Is San Juan County, NM a radon risk area?

San Juan 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. San Juan County sits at the 61st percentile nationally for radon potential — above 61 of every 100 rated counties.

How San Juan County compares

About 120,817 people live in San Juan County, New Mexico, spread over 5,517.23 square miles. Population density there runs about 22 people per square mile. Rank 169 by population within its EPA zone puts San Juan County at the 84th percentile among zone peers. EPA's geology-based Region 6 groups San Juan County with 502 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in San Juan County

San Juan County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Nothing about a Zone 2 label lowers the case for testing in San Juan County — EPA recommends it in every zone, moderate included.

If San Juan County tests above the action level

Nothing about San Juan County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find New Mexico's state radon program

San Juan County's test kit answers today; a Airthings radon monitor keeps answering for San Juan County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

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.