Puerto Rico PFAS results from EPA's final data
Report published Nov 14, 2026 · EPA UCMR 5 final data file of Oct 15, 2026 (samples collected 2023–2025) · Method · National results →
15 Puerto Rico water systems serving 1.5 million people had PFAS above a 2024 federal limit in EPA's final round of nationwide PFAS testing: 16% of the 96 Puerto Rico systems tested, compared with 11% nationally.
Highest PFOA or PFOS averages in Puerto Rico
- PRASA – Aibonito la Plata Aibonito · PFOS25.6 ppt
- PRASA – Ponce Urbano Ponce · PFOS25.3 ppt
- PRASA – Experimental Juana Díaz · PFOA17.4 ppt
- PRASA – Jacaguas Juana Díaz · PFOS12 ppt
- PRASA – Salinas Urbano Salinas · PFOS8.25 ppt
- PRASA – Cidra Urbano Cidra · PFOS7.73 ppt
- PRASA – Patillas Urbano Patillas · PFOS7.15 ppt
- PRASA – Las Bocas Barranquitas · PFOS6.9 ppt
- PRASA Metropolitano San Juan · PFOS6.25 ppt
- PRASA – Aruz Juana Díaz · PFOS5.4 ppt
- PRASA – Aguadilla Aguadilla · PFOS5.25 ppt
- PRASA – Santa Isabel Urbano Santa Isabel · PFOS5.15 ppt
- PRASA – Manati East Manatí · PFOS4.63 ppt
- PRASA – Maunabo Urbano Maunabo · PFOS4.4 ppt
- PRASA – Aibonito Urbano Aibonito · PFOS4.3 ppt
Chart data as a table
| System | ppt |
|---|---|
| PRASA – Aibonito la Plata · Aibonito · PFOS | 25.6 |
| PRASA – Ponce Urbano · Ponce · PFOS | 25.3 |
| PRASA – Experimental · Juana Díaz · PFOA | 17.4 |
| PRASA – Jacaguas · Juana Díaz · PFOS | 12 |
| PRASA – Salinas Urbano · Salinas · PFOS | 8.25 |
| PRASA – Cidra Urbano · Cidra · PFOS | 7.73 |
| PRASA – Patillas Urbano · Patillas · PFOS | 7.15 |
| PRASA – Las Bocas · Barranquitas · PFOS | 6.9 |
| PRASA Metropolitano · San Juan · PFOS | 6.25 |
| PRASA – Aruz · Juana Díaz · PFOS | 5.4 |
| PRASA – Aguadilla · Aguadilla · PFOS | 5.25 |
| PRASA – Santa Isabel Urbano · Santa Isabel · PFOS | 5.15 |
| PRASA – Manati East · Manatí · PFOS | 4.63 |
| PRASA – Maunabo Urbano · Maunabo · PFOS | 4.4 |
| PRASA – Aibonito Urbano · Aibonito · PFOS | 4.3 |
Largest systems above a limit
| # | System | People served |
|---|---|---|
| 1 | PRASA Metropolitano San Juan Above: PFOS | 1.1 million |
| 2 | PRASA – Aguadilla Aguadilla Above: PFOS | 124,782 |
| 3 | PRASA – Ponce Urbano Ponce Above: PFOS, PFHxS, Hazard Index | 113,972 |
| 4 | PRASA – Santa Isabel Urbano Santa Isabel Above: PFOS | 39,925 |
| 5 | PRASA – Cidra Urbano Cidra Above: PFOS | 34,424 |
| 6 | PRASA – Patillas Urbano Patillas Above: PFOS | 32,222 |
| 7 | PRASA – Aibonito la Plata Aibonito Above: PFOS | 16,354 |
| 8 | PRASA – Manati East Manatí Above: PFOS | 13,580 |
| 9 | PRASA – Las Bocas Barranquitas Above: PFOS | 11,022 |
| 10 | PRASA – Maunabo Urbano Maunabo Above: PFOS | 9,380 |
All 15 Puerto Rico systems above a limit
Every Puerto Rico community water system whose UCMR 5 results averaged above a 2024 federal PFAS limit, largest first. Systems that were not tested are not listed: not tested is not the same as not detected.
Full list: 15 systems, largest first
| System | People served |
|---|---|
| PRASA Metropolitano San Juan Above: PFOS | 1.1 million |
| PRASA – Aguadilla Aguadilla Above: PFOS | 124,782 |
| PRASA – Ponce Urbano Ponce Above: PFOS, PFHxS, Hazard Index | 113,972 |
| PRASA – Santa Isabel Urbano Santa Isabel Above: PFOS | 39,925 |
| PRASA – Cidra Urbano Cidra Above: PFOS | 34,424 |
| PRASA – Patillas Urbano Patillas Above: PFOS | 32,222 |
| PRASA – Aibonito la Plata Aibonito Above: PFOS | 16,354 |
| PRASA – Manati East Manatí Above: PFOS | 13,580 |
| PRASA – Las Bocas Barranquitas Above: PFOS | 11,022 |
| PRASA – Maunabo Urbano Maunabo Above: PFOS | 9,380 |
| PRASA – Salinas Urbano Salinas Above: PFOS | 8,977 |
| PRASA – Experimental Juana Díaz Above: PFOA, PFOS | 6,445 |
| PRASA – Aibonito Urbano Aibonito Above: PFOS | 5,580 |
| PRASA – Aruz Juana Díaz Above: PFOS | 5,105 |
| PRASA – Jacaguas Juana Díaz Above: PFOS | 4,261 |
The same list, with PFOA and PFOS averages, is in the data download.
Which limits were exceeded
| PFAS | Federal limit | Systems above it |
|---|---|---|
| PFOA 6,445 people | 4 ppt | 1 |
| PFOS 1.5 million people | 4 ppt | 15 |
| PFHxS 113,972 people | 10 ppt | 1 |
| PFNA | 10 ppt | 0 |
| GenX (HFPO-DA) | 10 ppt | 0 |
| Hazard Index 113,972 people | 1 | 1 |
"–" in the table above means not detected. A system can be above more than one limit. EPA proposed in May 2026 to rescind the PFHxS, PFNA, GenX and Hazard Index limits. That proposal is not final.
Data and how to cite it
- Download every Puerto Rico water system as CSV (PFOA and PFOS averages, systems above a limit, lead, violations).
- EPA's source file: UCMR 5 occurrence data.
Suggested citation:
Tap Water Results, "Puerto Rico PFAS results from EPA's final UCMR 5 data" (published Nov 14, 2026, EPA data file of Oct 15, 2026). https://tapwaterresults.com/pfas/puerto-rico/
You're welcome to quote and republish these figures with a link back. Questions from reporters: see contact.
Method
For each system we average each entry point's UCMR 5 results (non-detects count as zero, complete sets of samples only) and compare the highest entry-point average with the 2024 federal limit, using EPA's rounding. This is how EPA compares UCMR 5 results to the limits in its own data summary, and our national counts match EPA's published table within 2% (how we check). Results are monitoring data from 2023–2025, not compliance determinations, and treatment installed since then is not reflected. Full method.
Questions
How many Puerto Rico water systems have PFAS above the limit?
15 of the 96 Puerto Rico community water systems EPA tested in 2023–2025 (16%) had at least one entry-point average above a 2024 federal PFAS limit. They serve 1.5 million people. Nationally the share is 11%.
Are these systems violating the law?
Not yet. Systems have until 2029 to meet the 2024 limits, and EPA has proposed moving the PFOA and PFOS deadline to 2031 and rescinding the other limits. EPA's UCMR 5 results are monitoring data and do not determine compliance.
Which systems were tested?
EPA's UCMR 5 tested every community water system serving more than 3,300 people and a representative sample of smaller ones. Systems that were not tested have no federal result, which is not the same as having no PFAS.
All Puerto Rico water systems → · National results → · PFAS results for every state →
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.