What Copper is, and why it's regulated
What the EPA limit means
1300 µg/L
Maximum Contaminant Level — the enforceable ceiling a supplier must stay under.
1300 µg/L
Health goal (MCLG) — the level with no known health effect. It is a goal, not a legal limit, and is often zero for carcinogens.
SYR4
Where these measurements come from. Hover the tag for the EPA programme and years.
Where Copper was found
The water suppliers reporting the highest levels, worst first. For lead and copper that is the 90th-percentile result the action level is written against; for Six-Year Review data, the 95th percentile of each system's samples.
| Supplier | City | State | Level vs EPA limit |
|---|---|---|---|
| Lakeside Water Supply 1 | Colmesneil | TX | 8510 µg/L 655% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Caribou Mobile Park Pws | Stockton | CA | 8200 µg/L 631% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Sonoma County Mutual Water Company | — | CA | 7800 µg/L 600% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Brewster Community Homeowners | Salem | OR | 7260 µg/L 558% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Lakeside Water Supply 3 | Colmesneil | TX | 6920 µg/L 532% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Hilton Sound (sc3250024) | Ballentine | MO | 6352.5 µg/L 489% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Olympic Park Trailer Court | Amanda Park | WA | 6225 µg/L 479% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Atmautluak Water System | Atmautluak | AK | 5925 µg/L 456% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Selawik Safewater Facility | Selawik | AK | 5904 µg/L 454% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Chignik Lake Water System | Chignik Lake | AK | 5550 µg/L 427% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Clarinda Treatment Complex | Clarinda | IA | 5261 µg/L 405% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Mountain View Mobile Village | Yuma | AZ | 5217 µg/L 401% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Dowling Village | North Smithfield | RI | 5207 µg/L 401% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Sebastian Lake Utility Operating Company | — | MO | 5142.75 µg/L 396% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Briar Court Estates | Goffstown | NH | 5078.4 µg/L 391% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Mount Rose Bowl Property Owners Water Co | Reno | NV | 5040 µg/L 388% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Oak Manor Estates | Milford | PA | 5003 µg/L 385% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Nantahala Village | Bryson City | GA | 4840.75 µg/L 372% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Lucky Waterworks | Bienville | LA | 4680 µg/L 360% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Cassie Water System | — | MO | 4623 µg/L 356% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Compton-City, Water Dept. | Compton | CA | 4427 µg/L 341% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| City of Mansfield Water System | Mansfield | LA | 4420 µg/L 340% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Pleasant Grove Subdivision | — | — | 4277.5 µg/L 329% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Friendship Water System | Saline | LA | 4160 µg/L 320% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
| Mushroom Farm | Tobyhanna | PA | 4138 µg/L 318% of the EPA limit, at the 95th percentile of samples — 1300 µg/L |
Frequently asked questions about Copper
What is Copper in drinking water?
Copper leaches from household plumbing; short-term exposure causes stomach upset and long-term exposure can damage the liver and kidneys.
What is the EPA limit for Copper?
The EPA's Maximum Contaminant Level for Copper is 1300 µg/L, and its health goal (MCLG) is 1300 µg/L. A result above the limit means the supplier must act; the goal is the level at which no health effects are expected.
How common is Copper in US tap water?
Of the 36,658 water suppliers with results on file, 32,617 detected Copper — 89% of those tested.