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” 😖
My city facilitated that a decade or two ago by building new indoor reservoirs specifically for water treatment. Now we have a small handful of facilities set upon for massive chemical insertion and holding about half a day’s worth.
That being said, you’d still need the cooperation of people at each site, security at each site, truckers and suppliers. But that’s only one city: multiply that by the thousands of cities plus now you’d need huge amounts of chemicals that someone would surely question. That’s a lot of moving parts.