The water? America has extraordinarily clean water systems overall, among the best in the world in fact. It also has one of the highest renewable water foundations (trailing only Brazil, Russian and Canada). It's also very diverse, some cities are much better than others. The notion that a person moving from China to America would worry about the water is borderline comical.

Most of America's cities have an overly abundant supply of clean drinking water. Those that don't are almost always situated in a desert.