You know, my neighbor to the w uses something like paint thinner or acetone when he does certain chemical attacks. I believe that this is done because he wants to thin out the cyanide into better nano particulates so his sprayer doesn't clog. Home made cyanide has to boil in order to increase it's potency. So maybe someone got scared of the drones and dumped their cyanide stock pile down the drain which eventually got back into the water reservoir or this is just a plain out genoicde attempt with what they had,