PFAS ("forever chemicals")
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) in U.S. tap water
28 public water systems across 10 U.S. states report 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) in their annual Consumer Confidence Report. 1 sit at or above the federal limit.
What it is
11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound.
Why it's regulated
Monitored under EPA rules as part of broad PFAS surveillance.
At or above the federal limit (1)
| Water system | Measured | vs. limit |
|---|---|---|
| Boonsboro Keedysville, MD 2024 annual report | 763051–9 | 1.8× the limit |
Within the federal limit (26)
| Water system | Measured |
|---|---|
| Albuquerque, NM 2024 annual report | Not detected |
| Brown Deer, WI 2024 annual report | Not detected ug/L |
| Butler, WI 2024 annual report | Not detected ug/L |
| Calvert Manor, MD 2024 annual report | Not detected |
| Chandler, AZ 2024 annual report | 0 ng/L |
| Dallas, TX 2024 annual report | Not detected ng/L |
| Dearborn, MI 2024 annual report | Not detected ug/L |
| Franklin, WI 2024 annual report | Not detected ug/L |
| Greendale, WI 2024 annual report | Not detected ug/L |
| Greenfield, WI 2024 annual report | Not detected ug/L |
| Hales Corners, WI 2024 annual report | Not detected ug/L |
| Menomonee Falls, WI 2024 annual report | Not detected ug/L |
| Mequon, WI 2024 annual report | Not detected ug/L |
| Milwaukee, WI 2024 annual report | Not detected ug/L |
| New Berlin, WI 2024 annual report | Not detected ug/L |
| Pasadena, CA 2023 annual report | Not detected ug/L |
| Salem, OR 2023 annual report | Not detected ug/L |
| Santa Clarita, CA 2024 annual report | Not detected ug/L |
| Shorewood, WI 2024 annual report | Not detected ug/L |
| St. Francis, WI 2024 annual report | Not detected ug/L |
| Thiensville, WI 2024 annual report | Not detected ug/L |
| Tracy, CA 2024 annual report | Not detected |
| Waukesha, WI 2024 annual report | Not detected ug/L |
| Wauwatosa, WI 2024 annual report | Not detected ug/L |
| West Allis, WI 2024 annual report | Not detected ug/L |
| Wilmington, NC 2024 annual report | Not detected ng/L |
Frequently asked
+What is 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)?
11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound. Monitored under EPA rules as part of broad PFAS surveillance.
+What is the federal limit for 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) in drinking water?
The federal MCL for 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) is 1.7 . The EPA enforces this against the regulated reporting statistic (typically a running annual average or 90th percentile), not a single-sample spike.
+How many U.S. water systems have 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) over the federal limit?
1 of the 28 public water systems on The Water Map report 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) at or above its federal limit, spanning 10 U.S. states. The full list is on this page.
+How can I check if 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) is in my city's tap water?
Search your city on The Water Map (https://www.thewatermap.com/) or browse the list on this page. Every U.S. public water utility is required to publish an annual Consumer Confidence Report that lists every contaminant it measured, including 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS).
See 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) on the map
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