Drinking water with more than 1,300 micrograms of copper per liter of water (µg/L) * can be a health risk for everyone. Infants and people with Wilson's disease may need water with an even lower level of copper to stay safe.
Copper can get into your drinking water as it passes through your plumbing system. Over time, plumbing parts with copper in them usually build up a natural coating that prevents copper from being dissolved into the water. Plumbing systems with copper parts less than three years old usually have not had time to build up this protective coating.
Knowing about your home’s plumbing system can help you understand your potential exposure to copper from your drinking water. If you cannot determine what type of material your home is plumbed with, consult a plumber, building inspector, or other qualified person.
You can take the steps below to help keep your drinking water safe:
- Let the water run for at least 30-60 seconds before using it for drinking or cooking if the water has not been turned on in over six hours.
- Use cold water for drinking, making food, and making baby formula. Hot water releases more copper from pipes than cold water.
- Test your water. In most cases, letting the water run and using cold water for drinking and cooking should keep copper levels low in your drinking water. If you are still concerned about copper, arrange with a certified laboratory to test your tap water. Testing your water for copper is important if an infant or someone with Wilson's disease drinks your tap water. Minnesota Department of Health (MDH) recommends using an accredited laboratory. See Search for Accredited Laboratories. Contact the laboratory to get sample containers and instructions or ask your county environmental or public health services if they provide water testing services.
- If tests show you have levels of copper over 1,300 µg/L in your drinking water after you let the water run 30-60 seconds, you may want to consider home water treatment. SeeHome Water Treatment.
* 1 microgram per liter (µg/L) = 1 part per billion (ppb)
If you have a private well
Copper is not usually found in the groundwater that feeds your well. Copper may enter your drinking water as it travels through your plumbing system. If your plumbing system has parts made with copper, follow the steps above to help keep your drinking water safe.
If you have a new well connected to your drinking water system, the new well may have different water characteristics than your old well. Be aware that the water from the new well may dissolve copper from your plumbing.
If you are on a public water system
The U.S. Environmental Protection Agency (EPA) has an action level of 1,300 µg/L for public water systems serving places where people live, work, go to school, and receive childcare. These systems have to take actions to reduce the amount of copper in the water if more than 10 percent of the water samples they take from homes and sampling sites served by the system have copper levels over 1,300 µg/L.
You can find the level of copper detected in a community water system (systems serving where you live) by reading the system's Water Quality Report (also known as a Consumer Confidence Report (CCR). You can call your community water system to get a copy of your CCR, or you may be able to find it online at Find Your Local CCR. Remember that your home may have higher levels of copper in drinking water than the homes your public water system tested. Follow the steps above to help keep your drinking water safe.
Noncommunity water systems serving schools, offices, factories, and childcare facilities test for copper; you can contact your noncommunity system to find the level of copper detected in the system. Noncommunity systems serving restaurants, resorts, and campgrounds are not required to test for copper.
