What EPA's radon map says about Ida County

EPA's own radon map rates Ida County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. That puts Ida County in the 73rd percentile nationally for radon potential — higher than 73% of the counties EPA has rated.

How Ida County compares

About 6,810 people live in Ida County, Iowa, spread over 431.513 square miles. Averaged across its land area, Ida County runs about 16 people per square mile. Among counties sharing Ida County's EPA zone, it outranks 20% of them by population. Geologically, Ida County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Zone vs. an actual test

Ida County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. Some Ida 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 Ida County tests above the action level

Mitigation cost doesn't depend on Ida County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Iowa's state radon program

Ida County's test kit answers today; a Airthings radon monitor keeps answering for Ida County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

More on how this number was built

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