Copper is a naturally occurring metal that is commonly used in household plumbing. While copper pipes have been installed in millions of homes because they are durable and corrosion-resistant, copper can sometimes enter drinking water as water passes through household plumbing.
In most cases, copper found in tap water comes from the home's plumbing rather than the water source itself. This guide explains where copper comes from, why it can appear in drinking water, current EPA regulations, potential health considerations, and practical steps homeowners can take to reduce exposure.
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What Is Copper?
Copper is a naturally occurring metal found in rocks, soil, water, and plants. It is also an essential nutrient that the human body needs in small amounts for normal growth and development.
Because copper is strong, corrosion-resistant, and relatively easy to work with, it has been widely used for residential plumbing, water service lines, fittings, and household fixtures for decades.
Although copper itself is beneficial in small dietary amounts, elevated concentrations in drinking water may become a concern.
Where Does Copper in Drinking Water Come From?
Unlike many other drinking water contaminants, copper usually enters water after it leaves the treatment plant.
The most common sources include:
- Copper household plumbing
- Copper service lines
- Brass faucets and fixtures
- Copper pipe fittings
- Corrosion inside household plumbing
Public water leaving the treatment facility often contains little copper. Instead, copper typically dissolves into water as it sits inside plumbing systems, particularly when water remains stagnant for several hours.
What Causes Copper to Leach Into Water?
Copper enters drinking water primarily through corrosion. Corrosion occurs when water slowly reacts with plumbing materials.
Several factors may influence corrosion, including:
- Acidic water (low pH)
- Soft water
- Water chemistry
- Long periods of stagnant water
- Older plumbing systems
- High water temperature
Because corrosion depends on water chemistry, neighboring homes can sometimes experience different copper levels even when they receive water from the same utility.
Can You Taste or See Copper?
Sometimes.
Higher copper concentrations may produce:
- A metallic taste
- Blue-green stains on sinks or fixtures
- Blue-green discoloration around faucets
- Greenish corrosion on plumbing components
However, copper may also be present without obvious taste or visible signs. Laboratory testing provides the most reliable information.
EPA Drinking Water Standards for Copper
Unlike many drinking water contaminants, copper is regulated under the EPA's Lead and Copper Rule.
Instead of a traditional Maximum Contaminant Level (MCL), copper has an Action Level of 1.3 milligrams per liter (mg/L).
If more than 10% of sampled homes exceed this level, the public water system must take corrective actions, such as improving corrosion control or replacing problem plumbing components.
Potential Health Considerations
Copper is an essential nutrient, but excessive intake may cause health concerns.
According to the EPA and other public health agencies, elevated copper concentrations may contribute to:
- Metallic taste
- Stomach discomfort
- Nausea
- Vomiting
- Digestive irritation
Long-term exposure to very high copper levels may present additional concerns, particularly for individuals with certain rare inherited disorders affecting copper metabolism.
Who May Be More Likely to Have Elevated Copper?
Copper may be more likely in homes that have:
- Copper plumbing
- Acidic water
- Water that sits unused overnight
- Recently installed copper pipes
- Corrosion problems
Older homes with brass plumbing fixtures may also contribute copper to drinking water.
How Can You Test for Copper?
Testing through a certified laboratory is the most reliable way to determine copper concentrations.
If you're concerned about household plumbing, laboratories may recommend collecting a first-draw sample after water has remained unused for several hours. This provides a better indication of copper contributed by household plumbing.
How Can Homeowners Reduce Copper Exposure?
If you're concerned about copper in drinking water, consider these practical steps:
- Review your local Consumer Confidence Report (CCR).
- Test your tap water through a certified laboratory.
- If water has been sitting overnight, run cold water briefly before using it for drinking or cooking.
- Use cold water rather than hot water for cooking and beverages.
- Consider a quality point-of-use filtration system.
- Replace plumbing components if corrosion is identified.
Can Boiling Remove Copper?
No.
Boiling water does not remove copper. Because water evaporates while dissolved copper remains, boiling may slightly increase copper concentration.
Berkey® Water Filters and Copper Reduction
Berkey® countertop gravity-fed water filter systems are designed for everyday household use.
When equipped with Black Berkey® Replacement Filters, Berkey® systems are designed to reduce a broad range of unwanted contaminants, including copper, while leaving beneficial minerals in the water.
For most households, the Big Berkey® Water Filter offers an excellent combination of capacity, convenience, and everyday performance.
Choosing the Right Berkey® System
| System | Capacity | Best For | Product |
|---|---|---|---|
| Travel Berkey® | 1.5 Gallons | Singles & Couples | View Product |
| Big Berkey® | 2.25 Gallons | Most Families | View Product |
| Royal Berkey® | 3.25 Gallons | Larger Families | View Product |
| Imperial Berkey® | 4.5 Gallons | High Daily Water Use | View Product |
| Crown Berkey® | 6 Gallons | Large Homes & Offices | View Product |
Frequently Asked Questions
Is copper naturally found in drinking water?
Yes. Copper occurs naturally in the environment, but elevated concentrations in household drinking water usually come from plumbing rather than the original water source.
Why does my water taste metallic?
A metallic taste can have several causes, including elevated copper levels. Laboratory testing is the best way to identify the specific cause.
Can boiling remove copper?
No. Boiling does not remove copper and may slightly increase its concentration as water evaporates.
What causes blue-green stains around faucets?
Blue-green stains often indicate copper corrosion somewhere within the plumbing system.
Should I use hot water for cooking?
Public health agencies generally recommend using cold tap water for drinking and cooking because hot water may dissolve metals from plumbing more readily.
Which Berkey® system is best for most households?
The Big Berkey® Water Filter is our most popular countertop gravity-fed system because it offers an excellent balance of capacity and convenience.
Where can I buy replacement filters?
You can shop genuine replacement elements and accessories on our Berkey® Replacement Filters page.
Final Thoughts
Copper is an essential mineral and an important plumbing material, but corrosion can sometimes allow elevated amounts to enter household drinking water. Understanding your plumbing, testing when appropriate, and taking simple steps such as using cold water for cooking can help reduce unnecessary exposure.
If you're looking for a convenient, gravity-fed countertop filtration system for everyday use, the Big Berkey® Water Filter remains our most popular choice for families.