Is Klickitat County, WA a radon risk area?

EPA's own radon map rates Klickitat County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally, Klickitat County ranks higher in radon potential than 48% of rated counties (the 48th percentile).

Klickitat County by the numbers

About 24,124 people live in Klickitat County, Washington, spread over 1,871.636 square miles. Averaged across its land area, Klickitat County runs about 13 people per square mile. Rank 562 by population within its EPA zone puts Klickitat County at the 46th percentile among zone peers. Klickitat County falls in EPA Radon Region 10, one of 142 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Klickitat County's Zone 2 prediction. Klickitat County's Zone 2 rating sits in the middle nationally; EPA's guidance is unchanged by that — test every home regardless of its zone.

If Klickitat County tests above the action level

Nothing about Klickitat 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 Washington's state radon program

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