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the Zambian schemes described above, as these were the only other schemes in existence at that time. User satisfaction was generally high, the main complaints being the intermittence of the water supply and the need for manual desludging of the aqua-privy tank. There were design faults with the settled sewer network, principally the shallow (often zero) depth of the connector and collector sewers and their junction boxes, but the system has worked well hydraulically. |
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Settled sewerage schemes installed in Africa have been mainly sewered aqua-privies. However, the aqua-privy itself is a questionable sanitation technology: the water-tight tank is expensive, and a better lower-cost alternative is the pour-flush toilet, which can of course be sewered (Kalbermatten et al., 1983) (and as recommended for parts of Tunis: Mara, 1992). The installation of sewered aqua-privies de novo thus cannot now be recommended, and a decision as to whether to install settled sewerage should follow the rationale set out by Mara (Chapter 2). However, the development of the sewered aqua-privy system by Vincent et al. (1963) has been most valuable as it has provided tropical, and indeed temperate, public health engineers with the now well proven technology of settled sewerage. |
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Black and Veatch International (1975). Storm Drainage and Sanitary Sewerage Master Plan Report for The City of N'Djamena, Chad. Abidjan: African Development Bank. |
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de Kruijff, G.J.W. (1978). Aqua-Privy Sewerage Systems: A Survey of Some Schemes in Zambia. Nairobi: University of Nairobi (Housing Research and Development Unit). |
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Feachem, R.G., Mara, D.D. and Iwugo, K.O. (1978a). Sanitation Studies in AfricaSite Report No. 4: Zambia (Lusaka and Ndola). Unpublished research report. Washington, DC: The World Bank. |
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Feachem, R.G., Mara, D.D. and Iwugo, K.O. (1978b). Sanitation Studies in AfricaSite Report No. 2: Nigeria (New Bussa). Unpublished research report. Washington, DC: The World Bank. |
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Feachem, R.G., Mara, D.D. and Iwugo, K.O. (1979). Alternative |
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