What EPA's radon map says about Noble County

EPA places Noble 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. Nationally that's the 7th percentile for radon potential — Noble County outranks 7% of every county EPA has rated.

Noble County by the numbers

About 10,896 people live in Noble County, Oklahoma, spread over 731.712 square miles. Averaged across its land area, Noble County runs about 15 people per square mile. Among counties sharing Noble County's EPA zone, it outranks 23% of them by population. Geologically, Noble County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

What this actually means for a house in Noble County

Noble County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Noble County testing above the action level often enough that skipping a test isn't the safe assumption.

Testing and mitigation in Noble County

Mitigation cost doesn't depend on Noble County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Oklahoma's state radon program

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

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.