U.S. Cities Where PFAS Exceeds the 2024 Federal Limit
25 of 746 city reports shown, ranked by PFOS, highest monitored result, from public EPA records (EPA UCMR5 (2024), released Jan 2026). It ranks the published record, not which water is safest.
Emmaus Borough Public Water tops this list in 2026
Emmaus Borough Public Water is first, at 153.0 ng/L (PFOS, highest monitored result). City of Grand Prairie (82.0 ng/L), City of Oxford (72.2 ng/L), Irondale Water System (59.4 ng/L) and Lafayette (56.0 ng/L) follow. Lantana Water Treatment Plant (35.7 ng/L) and Tarpon Springs Water System (36.9 ng/L) are last on this list.
All 25 ranked water systems
- 1Emmaus Borough Public WaterEmmaus, PAMonitored in the 2024 federal UCMR5 round153.0 ng/L
- 2City of Grand PrairieGrand Prairie, TXMonitored in the 2024 federal UCMR5 round82.0 ng/L
- 3City of OxfordOxford, MSMonitored in the 2024 federal UCMR5 round72.2 ng/L
- 4Irondale Water SystemIrondale, ALMonitored in the 2024 federal UCMR5 round59.4 ng/L
- 5LafayetteLaFayette, GAMonitored in the 2024 federal UCMR5 round56.0 ng/L
- 6City of TempeTempe, AZMonitored in the 2024 federal UCMR5 round55.8 ng/L
- 7Moses Lake City ofMoses Lake, WAMonitored in the 2024 federal UCMR5 round52.2 ng/L
- 8Broken Arrow Municipal AuthorityBroken Arrow, OKMonitored in the 2024 federal UCMR5 round51.3 ng/L
- 9Augusta-Richmond Co WsAugusta, GAMonitored in the 2024 federal UCMR5 round51.0 ng/L
- 10Dartmouth Water DivisionDartmouth, MAMonitored in the 2024 federal UCMR5 round50.6 ng/L
- 11Elko City ofElko, NVMonitored in the 2024 federal UCMR5 round46.0 ng/L
- 12North Miami, City ofNorth Miami, FLMonitored in the 2024 federal UCMR5 round45.0 ng/L
- 13City of AtwaterAtwater, CAMonitored in the 2024 federal UCMR5 round45.0 ng/L
- 14Downey - City, Water Dept.Downey, CAMonitored in the 2024 federal UCMR5 round44.0 ng/L
- 15Payson Town ofPayson, AZMonitored in the 2024 federal UCMR5 round42.2 ng/L
- 16City of Sacramento MainSacramento, CAMonitored in the 2024 federal UCMR5 round41.4 ng/L
- 17City of ClovisClovis, CAMonitored in the 2024 federal UCMR5 round41.0 ng/L
- 18Liberty Water Rio RicoRio Rico, AZMonitored in the 2024 federal UCMR5 round40.9 ng/L
- 19Palm Springs, Village ofPalm Springs, FLMonitored in the 2024 federal UCMR5 round39.0 ng/L
- 20Ocala, City of (2 Wtps)Ocala, FLMonitored in the 2024 federal UCMR5 round39.0 ng/L
- 21Mdwasa/Rex UtilitiesMdwasa/rex, FLMonitored in the 2024 federal UCMR5 round37.4 ng/L
- 22Natick Water and Sewer DivisionNatick, MAMonitored in the 2024 federal UCMR5 round37.3 ng/L
- 23Lauderhill, City ofLauderhill, FLMonitored in the 2024 federal UCMR5 round37.0 ng/L
- 24Tarpon Springs Water SystemTarpon Springs, FLMonitored in the 2024 federal UCMR5 round36.9 ng/L
- 25Lantana Water Treatment PlantLantana, FLMonitored in the 2024 federal UCMR5 round35.7 ng/L
Marker: 4.0 ng/L limit. The top 25 of 746 city reports are listed. Shown: the highest monitored PFOS results among cities with a PFAS page. Additional cities also had a PFOS sample above the limit.
How this snapshot is built
- How this snapshot is built
From EPA UCMR5 (2024) occurrence data, community water systems are ranked by their highest reported PFOS result against the 4.0 ng/L federal maximum. Only systems with a published PFAS finding and a city report are listed.
- Reading the order
Figures are monitored public-system results for the stated period, not necessarily current treated water. Utilities may treat before delivery. Each figure is one EPA sample. EPA's 2024 limits are judged on a yearly average, and water systems have until 2029 to meet them, so a single sample is not a violation, and it is not an individual health verdict.
- Exclusions
The top 25 of 746 city reports are shown. Shown: the highest monitored PFOS results among cities with a PFAS page. Additional cities also had a PFOS sample above the limit.
Comparable does not mean complete.
This ranking compares water systems on one measure. It never replaces a full system report, a city-resolution check, or a certified household test, and missing monitoring is excluded, never scored as favourable.