Malheur County, OR: EPA's radon zone, explained

Malheur 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. Nationally, Malheur County ranks higher in radon potential than 51% of rated counties (the 51st percentile).

Where Malheur County sits nationally

Malheur County, Oregon is home to about 32,315 people across 9,887.707 square miles. Population density there runs about 3 people per square mile. By population, Malheur County is the 468th largest of every county sharing its EPA zone — the 55th percentile by population within that zone. Malheur 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

EPA's Zone 2 rating for Malheur County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Middle-of-the-pack doesn't mean risk-free for any one Malheur County address — a moderate county average still leaves individual homes to test either side of it.

Testing and mitigation in Malheur County

For a Malheur County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Oregon's state radon program

For Malheur County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Malheur County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Malheur County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Malheur County carries, the zone explainer covers what it does and doesn't tell you about any one house.