What EPA's radon map says about Lexington County

EPA places Lexington County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Lexington County sits at the 30th percentile nationally for radon potential — above 30 of every 100 rated counties.

How Lexington County compares

About 313,774 people live in Lexington County, South Carolina, spread over 698.548 square miles. Averaged across its land area, Lexington County runs about 449 people per square mile. Among counties sharing Lexington County's EPA zone, it outranks 92% of them by population. Lexington County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

A Zone 3 county like Lexington County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 label describes Lexington County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

Testing and mitigation in Lexington County

Mitigation cost doesn't depend on Lexington 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

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

Lexington County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.