Rhode Island 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 →
7 Rhode Island water systems serving 207,864 people had PFAS above a 2024 federal limit in EPA's final round of nationwide PFAS testing: 27% of the 26 Rhode Island systems tested, compared with 11% nationally.
Highest PFOA or PFOS averages in Rhode Island
- University of Rhode Island Water System South Kingstown · PFOA16 ppt
- Town of North Kingstown North Kingstown · PFOA7.65 ppt
- Westerly Water Department Westerly · PFOA7.5 ppt
- Kent County Water Authority West Greenwich · PFOA7.1 ppt
- South Kingstown-South Shore Water System South Kingstown · PFOA6.1 ppt
- Town of Cumberland Cumberland · PFOS5.45 ppt
- Kingston Water District South Kingstown · PFOA5.25 ppt
- North Tiverton Fire District Tiverton · PFOA2.27 ppt
- Narragansett Water Dept-North End Narragansett · PFOA2.15 ppt
- Woonsocket Water Division Woonsocket · PFOA1.45 ppt
Chart data as a table
| System | ppt |
|---|---|
| University of Rhode Island Water System · South Kingstown · PFOA | 16 |
| Town of North Kingstown · North Kingstown · PFOA | 7.65 |
| Westerly Water Department · Westerly · PFOA | 7.5 |
| Kent County Water Authority · West Greenwich · PFOA | 7.1 |
| South Kingstown-South Shore Water System · South Kingstown · PFOA | 6.1 |
| Town of Cumberland · Cumberland · PFOS | 5.45 |
| Kingston Water District · South Kingstown · PFOA | 5.25 |
| North Tiverton Fire District · Tiverton · PFOA | 2.27 |
| Narragansett Water Dept-North End · Narragansett · PFOA | 2.15 |
| Woonsocket Water Division · Woonsocket · PFOA | 1.45 |
Largest systems above a limit
| # | System | People served |
|---|---|---|
| 1 | Kent County Water Authority West Greenwich Above: PFOA | 94,107 |
| 2 | Westerly Water Department Westerly Above: PFOA, PFOS | 35,298 |
| 3 | Town of North Kingstown North Kingstown Above: PFOA, PFOS | 27,732 |
| 4 | Town of Cumberland Cumberland Above: PFOA, PFOS | 21,235 |
| 5 | University of Rhode Island Water System South Kingstown Above: PFOA, PFOS | 19,354 |
| 6 | South Kingstown-South Shore Water System South Kingstown Above: PFOA | 6,170 |
| 7 | Kingston Water District South Kingstown Above: PFOA | 3,968 |
Which limits were exceeded
| PFAS | Federal limit | Systems above it |
|---|---|---|
| PFOA 207,864 people | 4 ppt | 7 |
| PFOS 103,619 people | 4 ppt | 4 |
| PFHxS | 10 ppt | 0 |
| PFNA | 10 ppt | 0 |
| GenX (HFPO-DA) | 10 ppt | 0 |
| Hazard Index | 1 | 0 |
"–" 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.
Rhode Island has its own PFAS rules. 'PFAS6' MCL. Results >70 ppt require a do-not-drink notice within 24 hours. RIDOH must adopt federal-equivalent rules by 2028-04-26. Details. This report compares results with the federal limits only.
Data and how to cite it
- Download every Rhode Island 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, "Rhode Island PFAS results from EPA's final UCMR 5 data" (published Nov 14, 2026, EPA data file of Oct 15, 2026). https://tapwaterresults.com/pfas/rhode-island/
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 Rhode Island water systems have PFAS above the limit?
7 of the 26 Rhode Island community water systems EPA tested in 2023–2025 (27%) had at least one entry-point average above a 2024 federal PFAS limit. They serve 207,864 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 Rhode Island 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.