What EPA's radon map says about Moultrie County

EPA places Moultrie 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. That puts Moultrie County in the 78th percentile nationally for radon potential — higher than 78% of the counties EPA has rated.

Moultrie County by the numbers

About 14,365 people live in Moultrie County, Illinois, spread over 335.958 square miles. Population density there runs about 43 people per square mile. Among counties sharing Moultrie County's EPA zone, it outranks 37% of them by population. Geologically, Moultrie 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 Moultrie County

Where the national indoor average runs about 1.3 pCi/L, Moultrie County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. That doesn't mean every Moultrie County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Next steps for a home in Moultrie County

Mitigation cost doesn't depend on Moultrie 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 Illinois's state radon program

Moultrie County's test kit answers today; a Airthings radon monitor keeps answering for Moultrie County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 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. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.