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Waterloo Pump

Pump brings water to the world

A pump designed by two University of Waterloo professors 20 years ago is still bringing clean water to people in developing countries.

Professors Alan Plumtree (mechanical engineering) and Alfred Rudin (chemistry) developed the hand-operated pump in the late 1970s after being approached by Tim Journey of the International Development Research Centre (IDRC).

In keeping with the IDRC's aim of fostering local industry in developing countries, Journey asked them to come up with a device that was within the capability of the countries to manufacture themselves. It also had to be inexpensive, corrosion- resistant, adaptable to a variety of local conditions, and easily repairable by the people who actually used it.

Standard water pumps then in use were made of iron or steel, expensive to manufacture and heavy to transport. They were often beyond the ability of villagers to repair, and spare parts were expensive and hard to find. As a result, many of these pumps broke down, and remained broken until technical help arrived from outside the community and sometimes from outside the country.

Rudin and Plumtree's design uses a piston action similar to that of an internal combustion engine. Their pump, however, is constructed of lightweight polyvinyl chloride (PVC) plastic, which can be glued rather than welded and does not rust.

Another crucial point is that while many developing countries may not have steel foundries, most have access to plastic-extrusion and molding technology and can manufacture the parts themselves fairly inexpensively.

While developing their design, the researchers visited Waterloo- area Mennonite farms to observe how people without advanced technology achieve something they want -- such as a safe water supply -- and how they manage to keep it going. What Rudin and Plumtree found was not a model for their pump, but a working philosophy that embraced resourcefulness and simplicity.

"You use what we call appropriate technology," Plumtree says. "You make the pump as simple and as versatile as possible, so it will be easily understood and easily repaired by whoever is using it." The result? "It was a bit of an ugly duckling, but it worked."

Because the Waterloo pump has fewer and simpler parts than standard metal pumps, repairs are easier, less costly and highly adaptable to the availability of local materials. For instance, the piston ring, which is the part that wears out first, can be a slice of polyethylene pipe, a piece of rope soaked in animal fat or part of a leather belt.

Again, the foot valve at the bottom of the water pipe is the same simple shape as the plunger that raises the water, so either could be exchanged for the other, or, in a pinch, carved from a piece of wood. Using their own resources, local people gain control of their water supply, instead of having to rely on the expertise of government technicians.

The pump was first tested by drawing water from the bottom to the top floor of UW's chemical engineering building. Further testing in England and in six different countries in Africa and Asia was followed by fine-tuning at the Asian Institute of Technology in Malaysia. The resulting Unimade pump now operates around the world in many different versions, supplying clean water to almost a million people in 13 countries.

There have been a few setbacks. In Bangladesh, for instance, parts were not made to the right tolerances, and the pumps would not work properly. In Malawi, the well casing was made of white plastic instead of the usual blue, and was gnawed by hyenas who mistook it for a large bone. But in some countries, such as Malaysia, the pump has produced a thriving industry as well as a flow of clean water.

Though the designers never profited from their work, Plumtree says he's enjoyed making contact with users and adapters of the pump over the years. It's rewarding, he says, to know that you've had a direct, beneficial impact on other people's lives.

The Waterloo pump is featured in a CRB Foundation "Heritage Minute," a 60-second mini-movie appearing on television and movie theatre screens across Canada.

~ Written by Patricia Bow From Jim Fox, UW News Bureau