Radon in Nevada
Radon in Nevada varies from house to house, so the county figures below describe areas, not homes. EPA places 8 of the state's 17 counties in Zone 1, its highest band of predicted indoor radon, where about 4% of residents live; 1 is in Zone 3. On the water side, EPA has recorded health-based violations at 49 of the state's 193 community water systems since 2016.
What Nevada's radon program offers
Past Nevada test results put 25% of homes above EPA's 4 pCi/L action level.
The University of Nevada's radon program gives out free short-term kits at Extension offices in January and February while supplies last, sells low-cost kits the rest of the year and lends digital monitors for up to two weeks. Radon line: (775) 336-0254.
The program publishes its own lists of NRPP and NRSB certified testers and mitigation contractors working in Nevada.
Read on University of Nevada, Reno Extension, Nevada Radon Education Program pages, checked 2026-10-29: state radon program.
Radon in Nevada by county
The Nevada radon map below groups counties by EPA zone; zones predict Nevada radon levels from geology and past surveys and are not home measurements. The largest county, Clark County (2,398,871 residents), is in Zone 3. EPA's map has no zone for Carson City.
| County | Residents | Water systems | Violations since 2016 | Unresolved |
|---|---|---|---|---|
| Douglas County | 49,564 | 24 | 12 | 1 |
| Eureka County | 1,877 | 4 | 1 | 0 |
| Lander County | 5,785 | 3 | 4 | 0 |
| Lincoln County | 4,345 | 5 | 1 | 0 |
| Lyon County | 63,718 | 6 | 2 | 0 |
| Mineral County | 4,475 | 4 | 2 | 1 |
| Pershing County | 6,536 | 4 | 0 | 0 |
| White Pine County | 8,534 | 7 | 0 | 0 |
| County | Residents | Water systems | Violations since 2016 | Unresolved |
|---|---|---|---|---|
| Churchill County | 26,033 | 9 | 15 | 0 |
| Elko County | 54,363 | 16 | 3 | 2 |
| Esmeralda County | 720 | 2 | 6 | 0 |
| Humboldt County | 17,116 | 7 | 20 | 0 |
| Nye County | 55,990 | 26 | 51 | 1 |
| Storey County | 4,112 | 2 | 0 | 0 |
| Washoe County | 507,280 | 25 | 101 | 2 |
| County | Residents | Water systems | Violations since 2016 | Unresolved |
|---|---|---|---|---|
| Clark County | 2,398,871 | 46 | 62 | 2 |
Nevada tap water: violations and PFAS
Nevada has 193 active community water systems serving about 3,121,600 people. Since January 2016, EPA has recorded at least one health-based violation at 49 of them (2% of the people served), and 9 have one still listed as unresolved. The most frequent cause was the rule on fecal contamination in well water, at 21 systems, followed by arsenic, which occurs naturally in some groundwater (13) and the revised lead and copper rule (10).
EPA tested 37 Nevada systems for PFAS between 2023 and 2025. 3 had a PFOA or PFOS result above the 4 ng/L limit that applies from 2029; the highest was Elko City of at 46 ng/L.
Records: EPA Map of Radon Zones, EPA ECHO drinking water data (2026Q3), EPA UCMR 5, University of Nevada, Reno Extension, Nevada Radon Education Program, US Census Bureau Vintage 2024. How zones and violations are counted: methodology · all states.