Alger County, MI: EPA's radon zone, explained

Alger County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Alger County in the 39th percentile nationally for radon potential — higher than 39% of the counties EPA has rated.

How Alger County compares

Alger County, Michigan is home to about 8,695 people across 915.04 square miles. That works out to roughly 10 people per square mile. By population, Alger County is the 848th largest of every county sharing its EPA zone — the 18th percentile by population within that zone. Alger County falls in EPA Radon Region 5, one of 524 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Alger County

EPA's Zone 2 rating for Alger County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Nothing about a Zone 2 label lowers the case for testing in Alger County — EPA recommends it in every zone, moderate included.

If Alger County tests above the action level

For a Alger 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 Michigan's state radon program

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.