Published on The Water Blog

Putting our waste to work for green growth

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Men are making a toilet, Bangladesh 2019 Men are making a toilet, Bangladesh 2019

On World Toilet Day, we raise awareness of the value of safe sanitation for all. We can all recognize the importance of toilets for dignity, health, and safety. But less well known is how valuable they can be for mitigating climate change and promoting sustainable development. 

The toilet is often taken for granted. But without it, we cannot prevent the spread of disease, protect the environment, keep our children in school, or maintain productive economies. 

In 2020, nearly half the world’s population is living without access to safely managed sanitation.  We need investment and innovation across the sanitation sector, from toilets to the transport, collection, and treatment of human waste, if we are to meet the sixth Sustainable Development Goal of water and sanitation for all by 2030. 

Poor sanitation is exacerbated by climate change. Floods and rising sea levels threaten sanitation facilities and can spread human waste into water sources and food crops, while extreme drought puts pressure on already scarce water resources for flushing sewage systems. 

Conversely, poor sanitation also reinforces the effects of climate change. Globally, 80 percent of wastewater generated flows back into the ecosystem without being treated or reused, and poorly managed wastewater is estimated to generate up to 9 percent of human-caused global methane emissions. Methane does not have the long-lasting effect that carbon dioxide has, but it is up to 34 times stronger. This makes methane control an area where we can make significant and rapid progress in the fight against climate change alongside our work towards longer-term decarbonization. 

Human waste is a liability—but it also presents us with an opportunity. Today, as we mark World Toilet Day, we would like to shift the conversation from human waste as a risk to a resource. We need sanitation systems that can mitigate and adapt to the changing demands of climate change. Safely reusing human waste saves water; reduces and captures greenhouse gas emissions; and can provide the agricultural sector with a reliable source of water, fertilizer, and nutrient-rich by-products. 

The World Bank Group is at the forefront of supporting innovation in this area.  

In 2018, we launched the Wastewater: From Waste to Resource initiative in Latin America and the Caribbean to address the wastewater challenge and raise awareness among decision makers about the potential of wastewater as a resource. Only about 60 percent of people in the region are connected to a sewerage system, and only about 30–40 percent of collected wastewater is treated. Using a circular economy approach to processing wastewater could transform sanitation from a costly service to one that is self-sustaining and adds value to the economy. 

In Ecuador’s largest city, Guayaquil, recent investments in wastewater collection and treatment are already improving water quality and reducing pollution. Two new wastewater treatment plants—currently under construction and bidding—incorporate co-generation facilities to transform biogas derived from sewage sludge digestion into electricity. This could potentially generate up to 35 percent of the onsite power needed to run the treatment plants.

Senegal’s Greater Dakar area consumes more than 445,000 m3 of water each day, but only 126,000 m3 of wastewater is collected by the sewerage system, and, of that, just 28 percent is treated.  The World Bank Group is supporting the National Sanitation Office of Senegal as it explores and implements several circular economy opportunities to improve water security, such as reusing waste under certain conditions for irrigating land and improving soil quality. 

This is a start. But to achieve real impact we need to move away from ad hoc and isolated wastewater projects to fully integrated and well-planned sanitation solutions for a sustainable future. 


Jennifer J. Sara

Global Director, Climate Change Group, World Bank

Ndeye Awa Diagne

Young Professional, World Bank

Nishtha Mehta

Water Supply and Sanitation Specialist

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