St. Landry Parish, LA Radon Zone Data

Is St. Landry Parish, LA a radon risk area?

EPA places St. Landry 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. That puts St. Landry Parish in the 25th percentile nationally for radon potential — higher than 25% of the counties EPA has rated.

How St. Landry Parish compares

About 80,869 people live in St. Landry Parish, Louisiana, spread over 923.378 square miles. Population density there runs about 88 people per square mile. Rank 251 by population within its EPA zone puts St. Landry Parish at the 76th percentile among zone peers. Geologically, St. Landry 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, St. Landry Parish's Zone 3 prediction is the low end of the scale. A Zone 3 rating means St. Landry 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.

If St. Landry Parish tests above the action level

Nothing about St. Landry 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

St. Landry Parish's test kit answers today; a Airthings radon monitor keeps answering for St. Landry 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 St. Landry Parish's numbers. Whatever zone St. Landry Parish carries, the zone explainer covers what it does and doesn't tell you about any one house.