The feasibility of desalination as an alternative means of water supply to Zinkwazi town.

Abstract

Desalination of seawater is a widely used technology throughout the world, but is not commonly used in South Africa for domestic water supply. The reasons for this are varied, but very often are based on the assumption that desalination is extremely costly in relation to more traditional water supplies. An economic analysis is undertaken comparing the cost of supplying water to the coastal town of Zinkwazi from various sources including desalination using reverse osmosis. Zinkwazi has an existing borehole water supply that is insufficient to meet current and future demands. The town is also remote from regional bulk surface water infrastructure, which makes it suitable for the investigation of an alternative stand-alone water supply such as desalination. Solving the water supply problems at Zinkwazi is important to Umgeni Water and would support two broad strategic goals of the organisation. Zinkwazi falls within the Ilembe District Municipality, which is an important stakeholder within Umgeni Water's area of jurisdiction. Improving the water supply situation at Zinkwazi is in line with Umgeni Water's goal of assisting Municipalities to meet their developmental objectives. Using desalination to meet this objective is in line with Umgeni Water's goal of using innovative products to alleviate problems of existing customers. Desalination is a multi-billion dollar industry that is growing as traditional surface and goundwater resources become fully utilized and more polluted. Desalination potentially represents a growth opportunity that Umgeni Water, with its expertise in water treatment and supply, could pursue in Africa and Southern Africa in particular. The investigation found that desalination is the most affordable method of supplying water to the town of Zinkwazi and the construction of a desalination pilot plant is recommended for further investigation.