Radon and home risks by county
Radon in Utah
7 of Utah's 29 counties are in EPA's highest radon zone, home to about 4% of the state's residents. Radon zones describe an area's potential; EPA recommends testing every home regardless of zone.
Zone 1 counties
7
high radon potential
Zone 2 counties
22
moderate potential
Zone 3 counties
0
low potential
Counties with water violations
27
since 2016; 4 with unresolved ones
Find your county by ZIP
Zone 1: high potential (7 counties)
| County | Residents | Water systems | Health violations since 2016 | Unresolved |
|---|---|---|---|---|
| Carbon County | 20,613 | 5 | 6 | 0 |
| Duchesne County | 20,803 | 15 | 9 | 0 |
| Grand County | 9,788 | 6 | 7 | 0 |
| Piute County | 1,534 | 6 | 2 | 1 |
| Sanpete County | 30,732 | 20 | 12 | 0 |
| Sevier County | 22,520 | 16 | 7 | 1 |
| Uintah County | 38,307 | 10 | 2 | 0 |
Zone 2: moderate potential (22 counties)
| County | Residents | Water systems | Health violations since 2016 | Unresolved |
|---|---|---|---|---|
| Beaver County | 7,424 | 4 | 0 | 0 |
| Box Elder County | 64,120 | 35 | 13 | 0 |
| Cache County | 145,487 | 24 | 23 | 0 |
| Daggett County | 956 | 4 | 14 | 0 |
| Davis County | 378,470 | 20 | 6 | 0 |
| Emery County | 10,161 | 11 | 9 | 1 |
| Garfield County | 5,290 | 12 | 9 | 1 |
| Iron County | 65,936 | 28 | 26 | 0 |
| Juab County | 13,297 | 5 | 1 | 0 |
| Kane County | 8,525 | 13 | 10 | 0 |
| Millard County | 13,572 | 16 | 15 | 0 |
| Morgan County | 13,093 | 11 | 6 | 0 |
| Rich County | 2,752 | 9 | 7 | 0 |
| Salt Lake County | 1,216,274 | 39 | 17 | 0 |
| San Juan County | 14,601 | 10 | 5 | 0 |
| Summit County | 43,109 | 27 | 25 | 0 |
| Tooele County | 84,488 | 13 | 0 | 0 |
| Utah County | 747,234 | 43 | 32 | 0 |
| Wasatch County | 37,858 | 20 | 37 | 0 |
| Washington County | 207,943 | 38 | 32 | 0 |
| Wayne County | 2,608 | 9 | 2 | 0 |
| Weber County | 276,118 | 33 | 43 | 0 |
How to read this table
Water systems counts community systems that list the county in their service area; one system can serve several counties. Health violations are breaches of a legal limit or treatment rule recorded by EPA since January 2016, not paperwork lapses. A violation stays unresolved until the state records it as fixed.
Other states
- Arizona
- California
- Colorado
- Florida
- Idaho
- Illinois
- Iowa
- Michigan
- Minnesota
- New Jersey
- New York
- Ohio
- Pennsylvania
- Texas
Sources: EPA Map of Radon Zones, EPA ECHO Safe Drinking Water Act data (2026Q3, published October 2026), US Census Bureau Vintage 2024 estimates. See the methodology.