Sierra County, NM radon potential

Sierra 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, Sierra County ranks higher in radon potential than 41% of rated counties (the 41st percentile).

Sierra County by the numbers

Sierra County, New Mexico is home to about 11,389 people across 4,181.214 square miles. Averaged across its land area, Sierra County runs about 3 people per square mile. Within its own EPA zone, Sierra County is bigger by population than 23% of the counties that share it. EPA's geology-based Region 6 groups Sierra County with 502 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

Call it a middle case: above the 1.3 pCi/L most US homes average, below the 4 pCi/L line EPA uses to recommend mitigation — that's Sierra County's Zone 2 prediction. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Sierra County — testing is the only way to know an individual home's actual level.

Next steps for a home in Sierra 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 New Mexico's state radon program

For Sierra County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Sierra County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Sierra County's figures come from

Sierra 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.