RAND WATER ANNUAL REPORT 2023

Production Water Quality Rand Water has an extensive monitoring capacity consisting of three ISO9001:2015 certified site labs, over 500 online instruments located at various Rand Water production sites, and an ISO17025:2017 accredited laboratory. Extensive monitoring

programmes have been documented and complied with. Bulk Distribution Water Quality Water Quality Supply to Water Services Authorities

The supply of safe potable water is of highest priority to Rand Water. To this effect, Rand Water provides water that is acceptable for lifetime consumption. Rand Water places a high premium on public health protection and, to this end, has adopted the SANS 241 drinking water quality standard to ensure the delivery of safe drinking water to Water Services Authorities. This is achieved by implementing stringent water quality standards, assessments and processes throughout supply chain under Rand Water control. This provides robust mechanisms to ensure that the water supplied to Water Services Authorities will continuously meet the SANS 241 standard. The quality of drinking water delivered to Rand Water customers during this Financial Year met all contractual and legislated standards. All physical, chemical, and biological health-related parameters were compliant to the SANS 241 drinking water quality standard, except for residual disinfectant as indicated in the table below. These non-compliances were assessed not to pose an unacceptable health risk for consumers. Residual disinfectant is used to control microbiological parameters. All microbiological parameters complied with the SANS 241 standard. Dosing of sodium hypochlorite at tertiary dosing plants (Hartebeeshoek, Daleside, Sasolburg, Wildebeesfontein, and Trichardt) ensures adequate chlorine residual concentrations at the furthest points in the distribution network to prevent microbiological regrowth in the system. The supply of sodium hypochlorite is a risk due to supply unreliability from both the supplier and the main source NCP/ Protea Chemicals. Sodium hypochlorite was partially available during the Financial Year resulting in disinfectant residual non-compliances. To minimise water quality risks, HTH is dosed at these tertiary dosing plants and microbiological quality is monitored closely. To enable improved water quality monitoring, an online instrument upgrade programme is in progress for the Booster sites. Additionally, a project to install online instruments in the bulk distribution network is currently underway. This will enable continuous real-time monitoring of water quality at critical and furthest points within the bulk distribution area resulting in improved decision-making.

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