Hydraulic ram pumps and Sling Pumps

WEDC - Conference Paper(Morgan, 1977). Since then thousands have given satisfactory service wherever solid material is used foranal cleaning. Some have rectangular shelters with doors, others are spiral in plan without doors (Figure9).Many VIP latrines are fine structures, of which the owners are very proud. Foreign donors are oftenanxious to give 'the best' to the people they are trying to help. Consequently it is not unusual for a projectto provide a few dozen very good VIPs, each costing several hundred dollars. If the funds had been usedto help householders build their own low-cost varieties the overall benefit would have been infinitelygreater.In Zimbabwe Peter Morgan has developed a range of VIP latrines in addition to the well-known spiraltype. He has rectangular VIPs using one bag, two bags, three bags and four bags of cement, withcorresponding reduced cost. The one bag VIP has sun-dried brick walls and a thatch roof.Ingenious variations have been introduced elsewhere, such as the type shown in Figure 10. This was builtin Tanzania entirely of 'bush sticks', mud, cow dung and thatch. A particular feature is ending the spiralwall at the vent pipe, which has an effective locally-made fly-proofing at the top (Mugenyi, 1993).Alternating pitsBuilding latrines with small pits seems an obvious way to make them affordable. The trouble is that theyonly last a short time before becoming full. I recently saw the folly of this practice in Freetown, SierraLeone, where the many householders I spoke to spent an average of twenty dollars a year to have theirpits emptied. The method of emptying there is similar to that common in West and East Africa, Myanmarand elsewhere. Solids removed from the pit are dumped elsewhere on the plot or nearby, with or withouta thin covering of soil. Because the solids include recently deposited faeces the practice is unpleasant,and may be malodorous, fly-ridden and a serious health hazard, especially where worm infection isprevalent.Building twin or double pits is cost effective, sanitary and is a valid alternative to large long-life pits.Each of the pits (or each chamber of a double pit) is only large enough for two or three years'accumulation of solids (Figure 11).Compost latrinesCompost latrines, like the Multrum, are high cost and not affordable by low income people. Batch types,as shown in Figure 12, have been successful in Vietnam and Guatemala, but are only appropriate wherethere is a positive demand for compost.The latrine shelterhttp://www.lboro.ac.uk/departments/cv/wedc/papers/pickford.html (5 of 8) [1/13/2005 12:50:14 PM]