There are many things that can give drinking water bad taste and smelly odors. It could be chemicals used to treat your drinking water, environmental contaminants or even concentrations of metal that have been cast off in old plumbing pipes.
Metals, like copper, iron, and lead found in tap water have their own unique smells and tastes. Usually copper and iron appear in low concentrations and are not harmful, although they can discolor your water. Rusty brown water is a result of high amounts of iron. Iron will stain and destroy everything from pipes to appliances and your favorite t-shirt; however, it is more of a taste concern than health concern.
There are things you can do to reduce the risk of lead in your drinking water. Some sources suggest running your tap water for a couple of minutes before filling a glass to flush any accumulated lead from the water line (lead dissolves into standing water over time). This isn’t a foolproof solution, however, since there is no way of knowing whether all of the lead has been removed. Also, lead can still dissolve into running water.