Guam tap water quality
5 active community water systems.
Largest water systems
| Grade | System | People | Health violations (5y) |
|---|---|---|---|
| D | GWA Northern Water System | 139,207 | 0 |
| C | U.S. Navy Water System | 12,780 | 2 |
| B | GWA Central Water System | 8,828 | 1 |
| A | Andersen Air Force Base Water System | 7,700 | 0 |
| A | GWA Southern Water System | 5,801 | 0 |
Most issues (systems serving 10,000+)
D
GWA Northern Water System
Serves 139,207 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFOA/PFOS average above the 4 ppt federal limit: PFOS, PFOA; Other PFAS above 2024 limits (rule proposed for repeal): PFHxS, Hazard Index; Lead 90th percentile below the action level (2025).
C
U.S. Navy Water System
Serves 12,780 people · Surface water · Full report →
2 health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
Cities
AdacaoAdelupAgana HeightsAgatAniguaApra HeightsAsanDededoGuam Naval FacilityGuam Naval MagazineGuam Naval Regional Medical CeGuam Naval Ship Repair FacilitGuam Naval StationGuam Naval Supply DepotNaval Communications Area MastNorth TipalaoPigoPitiSanta RitaSouth TipalaoSumayTalofofoTamuningTumonUnatac