Is Grant County, KS a radon risk area?

EPA's own radon map rates Grant County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally, Grant County ranks higher in radon potential than 73% of rated counties (the 73rd percentile).

Grant County by the numbers

About 7,097 people live in Grant County, Kansas, spread over 574.808 square miles. Population density there runs about 12 people per square mile. Rank 842 by population within its EPA zone puts Grant County at the 21st percentile among zone peers. EPA's geology-based Region 7 groups Grant County with 411 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Grant County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. Being in Zone 1 raises the odds Grant 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.

If Grant County tests above the action level

Nothing about Grant 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

Grant County's test kit answers today; a Airthings radon monitor keeps answering for Grant 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 Grant County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.