Why is New York City's water so contaminated?

New York City's water is not contaminated. It is among the best tap water of any city in the world.

New York City's water supply comes from the Catskill Mountains watershed in upstate New York. As New York City is at sea level, and the Catskill Mountains are upstate, the city does not have to do much to get the water here. It basically just flows downhill from upstate springs, straight to the city. That is why New York City tap water is so good.

In fact, New York City is one of only four major U.S. cities that has tap water so pure, it does not need to be purified by a water treatment plant.