Altair water was a beverage exported from the Altair system and served on such planets as Earth. Spock was known to drink Altair water.
In 2285, Leonard McCoy, who was under the influence of Spock's katra, ordered a glass of Altair water at a bar he frequented on Earth. (Star Trek III: The Search for Spock)
According to the first draft of the
Search for Spock screenplay, Altair water came from Altair IV.