Beer and society have been inseparable companions for thousands of years. Literally, the two have gone hand in hand. All the thoughts, feelings, and beliefs the colonists brought with them to North America were the result of society's millennia-old marriage with beer. Indeed, drawing a fresh mug of ale was, at that time, as indispensable as drawing a breath. More than a mere cultural habit, beer drinking evolved into a healthful practice.
Brewers have to boil water to make beer, thus killing the microbes that imperil health.
In England, Parliament tried to enact laws against pollution, but it was too late to prevent widespread disease. Nearly every supply was horribly tainted. True enough, the pristine streams running through the virgin forests of the new land were pure and clean, but still, the settlers simply wouldn't drink the water, because they brought with them frightening memories of their homelands' deteriorating water supplies. There, rivers and streams were becoming the equivalents of flowing dumps. By the mid-1400s the bias against drinking water in Europe was deeply ingrained.