Cloudy Water
Cloudy water is usually caused by temperature change and the presence of dissolved air in the water. It is very common in the winter and can last for quite a long time.
When water appears to have a milky white, gray, or carbonated appearance a simple test may suffice to denote its origin. Fill a clear glass with tap water and observe it over a minute or so. If the glass clears from bottom to top, then it is dissolved air escaping into the atmosphere.
There is no health risk associated with this situation.

Learn about other Common Water Quality Concerns.