Santa Rosa County, FL: EPA's radon zone, explained

Santa Rosa County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally, Santa Rosa County ranks higher in radon potential than 29% of rated counties (the 29th percentile).

Where Santa Rosa County sits nationally

Santa Rosa County, Florida is home to about 207,653 people across 1,012.402 square miles. Population density there runs about 205 people per square mile. By population, Santa Rosa County is the 127th largest of every county sharing its EPA zone — the 88th percentile by population within that zone. Santa Rosa County falls in EPA Radon Region 4, one of 736 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Santa Rosa County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. Even at Zone 3, Santa Rosa County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

If Santa Rosa County tests above the action level

For a Santa Rosa 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 Florida's state radon program

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

Where Santa Rosa 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. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.