Berkeley County, SC radon potential

EPA's own radon map rates Berkeley 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 Berkeley County lands in the 30th percentile for radon potential.

Berkeley County by the numbers

Berkeley County, South Carolina is home to about 264,276 people across 1,103.61 square miles. That works out to roughly 239 people per square mile. Within its own EPA zone, Berkeley County is bigger by population than 91% of the counties that share it. EPA's geology-based Region 4 groups Berkeley County with 735 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Berkeley County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Don't read Zone 3 as a pass for Berkeley County — EPA's guidance to test every home makes no exception for counties predicted low.

If Berkeley County tests above the action level

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find South Carolina's state radon program

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

Where Berkeley County's figures come from

Berkeley 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.