PFAS · Puerto Rico
PFAS in Puerto Rico drinking water: EPA’s final survey results
EPA’s national PFAS survey (UCMR 5) tested 96 of the community water systems that serve homes in Puerto Rico. 37 found at least one of 29 PFAS above the laboratory reporting level, and 15 had a PFOA or PFOS sampling-location yearly average at or above EPA’s 4.0 ppt limit. Samples were collected from January 2023 to January 2026.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
PFOS was the compound Puerto Rico community systems found most often: 25 of 96 tested systems measured it above the reporting level. Across the country, 35% of surveyed community systems found at least one PFAS; in Puerto Rico the share is 39%. The largest Puerto Rico system with a detection, Metropolitano, serves 1,084,637 people and found 8 of the 29 compounds.
Which PFAS were found most often in Puerto Rico
Each row counts the Puerto Rico community water systems where that compound was measured above the reporting level at least once. A detection is a measurement, not a violation: most of these compounds have no federal limit.
| Compound | Systems where found | Systems tested | Share |
|---|---|---|---|
| PFOS | 25 | 96 | 26% |
| PFBA | 16 | 96 | 17% |
| PFBS | 15 | 96 | 16% |
| PFPeA | 15 | 96 | 16% |
| PFHxA | 10 | 96 | 10% |
| PFHxS | 7 | 96 | 7% |
| PFOA | 5 | 96 | 5% |
| 6:2 FTS | 3 | 96 | 3% |
| PFDA | 3 | 96 | 3% |
| PFDoA | 3 | 96 | 3% |
| 8:2 FTS | 1 | 96 | 1% |
| PFHpA | 1 | 96 | 1% |
Puerto Rico systems with the most PFAS found
The 10 surveyed community water systems that found the most different PFAS, with PFOA and PFOS compared to EPA’s 4.0 ppt limits on the yearly average at the highest sampling location. Larger systems come first when counts tie.
| Water system | People served | PFAS found (of 29) | PFOA | PFOS |
|---|---|---|---|---|
| Metropolitano PR0002591 | 1,084,637 | 8 | 2.7 ppt below the MCL | 6.3 ppt at or above the MCL |
| Ponce Urbano PR0003824 | 113,972 | 8 | 2.6 ppt below the MCL | 25.3 ppt at or above the MCL |
| Experimental PR0004604 | 6,445 | 7 | 17.5 ppt at or above the MCL | 5.4 ppt at or above the MCL |
| Aibonito la Plata PR0004545 | 16,354 | 6 | — not detected above the reporting level | 25.6 ppt at or above the MCL |
| Aguadilla PR0003293 | 124,782 | 5 | — not detected above the reporting level | 5.2 ppt at or above the MCL |
| Cidra Urbano PR0004695 | 34,424 | 5 | — not detected above the reporting level | 7.7 ppt at or above the MCL |
| Salinas Urbano PR0004885 | 8,977 | 5 | — not detected above the reporting level | 8.3 ppt at or above the MCL |
| Santa Isabel Urbano PR0003904 | 39,925 | 4 | — not detected above the reporting level | 5.2 ppt at or above the MCL |
| Patillas Urbano PR0004835 | 32,222 | 4 | — not detected above the reporting level | 7.2 ppt at or above the MCL |
| Gurabo Urbano PR0005096 | 25,469 | 4 | — not detected above the reporting level | 1.1 ppt below the MCL |
Counties with the most systems that found PFAS
- Juana Díaz Municipio 3 of 3 surveyed systems
- Ponce Municipio 2 of 4 surveyed systems
- Dorado Municipio 2 of 2 surveyed systems
- Vega Baja Municipio 2 of 2 surveyed systems
- Aibonito Municipio 2 of 2 surveyed systems
- Bayamón Municipio 1 of 3 surveyed systems
- San Juan Municipio 1 of 2 surveyed systems
- Toa Alta Municipio 1 of 2 surveyed systems