So—beer was certainly the primary beverage, but people still drank water without boiling it (which is, after all, rather time and energy consuming and requires a ready fire).

I have ready links to provide better context, and this is literally the most hated question on /r/AskHistorians, so I'm sure you could get rapid replies for follow-up questions. It's an extremely useful resource to tap into to get a professional historian with training in historiography to weigh in on arbitrary questions.

On the general claim of using alcohol to decontaminate water: https://old.reddit.com/r/AskHistorians/comments/ol1h45/delet...

On use of aqueducts in Britain to transport potable water: https://old.reddit.com/r/AskHistorians/comments/mnlf9n/when_...

On general access to fresh water: https://old.reddit.com/r/AskHistorians/comments/1svj1q/how_d...

On understanding of germ theory in water: https://old.reddit.com/r/AskHistorians/comments/676bg6/befor...

On poisoning wells: https://old.reddit.com/r/AskHistorians/comments/6qljlt/when_...

2nd one on poisoning wells: https://old.reddit.com/r/AskHistorians/comments/6kt7nh/poiso...

Addressing beer directly: https://old.reddit.com/r/AskHistorians/comments/2bewpo/what_...