According to Water-UN, the costs of wastewater management are greatly outweighed by the benefits to human health, the economy and the environment. It can create new businesses, create “green jobs”, and help conserve a scarce resource. In 2017, Water-UN calls for wastewater to be seen as an untapped resource in agriculture, business and everyday life.
“Wastewater is a valuable resource in a world where water is finite and demand is growing,” says Guy Ryder, Chair of UN-Water and Director-General of the International Labour Organization. “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. It’s all about carefully managing and recycling the water that runs through our homes, factories, farms and cities. Let’s all reduce and safely reuse more wastewater so that this precious resource serves the needs of increasing populations and a fragile ecosystem.”
But what are some of the ways we could use wastewater? Globally, there are a number of initiatives that aim to treat wastewater through environmental enhancements, industrial reuse, agricultural irrigation, landscape irrigation and other non-potable urban uses. In a report compiled by researchers Jonathan Lautze, Emilie Stander, Pay Drechsel, Allegra K. da Silva and Bernard Keraita, it was found that properly treating water could help in meeting the total water needs in many nations but the dialogue around water reuse needs to be increased in all corners of the globe.
The idea of repurposing wastewater is not new. For 45 years, the city of Windhoek in Namibia has reclaimed potable water from its municipal sewage system. Now, its New Goreangab Water Reclamation Plant completed in 2002 has made the process even more efficient. According to the UNEP/SEI sanitation reuse book, reclaimed water constitutes about 35 per cent of the water supplied to households in Namibia.
Water scarcity is also extreme in several Brazilian cities. As a result, they rely on several water conservation practices. In Vitória, apartment buildings have incorporated building-level grey water reuse. According to the Stockholm Environment Institute, this system uses systems that collect separated greywater, minimally treating it, and then making it available for various non-potable uses, including flushing toilets, washing public spaces and garden irrigation. “Some buildings are able to save up to 30 per cent of potable water as a result,” says the institution.
In the deserts of Egypt, a farm outside of the city of Gerga in Sohag uses treated sewage wastewater to irrigate and fertilise crops in an otherwise dry and arid environment, fertilising the otherwise infertile soil in the process. This system is able to simultaneously save water and meet a growing need for food.
To see more global wastewater case studies check out the book released by SEI and the United Nations Environment Programme (UNEP) in 2016.
World Water Day, on 22 March every year, is a call to action around the world. Today, there are over 663 million people living without a safe water.