What EPA's radon map says about Wapello County

Wapello County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. That puts Wapello County in the 87th percentile nationally for radon potential — higher than 87% of the counties EPA has rated.

How Wapello County compares

About 35,681 people live in Wapello County, Iowa, spread over 431.848 square miles. Averaged across its land area, Wapello County runs about 83 people per square mile. Among counties sharing Wapello County's EPA zone, it outranks 61% of them by population. Geologically, Wapello County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Wapello County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. That doesn't mean every Wapello County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

If Wapello County tests above the action level

Mitigation cost doesn't depend on Wapello 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

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

More on how this number was built

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