Original Article Water, Sanitation and Hygiene Interventions in the Pacific: Defining, Assessing and Improving ‘Sustainability’ Matthew Clarke a , Simon Feeny b and John Donnelly b a Deakin University, Geelong, Australia. b RMIT University, Melbourne, Australia. Abstract Through the conduct of ex post evaluations, this article examines the impact of aid projects and programmes beyond the funding period in the water and sanitation sector, which, since the inclusion of hygiene, has recently become known as Water, Sanitation and Hygiene (WASH). The evaluations were conducted in rural areas of three Pacific countries: Papua New Guinea, the Solomon Islands and Vanuatu. This article argues that in assessing the lasting impact of community development projects (in this instance, WASH) the term benefit persistence better captures the wider scope of impact that a project might have on a community extending beyond the stated project goals and objectives. These ‘additional’ or unstated impacts can extend the benefit that aid projects can have. A number of areas that strengthen the likelihood of benefit persistence were also identified. A travers des évaluations ex-post, cet article examine l’impact, au delà des périodes de financement, des projets et programmes d’aide au secteur de l’eau et de l’assainissement qui, depuis l’inclusion de la composante hygiène, a récemment pris le nom d’« eau, assainissement et hygiène » (WASH). Les évaluations ont été effectuées dans les zones rurales de trois pays du Pacifique: la Papouasie-Nouvelle- Guinée, les îles Salomon et la République de Vanuatu. Cet article fait valoir que lorsque l’on évalue l’impact durable des projets de développement communautaires (dans ce cas, WASH), l’expression « persistance des bénéfices » rend mieux compte de l’impact plus large qu’un projet peut avoir sur une communauté et qui peut dépasser les buts et objectifs énoncés du projet. Ces effets « supplémentaires » ou non anticipés peuvent étendre les bénéfices potentiels des projets d’aide. Un certain nombre d’aspects renforçant la probabilité de la persistance des bénéfices ont également été identifiés. European Journal of Development Research (2014) 26, 692–706. doi:10.1057/ejdr.2013.67; published online 23 January 2014 Keywords: aid; sustainability; water; sanitation; hygiene; Pacific Introduction A primary purpose of official development assistance (or foreign aid) is to improve human well- being. The impact of foreign aid occurs across a range of spheres, including the economic, social, health and political. This impact is most effective when it not only successfully improves human well-being but does so in a manner that is long-lasting. The focus on the lasting impact of aid interventions is widely referred to as ‘sustainability’ by aid agencies. Sustainability of impact is often a primary concern when measuring the benefits of an aid project in terms of whether these benefits are likely to continue after donor funding has been withdrawn (Development Assistance Committee (DAC), 2010). There are, however, widespread concerns that the impacts of foreign aid are short-lived, thus perpetuating the need for further foreign aid (Easterly, 2006; Riddell, 2007). If impacts of foreign aid are not sustained they are less likely to break poverty cycles and high levels of assistance will need to continue. © 2014 European Association of Development Research and Training Institutes 0957-8811 European Journal of Development Research Vol. 26, 5, 692–706 www.palgrave-journals.com/ejdr/