Recycled water that is potable goes through a rigorous purification process designed to filter out and kill off anything that would make us sick. Once it’s done, the water is completely safe to drink, said Brent Haddad, a professor of environmental studies at the University of California, Santa Cruz.

“It is so clean that you have to add back minerals for flavor,” Haddad said. “It comes out the equivalent [of] distilled water.”

Our repulsion to drinking recycled sewage can be explained by one of the principles underlying human beliefs called “magical contagion.”