Clay County, FL radon potential

EPA places Clay County in Zone 3 - Low Potential — a predicted county-wide average indoor radon level below 2 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Clay County sits at the 29th percentile nationally for radon potential — above 29 of every 100 rated counties.

Where Clay County sits nationally

Clay County, Florida is home to about 236,760 people across 604.598 square miles. Averaged across its land area, Clay County runs about 392 people per square mile. Within its own EPA zone, Clay County is bigger by population than 90% of the counties that share it. Clay County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

A Zone 3 county like Clay County is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. Even at Zone 3, Clay County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

If Clay County tests above the action level

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 Florida's state radon program

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

Where Clay County's figures come from

Clay 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.