SUB sign with MO in background

Water Quality FAQ Color & Appearance of Water

Why does tap water sometimes look milky or cloudy?

Milky or cloudy water is often caused by oxygen bubbles in the pipes that are released when the water leaves the tap. Cloudiness and air bubbles do not present a health risk. During colder months, water in outdoor pipes is colder and holds more oxygen than household pipes. Consequently, when the cold water enters your building and begins to warm, the oxygen bubbles escape and cause the water to look cloudy or milky. Construction in the distribution system can also allow air to enter the pipes and cause the appearance of cloudy water. Hot water can sometimes be cloudy due to dissolved gases in the water escaping as the water is heated. Cloudiness and air bubbles should naturally disappear in a few minutes.

You can test this by running the cold water into a clear container and observing it for a few minutes. If the water clears from the bottom to the top of the container, air bubbles are rising to the surface. If the water in the glass clears from the top-down, and white or grey particles settle to the bottom, this may indicate a water heater issue.

Why are my ice cubes cloudy or have white particles in them?

Ice crystals trap air as they form and the water freezes. This can make ice cubes appear cloudy. Minerals in the water and soap residue in the tray can cause ice cubes to stick to the tray. Try cleaning the ice cube trays with vinegar. Wash and rinse thoroughly before refilling with water.

Ice cubes freeze from the outside in. Ice is formed from pure water (hydrogen and oxygen) therefore the minerals such as calcium and magnesium normally found in the water sometimes end up as visible particulates in the core of the ice cube. The white particles are not toxic.

Why does my water sometimes look brown or yellow on first draw?

The internal plumbing of your house is likely the culprit if discolored water appears only for a minute or two after you turn on the tap. Many houses have galvanized iron pipes, when the zinc coating on the inside of galvanized iron pipe wears thin, the water becomes discolored as it comes in contact with bare iron. The longer the water sits in the pipes, the worse the discoloration will be. That is why this problem is most noticeable the first time you turn on the tap in the morning. If only a few taps are affected, only a portion of your internal plumbing has galvanized pipe.

After running your tap for a few minutes, clean water from the water main will replace the discolored water. If the discoloration bothers you, however, flush the tap until the water becomes clear and save the water for iron-loving plants. 

Why is my water constantly brown or yellow?
Light yellow to dark brown water is typically caused by a disturbance of pipeline sediments in the water main.

If the water’s speed becomes great enough, iron and manganese sediment lying on the bottom of the mains may get stirred up, resulting in discolored water. Any of the following circumstances may have created flow reversals or increased speeds in the water mains causing sediment to be disturbed:

  • The discolored water may be due to planned cleaning of the water main to remove pipeline sediments in your area.
  • A nearby water hydrant may have been knocked over due to a vehicle collision or maybe in use.
  • There may be some pipeline repair work (or construction activity) in the area and some valves may have been closed for this work.
  • Valve turning, routine maintenance, or main breaks.
  • Extremely high system demands or the start-up or shutdown of water treatment facilities.

Despite its appearance, this does not indicate that the water is unsafe or that the integrity of the water main has been compromised. A disinfectant residual is maintained at all times to ensure that the water is safe for household use, including cooking and drinking.

What should I do if my tap water has constantly brown or yellow water?

In most cases, the water will clear on its own within 2 hours or less. If your water is discolored:

  • Water use should be avoided if there are particles or sediment in the water. It may not be harmful but sediments can clog aerators and home filters. It is fine to use this water to flush toilets.
  • If possible, do not run the washing machine or dishwasher until the water has cleared.
  • Wait an hour for the system to settle, and then run water at one tap for up to five minutes to see if it clears. If it does not clear, wait another hour and try again. When the water runs clear, run water throughout the house to flush any sediment that may have been drawn into your pipes.
  • If discolored water has been drawn into the hot water system, the hot water can continue to be used until the discoloration dissipates and is no longer an aesthetic issue.
  • Customers may choose to drink bottled water while they wait for the discoloration to clear.
Why is my water blue?


Having blue water is rare. The blue disinfectant you use in your toilet can cause discoloration of your tap water. If your water supply was recently turned off, a condition may have been created in which water from the toilet tank was siphoned into the plumbing of your house. These disinfectants contain chemicals that may pose health hazards if ingested or touched. Flush your plumbing by opening each tap until the water runs clear. Do not drink this water.

Extreme copper plumbing corrosion, which is a rare circumstance, may create blue (or blue-green) water. If this is happening, the water will usually have a bluish-green tint and/or will leave a bluish-green stain around fixtures and on a white surface if the water drips from a faucet. This copper corrosion can be caused by your electrical system being grounded to your water pipes, especially if you have a mixture of pipe material (i.e., some copper and some galvanized iron).

Why does my water look green?


Standing water, such as in a white bathtub, will sometimes appear to have a greenish cast to it. Fluorescent lights will make your water appear green. To test this, fill a white bucket with water and take it outside. In the sunlight, the water will look clear and no longer appear green.