Mills County, IA radon potential

EPA's own radon map rates Mills County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. That puts Mills County in the 79th percentile nationally for radon potential — higher than 79% of the counties EPA has rated.

Where Mills County sits nationally

Mills County, Iowa is home to about 14,717 people across 437.431 square miles. Averaged across its land area, Mills County runs about 34 people per square mile. Within its own EPA zone, Mills County is bigger by population than 38% of the counties that share it. Mills County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

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 Mills County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Some Mills 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.

Testing and mitigation in Mills 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 Iowa's state radon program

For Mills County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Mills 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 Mills County's figures come from

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