Validation of the Goreangab Reclamation Plant in Windhoek, Namibia against the 2008 Australian Guidelines for Water Recycling

Australia has had Guidelines in place for water recycling (for all uses other than the augmentation of drinking water supplies) since 2006. These Guidelines were extended to cover potable reuse in May 2008 and have been applied to two potable reuse projects in Australia – one a trial plant in Perth, Western Australia and the second for a large AUD$2.6 × 109 scheme in Brisbane, Queensland. All reclamation plants in Australia must be ‘validated’ against the Australian Guidelines for Water Recycling prior to being put into operation. The majority of advanced reuse schemes incorporate the dual membrane process – microfiltration or ultrafiltration followed by reverse osmosis (RO) – in the treatment trains and while this membrane based treatment has been shown to produce a very high quality of product water, it does come at a cost and there is renewed interest in alternative treatment technologies that offer cost savings and are more sustainable. This paper uses data gathered in Australia from a range of advanced reclamation plants, as well as design and actual performance criteria from the Goreangab Plant, to ‘validate’ the latter and, given the longevity of the Windhoek direct potable reuse experience, lend support to more serious consideration of non-RO based plants for potable reuse applications.