Metals
Copper in U.S. tap water
1,346 public water systems across 44 U.S. states report Copper in their annual Consumer Confidence Report. 8 sit at or above the federal limit.
What it is
A metal that enters water from corroding household plumbing.
Why it's regulated
Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
At or above the federal limit (8)
| Water system | Measured | vs. limit |
|---|---|---|
| Casa Dulce Estates — Agua Dulce, Ca, CA 2021 annual report | 2 mg/L | 1.5× the limit |
| Atascadero State Hospital — Atascadero, Ca, CA 2022 annual report | 1.7 mg/L | 1.3× the limit |
| Gramercy, MD 2024 annual report | 1.69 mg/L | 1.3× the limit |
| White Fence Farms Mwc No.3 — Lancaster, Ca, CA 2021 annual report | 1.5 mg/L | 1.2× the limit |
| Humboldt C.s.d. — Cutten, Ca, CA 2023 annual report | 1.3 mg/L | 1.0× the limit |
| Salt Lake City, UT 2024 annual report | 1.3 mg/L | 1.0× the limit |
| South Montebello Irrigation Dist. — Montebello, Ca, CA 2020 annual report | 1.3 mg/L | 1.0× the limit |
| Western MWD — Riverside, Ca, CA 2023 annual report | 1.3 mg/L | 1.0× the limit |
Approaching the limit (14)
| Water system | Measured | vs. limit |
|---|---|---|
| Alpine Water Users Association — Twin Peaks, Ca, CA 2023 annual report | 1.2 mg/L | 0.9× the limit |
| Los Angeles Cwwd 21-kagel Canyon — Alhambra, Ca, CA 2021 annual report | 1.2 mg/L | 0.9× the limit |
| Los Angeles Cwwd 21-kagel Canyon — Alhambra, Ca, CA 2020 annual report | 1.2 mg/L | 0.9× the limit |
| Pico Rivera - City, Water Dept. — Pico Rivera, Ca, CA 2023 annual report | 1.2 mg/L | 0.9× the limit |
| Pico Rivera - City, Water Dept. — Pico Rivera, Ca, CA 2021 annual report | 1.2 mg/L | 0.9× the limit |
| Pico Rivera - City, Water Dept. — Pico Rivera, Ca, CA 2022 annual report | 1.2 mg/L | 0.9× the limit |
| Arcata, City of — Arcata, Ca, CA 2023 annual report | 1.1 mg/L | 0.8× the limit |
| Blythe - City of — Blythe, Ca, CA 2022 annual report | 1.1 mg/L | 0.8× the limit |
| City of Buellton Water Division — Buellton, Ca, CA 2023 annual report | 1.1 mg/L | 0.8× the limit |
| Rockford, IL 2024 annual report | 1.1 mg/L | 0.8× the limit |
| San Miguelito Mwc — Avila Beach, Ca, CA 2023 annual report | 1.1 mg/L | 0.8× the limit |
| Town of Accident, MD 2024 annual report | 19–1100 ug/L | 0.8× the limit |
| Vineyard Ave Estates Mwc — Oxnard, Ca, CA 2022 annual report | 1.1 mg/L | 0.8× the limit |
| Jacksonville, FL 2024 annual report | 1.04 mg/L | 0.8× the limit |
Within the federal limit (1305)
Showing 50 of 1305. The full list is in the JSON API.
Copper by state
Every state where a public water system reports Copper in its annual report, ranked by systems at or above the federal limit.
Frequently asked
+What is Copper?
A metal that enters water from corroding household plumbing. Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
+What is the federal limit for Copper in drinking water?
The federal MCLG for Copper is 1.3 mg/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 Copper over the federal limit?
8 of the 1346 public water systems on The Water Map report Copper at or above its federal limit, spanning 44 U.S. states. The full list is on this page.
+Which states report the most Copper in their drinking water?
Of the systems on The Water Map, California (6 systems at or above the limit), Maryland (1 system at or above the limit), Utah (1 system at or above the limit) report the most Copper exceedances. The state-by-state table on this page lists every state.
+How can I check if Copper 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 Copper.