It does not go bad. If stored in plastic, the plastic can start to break down- usually a year or two. Glass- until the metal lid rusts through. It can pick up flavors from the container. If the water was chlorinated, no harmful organisms can grow in it.
Remember- all of the water on earth has been here since Genesis 1, verse 2. It just gets recycled by evaporation/ condensation.
What we have heah is.... failure to communicate.