Is Dolores County, CO a radon risk area?

EPA's own radon map rates Dolores County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Nationally, Dolores County ranks higher in radon potential than 68% of rated counties (the 68th percentile).

How Dolores County compares

About 2,467 people live in Dolores County, Colorado, spread over 1,067.17 square miles. Population density there runs about 2 people per square mile. Rank 1001 by population within its EPA zone puts Dolores County at the 6th percentile among zone peers. Geologically, Dolores County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Dolores County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. Being in Zone 1 raises the odds Dolores County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Next steps for a home in Dolores County

Nothing about Dolores 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 Colorado's state radon program

Dolores County's test kit answers today; a Airthings radon monitor keeps answering for Dolores 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. Whatever zone Dolores County carries, the zone explainer covers what it does and doesn't tell you about any one house.