Is Franklin County, AL a radon risk area?

Franklin County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Franklin County ranks higher in radon potential than 86% of rated counties (the 86th percentile).

How Franklin County compares

About 31,874 people live in Franklin County, Alabama, spread over 633.959 square miles. Averaged across its land area, Franklin County runs about 50 people per square mile. Rank 451 by population within its EPA zone puts Franklin County at the 58th percentile among zone peers. Franklin County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Franklin County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. Some Franklin County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

If Franklin County tests above the action level

Nothing about Franklin County'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 Alabama's state radon program

Franklin County's test kit answers today; a Airthings radon monitor keeps answering for Franklin County 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

Franklin County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Franklin County carries, the zone explainer covers what it does and doesn't tell you about any one house.