PFAS ("forever chemicals")
Perfluorohexanoic acid in U.S. tap water
134 public water systems across 26 U.S. states report Perfluorohexanoic acid in their annual Consumer Confidence Report. 17 sit at or above the federal limit.
What it is
Perfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.'
Why it's regulated
Monitored under EPA rules; persistent and widely detected.
At or above the federal limit (17)
| Water system | Measured | vs. limit |
|---|---|---|
| New Braunfels, TX 2024 annual report | 2024 | 674.7× the limit |
| Burbank, CA 2024 annual report | 0–87 ng/L | 29.0× the limit |
| Pomona, CA 2024 annual report | 0–5 ng/L | 2.5× the limit |
| Boonsboro Keedysville, MD 2024 annual report | 7.4 ng/L | 2.5× the limit |
| Tampa, FL 2024 annual report | 0.0056 ug/L | 1.9× the limit |
| Jersey City, NJ 2024 annual report | 3.7 ng/L | 1.9× the limit |
| City of Hampton, VA 2024 annual report | 0–3.5 ng/L | 1.8× the limit |
| City of Newport News, VA 2025 annual report | 3.5 ng/L | 1.8× the limit |
| City of Poquoson, VA 2025 annual report | 3.5 ng/L | 1.8× the limit |
| City of Poquoson, VA 2024 annual report | 0–3.5 ng/L | 1.8× the limit |
| Hampton, VA 2025 annual report | 3.5 ng/L | 1.8× the limit |
| James City County, VA 2025 annual report | 0–3.5 ng/L | 1.8× the limit |
| James City County, VA 2024 annual report | 0–3.5 ng/L | 1.8× the limit |
| Newport News, VA 2024 annual report | 0–3.5 ng/L | 1.8× the limit |
| York County, VA 2024 annual report | 3.5 ng/L | 1.8× the limit |
| York County, VA 2025 annual report | 3.5 ng/L | 1.8× the limit |
| Tempe, AZ 2024 annual report | 0.003 ug/L | 1.0× the limit |
Within the federal limit (57)
| Water system | Measured |
|---|---|
| Gilbert, AZ 2024 annual report | 7 |
| Chandler, AZ 2024 annual report | 0.07 ng/L |
| Saint Paul, MN 2024 annual report | 0–2.2 |
| Green Bay, WI 2024 annual report | 0.96–1.4 ng/L |
| Minneapolis, MN 2023 annual report | 1 |
| Rochester, MN 2025 annual report | 0–0.89 |
| Stamford, CT 2024 annual report | 1 ng/L |
| Colorado Springs, CO 2024 annual report | 1.3 ng/L |
| Alameda, CA 2024 annual report | Not detected ng/L |
| Albany, CA 2024 annual report | Not detected ng/L |
| Albuquerque, NM 2024 annual report | Not detected |
| Berkeley, CA 2024 annual report | Not detected ng/L |
| 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 |
| Castro Valley, CA 2024 annual report | Not detected ng/L |
| Crockett, CA 2024 annual report | Not detected ng/L |
| Dearborn, MI 2024 annual report | Not detected ug/L |
| El Cerrito, CA 2024 annual report | Not detected ng/L |
| El Monte, CA 2024 annual report | Not detected ng/L |
| El Sobrante, CA 2024 annual report | Not detected ng/L |
| Emeryville, CA 2024 annual report | Not detected ng/L |
| Franklin, WI 2024 annual report | Not detected ug/L |
| Freedom District, MD 2024 annual report | Not detected ng/L |
| Grand Rapids, MI 2025 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 |
| Hayward, CA 2024 annual report | Not detected ng/L |
| Hercules, CA 2024 annual report | Not detected ng/L |
| Kensington, CA 2024 annual report | Not detected ng/L |
| Lafayette, CA 2024 annual report | Not detected ng/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 |
| Moraga, CA 2024 annual report | Not detected ng/L |
| New Berlin, WI 2024 annual report | Not detected ug/L |
| Oakland, CA 2024 annual report | Not detected ng/L |
| Orinda, CA 2024 annual report | Not detected ng/L |
| Pasadena, CA 2023 annual report | Not detected ug/L |
| Piedmont, CA 2024 annual report | Not detected ng/L |
| Pinole, CA 2024 annual report | Not detected ng/L |
| Richmond, CA 2024 annual report | Not detected ng/L |
| Rodeo, CA 2024 annual report | Not detected ng/L |
| Salem, OR 2023 annual report | Not detected ug/L |
| San Leandro, CA 2024 annual report | Not detected ng/L |
| San Lorenzo, CA 2024 annual report | Not detected ng/L |
| San Pablo, CA 2024 annual report | Not detected ng/L |
| Santa Clarita, CA 2024 annual report | Not detected ug/L |
Showing 50 of 57. The full list is in the JSON API.
Frequently asked
+What is Perfluorohexanoic acid?
Perfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and widely detected.
+What is the federal limit for Perfluorohexanoic acid in drinking water?
The federal NL for Perfluorohexanoic acid is 1 ng/L. 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 Perfluorohexanoic acid over the federal limit?
17 of the 134 public water systems on The Water Map report Perfluorohexanoic acid at or above its federal limit, spanning 26 U.S. states. The full list is on this page.
+How can I check if Perfluorohexanoic 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 Perfluorohexanoic acid.