Oneida County, ID: EPA's radon zone, explained

EPA's own radon map rates Oneida County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally that's the 36th percentile for radon potential — Oneida County outranks 36% of every county EPA has rated.

How Oneida County compares

Oneida County, Idaho is home to about 4,976 people across 1,198.951 square miles. Averaged across its land area, Oneida County runs about 4 people per square mile. By population, Oneida County is the 945th largest of every county sharing its EPA zone — the 8th percentile by population within that zone. Geologically, Oneida County is grouped into EPA Region 10 alongside 141 other counties that share its rock and soil setting.

Zone vs. an actual test

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Oneida County's Zone 2 prediction lands in the gap between the two. Nothing about a Zone 2 label lowers the case for testing in Oneida County — EPA recommends it in every zone, moderate included.

Next steps for a home in Oneida County

For a Oneida County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Idaho's state radon program

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

Where Oneida County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Oneida County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.