Puerto Rico water quality
Puerto Rico has 441 active public water systems (975 on file total), 381 of them graded by TapGraded.
Grade distribution
Biggest water systems
MAYAGUEZ
MAYAGUEZ, PR · 152,342 served
AGUADILLA
AGUADILLA, PR · 124,782 served
RIO BLANCO,VIEQUES,CULEDRA
NAGUABO, PR · 79,822 served
EL YUNQUE
RIO GRANDE, PR · 68,114 served
FAJARDO CEIBA
FAJARDO, PR · 59,044 served
ISABELA
SANTURCE, PR · 49,937 served
CAGUAS NORTE
CAGUAS, PR · 47,352 served
LAJAS
LAJAS, PR · 47,350 served
SANTA ISABEL URBANO
SANTA ISABEL, PR · 39,925 served
LAS PIEDRAS HUMACAO
HUMACAO, PR · 38,897 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
COMERIO URBANO
COMERIO, PR · 14,912 served
EL YUNQUE
RIO GRANDE, PR · 68,114 served
JUNCOS - CEIBA SUR
JUNCOS, PR · 36,835 served
AGUADILLA
AGUADILLA, PR · 124,782 served
AGUAS BUENAS URBANO
AGUAS BUENAS, PR · 13,233 served
LAS BOCAS
SANTURCE, PR · 11,022 served
SANTA ISABEL URBANO
SANTA ISABEL, PR · 39,925 served
VEGA BAJA URBANO
VEGA BAJA, PR · 26,935 served
AIBONITO LA PLATA
AIBONITO, PR · 16,354 served
GURABO URBANO
GURABO, PR · 25,469 served
Source: EPA SDWIS/ECHO · Data as of 2026Q2