What EPA's radon map says about Rockingham County

EPA's own radon map rates Rockingham County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. That puts Rockingham County in the 93rd percentile nationally for radon potential — higher than 93% of the counties EPA has rated.

How Rockingham County compares

About 93,517 people live in Rockingham County, North Carolina, spread over 565.642 square miles. Averaged across its land area, Rockingham County runs about 165 people per square mile. Among counties sharing Rockingham County's EPA zone, it outranks 81% of them by population. EPA's geology-based Region 4 groups Rockingham County with 735 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Where the national indoor average runs about 1.3 pCi/L, Rockingham County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Rockingham County specifically.

Testing and mitigation in Rockingham County

Mitigation cost doesn't depend on Rockingham County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find North Carolina's state radon program

Rockingham County's test kit answers today; a Airthings radon monitor keeps answering for Rockingham County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Rockingham County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.