EPA Zone Data 2026
New Hampshire Radon Map, Levels & Testing Guide
View EPA radon zone classifications for every county in New Hampshire. Open your county to compare basement test meaning, EPA action thresholds, and when mitigation pricing becomes worth checking.
1
Zone 1
High Risk
High Risk
9
Zone 2
Moderate
Moderate
0
Zone 3
Low Risk
Low Risk
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Browse Counties
Jump to the Directory
Open your county to see its EPA zone, testing meaning, and the point where mitigation becomes worth pricing.
Belknap County
Zone 2
Carroll County
Zone 1
Cheshire County
Zone 2
Coos County
Zone 2
Grafton County
Zone 2
Hillsborough
Zone 2
Merrimack County
Zone 2
Rockingham County
Zone 2
Strafford County
Zone 2
Sullivan County
Zone 2
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