Is Ottawa County, OK a radon risk area?

Ottawa County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally that's the 18th percentile for radon potential — Ottawa County outranks 18% of every county EPA has rated.

How Ottawa County compares

About 30,404 people live in Ottawa County, Oklahoma, spread over 470.817 square miles. That works out to roughly 65 people per square mile. Rank 478 by population within its EPA zone puts Ottawa County at the 54th percentile among zone peers. Ottawa County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Ottawa County

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Ottawa County's Zone 3 prediction is the low end of the scale. A Zone 3 label describes Ottawa County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Ottawa County tests above the action level

Nothing about Ottawa County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find Oklahoma's state radon program

Ottawa County's test kit answers today; a Airthings radon monitor keeps answering for Ottawa County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Use code RADONZONE-10OFF at checkout for 10% off.

More on how this number was built

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