Butte County, ID radon potential

EPA places Butte County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Butte County ranks higher in radon potential than 68% of rated counties (the 68th percentile).

How Butte County compares

Butte County, Idaho is home to about 2,735 people across 2,236.487 square miles. Averaged across its land area, Butte County runs about 1 people per square mile. Within its own EPA zone, Butte County is bigger by population than 7% of the counties that share it. EPA's geology-based Region 10 groups Butte County with 141 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Butte 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. Some Butte County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

If Butte County tests above the action level

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Idaho's state radon program

For Butte County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Butte County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Butte County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Butte County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.