of tubing and high quality rubber diaphragms, which are costly and are relatively inefficient due to the extra work needed to deform the diaphragm. Rubber diaphragms will eventually leak and need to be replaced. Because this is usually complicated and costly, diaphragm pumps operating in poor rural areas are often abandoned once the diaphragm wears out. Progressive cavity Progressive cavity pumps consist of a single helix rotor inserted into a double helix stator. As the rotor is turned, the voids in the stator are screwed upwards along the axis of rotation. Progressive cavity pumps can have complicated gearing mechanisms and are difficult for local pump technicians to maintain and repair. A rope and washer pump is a type of progressive cavity hand pump. Range of lift The range of lift of different types of hand pumps is given below: Hand pumps and access to clean water In November 2002, the United Nations Committee on Economic, Social and Cultural Rights asserted that access to clean, safe water goes beyond the classification of water as an economic commodity. The committee stressed the fundamental right of sufficient access to clean water for both domestic and personal use. “The human right to water is indispensable for leading a life in human dignity.” With this in mind, manufacturers of water pumps, like those produced by GOAZ Development in Malaysia, have a wide range of potential customers: governments, non- governmental organizations, women’s groups, community groups and other organizations of various types interested to developing access to groundwater. Village level operation and maintenance VLOM, meaning Village Level Operation and Maintenance, is a term first used during the UNDP and World Bank Rural Water Supply Hand Pumps Project. This project lasted from 1981 to 1991, and studied the availability and maintenance of hand pump systems. 40 kinds of hand pumps were analyzed in laboratories, and the performance of 2700 hand pumps was analyzed in the field. The study established that centralized maintenance structure was a cause of many problems in hand pump programs, and that maintenance at the village level is best. The VLOM concept was initially applied to hardware, with the following aims: the possibility of maintenance by village workers, having spare parts manufactured within the country to make sure spare parts are available, endurance in the field, and cost effectiveness. With time, more emphasis was placed on maintenance management. Thus, the “M” came to represent “management