Presented at the WISA 2000 Biennial Conference, Sun City, South Africa, 28 May - 1 June 2000
DRINKING-WATER QUALITY MANAGEMENT PROCEDURES FOR RURAL COMMUNITIES - South African Case Studies G Mackintosh, E Delport1, M Ramba2 and B Genthe Cape Water Programme, CSIR, PO Box 320, Stellenbosch Tel: (021) 888 - 2631 Fax: (021) 888 - 2682 E-mail:
[email protected] 1
The Town Engineer, Stellenbosch Municipality, PO Box 17, Stellenbosch 2 Barrox Projects, PO Box 84, Bisho
Summary The impact of water-borne disease in South Africa is significant. Diarrhoea is responsible for some 20% of all deaths in the one to five age group and about 43 000 deaths per annum. Drinking-water quality in rural communities in both the Eastern and Western Cape, and in particular where groundwater systems have failed, is very poor. A further issue of concern is the increasing detection and presence of parasites, which are resistant to conventional disinfection. Inadequate water treatment is compounded by the lack of procedures to assess and manage drinking-water quality. The introduction of suitable monitoring, evaluation and mentoring procedures can contribute significantly to turning a previously unacceptable drinkingwater quality to one which satisfies drinking-water specifications.
1.
Introduction
In almost all South African metropolitan areas, and those areas provided with water from the major water boards, the consumer is provided with a high quality drinking-water. These drinking-water supply systems are usually well managed, and water quality is monitored and maintained in structured scientific programmes. However, in the many rural communities and small towns that fall outside these areas, the situation is very different. First, in the poorer regions an estimated 12 million South Africans are without access to adequate water supply [1]. In the second instance, even in those regions in which water supply/treatment systems are in existence, inadequate monitoring and management of water quality often results in drinking-water quality which fails national guidelines [2]. It is well understood and documented that the health of a community is significantly influenced by its drinking-water quality and South Africa is no exception to this. Dramatic statistics emphasising the influence of drinking-water quality on health in South Africa include: ` 20% of all deaths in the one to five age group are attributable to diarrhoea [3]; ` a Shigella dysentariae epidemic in KwaZulu-Natal in 1995/96 resulted in thousands of observed cases with many hundreds of deaths [4]; and ` every year an estimated 43 000 deaths and 3 million incidences of illness requiring treatment and R3.4 billion (approximately US$ 583 million) may be directly attributed to diarrhoeal disease [4]. These staggering figures have made the provision of suitable water and sanitation a well recognised central component of the South African government’s Reconstruction and Development Programme [5]. In addition to implementation of water supply schemes, water
quality related government initiatives include the development of a “national microbiological water quality monitoring programme” to focus on high risk areas and with the principal aim of providing macro scale management information [6], and the development of a simple guide for the assessment of the health-related quality of water supplies [7]. An aspect hitherto neglected is the introduction of suitable procedures and technical measures to enable rural communities to manage drinking-water quality.
2.
The purpose of this paper
This paper has the main objectives to: ` document typical drinking-water quality in existing rural water supply schemes in the Eastern and Western Cape, South Africa; ` introduce the concept of “drinking-water quality management” procedures for implementation in rural communities; ` describe the successful introduction of such procedures at rural communities; ` describe the presence and implications of water borne parasites; and ` briefly introduce the Stellenbosch Municipality parasite management protocol. This paper highlights the need for, and the value of, implementation of drinking-water quality management procedures in rural communities.
3.
Rural drinking-water quality investigative study design
3.1
Identification of communities for assessment
The selection of communities was carried out at two levels. First, at a macro- level, rural communities of both the Western and Eastern Cape were included. The rural communities of these two provinces differ considerably. The population of the Eastern Cape is largely nonurban, poor and with inadequate water supply infrastructure. The poverty rate is 70,7 % [8], and only 24,7 % of the households have a tap inside the dwelling [9]. The Western Cape is largely urban, relatively wealthy, and with relatively well developed water supply infrastructure. The poverty rate is 28% [8] and 76,4% of households have a tap inside the dwelling [9]. Rural communities of the Western Cape typically are formalised towns connected to commercial agriculture and enterprise. Rural communities of the Eastern Cape comprise both scattered villages and subsistence farmers, and formalised towns serving subsistence farmers. In the second instance, on a micro-level, typical rural communities 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. Three larger communities, and 16 smaller communities were identified for consideration in the Eastern Cape. Two larger communities, and 18 small communities were identified for consideration in the Western Cape. These communities fall within the regions shown in Figure 1 below.
3.2
Selection of sampling sites
Samples were collected throughout the water supply system in the communities visited. Typically, sampling sites were chosen to include raw water sources, reservoirs, tapstands and homes; and schools, municipal offices and hospitals where the latter existed. The number of samples varied with size of community. The data represented in this section of the paper
pertains only to the result of a single sampling occasion. (Whilst the limitation of single sample results is acknowledged, this information is a valuable indication as to water quality and management thereof.)
Pretoria Johannesburg
Durban
East London
Cape Town
Port Elizabeth
Figure 1: 1 Approximate location of sampling areas in the Eastern and Western Cape, South Africa
3.3
Selection of water quality variables
Microbiological testing was limited to SABS 241-1984 guideline indicator organisms, namely heterotrophic plate count, total coliform and faecal coliform counts [10,11]. In addition, chemical and physical determinands that are linked to the survival of micro-organisms (such as pH, temperature and turbidity), and those which provide an indication as to the condition of the distribution network (calcium, total alkalinity, iron and electrical conductivity) were measured according to standard techniques [12].
3.4
Further observations
Assessment included consideration of inter alia type of raw water source, the management thereof, disinfection practises, water treatment practises (other than disinfection), and water quality monitoring practises.
3.5
Summary of findings
A descriptive summary of the community water supply schemes visited in the Eastern and Western Cape is given in Table 1. Figures 2 and 3 provide a summary of drinking-water quality as tested at the various rural water supply schemes in the Eastern and Western Cape respectively. Each chart is divided into four quadrants which represent results for faecal and total coliforms, as well as turbidity and iron levels. The quadrants are further divided into three according to type of water supply source. In Figure 2, which presents the results of the Eastern Cape, as a result of the high incidence of non-functional groundwater supply schemes, results are separated into whether the sample originated from a surface water scheme, a functional groundwater scheme, or a non-functional groundwater scheme. In Figure 3 which presents the
results of the Western Cape, where all groundwater supply schemes visited were functional, results are separated into whether the sample originated from a surface water scheme, a treated groundwater scheme, or a non-treated groundwater scheme. Adherence, or failure to adhere, to SABS 241-1984 is indicated by shading.
Table 1. Descriptive summary of the community water supply schemes visited in the Eastern and Western Cape, South Africa Eastern Cape
Western Cape
Number of communities assessed
19
20
Total number of samples collected
36
117
Schemes with only groundwater as the intended raw water source
37%
35%
Schemes with only surface water as the intended raw water source
58%
50%
Schemes designed to provide disinfected water
58%
70%
Schemes designed to include water treatment processes additional to disinfection
58%
35%
Schemes with water quality monitoring programmes
26%
80%
Non-functional groundwater schemes (users forced to use alternative untreated sources)
71%
0%
Figures 2 and 3 provide a clear indication as to the range, and the problematic nature, of drinking-water quality. For example, Figure 3 illustrates that in the Western Cape, whilst most samples collected satisfied SABS 241 Maximum Allowable Limits for turbidity (
