Ideas put forward to boost water supplies

City embarks on various small-scale augmentation schemes

WATER industry specialists have been responding with ideas to the City of Cape Town’s request for their input on ways to supplement dwindling water resources. Mayor Patricia de Lille’s spokesperson Zara Nicholson said that in a bid to reduce “over reliance on rainwater and increasingly embrace more non-surface water options such as water reuse and desalination”, the city had already embarked on “various small-scale augmentation schemes”.

This includes drawing water from the Table Mountain Group aquifer and Cape Flats aquifers and on a small-scale desalination plant at Koeberg, said Nicholson.

“We are working tirelessly to bring online even more modular desalination and water reuse options,” she said.

Nicholson said temporary solutions would be funded as operating expenses and financial commitments will only be evaluated once the city has received information from the industry.

Tom Callaghan, business development head of Graham Tek Water Waste Energy Innovations, said in their proposal they recommend smaller water desalination plants be built with the capacity of 5 to 10 megalitres a day and this could be operational within three to six months.

Building five to 10 plants at small harbours, such as Hout Bay, Kalk Bay or Gordon’s Bay, among others, would be a viable option, as they would be owned, operated and maintained by Graham Tek which would sell the water to the city within the range of municipal water tariffs, he said.

“With smaller plants, the water is cleaned and pumped directly into the closest distribution and piping network and this would service nearby communities. What is brilliant about reverse osmosis is that it cleans out all the E coli, bugs and pathogens, so the water is clean, and of SANS 241 standards.”

“We test the quality of the water every hour,” said Callaghan.

Ray de Vries, chief executive of Durban company Water from Air, said their machines which can make 1 500 litres a day are ideal for places like hospitals and schools.

Grant Vanderwagen proposed that 1 000 mesh net units be placed in foggy areas and these nets then “catch the fog” which drops down into troughs and forms water. Up to 11 000 litres can be gathered this way at one net unit, said Vanderwagen.

PROPOSAL TO BUILD A NUMBER OF DESALINATION PLANTS AT SMALL HARBOURS