Arthur County, NE: EPA's radon zone, explained

Arthur County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Arthur County in the 0th percentile nationally for radon potential — higher than 0% of the counties EPA has rated.

Where Arthur County sits nationally

Arthur County, Nebraska is home to about 423 people across 715.152 square miles. That works out to roughly 1 people per square mile. By population, Arthur County is the 1026th largest of every county sharing its EPA zone — the 0th percentile by population within that zone. EPA's geology-based Region 7 groups Arthur County with 411 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

At Zone 3, Arthur County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Arthur County testing above the action level often enough that skipping a test isn't the safe assumption.

Testing and mitigation in Arthur County

For a Arthur 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 Nebraska's state radon program

For Arthur County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Arthur 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 Arthur 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. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.