What EPA's radon map says about Allen Parish

Allen Parish is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Allen Parish in the 15th percentile nationally for radon potential — higher than 15% of the counties EPA has rated.

How Allen Parish compares

About 22,501 people live in Allen Parish, Louisiana, spread over 762.085 square miles. Population density there runs about 30 people per square mile. Among counties sharing Allen Parish's EPA zone, it outranks 45% of them by population. Allen Parish falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Allen Parish's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. A Zone 3 label describes Allen Parish's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Testing and mitigation in Allen Parish

Mitigation cost doesn't depend on Allen 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

Allen Parish's test kit answers today; a Airthings radon monitor keeps answering for Allen 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 Allen Parish's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.