PVC against poverty
In the field of water supply, there is hardly a subject on which opinions very so widely, and on which temperaments flare so easily, as on the subject of hand pumps. Basically, you can divide proponents of different types of hand pumps into two camps, which I will call ‚Äòno-repairs-needed‚Äô, and ‚Äòrepairable‚Äô. I am firmly in the ‚Äòrepairable‚Äô camp.
For people in the no-repairs-needed camp, the goal is to make a hand pump that is of such a good quality, that it does not need any maintenance, and will never break down. To the ‚Äòrepairable‚Äô camp, on the other hand, I count people that believe that all technology breaks down eventually, and that it is important what happens when it does. Therefore, they like pumps that have been designed with repairability in mind. Of course, most people occupy the middle ground between these extremes, but you get the point.
Photo above: Learning how to create pumps out of PVC at the EMAS course in Bolivia. See who’s who here.
The no-repairs-needed camp has a lofty and commendable goal, which of course can never be reached because everything that moves breaks down eventually. In practice, therefore, the goal becomes to make a pump that fails only after a very long time, say 10-15 years, and when it does, there should be a supply chain of spare parts. Because of the high quality standard, the pumps are produced in countries that have the ability to do so, and shipped overseas to their destination. The most common pumps in Africa, the India Mark II and the Afridev, have been designed with this goal in mind, and, indeed, they break down after some 10 years. Across Africa, about 30% of these pumps are today broken – in some countries it’s 70%. And they’re not being repaired. What happened?
Tragedy of the Commons
Experience shows that one of the main shortcomings of the no-repairs-needed approach is actually the long time span that passes before maintenance or repair is necessary. No-repairs-needed pumps are heavy, sturdy, of high quality, and because of that, they are expensive. That means that the pumps are communal, because no government, let alone villagers themselves, can pay for a no-repairs-needed pump for each family. And here the Tragedy of the Commons raises its ugly head.
Say, you live in a village, which has a communal water pump. It was installed by some organisation, the name of which you don‚Äôt quite remember, about ten years ago, and it has worked fine ever since. At the time, you seem to recall, a water committee was formed which was supposed to collect money each month to cover the cost of maintenance and repairs, but after three years of good operation of the pump, this committee stopped its activities and the money was used for other purposes. Unfortunately, today the pump is broken, and needs a repair. It will cost 35.000 dollars to repair (this may seem excessive, but if you earn one dollar a day, then this is about the right comparison for a 300 dollar repair). Who is going to pay? The problem is that high-quality pumps often just don‚Äôt fit the technology management capacity of a village.
A pedal-powered EMAS pump in action.
Let‚Äôs go over to the other camp, and see what they have to offer. According to the ‚Äòrepairable‚Äô camp, the technology management capacity of people comes first. They argue that it is not a problem if a pump needs regular maintenance and repairs (within bounds of course, say, at most each 6 months), as long as maintenance and repairs are cheap, and can be carried out by the users themselves. In fact, if regular maintenance and repairs are required, people will remember how to do it. Pumps that fall into this category are the rope pump and the EMAS hand pump. Both use only standard materials and can be made locally, and no special spare parts are needed. Nothing needs to cross a border. Because the pumps are repairable, it also means that need to be light-weight, of simple construction, and therefore cheap. Therefore, they become affordable for families, and then it is very clear who is going to pay when a repair comes along, and who should take good care of the pump to prevent damage. Fortunately, the repair will be affordable, because it was designed that way. Studies in Nicaragua show that 95% of rope pumps stay in use after 5 years, because they are maintained by the users.
PVC is Very Useful Stuff
Interestingly, both the EMAS hand pump and the rope pump use PVC as a main ingredient. This is not a coincidence, as PVC is by far the most versatile and flexible material that is widely available in developing countries. When heated, it becomes moldable like gum. A joint between two pipes can simply be made by heating the end of one of the pipes and pushing it into the other one. You can ‚Äòweld‚Äô two pieces together by heating both pieces until they get sticky, and push them firmly together. T-joints, elbows, connections between steel pipes and PVC pipes, pieces of different diameter – they can all be made from PVC pipe alone, if you have a fire, a hacksaw, a knife, car-tire rubber and the right skills, as shown in this EMAS movie.
No-repairs needed vs. repairable
A model of the EMAS standard handpump.
The EMAS hand pump (or this variant with valves made from pipes)is a prime example. When finished, it looks like a commercial product, with lots of different shaped parts made of PVC. In reality, only three sizes of PVC tubes were used, and two glass marbles. And some old car tyre. It takes about 30 individual actions to make the pump from the pipes, but all steps only require cutting, heating, and manipulating the pipes. A complete pump, including pipes for a 20m deep well and installation by a professional, sells for about 23 Euro in Bolivia. That is reachable for many families.
When designing things that are going to need repairing, you need a material which is flexible and is easy to work with, both in the workshop and in the field. That material is PVC. PVC against poverty!
Mark Westra is editor of the Akvopedia. He’s fresh back from a month at the EMAS school near La Paz, Bolivia.