Vermilion Parish, LA: EPA's radon zone, explained

EPA places Vermilion Parish 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. Nationally that's the 23rd percentile for radon potential — Vermilion Parish outranks 23% of every county EPA has rated.

How Vermilion Parish compares

Vermilion Parish, Louisiana is home to about 57,641 people across 1,172.061 square miles. Population density there runs about 49 people per square mile. By population, Vermilion Parish is the 310th largest of every county sharing its EPA zone — the 70th percentile by population within that zone. Geologically, Vermilion Parish is grouped into EPA Region 6 alongside 502 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, Vermilion Parish's Zone 3 prediction is the low end of the scale. A Zone 3 label describes Vermilion Parish's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Testing and mitigation in Vermilion Parish

For a Vermilion Parish homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Louisiana's state radon program

For Vermilion Parish, an ongoing number beats a one-time test - a Airthings radon monitor tracks Vermilion Parish's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Vermilion Parish's figures come from

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.