Toilet to tap water is becomming real. It's the brave new world of water shortage. Brace yourself for more jolts like this.
San Diego is now using reclaimed wastewater (after treatment) in city water supplies. It took some time for people to get over the yuck factor, but the resistence has mostly subsided. Drought and rationing did a good job of letting people know why the idea was proposed.
And it's not really that new. Forever we've been drinking water from someone else's waste stream, we all live downstream from somebody. The new approach makes it a little more direct, but also a lot more carefully treated.
It won't be long before there's no such things as "waste" water.