Safe use of wastewater, excreta and greywater

Growing world population, unrelenting urbanization, increasing scarcity of good quality water resources and rising fertilizer prices are the driving forces behind the accelerating upward trend in the use of wastewater, excreta and greywater for agriculture and aquaculture.

The health risks associated with this practice have been long recognized, but regulatory measures were, until recently, based on rigidguideline values whose application often was incompatible with the socio-economic settings where most wastewater use takes place.

In 2006, WHO published a third edition of its Guidelines forthe Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture. In four volumes, these Guidelines propose a flexible approach of risk assessment and risk management linked to health-based targets that can be established at a level that is realistic under localconditions. The approach is to be backed-up by strict monitoring measures.