Metals
Mercury in U.S. tap water
32 public water systems across 12 U.S. states report Mercury in their annual Consumer Confidence Report. 2 sit at or above the federal limit.
What it is
A toxic metal from erosion of natural deposits and industrial runoff.
Why it's regulated
Long-term exposure above the federal limit can damage the kidneys.
At or above the federal limit (2)
| Water system | Measured | vs. limit |
|---|---|---|
| St Petersburg, FL 2024 annual report | 4 ug/L | 2.0× the limit |
| St George, UT 2024 annual report | 0–0.2 ug/L | 1.0× the limit |
Within the federal limit (29)
| Water system | Measured |
|---|---|
| Bend, OR 2025 annual report | 1 |
| Chandler, AZ 2024 annual report | 0.59 ug/L |
| Fort Lauderdale, FL 2024 annual report | 0–0.31 ug/L |
| Tallahassee, FL 2024 annual report | 0–0.1 ug/L |
| Dallas, TX 2024 annual report | 0.08 ug/L |
| Ann Arbor, MI 2024 annual report | Not detected ug/L |
| Birmingham, AL 2024 annual report | Not detected |
| City of Hampton, VA 2024 annual report | Not detected ug/L |
| City of Newport News, VA 2025 annual report | Not detected ug/L |
| City of Poquoson, VA 2025 annual report | Not detected ug/L |
| City of Poquoson, VA 2024 annual report | Not detected ug/L |
| Cleveland, OH 2024 annual report | Not detected |
| Columbus, OH 2025 annual report | Not detected |
| Grand Rapids, MI 2025 annual report | Not detected ug/L |
| Hampton, VA 2025 annual report | Not detected ug/L |
| High Point, NC 2024 annual report | Not detected ug/L |
| James City County, VA 2025 annual report | Not detected ug/L |
| James City County, VA 2024 annual report | Not detected ug/L |
| Mesquite, TX 2024 annual report | 0–0 ug/L |
| Mobile, AL 2024 annual report | Not detected |
| Montgomery, AL 2024 annual report | Not detected |
| Nashville, TN 2023 annual report | Not detected |
| Newport News, VA 2024 annual report | Not detected ug/L |
| Plano, TX 2024 annual report | 0–0 ug/L |
| Salt Lake City, UT 2024 annual report | Not detected |
| West Jordan, UT 2024 annual report | Not detected ug/L |
| West Valley City, UT 2024 annual report | Not detected ug/L |
| York County, VA 2024 annual report | Not detected ug/L |
| York County, VA 2025 annual report | Not detected ug/L |
Frequently asked
+What is Mercury?
A toxic metal from erosion of natural deposits and industrial runoff. Long-term exposure above the federal limit can damage the kidneys.
+What is the federal limit for Mercury in drinking water?
The federal MCL for Mercury is 2 . 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 Mercury over the federal limit?
2 of the 32 public water systems on The Water Map report Mercury at or above its federal limit, spanning 12 U.S. states. The full list is on this page.
+How can I check if Mercury 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 Mercury.