A PlayPump™ is a water pump powered by a playground roundabout or merry-go-round. It was conceived as a means of supplying water for domestic use in developing-world villages by taking advantage of the energy produced by children playing at it. The general failure of the idea has provided what is perhaps the best-known example of ineffective altruism.
The rotational movement of the roundabout is converted into the reciprocal vertical motion of a pump, by the work of which water is pumped up into an elevated tank, typically bearing advertising billboards, from where it is carried by gravity to a tap stand. System maintenance was supposed to be covered by the revenue generated from advertisers.
The roundabout pump was invented by Ronnie Stuiver, a South African engineer. In 1989, Trevor Field, a British advertising professional, noticed a model of it in an agriculture fair in Johannesburg and bought the patent from Stuiver. Field decided to focus full-time on the project and founded Roundabout Outdoor, which won the World Bank's Development Marketplace competition in 2000, and subsequently received international attention and increasing funding. In 2006, with backing from the Case Foundation, PlayPumps International, based in the US, was set up. By 2009, Field and his charity had installed eighteen hundred PlayPumps across South Africa.
After a series of criticism, the Case Foundation acknowledged the failure of the program, and PlayPumps International was shut down. Despite this major setback, Roundabout Outdoor kept on functioning and receiving funding from other sources. As of February 2022, Field continues to install the same model of PlayPump in African communities.
No negative review was written before 2007, when UNICEF issued a report. It was the first of a series of critical evaluations that went on to reveal multiple problems arising from the PlayPumps. Among the most serious of these are the following: