Richard Arconti 
Copper is an essential nutrient for our bodies, however, consuming too much of it can lead to negative health consequences. Since copper in water is the most common heavy metal found, knowing how it affects us is critical.
Fear not! This guide will cover everything you need to know, including how copper enters our water, its negative effects, and how to test for and remove it.
Key Takeaways:
- Copper is a naturally occurring metal (Cu) that leaches into the water supply by flowing through old copper plumbing or service lines that have become corroded.
- A high level of copper in drinking water will have a bitter or metallic taste, while a low level of copper can leave green and blue staining on plumbing fixtures.
- Ingesting high levels of copper can be dangerous and cause vomiting, nausea, diarrhea, headaches, and kidney disease.
- The EPA maximum contaminant level for copper is set at 1.3 ppm which is the safe level to avoid any potential health problems and manage plumbing corrosiveness.
- A certified laboratory test is the only accurate method to test for copper in water
- The most effective treatment to remove copper from drinking water is reverse osmosis, activated carbon, or water distillation.
How Does Copper Get Into Drinking Water?
The most common way copper enters drinking water is via leaching from copper pipes. A combination of copper plumbing fixtures and acidic water will create a higher likelihood of dissolved copper in water due to its corrosiveness. Older homes are more likely to have copper or lead plumbing materials, as many of the homes built today use PVC or PEX.
However, once copper pipes age a bit, they form a protective coating that limits the amount of copper that leaches into the water. If a newer home is constructed that uses copper pipes, for the first three years, some copper is likely to dissolve into the water supply.
How Much Copper Is In Drinking Water?
How much copper is dissolved into the water depends on a few factors:
- Types and amounts of minerals in water supply: Certain minerals are more corrosive than others. The more corrosive water is, the more likely copper will be dissolved into water.
- Acidity: Water with a lower pH, or water that is more acidic, will be more corrosive to pipes and plumbing fixtures.
- Amount of time in pipes: How long water sits in pipes is also an indicator of how much copper will dissolve into the water supply.
- Water temperature: Hot water is more likely to erode pipes compared to cold water. To reduce copper levels, use cold water as much as possible.
High copper concentrations aren’t usually found in groundwater. However, copper compounds are used in industries like mining and agriculture – which can cause copper to leach into the groundwater supply.
Additionally, it’s become popular to use copper pots, copper containers, and other copper cookware. Old or worn cookware with a faulty lining can allow copper to mix with food.
What Are Safe Levels Of Copper In Drinking Water?
The Environmental Protection Agency (EPA) introduced the Lead and Copper Rule (LCR) in 1991. In 2023, the agency amended the rule, but the change primarily affected regulations around lead in drinking water.
The rule requires all public water systems to monitor the levels of these two metals in the water supply. The rule states that if copper levels exceed 1.3 ppm (1.3 mg/L) in more than 10% of customer taps sampled, the system must take action to control the corrosion rate with phosphate treatment, thus reducing copper and lead levels in the water. Concentrations over 1.3 mg/L are when drinking water becomes hazardous.
As previously alluded to, we can process some copper from drinking water. Copper is involved in energy production, iron metabolism, neuropeptide activation, connective tissue synthesis, and neurotransmitter synthesis.
The Food and Drug Administration (FDA) recommends a daily value (DV) of 0.9 milligrams (mg) of copper a day for optimal health.
Copper deficiency is rare in healthy people living in the United States. A condition called Menke’s disease messes with the body’s ability to absorb copper, and some other health conditions make people more prone to a deficiency.
The recommended daily amounts of dietary copper are:
- Adults 18+ = 900 micrograms daily (0.9 mg)
- Women who are pregnant or breastfeeding = 1300 micrograms (1.3 mg)
- Kids aged 14-18 = 1000 micrograms (1 mg)
- The tolerable upper intake level (UL) for adults = 10,000 micrograms (10 mg)
Copper sulfate is a copper compound that comes with a different set of risks, as it is more toxic. Ingesting more than one gram of copper sulfate can lead to copper toxicity or copper poisoning.
What Are The Effects Of Copper In Drinking Water?
Unlike other metal contaminants like arsenic and lead which are highly toxic substances to humans, copper in drinking water is unlikely to elicit very dangerous health effects. The Centers for Disease Control and Prevention (CDC) provides information regarding the health effects of copper in drinking water.
Short-term exposure to excess copper levels in drinking water can cause gastrointestinal issues like:
- vomiting
- nausea
- abdominal pain
- diarrhea
Long-term exposure to high levels of copper in water can cause:
- kidney disease
- liver damage
- Wilson’s disease
Copper is not classified as carcinogenic by the IARC, EPA, or the DHHS. There has not been any substantial research on the matter to determine if copper should receive a classification since it is widely regarded as safe for consumption in regulated amounts.
People diagnosed with Wilson disease are much more vulnerable to levels of copper in drinking water. This genetic condition affects how the body processes copper.
How Do You Test For Copper In Water?
If you notice any signs of copper in your water like blue-green stains around fixtures or if the water has a bitter or metallic taste, it’s a good idea to test your water supply.
If your water is from a public water supply, all public systems must test water for copper under the EPA’s Lead and Copper Rule. You can check your local water quality report on the EPA’s search tool.
For private well water users, testing is up to their discretion since their water supply is unregulated. The authors of a 2016 study produced a map of potentially corrosive groundwater locations in the US. This can be used as a tool to deduce the likelihood of elevated levels of copper in your water should you have copper pipes.
Certified Laboratory Test
Using a certified laboratory test is the most accurate way to measure copper in your water supply. Other methods do not specifically test your home’s tap water and are less reliable.
I recommend the Freshnss Labs water test kit that scans for copper, lead, aluminum, and dozens of other water contaminants. The kit comes with everything you need to properly collect a water sample and send it to a certified laboratory for professional analysis.
Within 3 business days, you will receive a detailed report with the exact copper concentration levels, any health or plumbing alerts, and the best treatment methods based on your test data.
Laboratory Water Test Kit
Analyzed in a certified laboratory
Includes detailed report with EPA benchmarking and safety concerns
DIY Test Strips
Do-it-yourself test strips may also be used to test levels of copper in water. These can be purchased at most major retailers for home maintenance. To use DIY test strips, simply dip the strip in a cup of tap water for 30 seconds. The color squares will change color depending on the concentration of contaminants present. You then compare the color of the strip to the comparison key on the test packaging.
Of course, these tests are not always accurate, and if you are concerned about the health effects of copper in water, you may want to acquire a certified test.
How To Reduce Exposure To Copper In Your Water
If you have high levels of copper in your water, here are the best methods to reduce your exposure.
- Flush your water: Run your tap water for 30 seconds in the morning to flush stagnant water from your home’s plumbing system.
- Use cold water: Use cold water for drinking or cooking. Hot water will dissolve copper and lead more quickly than cold water.
- Replace damaged plumbing: Replace any corroded or damaged copper plumbing fixtures with updated materials.
- Remove loose debris: Remove loose debris and solder from recently installed plumbing materials by removing the faucet aerator from the tap and running water for 5 minutes.
- Water filtration: Using reverse osmosis, activated carbon, or water distillation is the best long-term solution to removing copper from tap water. More information on these methods is below.
How To Remove Copper From Water
If your water samples illuminate higher than average levels of copper, you will want to form a removal plan. There are three main treatment methods to remove copper in water: reverse osmosis, ion exchange, and distillation.
Reverse Osmosis
Reverse osmosis (RO) is a common method for removing contaminants from drinking water. RO can remove over 95% of copper from water.
During reverse osmosis, water is forcefully pushed through a semipermeable membrane. From there, the clean water gets through and the contaminants are left behind.
Recommended: Best Reverse Osmosis Systems For Copper
Distillation
Distillation results in some of the purest forms of water. This is when water is heated to a high temperature so that it boils and turns to vapor. Contaminants and metals like copper can’t turn to steam as water does, so these molecules are left behind when the vapor is cooled and turns back into water.
Recommended: Best Water Distillers For Copper
Ion Exchange
An ion exchange system uses resin beads to filter the exchange of charged ions for a contaminant like copper. A water softener is an ion exchange filter that removes dissolved copper from water. Water softeners work by introducing sodium ions to enter the water in exchange for copper ions.
Recommended: Best Ion Exchange Systems For Copper
