What EPA's radon map says about Aiken County

EPA's own radon map rates Aiken County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Rank it against the rest of the country and Aiken County lands in the 28th percentile for radon potential.

Where Aiken County sits nationally

About 179,245 people live in Aiken County, South Carolina, spread over 1,070.676 square miles. Averaged across its land area, Aiken County runs about 167 people per square mile. Among counties sharing Aiken County's EPA zone, it outranks 86% of them by population. Geologically, Aiken County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Zone vs. an actual test

A Zone 3 county like Aiken County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Don't read Zone 3 as a pass for Aiken County — EPA's guidance to test every home makes no exception for counties predicted low.

Testing and mitigation in Aiken County

Mitigation cost doesn't depend on Aiken 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 South Carolina's state radon program

Aiken County's test kit answers today; a Airthings radon monitor keeps answering for Aiken County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.