PFAS ("forever chemicals")
PFBA in U.S. tap water
137 public water systems across 28 U.S. states report PFBA in their annual Consumer Confidence Report. 16 sit at or above the federal limit.
What it is
Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.'
Why it's regulated
Monitored under EPA rules; persistent in the environment and the human body.
At or above the federal limit (16)
| Water system | Measured | vs. limit |
|---|---|---|
| New Braunfels, TX 2024 annual report | 2024 | 198.4× the limit |
| Burbank, CA 2024 annual report | 0–20 ng/L | 4.0× the limit |
| City of Hampton, VA 2024 annual report | 3.8 ng/L | 1.9× the limit |
| City of Newport News, VA 2025 annual report | 3.8 ng/L | 1.9× the limit |
| City of Poquoson, VA 2025 annual report | 2.6–3.8 ng/L | 1.9× the limit |
| City of Poquoson, VA 2024 annual report | 3.8 ng/L | 1.9× the limit |
| Hampton, VA 2025 annual report | 3.8 ng/L | 1.9× the limit |
| James City County, VA 2025 annual report | 3.8 ng/L | 1.9× the limit |
| James City County, VA 2024 annual report | 2.6–3.8 ng/L | 1.9× the limit |
| Newport News, VA 2024 annual report | 2.6–3.8 ng/L | 1.9× the limit |
| York County, VA 2024 annual report | 3.8 ng/L | 1.9× the limit |
| York County, VA 2025 annual report | 2.6–3.8 ng/L | 1.9× the limit |
| San Antonio, TX 2023 annual report | 0.0075 ug/L | 1.5× the limit |
| Lubbock, TX 2024 annual report | 7.1 ng/L | 1.4× the limit |
| Mckinney, TX 2024 annual report | 0.00636 ug/L | 1.3× the limit |
| Pomona, CA 2024 annual report | 5 ng/L | 1.0× the limit |
Approaching the limit (1)
| Water system | Measured | vs. limit |
|---|---|---|
| Boonsboro Keedysville, MD 2024 annual report | 375–4 | 0.8× the limit |
Within the federal limit (33)
| Water system | Measured |
|---|---|
| Tempe, AZ 2024 annual report | 0.001 ug/L |
| Green Bay, WI 2024 annual report | 1.7–1.9 ng/L |
| Rockville, MD 2024 annual report | 1.42 |
| Chandler, AZ 2024 annual report | 0.26 ng/L |
| Saint Paul, MN 2024 annual report | 13.1–26 |
| Gilbert, AZ 2024 annual report | 25 |
| Minneapolis, MN 2023 annual report | 7.43–12 |
| Rochester, MN 2025 annual report | 0–3.4 |
| 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 |
| 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 |
| New Berlin, WI 2024 annual report | Not detected ug/L |
| Pasadena, CA 2023 annual report | Not detected ug/L |
| Round Rock, TX 2024 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 |
Frequently asked
+What is PFBA?
Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment and the human body.
+What is the federal limit for PFBA in drinking water?
The federal MCL for PFBA 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 PFBA over the federal limit?
16 of the 137 public water systems on The Water Map report PFBA at or above its federal limit, spanning 28 U.S. states. The full list is on this page.
+How can I check if PFBA 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 PFBA.