 Kansas's state radon program

For Leavenworth County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Leavenworth 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 Leavenworth County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Leavenworth County's numbers. Whatever zone Leavenworth County carries, the zone explainer covers what it does and doesn't tell you about any one house.