[Suzerain of Sheol]

Wormwood, in the Book of Revelation, is a "star" that falls into the ocean and makes 1/3 of the earth's water undrinkable. It's actually a metaphor for "times of strife" layered over itself about three times.

In the RP, just assume it's some kind of element in the water, not radioactive, just highly poisonous. How did it get there? The same way the sun no looks like a pie-piece. A wizard God did it. :p

Edit: Suzerain knows less about drinks than Espy. :p