Towards Brown Gold?: Reimagining off-grid sanitation in rapidly urbanising areas in Asia and Africa Once viewed as the 'the last taboo' in international development, sanitation is now considered pivotal for human wellbeing, productivity and health, and to realising all the UN Sustainable Development Goals (SDGs). Currently, 4.5 billion people lack safely managed sanitation with about 700 million defecating in the open (WHO 2019) exposing them to various health hazards. Work and time burdens as a result of unmet or poor sanitation are disproportionate for these  marginalised groups (especially women)  who are not only users of inappropriate services, they are often the service providers of high-risk, poor quality sanitation facilities and infrastructure. BROWN GOLD focuses on marginality, sanitation and wastewater challenges in five growing towns in Ethiopia, Ghana, India and Nepal. While toilet coverage has increased in all these towns due to massive and capital intensive  sanitation campaigns, they have neglected a portion of the population, in particular, poor residents, migrants, lower castes, landless slum-dwellers and scavengers who are still denied their basic rights to clean water and safely managed sanitation. They live in areas not connected to centralised systems and are unlikely to be in the foreseeable future. This has important social and health consequences for these communities linked to the invisible flows of dangerous pathogens and water quality contamination. We view these challenges as an opportunity to rethink and reimagine these off-grid areas that fall beyond central urban planning as a fertile ground for social and technological innovations that are people centred, sustainable, equitable and in line with the idea of the circular economy. Indeed, faecal sludge is rich in water, nutrients and organic compounds, but the potential of this 'brown gold' remains hidden in the sludge and thus largely untapped. We will explore ways to re-use shit with the view to ensure that these innovations help address the sanitation crisis, enhance local livelihoods and the local and regional economies and the well-being of the excluded and marginalised. The project asks:   1) How do local communities perceive, experience and live with off-grid sanitation challenges and how do these lead to processes of marginalisation?  2) Which kinds of socio- technical and institutional processes/ innovations are required to re-imagine shit as 'brown gold' in ways that are environmentally safe, economically viable and also tackle social exclusions?  3) How can these locally appropriate innovations be facilitated to be socio-culturally acceptable, and socially inclusive? What are the trade-offs?  4) What kinds of policy, business and regulatory frameworks enable/ disable the uptake, scaling up and sustenance of these innovations?    These questions will be addressed by an interdisciplinary team bringing together social science, law, engineering, microbiology as well as creative arts. We will facilitate bottom up socio-technical processes and innovations co-produced between user communities, private entities, state agencies and civil society. We will employ an innovative mixed-methods approach, bringing together ethnographic, participatory, creative, quantitative and scientific data collection methods to examine whether innovations to consider shit as a resource or 'brown gold' can be a lens to reimagine the city. The project will generate evidence, knowledge and learning that will be useful to a range of academic and policy audience. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.