the protagonist is drinking the water and they describe it as sweet tasting!
I’m sorry but if I entered a foreign place and the tap water tasted sweet, I would be highly concerned because water shouldn’t taste like anything and specifically concerned because it’s sweet… which could mean the water is contaminated with lead.
While it's true that a sweet taste in water could be a sign of lead, it could also be a sign of other factors such as dehydration, the presence of benign water impurities, or certain health conditions, and given the context, the case of dehydration fits rather well.
The adjective could have also been meant in a figurative sense rather than a literal one.
