Systems with a yearly average at or above an EPA-based study benchmark
16.1%14 of 87 active community water systems
All 87 systems had enough required samples to calculate a yearly average. 14 had at least one yearly average at or above a study benchmark; 73 did not.
EPA-based study benchmark: the unrounded cutoff this research uses to reproduce EPA’s January 2026 technical-assistance classification around the April 2024 federal levels. It is not a current standard or compliance finding and cannot determine household exposure or health risk.
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ZIP codes are used only to route visitors to public water systems that reported serving them. Confirm the actual provider using a water bill or utility record.
Compound summary
System counts in Puerto Rico
Each count shows how many included water systems had a yearly average at or above the named study benchmark.
| Study benchmark | Systems at or above benchmark | Water systems included | Percent |
|---|---|---|---|
| PFOA: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 1 | 87 | 1.1% |
| PFOS: 4.05 ppt study benchmark (reproduces EPA classification around 4 ppt) | 14 | 87 | 16.1% |
| PFHxS: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 1 | 87 | 1.1% |
| PFNA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 87 | 0.0% |
| HFPO-DA: 15 ppt study benchmark (reproduces EPA classification around 10 ppt) | 0 | 87 | 0.0% |
| Hazard Index: 1.5 study benchmark with at least two detected components (reproduces EPA classification around 1) | 1 | 87 | 1.1% |
System directory
Community water systems with complete monitoring
“Complete monitoring” means at least one sampling location had all required samples needed for a yearly average. Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | Study benchmark result |
|---|---|---|---|---|---|
| ACEITUNAS | PR0004654 | 9,030 | Surface water | 1 | Below all study benchmarks |
| AGUADILLA | PR0003293 | 124,782 | Surface water | 14 | At or above a study benchmark |
| AGUAS BUENAS URBANO | PR0005046 | 13,233 | Surface water | 2 | Below all study benchmarks |
| AIBONITO LA PLATA | PR0004545 | 16,354 | Surface water | 4 | At or above a study benchmark |
| AIBONITO URBANO | PR0004955 | 5,580 | Surface water | 3 | At or above a study benchmark |
| ARECIBO URBANO | PR0002652 | 61,626 | Surface water | 11 | Below all study benchmarks |
| BAJADERO | PR0003222 | 3,402 | Ground water | 1 | Below all study benchmarks |
| BARCELONETA URBANO | PR0002722 | 16,404 | Surface water | 3 | Below all study benchmarks |
| BARRANQUITAS URBANO | PR0004605 | 3,538 | Surface water | 1 | Below all study benchmarks |
| BO. JACABOA- HIGUERO | PR0556075 | 70 | Ground water | 1 | Below all study benchmarks |
| CABO ROJO | PR0003373 | 20,356 | Surface water | 1 | Below all study benchmarks |
| CAGUAS NORTE | PR0005086 | 47,352 | Surface water | 2 | Below all study benchmarks |
| CAGUAS SUR | PR0005066 | 34,261 | Surface water | 1 | Below all study benchmarks |
| CAYEY URBANO | PR0004635 | 18,335 | Surface water | 1 | Below all study benchmarks |
| CEDRO ARRIBA | PR0005517 | 5,444 | Surface water | 1 | Below all study benchmarks |
| CERRILLOS | PR0004634 | 5,658 | Surface water | 1 | Below all study benchmarks |
| CIALES URBANO | PR0002752 | 4,841 | Surface water | 1 | Below all study benchmarks |
| CIDRA URBANO | PR0004695 | 34,424 | Surface water | 1 | At or above a study benchmark |
| CIENEGA | PR0003862 | 3,952 | Ground water | 2 | Below all study benchmarks |
| COAMO URBANO | PR0003914 | 4,603 | Surface water | 1 | Below all study benchmarks |
| COCOS | PR0004895 | 9,930 | Ground water | 6 | Below all study benchmarks |
| COMERIO URBANO | PR0004705 | 14,912 | Surface water | 3 | Below all study benchmarks |
| COQUI | PR0004915 | 6,237 | Ground water | 4 | Below all study benchmarks |
| COROZAL URBANO | PR0005487 | 6,162 | Surface water | 1 | Below all study benchmarks |
| COTTO LAUREL | PR0004524 | 12,979 | Surface water | 1 | Below all study benchmarks |
| DEPORTIVO | PR0004444 | 3,420 | Ground water | 2 | Below all study benchmarks |
| DORADO URBANO | PR0005607 | 37,244 | Surface water | 2 | Below all study benchmarks |
| EL ROSARIO | PR0003423 | 2,374 | Ground water | 1 | Below all study benchmarks |
| EL YUNQUE | PR0005296 | 68,114 | Surface water | 1 | Below all study benchmarks |
| EXPERIMENTAL | PR0004604 | 6,445 | Ground water | 5 | At or above a study benchmark |
| FAJARDO CEIBA | PR0005306 | 59,044 | Surface water | 1 | Below all study benchmarks |
| FLORIDA URBANO | PR0002732 | 10,405 | Ground water | 6 | Below all study benchmarks |
| GARROCHALES | PR0002782 | 7,465 | Ground water | 1 | Below all study benchmarks |
| GARZAS | PR0004584 | 3,354 | Surface water | 1 | Below all study benchmarks |
| GUANICA URBANO | PR0004074 | 6,881 | Ground water | 2 | Below all study benchmarks |
| GUAYAMA URBANO | PR0004745 | 37,076 | Surface water | 2 | Below all study benchmarks |
| GURABO URBANO | PR0005096 | 25,469 | Surface water | 2 | Below all study benchmarks |
| HATILLO-CAMUY | PR0002662 | 28,935 | Surface water | 1 | Below all study benchmarks |
| HORMIGUERO | PR0003383 | 10,587 | Ground water | 5 | Below all study benchmarks |
| ISABELA | PR0002672 | 49,937 | Surface water | 1 | Below all study benchmarks |
| JACAGUAS | PR0004534 | 4,261 | Ground water | 3 | At or above a study benchmark |
| JAGUAL | PR0005416 | 4,021 | Surface water | 1 | Below all study benchmarks |
| JAGUAS PESAS (POZAS) | PR0003802 | 4,699 | Surface water | 1 | Below all study benchmarks |
| JAYUYA URBANO | PR0002712 | 7,746 | Surface water | 1 | Below all study benchmarks |
| JUNCOS - CEIBA SUR | PR0005166 | 36,835 | Surface water | 3 | Below all study benchmarks |
| LA GRUA | PR0005496 | 3,578 | Ground water | 2 | Below all study benchmarks |
| LAGO GUAJATACA | PR0003772 | 10,018 | Surface water | 1 | Below all study benchmarks |
| LARES ESPINO | PR0003872 | 16,896 | Surface water | 1 | Below all study benchmarks |
| LARES URBANO | PR0002692 | 12,138 | Surface water | 1 | Below all study benchmarks |
| LAS BOCAS | PR0004945 | 11,022 | Surface water | 9 | At or above a study benchmark |
| LAS MARIAS | PR0003363 | 7,193 | Surface water | 1 | Below all study benchmarks |
| LAS PIEDRAS HUMACAO | PR0005376 | 38,897 | Surface water | 2 | Below all study benchmarks |
| LUQUILLO URBANO | PR0005316 | 9,001 | Surface water | 1 | Below all study benchmarks |
| MAGUAYO | PR0005597 | 30,235 | Surface water purchased | 1 | Below all study benchmarks |
| MANATI EAST | PR0003262 | 13,580 | Surface water | 3 | At or above a study benchmark |
| MAUNABO URBANO | PR0004815 | 9,380 | Surface water | 5 | At or above a study benchmark |
| MAYAGUEZ | PR0003283 | 152,342 | Surface water | 12 | Below all study benchmarks |
| METROPOLITANO | PR0002591 | 1,084,637 | Surface water | 5 | At or above a study benchmark |
| MOROVIS URBANO | PR0002762 | 20,927 | Surface water | 2 | Below all study benchmarks |
| MULAS | PR0556015 | 652 | Surface water | 1 | Below all study benchmarks |
| NEGROS | PR0005537 | 14,939 | Surface water | 1 | Below all study benchmarks |
| OROCOVIS URBANO | PR0004044 | 16,992 | Surface water | 2 | Below all study benchmarks |
| PATILLAS URBANO | PR0004835 | 32,222 | Surface water | 6 | At or above a study benchmark |
| PENUELAS | PR0004324 | 17,326 | Surface water | 3 | Below all study benchmarks |
| PIEDRAS BLANCAS | PR0004474 | 3,351 | Ground water | 1 | Below all study benchmarks |
| PLATA I Y II | PR0003296 | 3,978 | Ground water | 2 | Below all study benchmarks |
| PONCE URBANO | PR0003824 | 113,972 | Surface water | 23 | At or above a study benchmark |
| PUGNADO | PR0002972 | 3,591 | Ground water | 2 | Below all study benchmarks |
| QUEBRADA | PR0002872 | 9,377 | Surface water | 1 | Below all study benchmarks |
| QUEBRADILLAS URBANO | PR0002682 | 27,760 | Surface water | 2 | Below all study benchmarks |
| REGIONAL VILLALBA TOA VACA | PR0004664 | 34,259 | Surface water | 1 | Below all study benchmarks |
| RIO BLANCO,VIEQUES,CULEDRA | PR0005386 | 79,822 | Surface water | 2 | Below all study benchmarks |
| SABANA GRANDE, PR | PR0003333 | 25,832 | Surface water | 2 | Below all study benchmarks |
| SABANA HOYOS | PR0002822 | 15,948 | Surface water | 1 | Below all study benchmarks |
| SALINAS URBANO | PR0004885 | 8,977 | Ground water | 4 | At or above a study benchmark |
| SAN LORENZO URBANO | PR0005106 | 26,470 | Surface water | 1 | Below all study benchmarks |
| SAN SEBASTIAN | PR0003303 | 25,752 | Surface water | 1 | Below all study benchmarks |
| SANTA ISABEL | PR0003712 | 3,402 | Surface water | 1 | Below all study benchmarks |
| SANTA ISABEL URBANO | PR0003904 | 39,925 | Ground water | 9 | At or above a study benchmark |
| SANTANA | PR0002832 | 19,657 | Surface water | 2 | Below all study benchmarks |
| SUPERACUEDUCTO | PR0002000 | 25 | Surface water | 1 | Below all study benchmarks |
| U.S. ARMY, FORT BUCHANAN | PR0132051 | 6,411 | Surface water | 2 | Below all study benchmarks |
| UTUADO URBANO | PR0002702 | 13,070 | Surface water | 1 | Below all study benchmarks |
| VEGA BAJA URBANO | PR0002772 | 26,935 | Surface water | 3 | Below all study benchmarks |
| VEGUITAS GRIPINAS | PR0238082 | 130 | Surface water | 1 | Below all study benchmarks |
| YABUCOA URBANO | PR0005196 | 14,728 | Surface water | 1 | Below all study benchmarks |
| YAUCO | PR0004314 | 35,639 | Surface water | 2 | Below all study benchmarks |
How the count works
What is included
Each active community water system with enough required samples for a yearly average is counted once, even if it is linked with several ZIP codes. This does not mean every home was tested. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system. This page does not apply Puerto Rico's state-specific standards or determine compliance. Use the official state or territory drinking-water program for current regulatory information.