Bernalillo County, NM: EPA's radon zone, explained

Bernalillo County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Bernalillo County sits at the 99th percentile nationally for radon potential — above 99 of every 100 rated counties.

Where Bernalillo County sits nationally

Bernalillo County, New Mexico is home to about 671,747 people across 1,161.245 square miles. Population density there runs about 578 people per square mile. By population, Bernalillo County is the 24th largest of every county sharing its EPA zone — the 98th percentile by population within that zone. Geologically, Bernalillo County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Bernalillo 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 Bernalillo County will test well under the action level, and EPA's guidance is to test regardless of zone.

Testing and mitigation in Bernalillo County

For a Bernalillo 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 New Mexico's state radon program

For Bernalillo County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Bernalillo 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 Bernalillo 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.