EACH member of an urban household uses at least 100 liters of water for drinking, washing and bathing. Of this volume, about 90 percent is disposed into the environment as wastewater (grey water).

The efficient reuse or recycling of "grey water" can significantly reduce water consumption, produce food like vegetables and fish and minimize environmental pollution.

Valentine's 2009 blog

To reduce the use of potable water in the household, the flushing of toilets with laundry wastewater can be done. One toilet flush requires 20-40 liters of water. Laundry wastewater applied at 1.28 liters per cubic meter per day was found to be a good liquid fertilizer for tilapia production (0.87 kg/m2 per day) in a backyard pond by Aquatic Biosystems (ABS), a private R&D firm, monitored by the PCAMRD-DOST.

In studies conducted by ABS on the use of human urine and kitchen wastewater for vegetable production, results showed that fertilization of pechay (Brassica compensis) with 10% human urine and 90% tap water gave a higher yield compared to that of the control (tap water only). The use of kitchen wastewater only and a combination of kitchen wastewater (90%) and human urine (10%) had a similar or better yield than that of the control respectively, for sweet potato vegetation after a month of culture in pots.

Household or domestic wastewater is a major pollutant of freshwater bodies (lakes and rivers) in areas of the country that lack adequate wastewater treatment facilities. The reuse or recycling of "grey water" will not only minimize aquatic pollution but also enhance food production and reduce the consumption of potable water in households. (Press release)