The goal of wastewater management is to clean and protect water. This means that water must be clean enough so that it can be used by people for drinking and washing, and by the industry for commercial purposes. It also must be clean enough to release into oceans, lakes, and rivers after it has been used.
World’s water resource will not change but the amount of wastewater produced is increasing, and the infrastructure and management systems are not adequate for this increasing volume. Globally, two million tons of sewage, industrial and agricultural waste is discharged into the world’s waterways, and that is not counting the unregulated or illegal discharge of contaminated water. This wastewater contaminates freshwater and coastal ecosystems, threatening food security, access to safe drinking and bathing water and being a major health and environmental management challenge.
In particular, the way food is produced uses 70–90 per cent of the available fresh water, and much of this water returns back to the system with additional nutrients and contaminants. Further downstream, agricultural pollution is joined by human and industrial waste.