When you turn on your faucet and notice the water looks white, cloudy, or milky, it’s natural to feel concerned. After all, water should appear clear and transparent. The good news is that in most cases, milky tap water is harmless and temporary. However, not all causes are benign, and understanding why it happens helps you determine whether you need to take action.

This guide breaks down the most common causes of milky faucet water, how to identify each one, and what to do to restore the clean, clear water you expect from your plumbing system.

1. Entrapped Air — The Most Common Reason

The number one cause of milky or cloudy tap water is air bubbles. When air becomes trapped in your plumbing system or mixed into the water supply, it turns the water white. This form of discoloration is completely harmless and usually resolves on its own.

How to identify it

Fill a glass of the cloudy water and set it on the counter. If the water clears from the bottom upward within a few minutes, air bubbles are the culprit. The bubbles rise and escape, leaving the water clear again.

Why it happens

Several everyday situations introduce excess air into water lines:

• A recent plumbing repair
• High water pressure
• Cold weather increasing air solubility, then releasing it indoors
• Municipal pipe flushing
• Well pumps pulling in air during operation

What to do

Nothing is required. Once the system stabilizes, your water will run clear again. If it continues for more than 48 hours, it may indicate higher water pressure or a pump issue that needs inspection.

2. Hard Water and Mineral Content

Water with high levels of calcium and magnesium—known as hard water—can also appear milky when it first exits the faucet. The minerals don’t actually create foam or bubbles, but they scatter light, making the water look cloudy.

How to identify it

Hard water cloudiness does not clear quickly. Instead, you may notice:

• White residue on faucets
• Limescale on the aerator
• Dry feeling on skin
• Spots on dishes

What causes it

Regions with naturally high mineral deposits in soils and aquifers produce groundwater that carries more dissolved minerals.

What to do

• Install a water softener
• Clean aerators regularly
• Use descaling agents to remove buildup

While not dangerous, mineral-rich water can damage appliances and reduce flow over time.

3. Sediment and Particulate Disturbances

If your water suddenly becomes cloudy after plumbing work or if your utility company is flushing the system, disturbed sediment inside pipes may enter your faucet.

This sediment can include:

• Sand
• Silt
• Rust particles
• Iron or manganese deposits

How to identify it

Cloudiness from sediment typically:

• Appears brownish or gray
• Settles to the bottom of a glass rather than clearing upward
• Occurs suddenly after maintenance or hydrant flushing

What to do

• Run the cold tap for several minutes to flush the line
• Clean faucet aerators
• Contact your water provider if it persists

This type of cloudiness is generally harmless but may indicate aging plumbing or deteriorating pipes.

4. Water Heater Issues

Cloudy hot water but clear cold water often points to a water heater problem.

Common causes

• Excessive sediment buildup inside the tank
• Overheating water, allowing more dissolved gases
• Anode rod corrosion releasing particles
• High pressure inside the tank

How to identify it

• Only the hot water appears milky
• Cloudiness may clear slowly
• You may hear popping or crackling from the water heater

What to do

• Flush the water heater tank
• Replace the anode rod
• Lower the temperature to 120°F
• Hire a technician if noise indicates heavy sediment buildup

If left untreated, sediment can reduce heater efficiency and lifespan.

5. Pressure Changes in the Plumbing System

Sudden changes in water pressure can cause dissolved gases to escape rapidly, creating a milky appearance. This happens when:

• Pressure regulators malfunction
• Municipal pressure changes occur
• Well systems fluctuate
• Expansion tanks fail

How to identify it

Milky water from pressure issues clears similarly to air entrapment—bottom to top—but may occur more frequently or unpredictably throughout the day.

What to do

• Test your home’s water pressure (ideal is 40–60 psi)
• Replace a faulty pressure regulator
• Call your water provider to check for temporary issues

Ignoring pressure problems can lead to leaks, appliance damage, or burst pipes.

6. Microbubbles Caused by Temperature Differences

When cold water travels through underground pipes and warms rapidly inside your home, dissolved gases may escape as microbubbles, giving the water a hazy look.

This is especially common in winter or early spring.

How to identify it

• The water looks hazy only when first turned on
• Clears quickly in a cup
• Occurs more often with cold water

What to do

No action is needed. This is a natural response to temperature changes and does not indicate contamination.

7. Organic Contamination (Less Common but Serious)

In rare cases, cloudy water can be caused by contaminants such as:

• Algae
• Bacteria
• Waste infiltration
• Organic matter from cracked well casings

This type of cloudiness often has a smell, taste, or color change.

Warning signs

• Water appears milky and smells musty or rotten
• Cloudiness does not clear
• You experience stomach issues after drinking tap water
• Wells are more susceptible

What to do

• Stop using water for drinking or cooking
• Test your water immediately
• Inspect wells or plumbing for cracks
• Install filtration or UV purification systems

Contaminated water requires immediate attention.

When Should You Be Concerned?

Most milky water issues are harmless, but you should investigate further if:

• Cloudiness lasts more than 48 hours
• Only hot water is affected
• Cloudiness does not clear in a glass
• Water has an odor or taste
• Cloudiness appears after heavy rain (common in well systems)

If unsure, contact your municipal water provider or a licensed plumber.

Final Thoughts: Why Faucet Water Comes Out Milky

Milky faucet water is a common issue with several potential causes—most of which are harmless and temporary. Air bubbles, pressure changes, and temperature shifts are the most frequent triggers, clearing quickly and requiring little to no action. Hard water, sediment, and water heater problems may require maintenance but are generally manageable.

By understanding the symptoms and performing a few simple checks, you can easily identify the cause and restore your water to a clear, clean appearance.