Is Linn County, OR a radon risk area?

Linn County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally that's the 27th percentile for radon potential — Linn County outranks 27% of every county EPA has rated.

Where Linn County sits nationally

About 132,474 people live in Linn County, Oregon, spread over 2,289.508 square miles. That works out to roughly 58 people per square mile. Rank 183 by population within its EPA zone puts Linn County at the 82nd percentile among zone peers. Linn 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 Linn County

Linn County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Even at Zone 3, Linn County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Linn County

Nothing about Linn 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 Oregon's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Linn County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.