Most human activities that use water produce wastewater. As the overall demand for water grows, the quantity of wastewater produced and its overall pollution load are continuously increasing worldwide. Over 80% of the world’s wastewater – and over 95% in some least developed countries – is released to the environment without treatment. Once discharged into water bodies, wastewater is either diluted, transported downstream or infiltrates into aquifers, where it can affect the quality (and therefore the availability) of freshwater supplies. The ultimate destination of wastewater discharged into rivers and lakes is often the ocean with negative consequences for the marine environment.
The 2017 edition of the United Nations World Water Development Report, entitled “Wastewater: The Untapped Resource”, demonstrates how improved wastewater management generates social, environmental and economic benefits essential for sustainable development and is essential to achieving the 2030 Agenda for Sustainable Development. In particular, the Report seeks to inform decision-makers, government, civil society and private sector, about the importance of managing wastewater as an undervalued and sustainable source of water, energy, nutrients and other recoverable by-products, rather than something to be disposed of or a nuisance to be ignored. The report’s title reflects the critical role that wastewater is poised to play in the context of a circular economy, whereby economic development is balanced with the protection of natural resources and environmental sustainability, and where a cleaner and more sustainable economy has a positive effect on the water quality. Improved wastewater management generates social, environmental and economic benefits, and is essential to achieving the 2030 Agenda for Sustainable Development.