Inventing Wine': The History Of A Very Vintage Beverage"You've got to remember [that] for thousands of years, if you lived in a town or a village, the water was pretty undrinkable. ... [I]f you lived in ancient Athens or if you lived in ancient Babylon or Alexandria, you couldn't drink the water, so wine was something that people drank from morning to night. Babies drank it; old people drank it; soldiers drank it; everybody drank wine all the time, and in order for them not to be falling down drunk by 10 in the morning, they mixed it with water and used it to sanitize or purify the water."
https://www.npr.org/2012/12/04/166186416/inventing-wine-the-history-of-a-very-vintage-beverage