Why does tap water sometimes look milky or cloudy?
Milky or cloudy water is often caused by air that enters pipes and escapes in the form of oxygen bubbles when water leaves your tap. Cloudiness and air bubbles do not present a health risk. During colder months, water in outside pipes is colder and holds more oxygen than your household pipes. Consequently, when the cold water enters your building and begins to warm, the oxygen bubbles escape and cause the water to look milky. Construction in the distribution system can also allow air to enter the pipes and cause the appearance of cloudy water. Cloudiness and air bubbles should naturally disappear in a few minutes. You can test this by running the water into a clear container and observing 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 cloudiness does not disappear, contact the DC Water Water Quality Division at 202-612 3440.
