Data study
PFAS in America's tap water: the systems reporting levels above the EPA's new limits
By PurityRadar · Published July 2026 · Data: EPA UCMR5 (2023–2025) & SDWIS
The EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR5) required water systems across the country to test for PFAS between 2023 and 2025 — the most comprehensive look at “forever chemicals” in U.S. tap water ever assembled. In 2024, the EPA set its first-ever enforceable limits for six of them.
Comparing the two, PurityRadar found that 1,673 systems — serving a combined 80 million people — reported at least one compound above its new limit. Of the 3,539 systems with PFAS results in our dataset, that is nearly one in two.
Which chemicals, and how many systems
| PFAS compound | EPA limit | Systems over the limit |
|---|---|---|
| PFOS | 4 ppt | 1,279 |
| PFOA | 4 ppt | 1,228 |
| PFHxS | 10 ppt | 166 |
| PFNA | 10 ppt | 19 |
| GenX (HFPO-DA) | 10 ppt | 16 |
PFOS and PFOA — the two most-studied and most-restricted PFAS — account for the large majority of exceedances.
The largest systems reporting PFAS above an EPA limit
Ranked by population served. Values are the highest reported result for each compound, in parts per trillion (ppt); the EPA limit for PFOA and PFOS is 4 ppt. Values over the limit are shown in red.
| Water system | Serves | People | PFOA | PFOS |
|---|---|---|---|---|
| MDWASA - MAIN SYSTEM | MIAMI, FL | 2.38M | 14 | 33 |
| PHILADELPHIA WATER DEPARTMENT | PHILADELPHIA, PA | 1.6M | 8.1 | 6 |
| DALLAS WATER UTILITY | DALLAS, TX | 1.36M | 6.3 | 5.1 |
| COLUMBUS PUBLIC WATER SYSTEM | COLUMBUS, OH | 1.31M | 5.3 | — |
| FAIRFAX COUNTY WATER AUTHORITY | HERNDON, VA | 1.12M | 7.4 | 5.7 |
| CITY OF AUSTIN WATER & WASTEWATER | AUSTIN, TX | 1.12M | — | 4.8 |
| SUFFOLK COUNTY WATER AUTHORITY | HAUPPAUGE, NY | 1.1M | 6.5 | 17.4 |
| METROPOLITANO | SAN JUAN, PR | 1.08M | 10.9 | 7.8 |
| SAN JOSE WATER | SAN JOSE, CA | 1.04M | — | 6.2 |
| CITY OF FORT WORTH | FORT WORTH, TX | 956k | 8.3 | 7.3 |
| AQUA PA MAIN SYSTEM | BRYN MAWR, PA | 823k | 12.6 | 9.2 |
| VEOLIA WATER NEW JERSEY HACKENSACK | HAWORTH, NJ | 793k | 14 | 8.1 |
| LOUISVILLE WATER COMPANY | LOUISVILLE, KY | 765k | 7.5 | — |
| CINCINNATI PUBLIC WATER SYSTEM | CINCINNATI, OH | 750k | — | 6.1 |
| EL PASO WATER UTILITIES PUBLIC SERVICE B | EL PASO, TX | 747k | — | 8.5 |
| CITY OF TAMPA WATER DEPARTMENT | TAMPA, FL | 734k | 4.6 | 6.9 |
| RALEIGH, CITY OF | RALEIGH, NC | 640k | — | 5.6 |
| PALM BEACH COUNTY WATER UTILITIES | WEST PALM BEACH, FL | 619k | 9 | 20 |
| NJ AMERICAN WATER - RARITAN | BRTIDGEWATER, NJ | 615k | 7.5 | 6.8 |
| CITY OF FRESNO | FRESNO, CA | 546k | 16 | 30 |
Where it's most common
| State | Systems over a limit |
|---|---|
| California | 161 |
| Florida | 152 |
| New Jersey | 151 |
| North Carolina | 111 |
| Pennsylvania | 109 |
| Massachusetts | 106 |
| Texas | 103 |
| Alabama | 77 |
| South Carolina | 69 |
| Ohio | 57 |
| New York | 50 |
| Georgia | 42 |
Exceedances are widespread, not confined to one region. See the full PFAS-by-state map.
Beyond PFAS: the lowest overall scores among large systems
PurityRadar assigns every system a transparent 0–100 score combining EPA violation records with how measured contaminants compare to their limits. Among the 487 systems serving 100,000+ people, most score well (352 rate “Excellent”), but 33 fall into the “Action needed” band (below 45) — driven largely by multiple contaminant exceedances, not violations.
| Water system | Serves | Score |
|---|---|---|
| CITY OF ABILENE | ABILENE, TX | 7 |
| EMERALD COAST UTILITIES AUTHORITY (ECUA) | PENSACOLA, FL | 9 |
| CITY OF FORT WORTH | FORT WORTH, TX | 21 |
| CITY OF ORANGE | ORANGE, CA | 26 |
| CITY OF GARDEN GROVE | GARDEN GROVE, CA | 28 |
| CITY OF CLOVIS | CLOVIS, CA | 31 |
| HIALEAH, CITY OF | HIALEAH, FL | 32 |
| FAYETTEVILLE PUBLIC WORKS COMM | FAYETTEVILLE, NC | 32 |
| PEMBROKE PINES, CITY OF | PEMBROKE PINES, FL | 32 |
| BOYNTON BEACH PWS | BOYNTON BEACH, FL | 32 |
| HESPERIA WD | HESPERIA, CA | 32 |
| AUGUSTA-RICHMOND CO WS | AUGUSTA, GA | 33 |
| CITY OF SACRAMENTO MAIN | SACRAMENTO, CA | 34 |
| CITY OF SANTA ANA | SANTA ANA, CA | 34 |
| COLUMBUS | COLUMBUS, GA | 34 |
This composite ranking reflects PurityRadar's methodology and blends multiple data sources — see the methodology.
What this means for you
- A number over the new limit isn't cause for panic. The limits are new, the compliance deadline is 2029, and levels are measured at the treatment plant during a monitoring window — not necessarily what's at your tap today.
- If you want certainty, read your utility's annual Consumer Confidence Report (CCR), ask them directly about PFAS, or use a state-certified lab to test your tap.
- If you choose to filter, certified reverse-osmosis and some activated-carbon filters are rated to reduce PFAS.
Methodology & caveats
PFAS data: EPA UCMR5 (Fifth Unregulated Contaminant Monitoring Rule), 2023–2025 monitoring. “Over the limit” means a system reported at least one result above the applicable EPA final limit; we use each system's highest reported value per compound. EPA limits: from the EPA's April 2024 PFAS regulation — PFOA and PFOS at 4 ppt; PFHxS, PFNA and HFPO-DA (GenX) at 10 ppt; compliance required by 2029. Registry & violations: EPA SDWIS; population is SDWIS “population served,” and because some wholesale systems overlap, combined population served is not a count of unique individuals. Composite score: PurityRadar's transparent methodology (details). Snapshot: July 2026.
This is general information from public records — not medical or legal advice, and not a substitute for your utility's official reporting. Always confirm with your water provider. Source: EPA UCMR5.
Cite this study: PurityRadar analysis of EPA UCMR5 and SDWIS data, July 2026. Data & methodology: purityradar.com/research/pfas-above-epa-limits