Berkshire County, MA: EPA's radon zone, explained

EPA places Berkshire County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 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 Berkshire County lands in the 61st percentile for radon potential.

Berkshire County by the numbers

Berkshire County, Massachusetts is home to about 128,726 people across 926.874 square miles. Population density there runs about 139 people per square mile. By population, Berkshire County is the 162nd largest of every county sharing its EPA zone — the 84th percentile by population within that zone. Geologically, Berkshire County is grouped into EPA Region 1 alongside 58 other counties that share its rock and soil setting.

Zone vs. an actual test

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Berkshire County's Zone 2 prediction lands in the gap between the two. A county-wide moderate average, like Berkshire County's, can still hide a specific house well above or below it — testing is what actually answers the question.

Next steps for a home in Berkshire County

For a Berkshire 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 Massachusetts's state radon program

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

Where Berkshire 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. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.