Hancock County, ME radon potential

EPA places Hancock 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. Nationally, Hancock County ranks higher in radon potential than 91% of rated counties (the 91st percentile).

Where Hancock County sits nationally

Hancock County, Maine is home to about 56,946 people across 1,587.182 square miles. Averaged across its land area, Hancock County runs about 36 people per square mile. Within its own EPA zone, Hancock County is bigger by population than 73% of the counties that share it. Geologically, Hancock County is grouped into EPA Region 1 alongside 58 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Hancock County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Hancock County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Hancock County tests above the action level

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Maine's state radon program

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

Where Hancock County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Hancock County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.