Circular Sanitation Toolbox. First Edition

Circular Sanitation, as presented in this toolbox, refers to approaches for treating wastewater that focus on recovering valuable resources, such as water, nutrients, and energy, for safe reuse. These solutions also prioritize the protection of human health and the environment. Unlike centralized, sewer-based systems, circular sanitation often works best at smaller, decentralized scales and by separating waste streams at the source. The Circular Sanitation TOOLBOX was created in response to requests from practitioners looking for know-how on resource-oriented and/or decentralized sanitation. Information in this emerging field is dispersed and difficult to navigate, particularly for newcomers. There is a demand for simplified information curated to stakeholders, beyond the environmental engineer, who play a key role in the planning, construction, and management of sanitation systems. To this end, the toolbox facilitates access to knowledge by presenting information that is brief, structured, and visually engaging. It does so by categorizing information across three levels of guides: goals, strategies, and technologies (see ‘What’s in the Toolbox’). While each guide functions as a stand-alone document, guides can also be used together to build a narrative that answers to “What goal do I want to achieve? Which strategy can I implement to achieve that goal? And which technology, and/or treatment train, suits my context and needs?” In addition to general information, the guides present case studies to illustrate strategies and technologies relevant for urban, peri-urban and rural contexts, from single household to neighborhood scales. The case studies also provide examples of relevant metrics, such as space requirements, scale, costs and energy. Typical values for such metrics are beyond the scope of the toolbox because they vary per configuration, context and implementation scale. Rather, the toolbox’s success lies in the documents’ brevity, structure, and visual appeal as a navigational portfolio to explore possible configurations for circular sanitation.