What EPA's radon map says about Oxford County

EPA places Oxford County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 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 Oxford County lands in the 91st percentile for radon potential.

Where Oxford County sits nationally

About 60,039 people live in Oxford County, Maine, spread over 2,076.958 square miles. Population density there runs about 29 people per square mile. Among counties sharing Oxford County's EPA zone, it outranks 74% of them by population. Oxford County falls in EPA Radon Region 1, one of 59 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Oxford County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Oxford County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. Being in Zone 1 raises the odds Oxford County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Testing and mitigation in Oxford County

Mitigation cost doesn't depend on Oxford 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 Maine's state radon program

Oxford County's test kit answers today; a Airthings radon monitor keeps answering for Oxford 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

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.