What EPA's radon map says about Yakima County

Yakima County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Rank it against the rest of the country and Yakima County lands in the 63rd percentile for radon potential.

How Yakima County compares

About 258,523 people live in Yakima County, Washington, spread over 4,294.512 square miles. Averaged across its land area, Yakima County runs about 60 people per square mile. Among counties sharing Yakima County's EPA zone, it outranks 91% of them by population. EPA's geology-based Region 10 groups Yakima County with 141 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Yakima County

Yakima County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. A county-wide moderate average, like Yakima County's, can still hide a specific house well above or below it — testing is what actually answers the question.

If Yakima County tests above the action level

Mitigation cost doesn't depend on Yakima County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Washington's state radon program

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

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. Whatever zone Yakima County carries, the zone explainer covers what it does and doesn't tell you about any one house.