What EPA's radon map says about Martin County

EPA's own radon map rates Martin County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Martin County sits at the 81st percentile nationally for radon potential — above 81 of every 100 rated counties.

Where Martin County sits nationally

About 19,561 people live in Martin County, Minnesota, spread over 712.336 square miles. That works out to roughly 27 people per square mile. Among counties sharing Martin County's EPA zone, it outranks 46% of them by population. EPA's geology-based Region 5 groups Martin County with 523 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Martin County

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Martin County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Martin County specifically.

Testing and mitigation in Martin County

Mitigation cost doesn't depend on Martin 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 Minnesota's state radon program

Martin County's test kit answers today; a Airthings radon monitor keeps answering for Martin 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 Martin County carries, the zone explainer covers what it does and doesn't tell you about any one house.