Wells for Zoë implemented a direct action pump called The Canzee pump. It was first developed in New Zealand by Owen Jones, and was further developed by Richard Cansdale, in Hartburn, near Newcastle in the North of England. The pump is also extensively used in Madagascar. Since the pump has had many changes since we first started using it we now refer to it as the Zoë pump and are periodically in touch with the boss about its development.
It uses a simple pumping principle. It consists of two pipes, one slightly larger than the other. At the bottom of each pipe is a non-return valve – that we now make using our Mould injection machine recycling the used plastic nursery potting tubes from the Planting indigenous Trees project. The pumping movement raises and lowers the inner pipe. The outer pipe remains still. When the inner pipe is raised it lifts the water contained within it. The atmospheric pressure pushes more water into the outer pipe. Each stroke lifts the water in the inner pipe to the top until it runs out through the spout. The pump is self-priming. A thin film of water between the two pipes ensures they do not touch: the pump lubricates itself and also floats the inner pipe in the outer.
Our Zoë pump is designed as a family pump for serving user groups of about up to 500. It can also be used for irrigation of family gardens. The above-ground pump head can be easily dismantled for access to the valves. The down hole components, like rising main and pump rod pipes, are made of standard uPVC pipes. We used to employ a (imported) stainless steel pump rod that is still seen on some older pumps (of which there are many!). But now the extra-simplified version is all pipes with a simple wooden handle where the inner pipe is one-piece topped with a walking-stick-handle-type spout, skilfully made by heating and shaping the hot pipe. The pump has very few parts and is now totally corrosion-free.
Operating depth in Malawi (and some parts of Zambia where WfZ also work) is up to 30 meters, in hand dug wells, currently achieving a volume of about 20 litres per minute for those from 0 to 20m. The plan employed is to install pumps so that no-one’s journey for clean safe drinking water is more than 500 metres. When there is a fault, there is a phone number heat stamped on the pump to get a rapid response.
The pumps are made in WfZ factory/Centre in Mzuzu, at a cost of about €80 with materials produced in Malawi, while replacement valves and parts cost very little and are left with Area Pump supervisors, and are of course available from the factory. Since WfZ have GPS and depth of each pump installed (along with lots of other details), the whole pump can be replaced in in a short time by a man on his bicycle and just as readily recycled. When the cost of cement and the pipes down the well are added the cost of a complete well is about €180, where the community supply bricks, sand, stone and most of the labour. The rest of the cost of the donation is in the travel, admin to get the details to the donors, and allowance for follow-up maintenance when needed.
For small communities this pump ticks all the boxes; being of low cost, corrosion-free, often maintainable by area supervisors, and long lasting.