Drinking water delivered through the municipal system can sometimes look "milky" or "cloudy." This cloudiness often occurs when air becomes trapped in the water. While this may impact the water's appearance, it does not affect the water's safety and will not harm household plumbing systems.
Air can be introduced in many ways, including the groundwater pumping process, water pipeline maintenance, or the process of bringing cold groundwater to the warmer surface.
Because water pipelines are pressurized, air remains trapped in the water until you open the faucet and release the pressure—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.
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.
It's important to understand that this cloudy appearance does not reduce the water's quality. Technicians collect and analyze thousands of drinking water samples a year from throughout the Water District's service area to ensure that tap water meets or surpasses the standards of the federal Safe Drinking Water Act.