Random thoughts just popped in my head and I just remembered that all the water in a given city is all centralized. Just add poison and boom, eradicated an entire city who are full of dissidents/opposition as punishment for voting the “wrong” way, or for a protest, or if the population is filled with “filthy undesirable [Insert Racial Group Here]”, or something like that.
Kinda unsettling to see that we are all just attached to “the grid” 😖
Not only that, the water supply is linear, so to keep the water dangerous, you gotta keep adding the substance.
Just worth pointing out, changing water source in Flint Michigan and not adding corrosion inhibitors seemed to do an excellent job for a short period.
Oh yeah, that is the other way of poisoning a water supply, sabotage it so that it keeps poisoning itself
See also the Camelford disaster