In the event of an emergency landing or mission abort, potable water would have been of paramount importance for the astronauts. Drinking water was included in one of the two emergency rucksacks stowed in the command module.
This container was flown on Apollo 15, in July/August 1971. It was transferred from NASA to the Smithsonian in 1978.
This object is on display in Human Spaceflight at the Steven F. Udvar-Hazy Center in Chantilly, VA.