PFAS ("forever chemicals")
Perfluoroheptanesulfonic acid (PFHpS) in U.S. tap water
28 public water systems across 11 U.S. states report Perfluoroheptanesulfonic acid (PFHpS) in their annual Consumer Confidence Report. 1 sit at or above the federal limit.
What it is
Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.'
Why it's regulated
Monitored under EPA rules; persistent in the environment.
At or above the federal limit (1)
| Water system | Measured | vs. limit |
|---|---|---|
| Boonsboro Keedysville, MD 2024 annual report | 375–8 | 2.7× 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 |
| 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 Perfluoroheptanesulfonic acid (PFHpS)?
Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
+What is the federal limit for Perfluoroheptanesulfonic acid (PFHpS) in drinking water?
The federal MCL for Perfluoroheptanesulfonic acid (PFHpS) 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 Perfluoroheptanesulfonic acid (PFHpS) over the federal limit?
1 of the 28 public water systems on The Water Map report Perfluoroheptanesulfonic acid (PFHpS) at or above its federal limit, spanning 11 U.S. states. The full list is on this page.
+How can I check if Perfluoroheptanesulfonic acid (PFHpS) 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 Perfluoroheptanesulfonic acid (PFHpS).
See Perfluoroheptanesulfonic acid (PFHpS) on the map
Color-coded by status across the whole country.
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