Overreacting to Risk

This is a crazy overreaction:

A 19-year-old man was caught on camera urinating in a reservoir that holds Portland's drinking water Wednesday, according to city officials.
Now the city must drain 38 million gallons of water from Reservoir 5 at Mount Tabor Park in southeast Portland.

I understand the natural human disgust reaction, but do these people actually think that their normal drinking water is any more pure? That a single human is that much worse than all the normal birds and other animals? A few ounces distributed amongst 38 million gallons is negligible.
Another story.