The short answer is: “Yes”. The long answer is the subject of this post.
In the abstract, if you have a clean container with nothing but water in it, and the container is sealed, the water should keep indefinitely. It starts with no bacteria. It is sealed, so no bacteria can enter. And there would be nothing in the container that any bacteria could use as food, to multiply. But that scenario is unrealistic.
Suppose that you buy bottled water, and keep it sealed. Will the water keep indefinitely? Perhaps not. A study of 57 different sources of bottled water, plus four samples of tap water, showed that many brands and types of bottled water contain bacteria, even in high amounts. Each water sample was tested for CFUs, colony forming units of bacteria. Each bacterial colony on a growing medium indicates at least one bacterium (because one or more bacteria are needed to give rise to each colony). (continue reading)