WATER DEMAND MANAGEMENT & WATER SECURITY
A proactive approach
TO LIFE-CYCLE COSTING
Climate change, population growth and urbanisation are placing increasing pressure on South Africa’s water and wastewater infrastructure. Finding sustainable solutions requires a value-engineered approach that looks beyond conventional design, says Dr Michele Kruger, functional general manager: Water Infrastructure, SMEC South Africa. By Alastair Currie
T
he introduction of the UN Sustainable Development Goals (SDGs) marked a turning point for the world by placing the emphasis on people and the environment first, rather than pure economic gain. Participating SDG countries, which include South Africa, as well as member firms, are required to effect meaningful change. “In many respects, the SDGs are a race against time and, from SMEC’s perspective, our responsibility is to design and execute positive outcomes, based on engineered solutions,” says Kruger, who prior to joining SMEC was an advisor to South Africa’s Minister of Water and Sanitation. Kruger’s passion for this field has been recognised both at home and abroad. In 2007, she won the Young Engineer of the Year Award at the SAACE Glenrand MIB Engineering Excellence Awards. Internationally, her doctoral research in water treatment was honoured by the UK’s Federation for Water Research as the best paper by a young South African in the field of water science and technology. “My key mandate is to make practical and implementable connections between water Dr Michele Kruger, functional general manager: Water Infrastructure, SMEC South Africa
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security and life-cycle costing,” Kruger explains. “That’s because our problems and challenges are heavily weighted towards treatment, or the lack thereof, where there’s minimal room for error.”
Asset registers, operations and maintenance, cost-reflective tariffs From previous experience and working as a Green Drop auditor in 2021, Kruger has a clear understanding of the current performance status of South Africa’s water and wastewater treatment plants. As defined by the Department of Water and Sanitation, “The Green Drop process measures and compares the results of the performance of water services authorities and their providers, and subsequently rewards (as incentive-based regulation) the municipality upon evidence of their excellence (or failures) according to the criteria that have been defined.” One of the key Green Drop audit criteria is an up-to-date asset register with evidence of how effectively this speaks to the municipality’s operations and maintenance (O&M) programme. The asset register – as a status report – forms the basis for a lifecycle costing model, based on a detailed risk analysis that identifies the critical gaps. “The fact that a higher-than-acceptable percentage of water and wastewater treatment plants are dysfunctional points to poor O&M, which can be improved together with the active management of asset registers,” says
Kruger. “Municipalities need to increase their inspection periods and response times, as well as develop realistic maintenance budgets and an action plan that works. Being able to collect cost-reflective tariffs is of course also essential to be able to afford such plans.” On a positive note, Kruger points out that there are treatment works that have passed their end of life but are still performing optimally. In these instances, this shows that the maintenance plan has worked exceptionally well. This presents opportunities to share success stories with struggling municipalities so they can improve their O&M capabilities.
Needs analysis Before building or upgrading a treatment plant, Kruger says the first step is scenario planning and risk analysis. The foremost consideration from a potable water perspective is establishing current and future security of supply. From a wastewater perspective, changing raw water quality and the effluent quality discharged to rivers or how the limits for these might change in future becomes a factor. From there, a risk register can be developed that ranks the likelihood of something happening, like a drought, and its impact, with a recommended contingency response. “Wastewater plants are designed for a specified treatment strength. In an extreme drought, however, like the situation experienced in Cape Town during the ‘Day Zero’ threat, you can end up receiving half the flow, but twice the contamination,” Kruger explains. “That makes it very challenging to treat to the required quality; however, in Cape Town’s case, they rose and overcame these challenges, thanks to contingency planning and process optimisation.”
