What EPA's radon map says about Vermillion County

Vermillion County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Rank it against the rest of the country and Vermillion County lands in the 79th percentile for radon potential.

Vermillion County by the numbers

About 15,516 people live in Vermillion County, Indiana, spread over 256.894 square miles. That works out to roughly 60 people per square mile. Among counties sharing Vermillion County's EPA zone, it outranks 39% of them by population. EPA's geology-based Region 5 groups Vermillion County with 523 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Vermillion 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 Vermillion County will test well under the action level, and EPA's guidance is to test regardless of zone.

Next steps for a home in Vermillion County

Mitigation cost doesn't depend on Vermillion 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 Indiana's state radon program

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.