Residents who have lived in the City for sometime (and more so in a high rise), are probably used to this happening on occasion. It is rare enough to catch you off guard, but does happen from time to time. Especially in the winter. Understandably, folks who’ve never observed this condition might worry. And this year, with another very cold winter, management has gotten several calls about this happening. We will of course send maintenance to make sure it’s not something else, and will make sure faucet aerators are clear and functioning.
However, there is no cause for concern. If you fill up a glass of water, and it almost looks like milk, just give it a few seconds. Pressure and temperature changes are forcing air that has dissolved to escape as very tiny air bubbles. It’s completely harmless, it just looks a little odd especially when you are expecting a crystal clear glass of water. A post at www.usgs.gov explains this phenomenon:
http://water.usgs.gov/edu/qa-chemical-cloudy.html