Dorchester County, SC radon potential
EPA places Dorchester 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. Nationally, Dorchester County ranks higher in radon potential than 28% of rated counties (the 28th percentile).
Dorchester County by the numbers
Dorchester County, South Carolina is home to about 174,663 people across 568.393 square miles. Population density there runs about 307 people per square mile. Within its own EPA zone, Dorchester County is bigger by population than 86% of the counties that share it. Geologically, Dorchester County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.
Zone vs. an actual test
Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Dorchester County's Zone 3 prediction is the low end of the scale. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Dorchester County testing above the action level often enough that skipping a test isn't the safe assumption.
Testing and mitigation in Dorchester County
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 Dorchester County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Dorchester 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 Dorchester County's figures come from
The methodology guide shows exactly which EPA and Census sources feed Dorchester County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.