EPA radon zones
Colorado radon map: every county's zone
53 of Colorado's 64 counties are EPA radon zone 1 (predicted average above 4 pCi/L), 11 are zone 2 and 0 are zone 3. High readings occur in every zone, so EPA recommends testing every home.
Adams CountyZone 1
Alamosa CountyZone 2
Arapahoe CountyZone 1
Archuleta CountyZone 2
Baca CountyZone 1
Bent CountyZone 1
Boulder CountyZone 1
Broomfield CountyZone 1
Chaffee CountyZone 1
Cheyenne CountyZone 1
Clear Creek CountyZone 1
Conejos CountyZone 2
Costilla CountyZone 2
Crowley CountyZone 1
Custer CountyZone 1
Delta CountyZone 1
Denver CountyZone 1
Dolores CountyZone 1
Douglas CountyZone 1
Eagle CountyZone 2
El Paso CountyZone 1
Elbert CountyZone 1
Fremont CountyZone 1
Garfield CountyZone 1
Gilpin CountyZone 1
Grand CountyZone 1
Gunnison CountyZone 1
Hinsdale CountyZone 2
Huerfano CountyZone 1
Jackson CountyZone 1
Jefferson CountyZone 1
Kiowa CountyZone 1
Kit Carson CountyZone 1
La Plata CountyZone 1
Lake CountyZone 1
Larimer CountyZone 1
Las Animas CountyZone 1
Lincoln CountyZone 1
Logan CountyZone 1
Mesa CountyZone 1
Mineral CountyZone 2
Moffat CountyZone 1
Montezuma CountyZone 1
Montrose CountyZone 1
Morgan CountyZone 1
Otero CountyZone 1
Ouray CountyZone 1
Park CountyZone 1
Phillips CountyZone 1
Pitkin CountyZone 1
Prowers CountyZone 1
Pueblo CountyZone 1
Rio Blanco CountyZone 1
Rio Grande CountyZone 2
Routt CountyZone 2
Saguache CountyZone 2
San Juan CountyZone 2
San Miguel CountyZone 1
Sedgwick CountyZone 1
Summit CountyZone 1
Teller CountyZone 1
Washington CountyZone 1
Weld CountyZone 1
Yuma CountyZone 1
How much does radon mitigation cost?
Most single-family systems cost $800 to $2,500 installed, depending on foundation type and how many suction points are needed. A follow-up test confirms the system works.
What do the zones mean?
EPA radon zones describe counties, not houses. Zone 1 counties have a predicted average indoor level above 4 picocuries per liter (pCi/L), Zone 2 between 2 and 4, Zone 3 below 2. Homes with high levels are found in every zone, which is why EPA recommends that every home be tested, and fixed at 4 pCi/L or above.
Colorado cities: water and radon
Source: EPA Map of Radon Zones.