Low Cost Water Well Drilling in Africa | The Water Page

R C Carter, Project Manager; P Ball, Principal Consultant; K Danert, Research Assistant The first step improvement in community water supply in many developing countries is to move from a traditional (unprotected, untreated, often distant and drought-prone) source to a well or borehole with handpump. With the exception of countries such as India which have strong indigenous manufacturing industries and large numbers of private contractors, costs of drilling water wells in developing countries can still be extremely high. It has often been pointed out that the cost of the well can be 10-20 times the cost of the handpump. High unit costs mean that too few wells are drilled to serve a community or district properly, and this is one reason for the under-performance or failure of some programmes. Broadly there are three approaches to well drilling (as opposed to digging) technology. The first is the large, sophisticated (usually hydraulic) drilling rig which is expensive in both capital (typically in excess of US$150 000) and recurrent terms, and complex to manage and maintain in remote areas; with this sort of rig it is almost impossible to achieve low costs per-well, especially in Africa. Costs per well typically exceed US$8 000, even in the case of wells for handpumps. The second approach is that of the small conventional rig; machines such as small cable-tool rigs, small trailer-mounted hydraulic rigs, or unconventional mechanical rigs (such as the Eureka Drill System and Port-A-Rig) provide a significantly lower-cost option which is appropriate to many situations. In this case rig costs are typically US$15-30 000, and wells can be drilled at a real cost of about US$1000-1500 The third approach is that of very low cost, human operated procedures such as hand-augering, hand-percussion, sludging, and wash-boring or well jetting. This group of techniques keeps costs and technical sophistication to a minimum, and applications are inevitably more restricted than with more powerful conventional rigs; nevertheless these techniques have significant potential for both drinking water supply and small irrigation well construction. In this case rig capital cost may be up to US$2000 and well cost a few hundred US dollars. Other approaches to well construction have received attention in recent years; these include collector wells, in which the philosophy has been to maximise yield from a single hand-dug shaft, especially in low-yielding Basement Complex aquifers, through the drilling of radial (horizontal) small diameter collectors. This approach has turned out to be relatively expensive, and to be questionable in water resource terms. Very Low Cost Drilling Methods Very low cost drilling methods are generally (rather inadequately) written up in the published and ‘grey’ literature, and they are not available as “off-the-shelf” hardware. The main exception to this is the Vonder Rig, a hand auger machine developed in the early 1980s and manufactured in Zimbabwe, and now used widely in Africa. Apart from this machine, there is no other widely available and very low cost rig manufactured or supplied in Africa. If a Contractor or Project Manager wishes to use such techniques, he first has to construct his own machine and experiment with the details of the design; time is wasted in this way through “re-inventing the wheel”, or promising techniques fail to be used for want of available hardware. Potential of the Private Sector It is widely considered that the private sector (both manufacturing and contractor businesses) represents an under-utilised potential in water supply provision in developing countries. It is the aim of this project to capitalise on some of this unused potential by introducing very low cost water well drilling technologies to small private businesses. This scale of technology has been selected to match the likely level of capital available to potential manufacturers and contractors, especially in Africa. The Project Project funding has been agreed by the UK Department for International Development (DFID) to develop a new drilling rig, arrange its commercial manufacture in at least one African country, and set up small-scale commercial drilling operations through local contractors. The project team consists of Dr Richard C Carter of Cranfield University at Silsoe (Project Manager), Mr Peter Ball (Principal Consultant), and Kerstin Danert (Research Assistant). Richard Carter is a community water supply and groundwater specialist with 24 years experience in private sector consultancy and academic environments. He has a special interest in low-cost water well drilling which he has developed through R&D and training activities in UK and sub-Saharan Africa. He has worked in the water sector in 14 developing countries, for a range of international agencies, consultants, and NGOs. Peter Ball is a drilling engineer and consultant with 27 years of practical engineering, project management, consultancy, and training experience in 19 developing countries. He has designed and developed a unique range of small drilling rigs (for which he won the Booker-Tate Award in 1993), and provided consultancy on groundwater development matters to international agencies, private sector clients, and NGOs.  Carter and Ball have collaborated regularly on training courses and R&D activities in water well drilling for about 10 years. Kerstin Danert is a mechanical engineer with a Masters degree in Community Water Supply. She takes up her post as full time Research Assistant in September 1998. Phase 1 (year 1) will involve a thorough review of work carried out to date by ourselves (Carter/Silsoe and Ball) and others, and the rapid development of a prototype for testing. Because of the large amount of conceptual and practical work carried out already by the project team, we believe that one year is adequate to design, test, and document the proposed new rig. This rig will use some of the established very-low-cost drilling principles, ie percussion, augering, sludging, and jetting, but without duplicating the existing Vonder rig. Early in year 1 an initial field visit will be made to identify potential collaborating manufacturers and other organisations in the three nominated countries (Kenya, Uganda, and Ghana). The major activity of Phase 2 (year 2) will be the production of the rig by a developing country manufacturer. Engineering support will be provided by the project team. Marketing and business advice will be provided by a local consultant. Dissemination of results will commence through the documentation, publicity, marketing, and technical literature and networks. Because of the public domain nature of the proposed design, it will be possible for other manufacturers to adopt and/or modify the new rig for production themselves. Wider adoption and modification of the initial designs will be encouraged. In Phase 3 (year 3) attention will transfer to potential local contractors who will be identified, trained, equipped, and assisted in business planning. An important goal of the project is the construction of several water wells on a contract arrangement between the new drilling contractors and suitable individual or corporate clients. The final period of the project will involve the full documentation and dissemination of findings through the appropriate literature and networks. Your Collaboration We welcome the interest and involvement of all organisations and individuals who wish to take an active part in the project, contribute ideas or contacts, or who simply wish to be kept informed of progress. We are setting up an internet site for those who wish to join the project network. If you wish to join this, please e-mail me at the above address. Richard Carter