Report to outline options for sewage treatment

Environmentalists have long campaigned against the City’s daily discharge of sewage into the sea

A draft scoping study report on marine outfalls, which the City expects to have by month-end, will help to chart the way ahead for improved sewage treatment, says mayoral committee member for water and sanitation Dr Zahid Badroodien.

On June 2, Dr Badroodien met with environmentalists, ward councillors and various experts, at the civic centre to discuss sewage contamination on the Atlantic seaboard.

Among those at the meeting were Dr Jo Barnes, senior lecturer emeritus in the faculty of medicine and health sciences at Stellenbosch University; Professor Leslie Petrik, group leader of environmental and nano sciences at UWC; Dr Cleeve Robertson, CEO of the National Sea Rescue Institute; and Jean Tresfon, a marine conservation photographer, all of whom have campaigned against the City’s daily discharge of sewage into the sea.

The City operates three marine outfalls: Hout Bay, Green Point and Camps Bay, and the Atlantic Sun has reported repeatedly on the pollution issue (“Camps Bay marine outfall causes a stink,” February 11, 2022; “Sewage matters under spotlight, March 16, 2023; and “Experts question Blue Flag water testing,” June 1, 2023).

Following the meeting with Dr Badroodien, Mr Tresfon said, “We have been engaged in dialogue with the City of Cape Town concerning the marine outfalls that pump many millions of litres of raw, untreated, effluent into our oceans every single day.

“With the appointment of Dr Badroodien in 2021, our relationship with the City leadership took a definite turn for the better, and he seems genuine in his desire to improve the situation within his portfolio. On 14 December 2021, he invited us to meet with him at Maiden’s Cove, overlooking the Camps Bay pump station and outfall, discuss our concerns and share our data.”

According to Mr Tresfon, the City, at the meeting, outlined three scenarios for costing:

1. Pumping the effluent to an existing sewage plant, which would, in any case, require an upgrade of the plant to cope with the bigger volumes.

2. Building a new sewage plant near each outfall’s pump station.

3. A possible extension of the outfall pipelines further out to sea.

Mr Tresfon described the meeting with Dr Badroodien and his colleagues as a positive step forward.

“Without trying to pre-empt the results of the costing, the first scenario has major logistical and engineering challenges and is likely to end up being significantly more costly than building new wastewater treatment works near to the existing pump stations. Extending the pipelines also does not matter if the effluent is not treated properly before being pumped out to sea,” Mr Tresfon said.

In a statement issued to the Atlantic Sun after the meeting, Dr Badroodien said a draft scoping study report on marine outfalls would be received by the City by the end of the month.

He added: “Seven major studies have been undertaken by different marine science experts (all investigating different measurable aspects) over the last six years. These studies included bacterial samples, toxicity samples, mussel growth monitoring, animal tissue samples, preliminary biodiversity surveys, chemicals of emerging concern (CEC) studies, dissolved oxygen and detailed numerical modelling.”

The key conclusion of the studies, he said, was that “the marine outfalls are meeting their design objectives in reducing potential deleterious ecological and/or human health effects of discharged effluent by taking advantage of increased effluent dilution offered by deep water”.

According to Dr Badroodien marine outfalls provide around 5% of total wastewater produced in Cape Town, while 95% of Cape Town’s wastewater is treated by land-based sewage plants.

“The viability of investments to expand the capacity and efficiency of sewage treatment plants, as well as a path ahead can only be determined once the draft scoping study report is received,” said Dr Badroon said.