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technical and institutional ways of providing water and sanitation, that the provision of such services to the low-income, informal settlements (favelas) was possible: in 1980 less than 1 per cent of the favela population had a sewerage system, whereas by 1990 this had increased to 15 per cent (Serageldin, 1994). In the Buenos Aires barrio of Martin Coronado a residential cooperative was responsible for many technological sanitation innovations as well as a sewer network of more than 60 km of domiciliary collectors (MAE/DGCS and CEFRE, 1993). |
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In African countries, including Kenya, Nigeria, Ghana and Zambia, there has been much interest in sewerage for aqua privies which are a common form of latrine in many areas. In some of the new Egyptian townships near the Suez Canal local designs for septic tanks and small-bore settled sewers are being used in conjunction with prototype gravel bed hydroponic wastewater treatment works based on donor-funded research in Egypt. |
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In Kumasi in Ghana on-site sanitation systems provide the services to most of the inhabitants in both the indigenous low-cost living areas and high-cost new government housing areas. As the housing density is not high, there is space for drainage fields, which are hydrogeologically satisfactory. However, for tenement areas, which house about 25 per cent of the population, the only technically feasible solution for the proper disposal of excreta and sullage was found to be sewerage (Obeng and Locussol, 1992). Capital cost comparisons for collection and treatment of the three sewerage options of simplified sewerage, settled sewerage and conventional sewerage, led to the conclusion that the most affordable and least-cost solution for the Kumasi tenement areas was simplified sewerage. Surprisingly, however, the difference in cost between this and conventional sewerage was not large (US$15m versus US$18m). The nature of the terrain in this instance reduced the potential cost saving of the former over the latter. |
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Further interesting findings from Kumasi, based on willingness-to-pay surveys undertaken by local officials, were that (MAE/DGCS and CEFRE, 1993): |
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families on average were willing to pay about the same amount for sanitation as they paid for rent, electricity or water; |
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the poorest people who used public latrines were spending more for sanitation than those with household systems; |
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