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

It is best for the cleanliness of the inside of your toilets to keep fresh, clean water in and dirty water out.

Also waste water is treated at water treatment plants and then recirculated. It is very hard for water to be cleaned so large plants are needed. It must be centralised because of this.