Copper, known for its red-gold hue and malleability, is a naturally occurring metal in earth’s crust. It is found all over the world in water, soil, rocks, plants, and animals, but you are most likely familiar with copper through its use in electrical wiring, plumbing materials, and even pennies made before 1982. Copper is also essential to human health, as it aids in energy production, the nervous system, and a healthy immune system. Most people receive the necessary 0.9 mg of copper from their diet. However, excessive copper can cause problems for your health and your home, and copper in drinking water is a water quality issue many homeowners face. In this article, you can learn answers to common questions about copper contamination in water.
How does copper get into drinking water?
Copper contaminates drinking water through the corrosion of copper pipes, faucets, and plumbing fixtures. When water runs through old 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 copper to enter the water supply even in young copper pipes. When water sits in these 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 than copper, and iron can also leech into water supplies via plumbing, as lead and iron plumbing fixtures are likewise vulnerable to corrosion.
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.
Learn more: 5 benefits to removing iron from water | What is groundwater contamination and how do you treat it?
Why is copper used for water pipes?
Copper has been regularly used in plumbing for its antibacterial properties, resistance to rust, and durability. When lead pipes became obsolete because of lead’s toxicity, copper became the standard for hard pipes in the plumbing industry. However, plastic PEX pipes have overtaken copper as a popular plumbing option because they are less expensive, more resistant to extreme temperatures, and easier to install.
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
Symptoms of copper toxicity
When consumed at high enough levels, copper can cause some undesirable side effects in your body. When too much copper is consumed, you can suffer from what is known as copper toxicity. The symptoms of copper toxicity include the following:
- Diarrhea
- Vomiting
- Fever and chills
- Muscle weakness or convulsions
- Jaundice
- Kidney damage
Effects of copper in water in the home
If copper gets into your drinking water, it will show signs in your pipes, appliances, and any other place that water runs. It will also give your water a distinct taste. If you think copper is contaminating your drinking water, look for one of the following two signs:
- Blue-green stains in sinks, showers, faucets, pipes, and appliances
- Bitter, metallic tasting water
How to test for copper in water
You can test for copper in water by sending samples to a state certified laboratory for a test or with an at-home test kit. Lab water tests are far more thorough and accurate than at-home kits, but at-home testing can give you a general idea of the contamination in your water source.
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 will not reveal if copper is entering your water through your home’s 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.
Learn more: Lab water tests vs at-home water test kits
How do you remove copper from water?
Copper can be removed from water through reverse osmosis, distillation, and ion exchange. Note that, since copper most often enters water supplies through plumbing, a whole-house filter is not a viable solution to removing copper from water. A point-of-use water treatment system must be installed if you wish to treat water after it has already run through your home’s pipes.
Reverse osmosis
Reverse osmosis (RO) 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 typically removes 97-98% of copper from water.
In addition to removing copper, RO systems remove most other contaminants from water. Reverse osmosis is an effective water treatment method for creating clean and safe drinking water from any source that is disinfected.
Learn more: What is a reverse osmosis system and how does it work?
Distillation
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 free from practically all contamination.
Water distillers are excellent at purifying water, but they do so very slowly. A typical countertop water distiller takes about four hours to distill one gallon of water. This characteristic makes water distillers impractical for many homeowners who wish to remove contaminants from their drinking and cooking water.
Learn more: What is a water distiller and how does it work? | What is distilled water and is it safe to drink?
Ion exchange
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, such as 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).
Note that you must use a point-of-use ion exchange system to eliminate copper from water effectively. A whole-house system will remove copper from water, but the water may pick up copper from your pipes as it makes its way to a faucet or other water outlet.
Learn more: What is a water softener and how does it work? | What is deionized water?
Does boiling water remove copper?
Boiling water does not remove copper. Since some water evaporates during the boiling process, boiling water technically increases the concentration of copper in the water.
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 using only cold water for drinking and cooking. To flush the water, simply allow 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, using unflushed water is perfectly safe to use for laundry, plants, cleaning, and washing the dishes.
You should avoid using hot water for drinking and cooking. Copper dissolves more easily in hot water than cold water and will lead to higher concentrations of copper in your water supply.
How does copper affect pool water?
Copper can affect pool water by staining the pool surface and even 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, but it is sometimes purposefully introduced to prevent algae buildup. When added to a pool, copper 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
Are there benefits to copper water bottles?
Copper water bottles began trending in 2020. 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. However, these claims are not backed by scientific studies.
While copper is necessary for your 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 and other unpleasant symptoms, so if you are curious about copper water bottles, consult 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 do not hesitate to contact us.