I dumped a gallon of LSD into the city's water supply
Why would you try to drug an entire city?
I could not resist to test what the consequences would be if people would shape their thinking patterns based on delusions.
You shouldn't have dumped LSD in the water supply. People can get sick or do unexpected things because of the LSD. Then you will be considered a terrorist.
People are already going to be affected by the drugs that they consume. I don't see the point of this question.
They do not know about this though so it will cause mass hysteria. You should never mess with the water supply for an entire city.