What EPA's radon map says about Garfield County

EPA places Garfield 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. Rank it against the rest of the country and Garfield County lands in the 23rd percentile for radon potential.

Garfield County by the numbers

About 62,007 people live in Garfield County, Oklahoma, spread over 1,058.507 square miles. Averaged across its land area, Garfield County runs about 59 people per square mile. Among counties sharing Garfield County's EPA zone, it outranks 71% of them by population. Garfield County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Garfield 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. A Zone 3 label describes Garfield County's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Garfield County tests above the action level

Mitigation cost doesn't depend on Garfield 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

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

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. Whatever zone Garfield County carries, the zone explainer covers what it does and doesn't tell you about any one house.