The City of Cape Town hopes to have desalination and other plants up and running and pumping out up to 500 million litres of sea water a day, to assist with the water shortage in the Western Cape. By the end of August‚ Capetonians will no longer be totally reliant on dams as a water source.
Companies and organisations interested in supplying‚ installing and operating temporary reverse osmosis plants “at various locations along the city’s seashore and certain inland locations”, has until July 10 to submit ideas and information to the City of Cape Town municipality, according to a report in the Sunday Times.
Kevin Balfour‚ head of infrastructure in the city council water and sanitation department‚ said the council wanted to have several small‚ intermediate and large plants‚ with the first commissioned in August and ready to produce drinking water by the end of the month.
Desalination Plants are not a new thing in South Africa. In May 2017, the Department of Water and Sanitation launched the critical Richards Bay Desalination Plant in KwaZulu-Natal (KZN). The launch of the plant is meant to assist in enhancing security of supply within the King Cetshwayo District Municipality.
In Mossel Bay, this turnkey desalination plant supplies 10 megalitres of potable water and 5 megalitres of process water to PetroSA.
The plant is supplied directly by an open sea water intake about 600m from shore. Water is pumped to a pump station, and then into a holding tank via drum screens, which screen incoming water to 500 microns or 0,5mm to get rid of kelp, sea shells and other impurities.
Water then passes through six filters before going to the reverse osmosis units for purification. The treated water is then fed from the plant into split tanks. A dedicated tank of 5 megalitres is designed to supply PetroSA as industrial process water.
The 10 megalitres of water is treated chemically to kill any bacteria and stabilise the pH balance, before joining up with the municipal water line.
This potable water treatment plant is the largest seawater desalination plant in South Africa to date.
