State rankings

Guam water-system rankings

Community water systems in Guam ranked by PurityRadar safety score — from EPA violations, enforcement, and PFAS data.

Lowest-scoring systems in Guam

Ranked lowest score first. Population shown for context.

1 GWA NORTHERN WATER SYSTEM MANGILAO, GU · ~139,207 served 40 2 GWA CENTRAL WATER SYSTEM MANGILAO, GU · ~21,398 served 100 3 ANDERSEN AIR FORCE BASE WATER SYSTEM APO AP, GU · ~7,700 served 100 4 GWA SOUTHERN WATER SYSTEM MANGILAO, GU · ~5,801 served 100

Highest-scoring large systems in Guam

Systems serving 10,000+ people with the best scores.

1 GWA CENTRAL WATER SYSTEM MANGILAO, GU · ~21,398 served 100 2 GWA NORTHERN WATER SYSTEM MANGILAO, GU · ~139,207 served 40

Guam directory → All states

Scores reflect EPA public records (violations, enforcement, PFAS), are system-level, and can’t account for your home’s plumbing. See the methodology.