Graywater

Greywater (also spelled gray water) refers to domestic wastewater generated in households, office buildings, hotels, commercial laundries, etc. from streams without fecal contamination, i.e., all streams except for the wastewater from toilets. Sources of grey water include sinks, showers, baths, washing machines or dishwashers. As grey water contains fewer pathogens than domestic wastewater, it is generally safer to handle and easier to treat and reuse onsite for toilet flushing, landscape or crop irrigation, and other non-potable uses.

The application of grey water reuse in urban water systems provides substantial benefits for both the water supply subsystem, by reducing the demand for fresh clean water, and the wastewater subsystems by reducing the amount of wastewater required to be conveyed and treated. Because of the presence of hairs and other fibers in greywater, Forsta sizes filters with wedge wire screens to prevent debris from stapling.