Water quality tests results at four water bodies show high levels of pollution

A recent sewage spill on the Big Lotus River resulted in Zeekoevlei being contaminated.

A recent sewage spill on the Big Lotus River resulted in Zeekoevlei being contaminated.

Published Nov 10, 2021

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Cape Town - Water quality results of four water bodies for the period May to October still show dangerously high levels of e-coli.

The City’s report released this week followed Outa and the Milnerton Ratepayers’ and Residents’ Association’s calls on the City to make its water quality data publicly available.

The latest results – taken on October 29 at three of the five different sampling points in the Zeekoevlei – show more than 100 000 cfu (colony forming unit per 100ml).

In Zandvlei more than 10 000 cfu was recorded at a sampling point at the south of the vlei, opposite Playwaters, while 430 000 cfu was recorded at the centre of the vlei, opposite Imperial Yacht Club, on the same day.

The highest e-coli results recorded at Rietvlei was 1 100 000 cfu at the Stormwater channel from Bayside Mall, while at the Milnerton Lagoon 1 150 000 cfu was recorded at Diep River Estuary opposite Broad Way sampling point on October 15.

One of the “Save the Zandvlei” petitioners, Mike Ryder, said that despite the high e-coli results in the vlei, the City had kept its mouth closed.

“The vlei is closed to the public because e-coli pollution caused by apparently unstoppable sewage inflows, which has caused algae bloom. This season is the time of peak fish migration,” said Ryder. “The weed harvester, which might help to clear the algae, is defective and rarely works.

“A new machine is on order, but delivery is not expected until some time next year. Closing the river mouth stops the flow, which helps to flush the polluted waters of the vlei, but interferes with fish migrations,” he said.

Friends of Zeekoevlei and Rondevlei vice-chairperson Tom Schwerdtfeger said sewage has been flowing into the Zeekoevlei continuously for three months, and the latest results were worse than the measurements recorded after the first incident on July 1.

“So we have moved backwards.

The Friends Groups from the three closed recreational vleis met recently and are working together to get a commitment from the City to repair failed infrastructure and to implement effective maintenance procedures for the future,” he said.

Schwerdtfeger said the City received a quote on October 1 to do the rehabilitation work at Zeekoevlei, but this, he said, has been sitting at the City for 40 days.

City spokesperson Luthando Tyhalibongo said the quote was in the process of being assessed internally.

He said that while the City generally does not make raw data available, it has done so previously in the event of a PAIA application, which requires agreement with Terms of Use.