What EPA's radon map says about Owyhee County

EPA's own radon map rates Owyhee County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. That puts Owyhee County in the 41st percentile nationally for radon potential — higher than 41% of the counties EPA has rated.

How Owyhee County compares

About 12,748 people live in Owyhee County, Idaho, spread over 7,668.204 square miles. That works out to roughly 2 people per square mile. Among counties sharing Owyhee County's EPA zone, it outranks 26% of them by population. Owyhee County falls in EPA Radon Region 10, one of 142 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Owyhee County

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 Owyhee County's Zone 2 prediction. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Owyhee County — testing is the only way to know an individual home's actual level.

Testing and mitigation in Owyhee County

Mitigation cost doesn't depend on Owyhee 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 Idaho's state radon program

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

Owyhee County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Owyhee County carries, the zone explainer covers what it does and doesn't tell you about any one house.