Radon in Bonner County, Idaho

About 3 in 10 homes tested here were at or above the EPA action level.

227 home tests, 2008–2017, CDC lab data
  • Below 2 pCi/L: 46%
  • 2 to 4 pCi/L: 21%
  • 4 pCi/L or more: 33%
The line marks the EPA action level, 4 pCi/L.
Median level
2.3 pCi/L
EPA radon zone
Zone 1
In Idaho
19th of 37

EPA Zone 1, the highest radon potential (predicted average above 4 pCi/L). The EPA zone map dates from 1993 and is meant for planning; high levels are found in every zone.

What to do next

  1. Test your home

    Radon levels vary between neighboring houses, so area data can't tell you your own home's level. A short-term test takes 2 to 7 days in the lowest lived-in floor. A long-term test (90 days or more) gives a more reliable average.

  2. If your result is 4 pCi/L or more, fix it

    Most homes are fixed with a sub-slab depressurization system: a pipe and a quiet fan that pull radon from under the foundation and vent it above the roof. We're still collecting real installation prices for Idaho.

  3. Use a certified professional

    Look for a professional certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB), or by your state if it certifies radon contractors.

How Bonner County compares

Share of homes tested at or above 4 pCi/L, with neighboring counties. Lab data 2008–2017, the only source that covers every state.

Share of homes tested at or above 4 pCi/L
Pend Oreille County, WA63%
Shoshone County63%
Kootenai County61%
Lincoln County, MT51%
Sanders County, MT50%
Spokane County, WA41%
Idaho40%
United States36%
Bonner County33%
Boundary County20%

Sources

Last updated October 2026. How we calculate these numbers.