Is Bienville Parish, LA a radon risk area?

EPA places Bienville 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 9th percentile for radon potential — Bienville Parish outranks 9% of every county EPA has rated.

Where Bienville Parish sits nationally

About 12,412 people live in Bienville Parish, Louisiana, spread over 811.327 square miles. Averaged across its land area, Bienville Parish runs about 15 people per square mile. Rank 764 by population within its EPA zone puts Bienville Parish at the 26th percentile among zone peers. Geologically, Bienville Parish is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Zone vs. an actual test

Bienville 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. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Bienville Parish testing above the action level often enough that skipping a test isn't the safe assumption.

If Bienville Parish tests above the action level

Nothing about Bienville Parish's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Louisiana's state radon program

Bienville Parish's test kit answers today; a Airthings radon monitor keeps answering for Bienville Parish over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Bienville Parish's numbers. Whatever zone Bienville Parish carries, the zone explainer covers what it does and doesn't tell you about any one house.