'Stinky' Cape Town wastewater treatment plant to get R5bn upgrade

A wastewater treatment plant which residents say is largely to blame for an unbearable stench and ongoing pollution of Milnerton Lagoon in Cape Town will benefit from a R5bn capacity upgrade.

In the meantime, short-term interventions to address complaints will be rolled out by the city.

Environmental protection non-profit #ReThinkTheStink and the Milnerton Central Residents’ Association last week shared the results of independent water tests taken on November 4 by an accredited company. They showed high levels of E coli in the Diep River catchment area which enters the lagoon and empties into the sea next to Lagoon Beach.

Pollution in the lagoon has long been a source of controversy. Signs erected by the city warn would-be bathers that “for health reasons swimming and recreational activities in these waters are at your own risk”.

Residents and business owners told TimesLIVE the situation was unbearable and hurting local establishments that would otherwise benefit from tourism, especially over the festive season.

“The Lower Diep River, including the Milnerton Lagoon, is in a poor ecological state due to diffuse sources of pollution. The city has identified and implemented critical short-term interventions that address the quantity of pollution entering the system,” the city said on Tuesday.

Environmental consultants were appointed earlier to help investigate and assess potential short-term interventions.

“Potsdam [treatment plant] is an old facility that we are steadily working towards an upgrade. We have placed Potsdam on the mayoral priority programme and the city closely monitors Potsdam operations,” said Siseko Mbandezi, acting mayoral committee member for water and sanitation.

“Our operational team progressively attends to the maintenance and refurbishing of the older infrastructure and equipment. This is in addition to gradually adding new technology and upgrading plant capacity between now and 2026.”

The plant, which treats 47-million litres of wastewater a day, is being upgraded to 100-million litres a day to accommodate urban growth. It will be equipped with “cutting-edge membrane technology” to ensure a high standard of wastewater treatment.

Responding to questions last week, the city acknowledged that “ageing infrastructure and capacity constraints do impact on Potsdam wastewater treatment plant’s operations from time to time”.

The latest test results obtained by residents indicated that treated effluent containing 750,000 E coli colony-forming units (cfu) per 100ml (the licence requirement is under 1,000 cfu/100ml) were being discharged into the Diep River at an estimated rate of more than 36-million litres a day — equivalent to 18 Olympic-size swimming pools. 

The city cautioned: “It must be noted that a water sample reflects a particular moment in time and cannot be extrapolated to draw broader conclusions.”

Residents, however, pointed out that previous water tests by the city during the long-running standoff suggested the plant did not always meet its water licence requirements. They called for swift intervention, saying the unpleasant situation could not be endured until the plant was fully upgraded in 2026.

The city is convening a community feedback meeting on November 30 to elaborate on its interventions and the condition of the lagoon.

It said pollution enters the lagoon from “various sources”, including:

• agricultural discharge and pesticides;
• greywater discharge;
• pump station failures caused by load-shedding;
• misuse of the sewerage system;
• treated effluent from Potsdam wastewater treatment works;
• unplanned urban development;
• illegal sewer connections to the stormwater system; and
• unauthorised industrial discharges”.

TimesLIVE

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