Time to Cure Sick Water

Transforming wastewater from a major health and environmental hazard into a clean, safe and economically-attractive resource is emerging as a key challenge in the 21st century. This is a challenge that will continue to intensify as the world undergoes rapid urbanisation and industrialisation and as demand for meat and other foods continue to rise.

Global populations are expected to exceed nine billion by 2050. Urban populations are projected to almost double in the next 40 years, from the current figure of 3.4 billion to over 6 billion people. Most cities already lack adequate wastewater management due to aging, absent or inadequate sewage infrastructure, however.

The report, entitled Sick Water?, describes how the way we produce our food uses 70-90% of the available fresh water. Much of this water is returned to the system with additional nutrients and contaminants. We have created a domino effect as downstream agricultural pollution is joined by human and industrial waste. This wastewater contaminates freshwater and coastal ecosystems, threatening food security, access to safe drinking and bathing water and providing a major health and environmental management challenge. Some two million tons of waste (up to 90% of wastewater, estimated to equal two or more billion tons), is being discharged daily into rivers and seas, spreading disease to humans and damaging key ecosystems such as coral reefs and fisheries. Marine dead zones already cover an area of 245,000 km2, approximately the same area as all the world's coral reefs.

The sheer scale of dirty water now means that more people die from contaminated and polluted water than from all forms of violence including wars. Over half of the world's hospitals beds are occupied with people suffering from illnesses linked with contaminated water.

However, many of the substances that make wastewater a pollutant (for example, nitrogen and phosphorus) can also be useful as fertilisers for agriculture. Wastewater can also generate gases to fuel small power stations or be used for cooking. The report notes that already some 10% of the world's population is being supplied with food grown using wastewater for irrigation and fertiliser. With better management and training of farmers, this could be substantially increased.

The report, launched to coincide with World Water Day, goes so far as to say that "Meeting the wastewater challenge is thus not a luxury but a prudent, practical and transformative act, able to boost public health, secure the sustainability of natural resources and trigger employment in better, more intelligent water management."