Not a drop goes out
Green buildings are adroit in water and waste management
Water consumption by building industry is not limited to use in toilets and kitchens alone. When a building is getting constructed, it consumes huge amounts of water. There is little data on the water footprint of buildings but available figures paint a grim future. According to usgbc, buildings account for over 12 per cent of potable water consumption in the us and almost 65 per cent of waste output comes from building construction sector. The us Environment Protection Agency (usepa) estimates that nearly 40 per cent of water consumed in a household goes for flushing purposes. Toilets, showers, and faucets combined represent two-thirds of all indoor water use. The average American uses about 34,000 litres of water to flush 870 litres of waste down the toilet per year, estimates usepa.Effective from January 1, 1994, the Energy Policy Act of 1992 (Public Law 102-486) requires that all new toilets produced for home use must operate on 6 litre per flush or less.
In Australia, building construction consumes 15 per cent of total water use. In the uk, more than 30 per cent of the total domestic water use goes into flushing toilets. In India, flushes are water-wasteful: with each flush, over 10 litres of clean water goes down the drain (Ecologically Mindless, Down To Earth, February 28, 2002).
A major aim of green building is to save water and minimise waste/sewage generation. Some buildings go in for water harvesting and water recycling, whereas others adopt technologies that minimise water consumption and wastage. Experts claim that green buildings consume 30-40 per cent less water than conventional buildings. Most green buildings are zero discharge structures: not a drop of water or sewage leaves their premises. Rainwater is harvested either to recharge groundwater or collected in a pond and reused for gardening and flushing. Sewage and grey water is collected separately and treated on campus and reused for non-potable purposes. Hence, there is a huge reduction in total water consumption. And there are various ways of reducing water consumption in a building/household (see box : Water less).