EPA radon zones
Massachusetts radon map: every county's zone
3 of Massachusetts's 14 counties are EPA radon zone 1 (predicted average above 4 pCi/L), 10 are zone 2 and 1 are zone 3. High readings occur in every zone, so EPA recommends testing every home.
Barnstable CountyZone 2
Berkshire CountyZone 2
Bristol CountyZone 2
Dukes CountyZone 2
Essex CountyZone 1
Franklin CountyZone 2
Hampden CountyZone 2
Hampshire CountyZone 2
Middlesex CountyZone 1
Nantucket CountyZone 2
Norfolk CountyZone 2
Plymouth CountyZone 2
Suffolk CountyZone 3
Worcester CountyZone 1
How much does radon mitigation cost?
Most single-family systems cost $800 to $2,500 installed, depending on foundation type and how many suction points are needed. A follow-up test confirms the system works.
What do the zones mean?
EPA radon zones describe counties, not houses. Zone 1 counties have a predicted average indoor level above 4 picocuries per liter (pCi/L), Zone 2 between 2 and 4, Zone 3 below 2. Homes with high levels are found in every zone, which is why EPA recommends that every home be tested, and fixed at 4 pCi/L or above.
Massachusetts cities: water and radon
Source: EPA Map of Radon Zones.