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State overview
Radon in Delaware
Of Delaware's 3 counties and county equivalents, EPA places 1 in Zone 2, 2 in Zone 3. Zones are county-wide predictions; testing is the only way to know your home's level.
Radon in the news
Delaware stories
- More than 15% of Delaware homes have high levels of carcinogenic radon gasDelaware Public Media · 2025-01-07
Headlines link to the original publishers via Google News. Updated 2026-10-27.
All 3 counties
| County | EPA zone |
|---|---|
| Kent County | Zone 3 |
| New Castle County | Zone 2 |
| Sussex County | Zone 3 |
Source: EPA radon zones spreadsheet (EPA 402/A-16/001).