Renville County, ND: EPA's radon zone, explained

Renville County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. That puts Renville County in the 68th percentile nationally for radon potential — higher than 68% of the counties EPA has rated.

Renville County by the numbers

Renville County, North Dakota is home to about 2,376 people across 877.244 square miles. That works out to roughly 3 people per square mile. By population, Renville County is the 1011th largest of every county sharing its EPA zone — the 5th percentile by population within that zone. EPA's geology-based Region 8 groups Renville County with 290 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Renville 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. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Renville County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Renville County tests above the action level

For a Renville 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 Dakota's state radon program

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

Renville 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.