Charles County, MD radon potential

EPA places Charles County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Charles County ranks higher in radon potential than 62% of rated counties (the 62nd percentile).

Charles County by the numbers

Charles County, Maryland is home to about 174,478 people across 457.819 square miles. Population density there runs about 381 people per square mile. Within its own EPA zone, Charles County is bigger by population than 87% of the counties that share it. Geologically, Charles County is grouped into EPA Region 3 alongside 244 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Charles County's Zone 2 prediction. Nothing about a Zone 2 label lowers the case for testing in Charles County — EPA recommends it in every zone, moderate included.

Testing and mitigation in Charles 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 Maryland's state radon program

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

Where Charles County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Charles County's numbers. Whatever zone Charles County carries, the zone explainer covers what it does and doesn't tell you about any one house.