Mugi no Mahoutsukai

[MangaDex]

 

[DanYHKim]

There was a time when drinking water was unsafe for everyone! People routinely drank small beer (low alcohol beer) and regular beer, to avoid it. They also drank boiled water, such as tea.

In the book "The Ghost Map", about a London cholera epidemic, one population that did not get sick were people working for a brewery.
https://www.amazon.com/Ghost-Map-Londons-Terrifying-Epidemic/dp/1594482691

 

[Levanah]

@DanYHKim

Water from springs and rivers was still the primary source of hydration for most of the population. People in that time already had some unsophisticated ideas in identifying safe sources of water.

Some further reading on the matter:

http://www.slate.com/blogs/quora/2013/05/21/medieval_europe_why_was_water_the_most_popular_drink.html

https://leslefts.blogspot.com.au/2013/11/the-great-medieval-water-myth.html

http://www.medievalists.net/2014/07/people-drink-water-middle-ages/

 

[DanYHKim]

You have a good point.

The London of "The Ghost Map" was way more modern than the middle ages, with a huge population, but little infrastructure to handle the huge burden of sewage.

I was overgeneralizing into the wrong time period.