Sustaining drinking water quality in water-stressed regions: a case study of the distribution network in Mpumalanga

The quality of drinking water is influenced by its source. In water-stressed regions such as Mpumalanga in South Africa, the availability of safe drinking water remains severely constrained, necessitating the augmentation of supplies by integrating alternative water sources. This study assessed the variability in water quality arising from blending drinking water within a single distribution network. The study focused on six parameters, including pH, electrical conductivity, total dissolved solids, turbidity, chlorine residual, and faecal coliform. The study determined how water quality and water security changed because of blending. It examined changes at the treatment plant and within the distribution network, while assessing compliance with the South African National Standard 241:15, for drinking water. The results revealed significant variation between single-source “unblended water” and multiple-source “blended water.” Although the study demonstrated that surface water supplies can be successfully augmented with reclaimed mining wastewater, it also showed a gradual decline in the overall quality of the single-source unblended water, contrasted with an increase in the quality of the blended water, suggesting that blending may not only increase water supplies but also improve water quality. The results also highlight the complex dynamics of water quality in water-stressed regions and underscore the urgent need for targeted strategies to ensure water security through the sustainability of water distribution networks.