Adams County, ID radon potential

EPA places Adams County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Adams County in the 3rd percentile nationally for radon potential — higher than 3% of the counties EPA has rated.

How Adams County compares

Adams County, Idaho is home to about 4,998 people across 1,362.804 square miles. Averaged across its land area, Adams County runs about 4 people per square mile. Within its own EPA zone, Adams County is bigger by population than 9% of the counties that share it. Geologically, Adams County is grouped into EPA Region 10 alongside 141 other counties that share its rock and soil setting.

What this actually means for a house in Adams County

A Zone 3 county like Adams County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Even at Zone 3, Adams County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Adams County

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

Where Adams County's figures come from

Adams County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Adams County carries, the zone explainer covers what it does and doesn't tell you about any one house.