PFAS ("forever chemicals")
Perfluoroundecanoic acid (PFUnA) in U.S. tap water
29 public water systems across 11 U.S. states report Perfluoroundecanoic acid (PFUnA) in their annual Consumer Confidence Report. 1 sit at or above the federal limit.
What it is
Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.'
Why it's regulated
Monitored under EPA rules; persistent and bioaccumulative.
At or above the federal limit (1)
| Water system | Measured | vs. limit |
|---|---|---|
| Boonsboro Keedysville, MD 2024 annual report | 2058–8 | 4.0× the limit |
Within the federal limit (27)
| 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 |
| West Valley City, UT 2024 annual report | Not detected ug/L |
| Wilmington, NC 2024 annual report | Not detected ng/L |
Frequently asked
+What is Perfluoroundecanoic acid (PFUnA)?
Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
+What is the federal limit for Perfluoroundecanoic acid (PFUnA) in drinking water?
The federal MCL for Perfluoroundecanoic acid (PFUnA) is 1.8 . 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 Perfluoroundecanoic acid (PFUnA) over the federal limit?
1 of the 29 public water systems on The Water Map report Perfluoroundecanoic acid (PFUnA) at or above its federal limit, spanning 11 U.S. states. The full list is on this page.
+How can I check if Perfluoroundecanoic acid (PFUnA) 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 Perfluoroundecanoic acid (PFUnA).
See Perfluoroundecanoic acid (PFUnA) on the map
Color-coded by status across the whole country.
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