What EPA's radon map says about Webster County

EPA places Webster County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Webster County in the 7th percentile nationally for radon potential — higher than 7% of the counties EPA has rated.

Webster County by the numbers

About 10,039 people live in Webster County, Mississippi, spread over 421.158 square miles. That works out to roughly 24 people per square mile. Among counties sharing Webster County's EPA zone, it outranks 20% of them by population. Geologically, Webster County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Webster County's Zone 3 prediction is the low end of the scale. A Zone 3 label describes Webster County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Next steps for a home in Webster County

Mitigation cost doesn't depend on Webster 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 Mississippi's state radon program

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

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.