What EPA's radon map says about Berkeley County

EPA places Berkeley County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Berkeley County ranks higher in radon potential than 95% of rated counties (the 95th percentile).

Where Berkeley County sits nationally

About 136,287 people live in Berkeley County, West Virginia, spread over 321.131 square miles. That works out to roughly 424 people per square mile. Among counties sharing Berkeley County's EPA zone, it outranks 86% of them by population. EPA's geology-based Region 3 groups Berkeley County with 244 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Berkeley County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Berkeley County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Berkeley County specifically.

Next steps for a home in Berkeley County

Mitigation cost doesn't depend on Berkeley 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 West Virginia's state radon program

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