Local Knowledge About Catchment, Conveyance, Filtration & Storage

Because conventional wastewater plumbing lines combine black and greywater, separating the two for graywater reuse generally involves a parallel wastewater system that separates greywater from blackwater (from the toilet). Systems typically consist of a three-way diverter valve, a treatment assembly such as a sand filter, a holding tank, a bilge pump, and an irrigation or leaching system. The holding tank cools the water and temporarily holds it back from the drain hose. Systems can either be custom designed and built, or purchased as a package. Techniques include recessed or raised planter soilboxes, water injection without erosion, gravity or pressure leach chamber, and irrigated greenhouses. Some system components can retrofit existing irrigation systems. More compact commercial greywater units are also on the market.