A new report on the Naandi Foundation by Rohini Mukherjee details how the organization’s model for providing safe drinking water to rural households has been successful through the collaboration of both the public and private sector. Having been established in 2006, the model has overcome the challenges of scale and evolved into a sustainable social business. In the context of millions of people in rural India still, in the year 2010, not having access to safe drinking water, Naandi Foundation has created a model for providing safe water to rural populations through community-based water systems at a nominal user fee. The innovation in this model is about bringing together the state, local governments and private technology providers in an arrangement that is well-defined, transparent, and on a path to sustainability. This model has been operational for four years and is still evolving as an effective example of private delivery of basic services for the poor. This paper traces the evolution of this model, examines the challenges in up-scaling it while ensuring equitable access and concludes with description of its latest incarnation – that of a ‘social business’ that will ensure sustainability. http://www.ingentaconnect.com/content/itpub/edm/2010/00000021/00000003/art00004