What EPA's radon map says about Stark County

EPA's own radon map rates Stark County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Stark County sits at the 98th percentile nationally for radon potential — above 98 of every 100 rated counties.

Stark County by the numbers

About 374,091 people live in Stark County, Ohio, spread over 574.94 square miles. Population density there runs about 651 people per square mile. Among counties sharing Stark County's EPA zone, it outranks 94% of them by population. Geologically, Stark County is grouped into EPA Region 5 alongside 523 other counties that share its rock and soil setting.

What this actually means for a house in Stark County

Stark County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Stark County will test well under the action level, and EPA's guidance is to test regardless of zone.

Testing and mitigation in Stark County

Mitigation cost doesn't depend on Stark 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 Ohio's state radon program

Stark County's test kit answers today; a Airthings radon monitor keeps answering for Stark 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 Stark County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.