Wastewater is the new black!

To achieve the Sustainable Development Goals (SDGs) we need to recognize wastewater and sanitation waste for what they are – a valuable resource – and their safe management as an efficient investment in long-term sustainability.

Sanitation, Wastewater Management and Sustainability: From Waste Disposal to Resource Recovery suggests that just the 330 km³ of municipal wastewater produced globally each year is enough to irrigate 40 million hectares – equivalent to 15% of all currently irrigated land – or to power 130 million households through biogas generation. When excreta from on-site systems such as pit latrines – still common across much of the world – and other organic waste such as livestock and agricultural residues and food waste are included, the potential for productive reuse gets much greater.

Furthermore, these waste streams are a rich source of plant nutrients essential for agriculture; globally produced municipal wastewater alone contains the equivalent of 25% of the nitrogen and 15% of the phosphorus applied as chemical fertilizers, as well as vital micro-nutrients and organic matter that chemical fertilizers lack. In just one day, a city of 10 million flushes enough nitrogen, phosphorus and potassium to fertilize about 500,000 hectares of agricultural land. In poor rural areas resource recovery could be a lifeline for small farmers.

The book presents many examples from around the world – from luxury condos in Brazil to the deserts of Egypt to the streets of Ouagadougou – where sustainable sanitation is already being used successfully. “The conclusion is clear: we can no longer ignore what comes out of the other end of the pipe,” says SEI Senior Research Fellow Arno Rosemarin, one of the book’s co-authors.

Sanitation and sustainability

One of the key themes running through the book is how sustainability in sanitation and wastewater management can contribute to so many other aspects of sustainable development. As this year’s Stockholm Water Prize Laureate, Professor Joan Rose, pointed out at World Water Week’s opening session, failures in sanitation and wastewater management are a leading cause of the degraded water quality afflicting around 5 billion people, and the deaths (to which we can add stunting and educational disadvantage) of millions of young children.

However, according to an analysis carried out by the authors, sustainable sanitation systems that protect people and ecosystems – while keeping valuable resources “in the loop” – can contribute significantly to no fewer than 32 targets in the Sustainable Development Goals, in areas as diverse as food security, gender equity, education, green business and climate change.

“Throughout history, sanitation has catalyzed development,” says Kim Andersson, an SEI Research Fellow and head of the SEI Initiative on Sustainable Sanitation. “We’re at a point where it can really do that again. I’d go so far as to say that a transition to sustainable development cannot happen without a radical rethink of the way we deal with our excreta and wastewater.”

The book promises to be a key text in a growing movement to frame wastewater as a resource issue. This trend is clear not only in the number of sessions this year on wastewater and resource recovery, but also in the theme announced for next year’s gathering: “Why Waste Water”.

“It is encouraging to see resource recovery getting so much attention at World Water Week – now we need to help this trend carry beyond the WASH community to the many other sectors that stand to benefit. How we deal with excreta and wastewater should be front and centre in discussions about water, food security and health and the future of cities – in fact about development and human well-being,” says Sarah Dickin, Research Fellow at SEI.

Read a blogpost on the book by co-authors Sarah Dickin, Kim Andersson and Caspar Trimmer »

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