Clatsop County, OR radon potential

EPA places Clatsop County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Clatsop County in the 53rd percentile nationally for radon potential — higher than 53% of the counties EPA has rated.

How Clatsop County compares

Clatsop County, Oregon is home to about 41,043 people across 828.241 square miles. Population density there runs about 50 people per square mile. Within its own EPA zone, Clatsop County is bigger by population than 62% of the counties that share it. Clatsop 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 Clatsop County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Nothing about a Zone 2 label lowers the case for testing in Clatsop County — EPA recommends it in every zone, moderate included.

Testing and mitigation in Clatsop County

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Oregon's state radon program

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

Where Clatsop County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Clatsop County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.