Northampton County, NC: EPA's radon zone, explained

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 that's the 11th percentile for radon potential — Northampton County outranks 11% of every county EPA has rated.

How Northampton County compares

Northampton County, North Carolina is home to about 16,580 people across 536.715 square miles. Population density there runs about 31 people per square mile. By population, Northampton County is the 683rd largest of every county sharing its EPA zone — the 34th percentile by population within that zone. Geologically, Northampton County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Northampton 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 Northampton County testing above the action level often enough that skipping a test isn't the safe assumption.

Testing and mitigation in Northampton County

For a Northampton County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find North Carolina'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. Use code RADONZONE-10OFF at checkout for 10% off.

Where Northampton County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.