What EPA's radon map says about Putnam County

EPA's own radon map rates Putnam County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Rank it against the rest of the country and Putnam County lands in the 52nd percentile for radon potential.

Putnam County by the numbers

About 34,206 people live in Putnam County, Ohio, spread over 482.544 square miles. Averaged across its land area, Putnam County runs about 71 people per square mile. Among counties sharing Putnam County's EPA zone, it outranks 57% of them by population. EPA's geology-based Region 5 groups Putnam County with 523 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Putnam County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. Nothing about a Zone 2 label lowers the case for testing in Putnam County — EPA recommends it in every zone, moderate included.

If Putnam County tests above the action level

Mitigation cost doesn't depend on Putnam 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

Putnam County's test kit answers today; a Airthings radon monitor keeps answering for Putnam County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

More on how this number was built

Putnam County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.