PFAS ("forever chemicals")
Perfluoroheptanoic acid in U.S. tap water
59 public water systems across 17 U.S. states report Perfluoroheptanoic acid in their annual Consumer Confidence Report. 3 sit at or above the federal limit.
What it is
Perfluoroheptanoic acid, a PFAS 'forever chemical.'
Why it's regulated
Monitored under EPA rules; persistent in the environment.
At or above the federal limit (3)
| Water system | Measured | vs. limit |
|---|---|---|
| Burbank, CA 2024 annual report | 0–13 ng/L | 4.3× the limit |
| Boonsboro Keedysville, MD 2024 annual report | 375–9 | 3.0× the limit |
| Pomona, CA 2024 annual report | 5 ng/L | 2.5× the limit |
Within the federal limit (29)
| Water system | Measured |
|---|---|
| Tempe, AZ 2024 annual report | 0.001 ug/L |
| Jersey City, NJ 2024 annual report | 1.1 ng/L |
| 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 |
| Dearborn, MI 2024 annual report | Not detected ug/L |
| Franklin, WI 2024 annual report | Not detected ug/L |
| Freedom District, MD 2024 annual report | Not detected ng/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 |
| Mobile, AL 2024 annual report | Not detected |
| 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 |
| Winston Salem, NC 2024 annual report | Not detected |
Frequently asked
+What is Perfluoroheptanoic acid?
Perfluoroheptanoic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
+What is the federal limit for Perfluoroheptanoic acid in drinking water?
The federal MCL for Perfluoroheptanoic acid 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 Perfluoroheptanoic acid over the federal limit?
3 of the 59 public water systems on The Water Map report Perfluoroheptanoic acid at or above its federal limit, spanning 17 U.S. states. The full list is on this page.
+How can I check if Perfluoroheptanoic acid 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 Perfluoroheptanoic acid.