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

EPA's own radon map rates Assumption Parish zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Nationally, Assumption Parish ranks higher in radon potential than 13% of rated counties (the 13th percentile).

Where Assumption Parish sits nationally

Assumption Parish, Louisiana is home to about 20,050 people across 344.018 square miles. Population density there runs about 58 people per square mile. By population, Assumption Parish is the 616th largest of every county sharing its EPA zone — the 40th percentile by population within that zone. Geologically, Assumption Parish is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

What this actually means for a house in Assumption Parish

Assumption Parish's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. A Zone 3 rating means Assumption Parish's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Next steps for a home in Assumption Parish

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

Where Assumption 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. Whatever zone Assumption Parish carries, the zone explainer covers what it does and doesn't tell you about any one house.