An aerial shot of the Diep River at Milnerton Lagoon mouth.
The City is ignoring spills from a Milnerton sewage-treatment plant, says a corruption watchdog.
The level of water contamination that can be traced to several points at the Potsdam Waste Water Treatment Works (WWTW) “borders on criminal”, says the Organisation for Undoing Tax Abuse (OUTA).
Andrea Korff, Outa legal project manager, says Outa has found five different discharge points along riverbanks around Potsdam WWTW with E Coli levels averaging 119 000 colony-forming units (cfu)/100ml and going as high as 8.4 million cfu /100ml, compared to the one official discharge point that the City is monitoring.
She said she did not know what the City’s latest tests results were as she had been “battling with the City for almost nine months to make the results freely available”.
Tabletalk asked the City for the latest results as well but did not get them by the time this article went to print. Our previous requests to the City for its water-testing results have also been unsuccessful.
“What is very concerning, and borders on criminal, is that water samples taken during our independent water testing at Potsdam WWTW on November 18 show an E coli level of 8.4 million parts per 100ml, which is extremely high. The test was taken at one of Outa’s well-documented sampling points, called PDZ, which was brought to the City’s attention on numerous occasions,” said Ms Korff.
However, the City said Outa had taken its most recent sample specifically at the site of a reed-bed collapse, which did not form part of Potsdam WWTW’s operations. The reed bed was retaining stormwater that was contaminated by sewer overflows in the area, said Xanthea Limberg, mayoral committee member for water and waste.
“The November 18 sample taken by Outa cannot be claimed to reflect final effluent quality at Potsdam. Nor should the specific reed-bed collapse incident be overstated, as it was quickly noticed and the embankment strengthened within 48 hours. It is therefore completely false to speak of the City ignoring ‘sewerage leaks’ or ‘unofficial discharge points’. The specific water sample result is an outlier compared to recent trends, which show that the quality of the Diep River/Milnerton Lagoon is improving,” said Ms Limberg.
Outa’s independent water samples are done by Makoya Amanzi Environmental Solutions.
In the Diep River sampling report, submitted on Tuesday November 24, sampler Craig Greggor said: “While it may be tempting to explain this as an operation accident, it is by no means an isolated incident, and Makoya Amanzi has identified this site as a regular (albeit undocumented) Potsdam discharge with high levels of E coli.”
In the routine round of sampling on November 18, Mr Greggor noted the PDZ discharge point was not flowing on that day but he was “dismayed” to find a strong flow out of one of the other undocumented discharge points.
“The water was odorous, and we started smelling it long before we arrived at it. The water was sent in for analyses and was found to be highly contaminated with E coli at 8.4 million colony-forming units (cfu) /100ml.”
Ms Korff has said previously that E coli should not exceed 1 000 parts per 100ml of water before it is diluted with fresh or sea water. According to the National Water Act, if the amount of E coli per 100ml exceeds 1000 (the general limit) it is deemed to be unsafe for recreational use.
The E coli upstream from the Potsdam plant was 108 cfu/100ml, one of the lowest ever recorded, said Mr Greggor while he recorded a level of 1 680 000 cfu/100ml below the treatment plant.
“While the Theo Marais stormwater channel has been blamed and does contribute to the Diep River pollution, it is usually to a lesser extent. On November 18, it was at a comparatively insignificant level of 1 810 cfu/100ml,” he said.
He added that the level of contamination further downstream was high, with the Milnerton Canoe Club reading 10 000 cfu/100ml, “which could be attributed to the Potsdam discharge”.
In September, the Green Scorpions ordered the City to clean up the lagoon. A month later, the City lodged an appeal against the terms and timelines in the directive. The outcome of the appeal will be heard on December 20.
“The water and waste directorate believes that there is no silver-bullet, civil-engineering solution to pollution in the Diep River given the intense pressure of urbanisation in the catchment area,” said Ms Limberg.
James-Brent Styan, spokesman for the Local Government, Environmental Affairs and Development Planning MEC Anton Bredell, said Outa’s latest water test results would not be considered in the City’s appeal of the directive.
“The appeal is limited to the issues at the time of the appeal,” said Mr Styan. The information submitted by the City in its appeals would be taken into account“ he said.
Head of the environmental portfolio of the Milnerton Central Ratepayers’ Association (MCRA), Caroline Marx, said the MCRA found it “shockingly disappointing” that 11 months after the Green Scorpions had issued its order against the “malfunctioning” Potsdam WWTW, the plant as well as other City infrastructures continued to allow effluent highly contaminated with sewage to flow into the Diep River on a regular basis.
“On 18 November the Diep River E coli count immediately above Potsdam but below Dunoon was 109 cfu/100ml. Just below Potsdam, 500m further downriver, it measured 1.68 million cfu/100ml. Only Potsdam staff have access to that strip of river bank. And yet the City continues to blame residents for illegal dumping and misuse of the sewer system?”
She questioned who was being held “criminally liable” for regular contravention of water licence and environmental laws.
She thanked Mr Bredell and the Green Scorpions for their investigation and appealed to the MEC to “act decisively to put an end to this pollution which has already caused so much environmental and economic damage as well as putting our residents’ health at risk”.