Is Clay County, IN a radon risk area?

EPA places Clay County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Clay County ranks higher in radon potential than 49% of rated counties (the 49th percentile).

Where Clay County sits nationally

About 26,424 people live in Clay County, Indiana, spread over 357.6 square miles. Averaged across its land area, Clay County runs about 74 people per square mile. Rank 529 by population within its EPA zone puts Clay County at the 49th percentile among zone peers. EPA's geology-based Region 5 groups Clay County with 523 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Clay County

Clay County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Middle-of-the-pack doesn't mean risk-free for any one Clay County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Clay County

Nothing about Clay 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 Indiana's state radon program

Clay County's test kit answers today; a Airthings radon monitor keeps answering for Clay 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

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.