Assessing life cycle environmental and economic costs and benefits of integrated sanitation and energy recovery strategies in low-income countries
By mid-century, the global population is set to increase by 2.2 billion people with 60% of growth projected to take place in cites of sub-Saharan Africa (SSA) and South Asia (SA) (UN-DESA, 2015). These regions also have some of the lowest rates of urban sanitation coverage and access to modern, clean fuels. Major infrastructure investments will be necessary for this rapidly growing population to meet the Sustainable Development Goals (SGDs) of universal access to sanitation and clean energy. In recent years, energy recovery from domestic waste has received attention as a strategy to offset operational costs of sanitation services, provide alternative energy resources and reduce environmental impacts of waste treatment systems. Moreover, new sanitation management approaches – including decentralized sewered and non-sewered options – have gained traction in low-income SSA and SA cities as alternatives to expensive and resource intensive conventional wastewater treatment. However, despite growing interest in energy recovery and increasing adoption of alternative sanitation approaches, little empirical evidence exists regarding the long-term environmental and financial costs and benefits of such approaches.
This research provides empirical evidence on the costs and benefits of integrated sanitation and energy recovery strategies in low-income countries through primary data collection from operational waste-to-energy systems in Tanzania and Zambia, (2) develops a life cycle framework to investigate the resource use, environmental impacts and financial costs and benefits of decentralized sewered and non-sewered sanitation approaches and (3) demonstrates application of this framework using primary data from sanitation systems in Zambia and India, thus also generating the first comparative life cycle analyses of decentralized sewered and non-sewered sanitation management in urban SSA and SA. Findings from this research indicate that integrated sanitation and energy recovery strategies offer significant energy and global warming potential benefits. However, greater financial incentives and different financing models are likely necessary to attract investment in such approaches. Additionally, we find that a system-wide life cycle approach, rather than simply a process approach, is essential to understanding and comparing the full life cycle costs and benefits of different sanitation alternatives.
