According to data from 1993, the amount of water used for flushing toilets for that year was about 13,600m3. 7000m3 of that was rainwater, and recycled drainage accounted for 4000m3. This means that within the City Office alone, 11,000m3 of water were saved during that one year. The Water Saving Devices report reviews the market for these products world-wide, assesses their market potential in the UK and examines what can be done to increase the uptake of this technology. Grey water is all waste water from baths, showers and hand basins, domestic appliances and fittings.
Black water is fouled water from toilets and bidets.
Grey water for toilet flushing can be supplemented by mains or rain water. The pay back time is reduced to 4-8 years in the South West where the price per M 3 is 2.30. Envirosink allows you to conserve the 'light' gray water from your kitchen. This is constructed of lapped limestone slate on a timber frame. The water collected drains down into a water tank which is located beneath the house.