Is Hamilton County, KS a radon risk area?

EPA's own radon map rates Hamilton County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Hamilton County lands in the 68th percentile for radon potential.

Hamilton County by the numbers

About 2,488 people live in Hamilton County, Kansas, spread over 996.514 square miles. Averaged across its land area, Hamilton County runs about 2 people per square mile. Rank 1000 by population within its EPA zone puts Hamilton County at the 6th percentile among zone peers. Hamilton County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Hamilton County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Hamilton 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 Hamilton County specifically.

Testing and mitigation in Hamilton County

Nothing about Hamilton County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Kansas's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Hamilton County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.