eli5 Is there a reason the waste water like from showers can’t be filtered through pipes and used for toilet water?

Question

eli5 Is there a reason the waste water like from showers can’t be filtered through pipes and used for toilet water?

In: 797

Answer 1

Yes because it would require adding a whole separate system of drain pipes to every home all the way to mains that feed into a plant meant to handle just that water. It’s cost prohibitive.