Wastewater and excreta are commonly seen as useless and potentially dangerous waste products. However, they are indeed valuable resources, which if utilized correctly, can serve to improve ecosystem health and human wellbeing. The rich organic matter contained in our excreta and wastewater can be used to improve soils or produce clean-turning, low-carbon biogas – and if properly treated, wastewater can be used for agricultural irrigation or even clean drinking water. Putting these resources to productive use is important, but for this to happen, a shift in public perception is needed – from seeing these products as an inferior waste product to seeing them as a valuable commodity, as part of a circular economy.

The book looks beyond human health, marine environment protection and resource recovery to the many other ways that sustainable sanitation and wastewater systems can contribute to meeting the social, environmental and economic goals of the 2030 Agenda for Sustainable Development. It highlights job opportunities along the entire sanitation and wastewater value chain of this circular economy as well as potential gains for education, economic productivity and gender equality.

In addition to the emerging circular economy approach, in recent years there has been a stronger focus on business models linked to sanitation and wastewater management, especially from a resource recovery perspective. The book highlights some lessons learnt on this topic and focuses on creating business models, for example, the use of faecal sludge to make briquettes for household cooking.

The book is a joint effort, across a global network of researchers and practitioners, to collect successful approaches and experiences which represent diverse geographic and socioeconomic contexts, as well as multiple challenges and potential solutions.

This publication was funded jointly by UNEP Global Programme of Action for the Protection of the Marine Environment from Land Based Activities (GPA) and SEI.