What EPA's radon map says about Jefferson Davis Parish

EPA's own radon map rates Jefferson Davis Parish zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts Jefferson Davis Parish in the 18th percentile nationally for radon potential — higher than 18% of the counties EPA has rated.

Jefferson Davis Parish by the numbers

About 31,436 people live in Jefferson Davis Parish, Louisiana, spread over 651.52 square miles. Population density there runs about 48 people per square mile. Among counties sharing Jefferson Davis Parish's EPA zone, it outranks 55% of them by population. EPA's geology-based Region 6 groups Jefferson Davis Parish with 502 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Jefferson Davis Parish

At Zone 3, Jefferson Davis Parish's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Don't read Zone 3 as a pass for Jefferson Davis Parish — EPA's guidance to test every home makes no exception for counties predicted low.

Next steps for a home in Jefferson Davis Parish

Mitigation cost doesn't depend on Jefferson Davis Parish'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 Louisiana's state radon program

Jefferson Davis Parish's test kit answers today; a Airthings radon monitor keeps answering for Jefferson Davis Parish 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

The methodology guide shows exactly which EPA and Census sources feed Jefferson Davis Parish's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.