Drinking Water Quality In Towns Of Alfred Nzo District Municipality In The Eastern Cape Province

Abstract

Background: Access to safe potable drinking water continues to be one of the most pressing challenges for rural communities in South Africa. It is estimated that 3.5 million of people in South Africa do not have access to safe drinking water. The Eastern Cape Province has been participating in Blue Drop assessments since 2009. The Blue Drop score for the Eastern Cape Province declined in 2014 with 10% from the previous assessment, from 82 to 72%. The Blue Drop results identified that municipal drinking water quality management in the Eastern Cape Province varied from excellent to unsatisfactory. Since 2009, the Alfred Nzo District Municipality was unsuccessful in obtaining Blue Drop certification. The aim of the study was thus to assess the quality of drinking water from six water distribution networks in the Alfred Nzo District Municipality over a period of three years. Methodology: Drinking water samples were collected on a monthly basis from 32 drinking water sampling points. Six drinking water samples were collected from the clean drinking water outlet of each drinking water distribution network and 26 drinking water samples from the end-user water sampling points. The drinking water samples were analysed for eight drinking water quality parameters. The parameters included turbidity, pH, temperature, electrical conductivity, total dissolved solids, free residual chlorine, Escherichia coli and coliform bacteria. The measurements were statistically analysed and also compared to the drinking water quality standards specified by SANS 241 (SABS, 2015). To ascertain the overall quality of a particular sampling site, a water quality index (WQI) was also calculated for each of the drinking water sampling points. The Canadian Council of Ministers of the Environment Water Quality Index (CCME–WQI) was selected and used, taking into account of the WQI that allowed for multiple rounds of measurements. Results: The drinking water quality measurement for pH, temperature, electrical conductivity, total dissolved solids and free residual chlorine were within acceptable limits in all three years according to SANS 241 (SABS, 2015). Although free residual chlorine was within prescribed limits, the measured values were at very low levels. The turbidity measurements of drinking water quality measured in all water distribution networks indicated that results were variable; from acceptable to unacceptable levels. The measurements of the two microbiological parameters, total number of Escherichia coli and total number of coliform bacteria exceeded the limits specified by SANS 241 (SABS, 2015). For the total number of coliform bacteria, 90% were non-compliant, while 94% of the measurements of total number of Escherichia coli were non-compliant. The CCME–WQI calculations supported statistically outcome. The CCME–WQI values of all water sampling points ranged from 68 to 80. These findings revealed that the drinking water quality of all water sampling points were of poor quality. Conclusions: The high turbidity may lead mostly to ineffective or poor disinfection. The presence of Escherichia coli indicates faecal pollution, possible presence of pathogens and ineffectiveness of the disinfection processes. Polluted drinking water may cause waterborne illnesses such as diarrhoea, which is one of the major causes of child mortality globally. The high levels of coliform bacteria in the drinking water are indicative that the treatment on the drinking water was incomplete.