Update: Dammit, I forget to mention the coolest thing about Zürich water! After treatment, the water flows through a glass tank with some daphnia in it (water

Update: Dammit, I forget to mention the coolest thing about Zürich water! After treatment, the water flows through a glass tank with some daphnia in it (water fleas). These are watched with a video camera and motion analysis done by computer. Apparently, they aren't just able to detect impurities by detecting differences in the way the daphnia move, they are capable of detecting individual compounds because they affect the daphnia differently...