Construction of Coegakop treatment works begins



16-07-2020
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HeraldLive
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Nelson Mandela Bay has launched a R260m “new era” biofiltration plant at Coegakop, a culmination of a long-standing drive to realise the metro’s groundwater potential.

Speaking on site on Wednesday , Bay water and sanitation director Barry Martin said the plant was designed to supply 15-20 megalitres of potable water a day to augment the metro’s existing sources.

“Once completed, it will be the largest biofiltration plant in South Africa.”

Biofiltration refers to the process whereby organic bacteria in the filters will digest the excess iron and manganese, he said.

“There is one other filtration plant of this kind in the country at Hermanus but it’s much smaller than this one will be.

“The normal filtration process requires the use of chemicals, so this approach reduces our cost and is also better for the environment.”

The construction of the biofiltration plant at the foot of Coegakop is the fourth and final phase of the Coegakop Wellfield and Treatment Works project which began a decade ago with a comprehensive survey of the Bay’s groundwater sources.

The Groot Winterhoek Aquifer, the same source that feeds the Springs holiday resort in Uitenhage, was the most promising, and Coegakop was found to be the best access point to this aquifer.

Martin said after obtaining a license from the national water department, 36 boreholes had then been drilled and tested and the five with the best output were equipped for the flow to be extracted and pumped up to the Coegakop Reservoir.

Between 2010 and 2018 a series of steps, at a total cost of R80m, were undertaken including the survey, identification of suitable areas, drilling of exploration and production boreholes and laying of pipelines, he said.

“The construction of the treatment works will cost R260m.

“Construction is under way and the anticipated completion date is August 4 2022.”

Bay infrastructure and engineering executive director Walter Shaidi said the metro had received R212.8m from national Treasury through the co-operative governance and traditional affairs department and the municipal disaster recovery grant to construct the plant.

“The metro will supply the balance and will make sure this project happens.”

He said he was confident that contractor Stefanutti Stocks would deliver, and noted that some 100 small, medium and micro-enterprises would benefit to the tune of R65m.

Martin said that with the metro’s dams west of the metro dwindling fast, the main concern was supply to that side of the city.

“The aim is that once this project is completed it will put an extra 20 megalitres a day into the system which can be piped across to the western suburbs if necessary, to allow us to reduce our extraction from the dams. The infrastructure is already in place to do that.

“We need to extract as much groundwater as possible to allow us to relieve pressure on the dams. That’s the broader picture.”

Asked about the sustainability of this exercise, he said the 2010 survey had identified maximum allowable yields and the process was also monitored by the national water department.

Bay acting executive mayor Thsonono Buyeye said he was happy that the project was under way after a number of delays.

On Monday, the Bay’s four main dams were down to a combined 17.9% of capacity, with Kouga Dam at just 6.83%.

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