EPA Zone Data 2026
CO Radon Levels
View EPA radon zone classifications for every county in CO. Select your county to see detailed risk data, testing recommendations, and mitigation cost estimates.
52
Zone 1
High Risk
High Risk
12
Zone 2
Moderate
Moderate
0
Zone 3
Low Risk
Low Risk
Adams
Zone 1
Alamosa
Zone 2
Arapahoe
Zone 1
Archuleta
Zone 2
Baca
Zone 1
Bent
Zone 1
Boulder
Zone 1
Broomfield
Zone 1
Chaffee
Zone 1
Cheyenne
Zone 1
Clear Creek
Zone 1
Conejos
Zone 2
Costilla
Zone 2
Crowley
Zone 1
Custer
Zone 1
Delta
Zone 1
Denver
Zone 1
Dolores
Zone 1
Douglas
Zone 1
Eagle
Zone 2
El Paso
Zone 1
Elbert
Zone 1
Fremont
Zone 1
Garfield
Zone 1
Gilpin
Zone 1
Grand
Zone 1
Gunnison
Zone 1
Hinsdale
Zone 2
Huerfano
Zone 1
Jackson
Zone 1
Jefferson
Zone 1
Kiowa
Zone 1
Kit Carson
Zone 1
La Plata
Zone 2
Lake
Zone 1
Larimer
Zone 1
Las Animas
Zone 1
Lincoln
Zone 1
Logan
Zone 1
Mesa
Zone 1
Mineral
Zone 2
Moffat
Zone 1
Montezuma
Zone 1
Montrose
Zone 1
Morgan
Zone 1
Otero
Zone 1
Ouray
Zone 1
Park
Zone 1
Phillips
Zone 1
Pitkin
Zone 1
Prowers
Zone 1
Pueblo
Zone 1
Rio Blanco
Zone 1
Rio Grande
Zone 2
Routt
Zone 2
Saguache
Zone 2
San Juan
Zone 2
San Miguel
Zone 1
Sedgwick
Zone 1
Summit
Zone 1
Teller
Zone 1
Washington
Zone 1
Weld
Zone 1
Yuma
Zone 1
Already tested? Get your itemized mitigation cost estimate.
View CO Mitigation Cost Estimates →