Wastewater — the untapped resource

World Water Day is held annually on 22 March as a means of highlighting the importance of freshwater and advocating for the sustainable management of freshwater resources by tackling the water crisis. Each year, World Water Day highlights a specific aspect of freshwater—2017’s theme is Wastewater. Globally, wastewater from residential, industry and agriculture flows back into the environment without being treated or reused—over 80 percent of it and over 95 percent in some less developed countries (https://www.unesco.org/ new/en/natural-sciences/environment/water/wwap/wwdr/2017-wastewaterthe- untapped-resource/).

On the occasion of World Water Day 2017, Ms Irina Bokova (Director- General of UNESCO) highlighted in her message that “in the face of growing demand, wastewater can be a reliable alternative source of water—this calls for shifting the paradigm of wastewater management from treatment and disposal to reduce, reuse, recycle and resource recovery”.

Ms Bokova also emphasised that wastewater should be seen as part of the solution as it can be a cost-efficient, environmentally friendly, safe and reliable alternative source of water for a variety of purposes, particularly under conditions of water scarcity. As such, improved wastewater management—balancing development with the conservation and sustainable use of natural resources—is crucial in order to reap the benefits of wastewater reuse.

“Everyone can do their bit to achieve the Sustainable Development Goal target to halve the proportion of untreated wastewater and increase safe water reuse by 2030,” urged Guy Ryder, Director-General of the UN International Labour Organization (ILO) and Chair of UN-Water.

Sustainable Development Goal 6 (SDG6) has specific targets for halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally (target 6.3), as well as supporting countries in wastewater treatment, recycling and reuse technologies (target 6.a).