Firm fingers sulfate-reducing bacteria for stench
AN INTERNAL investigation by EnviroServ has identified a kind of bacteria in the waste at the Shongweni landfill as the cause of the odour which has had Upper Highway residents up in arms in recent months.
Coastal operations manager Clive Kidd said new waste management regulations passed in 2013 allowed for an overall lower pH level of the waste, which allowed Desulfovibrio vulgaris to breed, causing the odour.
Desulfovibrio vulgaris is a sulfate-reducing bacteria, which is known to feast on sulphates and release hydrogen sulphide, cause of the odour.
But the revelation goes against the community’s claims that the site was being used for toxic waste.
Community members say attempts to improve the situation by treating waste with lime have failed, as the smell is worse than ever.
In an attempt to combat “misconceptions” about the nature of the odour, EnviroServ hosted a media tour of the facility yesterday.
Employees, at a presentation, said that this would “help journalists do their jobs” in communicating information about the site.
Kidd dismissed the idea that the site took in toxic waste as residents had alleged.
“The previous regulations allowed for pH-9 and above. The new regulations were pH-6 and above. So overall, the pH of the waste dropped.”
He said this had allowed the bacteria to thrive.
Kidd said that, as of last September, they began treating the waste with lime to increase the pH level, which had shown progress in killing the bacteria.
He said waste was treatedthroughout the day.
He said the public erroneously called the site a dump, whereas it was in fact a “carefully engineered facility run by people with degrees in engineering”.
“It’s not a hole in the ground where you ‘gooi’ your waste,” Kidd said.
While the site did not take toxic waste, he said they did take in small amounts of treated medical waste.
EnviroServ, however, would not divulge its list of clients to journalists because it was “competitor-sensitive information”.
They would also not let journalists see a list of clients, even if names were not published.
But the Upper Highway Air NPO and their lawyer said that sulfate-reducing bacteria had always been present at the landfill.
Lawyer Charmane Nel rejected this as being the sole reason for the smell that was plaguing the communities of Hillcrest, Shongweni, Kloof, Dassenhoek and surrounding neighbourhoods.
“There is no proof that (bacteria) is the only problem. EnviroServ have been in business, they say, for 30 years. They know (that kind of bacteria) is there and would thrive if the pH dropped.”
She said that the company had not let them see waste inventories since 2013 to see how they had handled dumping.
“The bacteria bloom in low pH environments,” said the NPO’s Lauren Johnson. She said they would welcome this kind of information directly from EnviroServ, but the company was generally not forthcoming with it.
“They are welcome to send us information because we’re also interested in educating the public about what’s going on.”
When asked whether Upper Highway residents noticed a reduction in odour when the site introduced the pH intervention last September, Johnson said: “Not at all – it has intensified and is more frequent now.”
About 2 000 Upper Highway residents marched in protest of the smell last Saturday.
EnviroServ is expected to respond to the Department of Environmental Affairs tomorrow about why it should not have its licence suspended.