What EPA's radon map says about Belmont County

EPA places Belmont County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally that's the 92nd percentile for radon potential — Belmont County outranks 92% of every county EPA has rated.

How Belmont County compares

About 64,692 people live in Belmont County, Ohio, spread over 532.173 square miles. That works out to roughly 122 people per square mile. Among counties sharing Belmont County's EPA zone, it outranks 76% of them by population. Geologically, Belmont 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 Belmont County

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Belmont County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. 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 Belmont County will test well under the action level, and EPA's guidance is to test regardless of zone.

Next steps for a home in Belmont County

Mitigation cost doesn't depend on Belmont 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

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

Belmont County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Belmont County carries, the zone explainer covers what it does and doesn't tell you about any one house.