Why is my water cloudy or milky?

Once in a while, you get a glass of water and it looks cloudy; maybe milky is a better term. After a few seconds it miraculously clears up! The cloudiness might be caused by the water in the pipes being under a bit more pressure than the water in the glass, but is more likely due to tiny air bubbles in the water. Like any bubble, the air rises to the top of the water and goes into the air above, clearing up the water. Cloudy water, also known as white water, is caused by air bubbles in the water. It is completely harmless.

It usually happens when it is very cold outside because the solubility of air in water increases as water pressure increases and/or water temperature decreases. Cold water holds more air than warm water. In the winter, water travels from the Tanks which is very cold and warms up during its travel to your tap. Some of the air that is present is no longer soluble, and comes out of solution.

Also, water pressure has something to do with it. The water in the pipes is pressurized to a degree (which helps to get the water all the way from the water tower to your home). Water under pressure holds more air than water that is not pressurized. Once the water comes out of your tap, the water is no longer under pressure and the air comes out of solution as bubbles (similar to a carbonated soft drink). The best thing to do is let it sit in an open container until the bubbles naturally disappear.