Drinking water delivered through the municipal system can sometimes look “milky” or “cloudy.” This cloudiness often occurs when air becomes trapped in the tap water. While this may impact the water’s appearance, it does not affect the water’s safety and will not harm household plumbing systems.
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 reservoir 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 the solution.
Source of Air in the Water
Air can be introduced in many ways and because water pipelines are pressurized, air remains trapped in the water until you open the faucet. This release of pressure is similar to the effect created when you open a bottle of soda. The thousands of tiny air bubbles that form give the water a slightly white appearance.
Cloudy Tap Water Test
There’s an easy way to test whether cloudy water is due to trapped air. Fill a glass with tap water and set it on the counter. Observe the water for a minute or two. As the air dissipates, water should start to clear up.
Trapped Air & Water Quality
It’s important to understand that this cloudy appearance does not reduce the water’s quality. Our Water Quality Technicians collect and analyze hundreds of drinking water samples a year from throughout our distribution system to ensure that your tap water meets or surpasses all drinking water requirements.