Completion Date: August 2010

The purpose of this project was to expand the desalination
capacity at the water treatment plant for Eskom’s Lethabo
power station. The excess saline water from the New Vaal Colliery is treated for use in the cooling towers. Aveng Water replaced an older reverse osmosis plant with more modern spiral-wound polyamide, reverse osmosis membranes, Helping Lethabo move closer to becoming a zero liquid discharge facility.

A multi–membrane system – consisting of TORAY microfiltration and reverse osmosis membranes – is used to achieve a water recovery of 80% in a single stage. The existing clarifiers are used as lime softening units as a pre-treatment to the ultrafiltration, reverse osmosis plant.

A major requirement was to provide Eskom with the right level of redundancy and reliability ensuring the power station would operate optimally. Construction and installation activities were carefully managed to ensure minimal disruption to the on-going operation of the power plant.