Northampton County, VA Radon Zone Data

Northampton County, VA radon potential

EPA places Northampton 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, Northampton County ranks higher in radon potential than 8% of rated counties (the 8th percentile).

Northampton County by the numbers

Northampton County, Virginia is home to about 12,004 people across 211.715 square miles. That works out to roughly 57 people per square mile. Within its own EPA zone, Northampton County is bigger by population than 25% of the counties that share it. Northampton County falls in EPA Radon Region 3, one of 245 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Northampton County

Northampton 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. Even at Zone 3, Northampton County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Northampton 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 Virginia's state radon program

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

Where Northampton County's figures come from

Northampton 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.