What EPA's radon map says about Bibb County

EPA places Bibb County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Bibb County sits at the 47th percentile nationally for radon potential — above 47 of every 100 rated counties.

Bibb County by the numbers

About 22,258 people live in Bibb County, Alabama, spread over 622.47 square miles. That works out to roughly 36 people per square mile. Among counties sharing Bibb County's EPA zone, it outranks 43% of them by population. Geologically, Bibb County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

EPA's Zone 2 rating for Bibb County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Bibb County — testing is the only way to know an individual home's actual level.

If Bibb County tests above the action level

Mitigation cost doesn't depend on Bibb County'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 Alabama's state radon program

Bibb County's test kit answers today; a Airthings radon monitor keeps answering for Bibb County 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 Bibb County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.