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

We have our shower and washer water just run out the side of the house as grey water vs the septic tank. Not reuseing technically though. Worried prob stink after a while if not flushed right away