Cape Town wastewater treatment plant pays off

29th July 2019 By: Kim Cloete - Creamer Media Correspondent

The largest privately owned modular wastewater treatment plant, together with a borehole water treatment plant at Cape Town’s Mutual Park, is working well and is able to provide treated water to between 10 000 and 15 000 people a day.

The plant was developed by Old Mutual and water reuse experts PCM Consulting, in partnership with the City of Cape Town and the departments of Water Affairs and Environment, Forestry and Fisheries, following the drought and crippling water shortages experienced in the Western Cape in recent years.

PCM Consulting CEO Jann Prinsloo last week told delegates at the Water Desalination, Reverse Osmosis (RO) Membrane and Wastewater Reuse Conference, in Cape Town, that there was a good business and sustainability case for investing in wastewater projects.

“Wastewater is quite straightforward . . . you know what goes in and what goes out.

If you have the right equipment, you can always have the right water quality.”

The installed plant, which is next to the Mutual Park building, produces an average 650 m3 a day of clean potable water under SANS 241 and World Health Organisation Standards. The amount can be increased to 900 m3 a day if required during peak demand seasons.

The wastewater treatment plant also treats effluent water from the municipality. The plant dovetails with a borehole plant, which can produce 240 m3 of treated water a day for the facility in case of an emergency.

In a Day Zero scenario, the plants can run continuously.

Prinsloo said the company was pleased with the overall water recovery rate of more than 85%, which made it sustainable.

Meanwhile, an automated desalination plant has been developed at the Netcare Christiaan Barnard Hospital, in Cape Town. Prinsloo said this was also prompted by the water shortages. The Netcare group was keen to put a contingency plan in place for the large hospital, as well as for its Kuils River, Blaauwberg and N1 City hospitals.

Prinsloo told the conference that the plant had a typical RO desalination filtration design.

The plant was built in the basement of the Christiaan Barnard hospital in the Cape Town central business district and is capable of producing 20 m3/h of SANS 241 potable water.

The feed water of the plant is mainly from sump water, but it can be topped up with borehole water during a Day Zero scenario, said Prinsloo.

In a Day Zero scenario, the water from the Christiaan Barnard Hospital could be trucked to the three other hospitals in the city.  All three have been fitted with bulk storage tanks.

Prinsloo said he welcomed competition in this pioneering market and suggested that investors interested in the sector should plan meticulously and get accurate data, so that they can size their plants correctly for current use, as well as for possible future expansion.

“We are in it to make a difference. We do need to make some profit, but the end-user is getting good, clean water. There is a big drive in Africa for people to get clean quality water every day.”