Green Point Sewage Disposal Options

Abstract

In the winter of 1989 severe seas destabilised the 1 700 metre long marine outfall at Green Point which had been commissioned in 1985. Divers had to detach a large section of the outfall to prevent further damage occurring. This resulted in virtually untreated sewage effluent being discharged 280 metres from the rocky shoreline. Public outrage and severe criticism from the media resulted in an emotional and environmentally sensitive issue having to be handled with considerable political and professional skill to enable the determination of the most appropriate solution for Green Point. Independent consultants were appointed by the Cape Town City Council to study basically two options to rectify the situation; reinstating the marine outfall or constructing a conventional sewage treatment plant in close proximity to a densely populated coastal area. This paper discusses the marine option in detail and the advantages and disadvantages of both marine and land options as well as the public involvement and the adopted decision making process. After a comprehensive investigation had identified and explored all aspects and after the public had been fully involved and consulted, the Cape Town City council accepted the City Engineer's recommendation with a vote of 33 to 1, in favour of a new marine outfall.