Nelson County, ND radon potential

EPA places Nelson County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Nelson County in the 69th percentile nationally for radon potential — higher than 69% of the counties EPA has rated.

Where Nelson County sits nationally

Nelson County, North Dakota is home to about 3,007 people across 981.815 square miles. Population density there runs about 3 people per square mile. Within its own EPA zone, Nelson County is bigger by population than 8% of the counties that share it. Geologically, Nelson County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

What this actually means for a house in Nelson County

Nelson County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. That doesn't mean every Nelson County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Testing and mitigation in Nelson 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 North Dakota's state radon program

For Nelson County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Nelson 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 Nelson County's figures come from

Nelson County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.