1、 外文资料Failure of rural schemes in South Africa to provide potable waterAbstract The impact of water-borne disease in South Africa is significant. An estimated 43,000 deaths per annum, including 20% of deaths in the 15 years age group, are directly attributable to diarrheal diseases. Drinking water qu
2、ality provision in many rural areas is substandard. This paper describes the results of sampling drinking water supplies in rural communities in the Western and Eastern Cape, South Africa. The majority of samples collected failed microbial drinking water quality standards. Overall, schemes dependent
3、 on groundwater provided a worse quality water at point of use than surface-water-dependant schemes. This is thought to be the result of pump breakdown, deterioration of the storage and reticulation system, and insufficient monitoring and management of the schemes. Importantly, it is shown that the
4、implementation of well-considered, community accepted drinking-water quality management procedures can effectively change an unacceptable water quality to one that satisfies drinking-water specifications. Keywords ：Failure of rural schemes Potable water South AfricaIntroductionIn almost all South Af
5、rican metropolitan areas, the consumer is provided with high-quality drinking water. However, in many rural communities, the situation is very different. In 1996, an estimated 12 million South Africans were without access to an adequate water supply (DWA1996) and, even where a water supply exists, q
6、uality is often poor (Mackintosh and Linde 1997) and the impact of water-borne disease is significant. In South Africa, diarrhea is responsible for about 20% of all deaths in the15 years age group (Bourne and Coetzee 1996) and an annual estimated 43,000 deaths and 3 million incidences of illness, wi
7、th an associated treatment cost of some R3.4 billion (approximately US$ 523 million, April 2000;Pegrum and others 1998).Groundwater plays an important role in meeting basic human needs for drinking water. Well-managed groundwater supply schemes reliably provide water of high microbiological and phys
8、ico-chemical quality. Typically, groundwater is advantageous for rural water supply in that it is protected from surface contamination and abstraction can be maintained during (short-term) periods of drought. However, where poorly designed groundwater schemes are installed, users are often supplied
9、with water of very poor quality. The challenge exists for hydro geologists and water utilizations engineers to ensure sustainable high-quality drinking-water provision.The purpose of this paperThis paper has three main objectives: To document typical drinking-water microbial quality in existing rura
10、l water supply schemes in the Eastern and Western Cape, South Africa; To draw attention to the very poor drinking-water quality that results from a high proportion of the groundwater supply schemes assessed. To introduce the concept of drinking-water quality management procedures for implementation
11、in rural communities and show that their introduction can change an unacceptable drinking-water quality to one that satisfies drinking-water specifications.Rural drinking-water quality investigationSelection of rural supply schemes Rural communities of the Eastern and Western Cape of South Africa we
12、re studied. The rural communities of these two provinces differ considerably. The population of the Eastern Cape is largely non-urban, poor, and with an inadequate water-supply infrastructure. Rural communities of the Eastern Cape comprise both scattered villages and subsistence farmers, and for mai
13、led towns serving subsistence farmers. The poverty rate in 1998 was 71%, and only 25% of the households had a tap inside the dwelling (CSS 1998; May 1998). The Western Cape is largely urban, relatively wealthy, and with a relatively well-developed water-supply infrastructure. Rural communities of th
14、e Western Cape typically are for mailed towns connected to commercial agriculture and enterprise.Rural communities typical of each region were identified. Communities selected included both smaller communities of about 1,000 to 4,000 inhabitants, and larger communities of about 40,000 inhabitants. T
15、hree larger communities and 16 smaller communities were studied in the Eastern Cape. Two larger communities and 18 small communities were studied in the Western Cape. Sampling Once-off sampling was carried out in the selected communities. Sampling was focused on points of use (e.g. tap stands, homes
16、, schools, municipal offices and hospitals). Storage reservoirs and the distribution system were also sampled, but no well-head samples were obtained. The number of samples varied with the size of community.Selection of water-quality variables Microbiological testing was limited to SABS 241-1984 guideline indicator organisms; namely heterotrophic plate count, total coli form and faucal coli form counts (SABS 1984, 1990). In a
