I hope someone is closely watching the reservoirs that supply NYC's water.
How we use them is up to us.
But if you act now, we'll even throw in some new, yes I said new, tactical neutron weapons at absolutely no charge. Delivered right to your door (or cave entrance).(Warning: Do not taunt Happy Fun Ball.)
Well, hopefully a keen eye would notice suspicious tanker trucks lining up at the reserviors, since it would take an awful lot of bad stuff to effect an entire water system.