Sedgwick County, KS: EPA's radon zone, explained

EPA's own radon map rates Sedgwick County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally, Sedgwick County ranks higher in radon potential than 65% of rated counties (the 65th percentile).

Where Sedgwick County sits nationally

Sedgwick County, Kansas is home to about 536,081 people across 997.001 square miles. Population density there runs about 538 people per square mile. By population, Sedgwick County is the 45th largest of every county sharing its EPA zone — the 96th percentile by population within that zone. Sedgwick County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Sedgwick County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Sedgwick County — testing is the only way to know an individual home's actual level.

If Sedgwick County tests above the action level

For a Sedgwick 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 Kansas's state radon program

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

The methodology guide shows exactly which EPA and Census sources feed Sedgwick County's numbers. Whatever zone Sedgwick County carries, the zone explainer covers what it does and doesn't tell you about any one house.