El Dorado County, CA radon potential

El Dorado 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. That puts El Dorado County in the 62nd percentile nationally for radon potential — higher than 62% of the counties EPA has rated.

El Dorado County by the numbers

El Dorado County, California is home to about 192,823 people across 1,707.842 square miles. Averaged across its land area, El Dorado County runs about 113 people per square mile. Within its own EPA zone, El Dorado County is bigger by population than 88% of the counties that share it. EPA's geology-based Region 9 groups El Dorado County with 94 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 El Dorado County's Zone 2 prediction. El Dorado 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 El Dorado 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 El Dorado County, an ongoing number beats a one-time test - a Airthings radon monitor tracks El Dorado County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

Where El Dorado County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.