Copper is a naturally occurring metal in earth’s crust. Known for it’s red-gold hue and malleability, copper is found all over the world in water, soil, rocks, and plants and animals, but you are most likely familiar with copper through its use in electrical wiring and plumbing materials. Before 1982, U.S. pennies were even made of copper! Copper is also essential to human health, as it aids in energy production, the nervous system, and a healthy immune system. The good news is the vast majority of people get the necessary 0.9 mg of copper from their diet. The bad news is excessive copper can cause problems for your health and your home, and copper in drinking water is a water quality issue many homeowners face. From upset stomachs to blue-green stains in your sink, excess copper can be a burden. Below you will learn about copper, how to find out if you have copper in your water supply, and how to remove copper from water through reverse osmosis, distillation, and ion-exchange.
How does copper get into drinking water?
Copper gets into drinking water through the corrosion of copper pipes, faucets, and plumbing fixtures. When water runs through copper pipes, copper is stripped from the pipes and dissolves into the water. Acidic or soft water, residual chlorine, and hot water exacerbate corrosion and allow more copper to enter the water supply. Also, when water sits in copper pipes for long periods of time, the copper breaks down and becomes concentrated in the water. Copper is not the only metallic contaminant that can make its way into your water supply through household or municipal plumbing. Lead (a far more dangerous contaminant) and iron can also leech into water supplies via plumbing, as lead and iron plumbing fixtures are likewise vulnerable to corrosion.
Additionally, if you have a well, copper can get into drinking water by contaminating your well’s groundwater source, but this isn’t as common a problem as pipe corrosion. Copper may contaminate a well’s groundwater source through mining, farming, and industrial and municipal operations. For example, copper is used in agricultural pesticides and to control algae in water reservoirs and may runoff and seep through the soil to the groundwater below.
What are safe levels of copper in drinking water?
1.3 parts per million (or 1.3 mg/L) or less is considered a safe level of copper in drinking water, according to the Environmental Protection Agency (EPA). The EPA set 1.3 parts per million (ppm) as the Maximum Contaminant Level Goal for copper in water, which is a health-based goal and the level at which no known adverse effects on human health occur.
Also, in 1991 the EPA created the Lead and Copper Rule. This regulation requires municipal water supplies to monitor the amount of lead and copper in their water supply. If lead concentrations exceed 15 parts per billion (ppb) and copper concentrations exceed 1.3 ppm in more than 10% of customer taps sampled, the municipality must take action to control the contamination.
Learn More: How to Remove Lead from Water
What are the side effects of copper in drinking water?
Copper in drinking water can negatively affect both your health and your home.
Side effects to your health:
- Liver damage (in severe cases)
- Kidney failure (in severe cases)
Side effects in your home:
- Blue-green stains in sinks, showers, faucets, pipes, and appliances
- Bitter, metallic tasting water
How do you test for copper in water?
Also, municipal water suppliers test the water supply frequently, and if you ask for the results, they are required by law to give them to you. However, a municipal water test would not reveal if copper is entering your water through your home plumbing, so if you know your pipes contain copper, we recommend periodic testing to keep tabs on potential corrosion.
If you are on well water, the safety of your water supply is your responsibility, so it is especially recommended to test your water frequently.
How do you remove copper from water?
Copper can be removed from water through reverse osmosis, distillation, and ion exchange filtration.
Reverse osmosis uses pressure to push unfiltered water through a semipermeable membrane. The membrane has small pores that block contaminants, such as copper, but allow clean water to flow through to the other side. Reverse osmosis can remove 97-98% of copper from water.
Distillation is a water treatment method that mimics how water is purified in nature: through evaporation in the atmosphere. Water distillers convert water into steam, eliminating copper and other contaminants because they cannot turn into steam as water can. Once the water returns to its liquid form, it is contaminant free.
In the ion exchange process, water percolates through a bed of resin beads. Contaminants are trapped in the resin and exchanged for ions that won’t affect water quality, such as sodium, hydrogen, or hydroxyl ions. The two most common ion exchange filters are water softeners and deionized water systems.
Water softeners remove hardness causing minerals like calcium and magnesium, and dissolved metals, including copper and iron. Sodium ions are released into the water in exchange for the contaminants.
Deionized water systems remove a host of contaminants and produce highly purified water. Deionization resin exchanges hydrogen ions for cations (positively charged ions) and hydroxyl ions for anions (negatively charged ions).
Does boiling water remove copper?
Boiling water does not remove copper. Since some water evaporates during the boiling process, copper concentrations can increase and render the water more dangerous if consumed.
How to reduce the risk of copper in your water
You can reduce the risk of copper in your water by flushing the water system and by using cold water for drinking and cooking. To flush the water, simply let a faucet run for about 30 seconds before using it. This is especially important any time a faucet has not been used for six or more hours, as copper is more likely to dissolve in stagnant water that sits in pipes for long periods of time. If you would prefer not to waste water, it is safe to use the “unflushed” water for laundry, plants, cleaning, and washing the dishes.
Also, it is recommended to use cold water for drinking and cooking, because hot water dissolves copper more readily than cold water and will lead to higher concentrations of copper in your water supply.
Does copper affect pool water?
Copper can affect pool water by staining the pool surface and even staining swimmers’ swimsuits, hair, and nails. While often blamed on chlorine, if your swimsuit and hair are tinted green after swimming, the culprit is usually dissolved copper in the water. Copper can enter pool water through copper pipes and plumbing fixtures and is sometimes purposefully introduced to prevent algae buildup, but concentrations should be kept below 1.0 ppm to avoid stains. We recommend testing your pool water regularly to keep track of copper levels.
Learn More: How to Accurately Test Pool Water
What are the benefits of copper water bottles?
Copper water bottles have become somewhat of a health trend. Inspired by Ayurveda, a system of holistic medicine that originated in India more than 3,000 years ago, proponents believe that drinking water from copper bottles can improve your immune system, improve joint health, and aid digestion. Although, these claims are not backed by scientific studies.
While copper is necessary for good health, the standard diet meets or exceeds the recommended 0.9 mg of copper per day, so it is likely not necessary to infuse your water with additional copper. Consuming excess copper can cause gastrointestinal upset, as well as other unpleasant symptoms, so if you are curious about copper water bottles, we recommend consulting your doctor first.
If you have further questions about copper in your drinking water or would like to address any other water quality concerns, please don’t hesitate to contact us.