Is Teller County, CO a radon risk area?

Teller County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Teller County ranks higher in radon potential than 83% of rated counties (the 83rd percentile).

How Teller County compares

About 24,862 people live in Teller County, Colorado, spread over 557.141 square miles. Averaged across its land area, Teller County runs about 45 people per square mile. Rank 518 by population within its EPA zone puts Teller County at the 51st percentile among zone peers. Geologically, Teller County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

Zone vs. an actual test

Teller 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 Teller 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.

If Teller County tests above the action level

Nothing about Teller 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

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

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.