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

EPA's own radon map rates Richland Parish zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts Richland Parish in the 13th percentile nationally for radon potential — higher than 13% of the counties EPA has rated.

How Richland Parish compares

Richland Parish, Louisiana is home to about 19,643 people across 555.613 square miles. Averaged across its land area, Richland Parish runs about 35 people per square mile. By population, Richland Parish is the 627th largest of every county sharing its EPA zone — the 39th percentile by population within that zone. Richland Parish falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

A Zone 3 county like Richland Parish is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 label describes Richland Parish's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Next steps for a home in Richland Parish

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

Where Richland Parish's figures come from

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