Cache County, UT: EPA's radon zone, explained

EPA places Cache County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Cache County sits at the 61st percentile nationally for radon potential — above 61 of every 100 rated counties.

How Cache County compares

Cache County, Utah is home to about 145,487 people across 1,164.687 square miles. That works out to roughly 125 people per square mile. By population, Cache County is the 152nd largest of every county sharing its EPA zone — the 85th percentile by population within that zone. Geologically, Cache County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

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, Cache County's Zone 2 prediction lands in the gap between the two. Cache County's Zone 2 rating sits in the middle nationally; EPA's guidance is unchanged by that — test every home regardless of its zone.

Testing and mitigation in Cache County

For a Cache 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 Utah's state radon program

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

Cache County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.