What EPA's radon map says about Anderson County

EPA's own radon map rates Anderson County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally, Anderson County ranks higher in radon potential than 62% of rated counties (the 62nd percentile).

Where Anderson County sits nationally

About 217,183 people live in Anderson County, South Carolina, spread over 713.854 square miles. Averaged across its land area, Anderson County runs about 304 people per square mile. Among counties sharing Anderson County's EPA zone, it outranks 89% of them by population. EPA's geology-based Region 4 groups Anderson County with 735 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Anderson County

Anderson County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. A county-wide moderate average, like Anderson County's, can still hide a specific house well above or below it — testing is what actually answers the question.

Testing and mitigation in Anderson County

Mitigation cost doesn't depend on Anderson 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

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

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