Mono County, CA radon potential

Mono 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 42nd percentile for radon potential — Mono County outranks 42% of every county EPA has rated.

How Mono County compares

Mono County, California is home to about 12,991 people across 3,048.904 square miles. Population density there runs about 4 people per square mile. Within its own EPA zone, Mono County is bigger by population than 27% of the counties that share it. EPA's geology-based Region 9 groups Mono County with 94 other counties nationally sharing its underlying rock and soil profile.

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, Mono County's Zone 2 prediction lands in the gap between the two. A county-wide moderate average, like Mono County's, can still hide a specific house well above or below it — testing is what actually answers the question.

Testing and mitigation in Mono 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 California's state radon program

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

Where Mono County's figures come from

Mono 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.