104: Graywater Collection
“Graywater waste (baths, tubs & laundry waste) must be plumbed separately from black water waste soruces such as commode & kitchen / dishwasher"
Graywater re-use for New Homes is simple if the Plumbing Design is changed to Dual Waste prior to pouring the foundation.
It’s really quite simple. Just have all baths, tubs and laundry waste plumbed to a second waste pipe, looped back into the black waste line, at least 6’ from the foundation — leaving room for the pumping basin for later installation, or install the basin at the same time as foundation plumbing rough-in.
We have found the average additional cost for dual plumbing in a new home ranges from $300—$400; a very small investment for the future landscape potential and protection provided.
Avoid Hand Basins / Lavatories.
Although waste water from these sources is classified as Graywater, our experience is this water is better utilized in the black water line, assisting in washing kitchen and commode solids down the line.