DeKalb County, GA: EPA's radon zone, explained

EPA places DeKalb 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. Rank it against the rest of the country and DeKalb County lands in the 99th percentile for radon potential.

How DeKalb County compares

DeKalb County, Georgia is home to about 770,307 people across 267.665 square miles. Averaged across its land area, DeKalb County runs about 2,878 people per square mile. By population, DeKalb County is the 19th largest of every county sharing its EPA zone — the 98th percentile by population within that zone. EPA's geology-based Region 4 groups DeKalb County with 735 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in DeKalb County

Where the national indoor average runs about 1.3 pCi/L, DeKalb County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. 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 DeKalb County specifically.

Next steps for a home in DeKalb County

For a DeKalb County 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 Georgia's state radon program

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

Where DeKalb County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.