The internal plumbing of your house may be the culprit if discolored water only appears for a minute or two after your tap is turned on. When the zinc coating on the inside of galvanized iron pipe begins to wear thin, water becomes discolored as it comes in contact with bare iron. The longer the water sits in the pipes, the worse the discoloration will be. That's why you are most likely to notice the problem first thing in the morning or when you have just returned from being out of your home for some period of time. After running your tap for a few minutes, clean water from your water heater or water main will replace the discolored water. Since iron is an essential nutrient, this condition poses no health hazard. If the discoloration bothers you, however, flush the tap until the water becomes clear.