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

Grant County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Nationally that's the 50th percentile for radon potential — Grant County outranks 50% of every county EPA has rated.

Grant County by the numbers

Grant County, New Mexico is home to about 27,541 people across 3,961.207 square miles. Population density there runs about 7 people per square mile. By population, Grant County is the 514th largest of every county sharing its EPA zone — the 50th percentile by population within that zone. Grant County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Grant County's Zone 2 prediction lands in the gap between the two. Middle-of-the-pack doesn't mean risk-free for any one Grant County address — a moderate county average still leaves individual homes to test either side of it.

If Grant County tests above the action level

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

The methodology guide shows exactly which EPA and Census sources feed Grant County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.