Ellis County, OK radon potential

EPA's own radon map rates Ellis County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Rank it against the rest of the country and Ellis County lands in the 35th percentile for radon potential.

Ellis County by the numbers

Ellis County, Oklahoma is home to about 3,601 people across 1,231.477 square miles. Averaged across its land area, Ellis County runs about 3 people per square mile. Within its own EPA zone, Ellis County is bigger by population than 6% of the counties that share it. Geologically, Ellis County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

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, Ellis County's Zone 2 prediction lands in the gap between the two. Nothing about a Zone 2 label lowers the case for testing in Ellis County — EPA recommends it in every zone, moderate included.

If Ellis 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 Oklahoma's state radon program

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

Where Ellis County's figures come from

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