EPA Zone Data 2026
Maryland Radon Map, Levels & Testing Guide
View EPA radon zone classifications for every county in Maryland. Open your county to compare basement test meaning, EPA action thresholds, and when mitigation pricing becomes worth checking.
8
Zone 1
High Risk
High Risk
8
Zone 2
Moderate
Moderate
8
Zone 3
Low Risk
Low Risk
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If you already have a radon result, skip the directory and move straight to local price guidance.
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Use the fastest valid radon test setup before you compare quotes or ask whether mitigation is worth it.
Browse Counties
Jump to the Directory
Open your county to see its EPA zone, testing meaning, and the point where mitigation becomes worth pricing.
Allegany County
Zone 2
Anne Arundel County
Zone 2
Baltimore County
Zone 2
Baltimore County
Zone 1
Calvert County
Zone 1
Carroll County
Zone 1
Cecil County
Zone 2
Charles County
Zone 2
Frederick County
Zone 1
Garrett County
Zone 2
Harford County
Zone 1
Howard County
Zone 1
Montgomery County
Zone 1
Prince George's County
Zone 2
St. Mary's County
Zone 2
Washington County
Zone 1
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