PFAS above EPA’s limit at 12 of the 50 largest US water systems
Published 20 Oct 2026 · VerifiedFilter analysis of EPA’s final UCMR 5 dataset (file dated 15 Oct 2026)
EPA tested the drinking water of every large US water system for 29 PFAS between 2023 and 2025, and released the final results in August 2026. We checked the 50 systems that serve the most people. At 12 of them, at least one sampling point averaged above EPA’s limit of 4.0 parts per trillion (ng/L) for PFOA or PFOS. Together those 12 systems serve about 12.8 million people.
Key findings
- 12 of 50 systems had a sampling point averaging above the PFOA or PFOS limit. 32 of the 49 systems with results found at least one PFAS.
- Highest averages: PFOS 31.45 ng/L at a Miami-Dade County sampling point, PFOS 19 ng/L at a Palm Beach County sampling point and PFOA 13 ng/L at a Bergen and Hudson counties sampling point, against a limit of 4.0.
- This is not a violation. UCMR 5 is screening data. Utilities must meet the PFAS limits by 2029, judged on running annual averages, and EPA has proposed letting them ask for until 2031 (not final).
The 12 systems
Highest sampling-point average for each chemical, and how many of the system’s sampling points averaged above 4.0 ng/L. A dash means no sampling point averaged above the limit for that chemical. Ranked by people served.
| # | Water system | People served | PFOA (ng/L) | PFOS (ng/L) | Points above / tested | Tested |
|---|---|---|---|---|---|---|
| 7 | Miami-Dade CountyMiami-Dade Water and Sewer (main system), FL | 2,377,460 | 12.35 | 31.45 | 3 / 4 | Nov 2023 – May 2024 |
| 11 | PhiladelphiaPhiladelphia Water Department, PA | 1,600,000 | 7.35 | 5.05 | 2 / 3 | Jan 2024 – Oct 2024 |
| 21 | Fairfax CountyFairfax Water (Fairfax County Water Authority), VA | 1,121,613 | 4.63 | – | 1 / 6 | Mar 2024 – Feb 2025 |
| 24 | Suffolk County, Long IslandSuffolk County Water Authority, NY | 1,100,000 | 6.05 | 12.1 | 7 / 242 | Jan 2023 – Sep 2025 |
| 26 | San Juan metro areaPRASA Metropolitano system, PR | 1,084,637 | – | 6.25 | 2 / 5 | Apr 2024 – Jan 2025 |
| 29 | Fort WorthCity of Fort Worth, TXAlso above: PFHxS, PFAS hazard index (limits EPA proposed to drop) | 955,900 | 5.9 | 6.17 | 2 / 5 | Jan 2023 – Jan 2024 |
| 33 | Philadelphia suburbsAqua Pennsylvania (main system), PA | 822,600 | 11.8 | 8.9 | 13 / 19 | Feb 2024 – Dec 2024 |
| 35 | CincinnatiGreater Cincinnati Water Works, OH | 800,000 | – | 5.15 | 1 / 2 | May 2023 – Feb 2024 |
| 36 | Bergen and Hudson countiesVeolia Water New Jersey (Hackensack system), NJ | 792,713 | 13 | 6.3 | 3 / 3 | Feb 2024 – Feb 2025 |
| 38 | El PasoEl Paso Water, TX | 747,168 | – | 6.4 | 1 / 27 | Jul 2023 – May 2026 |
| 40 | TampaCity of Tampa Water Department, FL | 733,886 | – | 5.67 | 1 / 2 | Jan 2023 – Sep 2025 |
| 45 | Palm Beach CountyPalm Beach County Water Utilities, FL | 671,114 | 8.15 | 19 | 2 / 4 | Nov 2024 – Aug 2025 |
What this does and does not mean
- A sampling point is not every tap. Large systems have many sources. In Suffolk County, for example, a few of 242 sampling points were above the limit. Your tap may get water from a source that tested well below it. Each system page lists every sampling point.
- The results are from 2023–2025. Some utilities may have added treatment since. Your utility’s latest annual water quality report is the newest word, and from 2027 it must list your PFAS levels.
- The limit is new. EPA set PFOA and PFOS limits of 4.0 ng/L in April 2024. On 20 May 2026 EPA proposed keeping them, letting systems ask for until 2031, and dropping the limits for four other PFAS. Those proposals are not final.
If you live in one of these areas
- Type your ZIP code to see which system serves you and every result EPA found there.
- To lower PFOA and PFOS at home, look for a filter whose certification listing covers them (NSF/ANSI 53 or 58). Start with the cheapest certified PFAS filters and whether reverse osmosis removes PFAS.
- Read PFOA and PFOS limits explained and how to read your water quality report.
How we counted
The 50 systems are the largest active community water systems by people served in EPA’s Safe Drinking Water Information System. Results are EPA’s final UCMR 5 occurrence data, compared with the limits the way EPA’s own UCMR 5 data summary does: each sampling point with a full set of samples is averaged, results below the reporting level count as zero, and the average is rounded to the limit’s significant digits. Limits are from 40 CFR 141.61(c). Full details are on our methodology page.
Download the data
Download the table as CSV (12 rows, one per system). You are free to use it with credit: “Source: VerifiedFilter analysis of EPA UCMR 5 data.”
For reporters
Questions about the data or the method: hello@verifiedfilter.com. We do not test water or filters; every number here comes from EPA’s public records and links back to them.