Greywater is defined as water from showers, baths, hand basins in the bathrooms and washing machines. It does not include water from the toilets, kitchen/scullery sinks or dishwasher (classified as black water).
grey water harvesting over at “monchasha”
Greywater is all wastewater generated in households or office buildings from streams without contamination, i.e. all streams except for the wastewater from toilets. Sources of grey-water include, sinks, showers, baths, clothes washing machines or dish washers. 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 use of non-toxic and low-sodium soap and personal care products is recommended to protect vegetation when reusing grey water for irrigation purposes. 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 as well as the wastewater subsystems by reducing the amount of wastewater required to be conveyed and treated.
In constructed wetlands, the plants use contaminants of greywater, such as food particles, as nutrients in their growth. However, salt and soap residues can be toxic to microbial and plant life alike, but can be absorbed and degraded through constructed wetlands and aquatic plants such as sedges, rushes, and grasses. This type of Grey Water Harvesting Model is used over at Monchasha Rural Tourism Project.