This WEDC self-paced online course has been designed in partnership with the Water and Sanitation Program (WSP) of the World Bank to address important global challenges facing the water and sanitation sector. It features as a unit in the WEDC MSc programme 'Management of Water and Sanitation', but is also available free of charge here as a non-accredited professional development unit for WSP staff and others faced with the issues of scaling-up sanitation in rural areas throughout the developing world.