PFAS ("forever chemicals")
Perfluoropentanoic acid in U.S. tap water
123 public water systems across 26 U.S. states report Perfluoropentanoic acid in their annual Consumer Confidence Report. 18 sit at or above the federal limit.
What it is
Perfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.'
Why it's regulated
Monitored under EPA rules; persistent in the environment.
At or above the federal limit (18)
| Water system | Measured | vs. limit |
|---|---|---|
| New Braunfels, TX 2024 annual report | 2024 | 674.7× the limit |
| Burbank, CA 2024 annual report | 0–54 ng/L | 18.0× the limit |
| Tampa, FL 2024 annual report | 0.0075 ug/L | 2.5× the limit |
| Jersey City, NJ 2024 annual report | 3.8 ng/L | 1.9× the limit |
| Pomona, CA 2024 annual report | 0–5.5 ng/L | 1.8× the limit |
| City of Hampton, VA 2024 annual report | 3.6 ng/L | 1.8× the limit |
| City of Newport News, VA 2025 annual report | 3.6 ng/L | 1.8× the limit |
| City of Poquoson, VA 2025 annual report | 3.6 ng/L | 1.8× the limit |
| City of Poquoson, VA 2024 annual report | 3.6 ng/L | 1.8× the limit |
| Hampton, VA 2025 annual report | 3.6 ng/L | 1.8× the limit |
| James City County, VA 2025 annual report | 2.5–3.6 ng/L | 1.8× the limit |
| James City County, VA 2024 annual report | 3.6 ng/L | 1.8× the limit |
| Newport News, VA 2024 annual report | 3.6 ng/L | 1.8× the limit |
| York County, VA 2024 annual report | 3.6 ng/L | 1.8× the limit |
| York County, VA 2025 annual report | 3.6 ng/L | 1.8× the limit |
| Boonsboro Keedysville, MD 2024 annual report | 3.2 ng/L | 1.1× the limit |
| San Antonio, TX 2023 annual report | 0.0032 ug/L | 1.1× the limit |
| City of Baltimore, MD 2024 annual report | 3 | 1.0× the limit |
Within the federal limit (27)
| Water system | Measured |
|---|---|
| Gilbert, AZ 2024 annual report | 7 |
| Tempe, AZ 2024 annual report | 0.002 ug/L |
| Chandler, AZ 2024 annual report | 0.16 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 |
| Dearborn, MI 2024 annual report | Not detected ug/L |
| El Monte, CA 2024 annual report | Not detected ng/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 |
| 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 |
| 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 |
Frequently asked
+What is Perfluoropentanoic acid?
Perfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
+What is the federal limit for Perfluoropentanoic acid in drinking water?
The federal MCL for Perfluoropentanoic 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 Perfluoropentanoic acid over the federal limit?
18 of the 123 public water systems on The Water Map report Perfluoropentanoic acid at or above its federal limit, spanning 26 U.S. states. The full list is on this page.
+How can I check if Perfluoropentanoic 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 Perfluoropentanoic acid.