Abstract
From October to November 2004, and from July to September 2005, a survey of 55 plants was conducted in five District Municipalities (Cacadu, Chris Hani, Amathola, Ukhahlamba and O.R. Tambo) of the Eastern Cape Province, with the aim of examining the disinfection practices used in small rural systems of the Eastern Cape and their effect on the quality of drinking water they supply to the communities. Eighty six percent of the visited plants were treating surface water while 7% were treating groundwater and another 7% were treating both ground- and surface water. The majority of plants surveyed employed some variation of conventional treatment (coagulation, flocculation, sedimentation, filtration, chlorination). Turbidity values in 55% of the plants were within the acceptable SABS limits while the other 45% showed high values. Out of the 55 surveyed plants only 18% complied with the SABS recommended limits in terms of microbiological quality. The major factors that contributed to high bacterial numbers were high turbidity and inefficient chemical (coagulant and chlorine) dosing, which led to low chlorine residuals. It was also noted that although some plants had low bacterial numbers at the point of treatment, bacterial re-growth occurred in the distribution system, thereby compromising the quality of water at the point of use. The worst technical problems encountered tended to be at the newly commissioned or upgraded plants where properly trained operators had yet to be appointed or where the existing staff lack proficiency in the use of the upgraded systems or why certain modifications to the treatment process were being made. Operators were lacking in the required technical knowledge such as flow rate and chemical dosing to effectively execute their duties. Lack of communication between consultants, operators and municipal officials on technical issues relating to plant operation appeared to be a problem. The results of this study gave conclusive evidence that rural water treatment plants are still failing to produce safe drinking water.
Original language | English |
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Pages (from-to) | 715-720 |
Number of pages | 6 |
Journal | Water S.A. |
Volume | 32 |
Issue number | 5 SPEC. ISS. |
Publication status | Published - 2006 |
Externally published | Yes |
Keywords
- Eastern cape
- Failure
- Rural areas
- Safe drinking water