PFAS ("forever chemicals")
Perfluorohexanesulfonic acid in U.S. tap water
128 public water systems across 29 U.S. states report Perfluorohexanesulfonic acid in their annual Consumer Confidence Report. 22 sit at or above the federal limit.
What it is
Perfluorohexanesulfonic acid, a PFAS 'forever chemical.'
Why it's regulated
Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
At or above the federal limit (22)
| Water system | Measured | vs. limit |
|---|---|---|
| New Braunfels, TX 2024 annual report | 2024 | 674.7× the limit |
| Burbank, CA 2024 annual report | 0–45 ng/L | 4.5× the limit |
| Chula Vista Sweetwater, CA 2024 annual report | 0–26 ng/L | 2.6× the limit |
| Jersey City, NJ 2024 annual report | 4.9 ng/L | 2.5× the limit |
| Tempe, AZ 2024 annual report | 0.007 ug/L | 2.3× the limit |
| City of Hampton, VA 2024 annual report | 0–3.7 ng/L | 1.9× the limit |
| City of Newport News, VA 2025 annual report | 0–3.7 ng/L | 1.9× the limit |
| City of Poquoson, VA 2025 annual report | 0–3.7 ng/L | 1.9× the limit |
| City of Poquoson, VA 2024 annual report | 3.7 ng/L | 1.9× the limit |
| Hampton, VA 2025 annual report | 3.7 ng/L | 1.9× the limit |
| James City County, VA 2025 annual report | 0–3.7 ng/L | 1.9× the limit |
| James City County, VA 2024 annual report | 3.7 ng/L | 1.9× the limit |
| Newport News, VA 2024 annual report | 3.7 ng/L | 1.9× the limit |
| York County, VA 2024 annual report | 3.7 ng/L | 1.9× the limit |
| York County, VA 2025 annual report | 3.7 ng/L | 1.9× the limit |
| Boonsboro Keedysville, MD 2024 annual report | 355–4 | 1.3× the limit |
| City of Hialeah, FL 2023 annual report | 10–10 ng/L | 1.0× the limit |
| City of Homestead, FL 2023 annual report | 10–10 ng/L | 1.0× the limit |
| City of North Miami Beach, FL 2023 annual report | 10–10 ng/L | 1.0× the limit |
| Fullerton, CA 2024 annual report | 3 ng/L | 1.0× the limit |
| Huntington Beach, CA 2025 annual report | 3 ng/L | 1.0× the limit |
| Miami Dade, FL 2023 annual report | 10–10 ng/L | 1.0× the limit |
Approaching the limit (2)
| Water system | Measured | vs. limit |
|---|---|---|
| Chico, CA 2024 annual report | 2.9 ng/L | 1.0× the limit |
| Santa Ana, CA 2024 annual report | 2.7 ng/L | 0.9× the limit |
Within the federal limit (65)
| Water system | Measured |
|---|---|
| Madison, WI 2024 annual report | 6.6–7.3 |
| Vancouver, WA 2024 annual report | 0–6.8 |
| Goodyear, AZ 2024 annual report | 5 ng/L |
| Palm Bay, FL 2024 annual report | 0.0046–0.0049 ug/L |
| Glendale, CA 2024 annual report | 4.3 ng/L |
| Columbus, GA 2024 annual report | 0–3.1 |
| Bakersfield, CA 2024 annual report | 0.8 ng/L |
| Georgetown, TX 2024 annual report | 1.9 ng/L |
| Lynn, MA 2024 annual report | 1.9 ng/L |
| Philadelphia, PA 2023 annual report | 1.9 |
| Raleigh, NC 2024 annual report | 1.52 |
| Town of Garner, NC 2024 annual report | 1.52 |
| Town of Knightdale, NC 2024 annual report | 1.52 |
| Town of Rolesville, NC 2024 annual report | 1.52 |
| Town of Wake Forest, NC 2024 annual report | 1.52 |
| Town of Wendell, NC 2024 annual report | 1.52 |
| Town of Zebulon, NC 2024 annual report | 1.52 |
| Newark, NJ 2024 annual report | 1.3 ng/L |
| Rockville, MD 2024 annual report | 1.13 |
| Washington Dc, DC 2023 annual report | 0.2 |
| Rochester, MN 2025 annual report | 0–4.8 |
| Stockton, CA 2024 annual report | 0.29 ng/L |
| Saint Paul, MN 2024 annual report | 0–1.9 |
| Visalia, CA 2024 annual report | 0.09 ng/L |
| Green Bay, WI 2024 annual report | 0–0.73 ng/L |
| Colorado Springs, CO 2024 annual report | 0.56 ng/L |
| Pomona, CA 2024 annual report | 0–7.9 ng/L |
| Albuquerque, NM 2024 annual report | Not detected |
| Anchorage, AK 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 |
| Cary, NC 2025 annual report | Not detected |
| Chandler, AZ 2024 annual report | 0 ng/L |
| Dearborn, MI 2024 annual report | Not detected ug/L |
| El Cajon, 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 |
| Glendale, AZ 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 |
| Louisville, KY 2024 annual report | 0 |
| Lubbock, TX 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 |
| New Berlin, WI 2024 annual report | Not detected ug/L |
Showing 50 of 65. The full list is in the JSON API.
Frequently asked
+What is Perfluorohexanesulfonic acid?
Perfluorohexanesulfonic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
+What is the federal limit for Perfluorohexanesulfonic acid in drinking water?
The federal MCL for Perfluorohexanesulfonic acid 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 Perfluorohexanesulfonic acid over the federal limit?
22 of the 128 public water systems on The Water Map report Perfluorohexanesulfonic acid at or above its federal limit, spanning 29 U.S. states. The full list is on this page.
+How can I check if Perfluorohexanesulfonic 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 Perfluorohexanesulfonic acid.
See Perfluorohexanesulfonic acid on the map
Color-coded by status across the whole country.
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