What EPA's radon map says about Allegan County

EPA's own radon map rates Allegan County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Allegan County sits at the 27th percentile nationally for radon potential — above 27 of every 100 rated counties.

Where Allegan County sits nationally

About 122,429 people live in Allegan County, Michigan, spread over 825.43 square miles. That works out to roughly 148 people per square mile. Among counties sharing Allegan County's EPA zone, it outranks 81% of them by population. EPA's geology-based Region 5 groups Allegan County with 523 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Allegan County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Allegan County testing above the action level often enough that skipping a test isn't the safe assumption.

If Allegan County tests above the action level

Mitigation cost doesn't depend on Allegan 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 Michigan's state radon program

Allegan County's test kit answers today; a Airthings radon monitor keeps answering for Allegan 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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Allegan County carries, the zone explainer covers what it does and doesn't tell you about any one house.