Here is a great Gray Water Study done by some college students that addresses the main concerns of residential gray water reuse.
It is strange that gray water is such an under developed industry since it is such an important part of green building everywhere. Eco Brooklyn is currently designing three gray water systems for residential New York brownstones. The gray water is collected from showers, tubs, laundry and bathroom sinks then is passed to the toilets and to the green areas outside the house (green roof, living wall, eco garden, rain garden).
What happens in between is the tricky part. How much it gets cleaned before it reaches the toilets and how it gets there are the real questions. We will be there soon and we’ll let you know.