Hamilton County, NY: EPA's radon zone, explained

EPA places Hamilton 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, Hamilton County ranks higher in radon potential than 3% of rated counties (the 3rd percentile).

How Hamilton County compares

Hamilton County, New York is home to about 5,082 people across 1,717.378 square miles. Population density there runs about 3 people per square mile. By population, Hamilton County is the 941st largest of every county sharing its EPA zone — the 9th percentile by population within that zone. EPA's geology-based Region 2 groups Hamilton County with 82 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

At Zone 3, Hamilton County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Even at Zone 3, Hamilton County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in Hamilton County

For a Hamilton County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find New York's state radon program

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

Where Hamilton County's figures come from

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Hamilton County carries, the zone explainer covers what it does and doesn't tell you about any one house.