What EPA's radon map says about Garfield County

EPA's own radon map rates Garfield County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Garfield County sits at the 92nd percentile nationally for radon potential — above 92 of every 100 rated counties.

How Garfield County compares

About 63,167 people live in Garfield County, Colorado, spread over 2,947.425 square miles. That works out to roughly 21 people per square mile. Among counties sharing Garfield County's EPA zone, it outranks 75% of them by population. EPA's geology-based Region 8 groups Garfield County with 290 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Where the national indoor average runs about 1.3 pCi/L, Garfield County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Garfield County specifically.

Testing and mitigation in Garfield County

Mitigation cost doesn't depend on Garfield 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 Colorado's state radon program

Garfield County's test kit answers today; a Airthings radon monitor keeps answering for Garfield 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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.