The collection, storage, treatment and redistribution of laundry and bathing effluent for toilet flushing, irrigation, janitorial cleaning, cooling and laundry washing.
Water conservation technologies are being developed to reduce the cost of municipal infrastructure and to increase opportunities for development. In addition, limited water supplies may be insufficient for population requirements. The use of greywater may increase capacity for population growth or development without the need for additional water resources.
Typically, water conservation techniques are applied in order to reduce the consumption of water for individual applications, such as bathing or toilet flushing.
The alternative approach - recycling - recognizes that wastewater and the entrained nutrients are recoverable resources. The whole-system life-cycle costs may be reduced by appropriate water management techniques on a small scale.
In a recycling system, wastewater is collected, treated, stored and re-distributed for appropriate uses within the house or community.
The amount of fresh make-up water required depends on normal losses, such as evaporation and spillage.
The break-even point is between fresh-water supply costs and in-house treatment costs.
The level of treatment (and associated costs) is determined by the intended utilization of the recycled water:
Depending on the extent that the water can be recycled, for various purposes, the net water demand can be reduced towards zero.
Municipal infrastructure costs can be reduced and a secure supply of safe water can be ensured in otherwise difficult-to-service regions.
Greywater recycling technology is most readily applied to new buildings where:
Cost depends on the: