To add into that if a glass ...
Published by Pule Lekone, Department of Defence(Engineering) - Engineer
To add into that if a glass of water appears milky, watch it for awhile. If the milkiness clears at the bottom first and gradually goes away, the milkiness was caused by air in the water. This condition has no health significance. Air in the storage tank or pressure tank (or well) has dissolved into the water. When the pressure drops (from in the pipe to in your glass) the air comes out (undissolves) forms tiny bubbles, floats to the top and rejoins the atmosphere.