A river of sewage, which started flowing nearly three years ago, appears to have contaminated a key Nelson Mandela Bay groundwater resource.
Though the municipality confirmed that the Driftsands aquifer had been contaminated, it argued that there was no proof as yet that it was caused by the pollution from the nearby wastewater treatment works.
However, critics monitoring the situation said the correlation between emerging test results and the lengthy period of severe pollution in the porous terrain, directly above the aquifer, was unequivocal evidence.
Wildlife and Environment Society of South Africa Eastern Cape chair Dr Gary Koekemoer said on Saturday the situation was unacceptable.
“We raised our concerns repeatedly with the metro that the Driftsands sewage pollution could contaminate the aquifer, but got no response,” Koekemoer said.
“Now it has happened and one of our key groundwater resources has been contaminated and it cannot be used.”
He said the presence of an open sewer running across the aquifer and the chemical results from the initial testing showed that the cause was the pollution from the wastewater treatment plant.
“The question now is whether it will gradually cleanse itself as the metro argues or whether the sewage may have triggered a change of chemistry with the aquifer rock that will negatively affect the Driftsands groundwater in the long term.
“So we are calling on the metro to release its quality testing of the Driftsands aquifer going forward to allow for scrutiny by independent scientists.”
DA infrastructure and engineering spokesperson Dries van der Westhuyzen confirmed the situation.
“We know 100% from the test results so far that there has been contamination,” Van der Westhuyzen said.
“And the cause is the sewage flowing from the Driftsands plant.
“The result is a lot of grant money to secure more fresh water has been wasted and an important resource has been put at risk.”
Van der Westhuyzen said the problem had been triggered nearly three years ago when thieves stripped the plant of its power cables, crippling its capacity to treat sewage.
“Thereafter, while the responsibility for repair was passed back and forth between the water and electricity directorates, largely untreated sewage was pouring out into the veld.
“This carried on until five months ago when a project was launched to stem the flow and repair the plant.”
The Herald exposed this situation in March 2025.
The plant superintendent pointed out to a reporter who visited the site how none of the machinery was working because of stolen power cables.
As a result, except for some manual removal of solid debris, the effluent was running out into the veld untreated.
He said this had been the situation since November 2023, that the plant had not been legally compliant in terms of sewage treatment since then and the metro was aware of the situation.
Replying to The Herald’s questions at the time, the metro rejected accusations of negligence and said it was working to restore electricity to the plant.
However, nearly a year later, in February 2026, the situation was the same.
In the company of Koekemoer, The Herald hiked the 7km-long stinking river of raw sewage from the plant through the Driftsands bush to the point where it exited into the ocean at Three Pools, on Marine Drive.
Van der Westhuyzen said on Saturday the metro had been assigned R350,000 of a R1m treasury grant to sink the Driftsands boreholes.
The aim was to extract 15ML of groundwater a day to inject into the metro’s water grid.
“They were in the final stages of the project earlier this year when they realised they had a major problem because the aquifer had been contaminated.
“So they had to stop operations and we currently cannot use the water from the Driftsands aquifer.”
He said the metro had since drilled a number of extra boreholes to test the extent of the contamination.
“The theory is the natural flow of fresh water into the aquifer will gradually clear the contamination.
“However, nobody knows how long this will take, if it will work or whether the ingress of sewage may have consumed the oxygen in the aquifer water and permanently changed its molecular structure.”
He said the metro, meanwhile, needed to urgently alert borehole owners in adjacent suburbs like Summerstrand.
An independent expert, who asked not to be named, slammed the situation.
“Imagine the right hand spending all that money drilling Driftsands like Swiss cheese, and then not being able to use the water because it has been contaminated by the left hand.”
He said many private boreholes in adjacent suburbs like Summerstrand had been drilled to access the same Driftsands aquifer.
“The contamination plume will move only slowly through the aquifer but if it is not dealt with, eventually it will reach those private boreholes and someone will get sick.”
He said the Driftsands terrain comprised a layer of dune sand over a layer of fractured calcrete rock.
“The sand would have held and gradually released the sewage like a sponge to seep down slowly through the fractures into the aquifer.”
He said for remediation, some of the boreholes near the sewage treatment works could be pumped to contain the effluent.
“This contaminated water could be returned to the plant and then, once it has been treated, it could be injected back into the aquifer.
“If this is not possible, the metro will have to spend more funds drilling more boreholes close by, to pump them and try to keep the contamination close to the source.
“Besides the extra boreholes that might need to be sunk, the cost of remediation will depend on what particular contaminants are in the sewage.”
Municipal spokesperson Sithembiso Soyaya said the metro had spent R104m drilling 52 Driftsands boreholes, capable of delivering 16ML of water per day.
“Any assertion that the aquifer became polluted solely as a result of operational challenges at the Driftsands works would be speculative and not supported by conclusive scientific evidence,” Soyaya said.
“The municipality is exercising a precautionary approach regarding abstraction from affected sections of the aquifer while ongoing assessments determine the extent of quality impacts.”
He said when thieves stole the plant’s electrical cables the metro had treated the incident as an emergency and had worked to install an interim solution.
“At no stage was there any deliberate decision to permit environmental harm.”
Soyaya said there was no immediate risk for private boreholes in suburbs adjacent to Driftsands but if this was detected the metro would send out the necessary alert.
He said the contamination was still being investigated.
“The appropriate remediation strategy and associated costs and timelines ... can only be determined once these assessments have been concluded.”
Asked if the metro had plugged the outflow of untreated or partially treated sewage, and about the status of the plant repair job, he said it had repaired the electrical power supply and it was now “progressively repairing the treatment works”.
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