/ 11 April 2022

Dead fish found in stream near Sasol’s Secunda plant

Sasol Secunda Photo Delwyn Verasamy
Sasol, South Africa’s second-biggest polluter behind Eskom, has committed to a net zero emissions target by 2050. (Delwyn Verasamy/M&G)

An internal Sasol report has revealed that dead fish were found in a stream near its operations in Secunda, Mpumalanga earlier this year.

The preliminary report said the dead fish were noted at the receiving environment surface monitoring station (RESM-7) on 31 January, during water-monitoring sampling and inspection of the Klipspruit. 

It cited “contaminated stormwater released into the environment” and described how the water quality measurements at RESM-7 indicated “elevated concentrations” compared to the limits stipulated in the water-use licence for the Klipspruit.

On the immediate corrective actions taken, the report notes that Sasol’s Secunda operations “stopped API stormwater release” as a potential cause. These API dams are the facility’s catchment dams for stormwater, as well as for hydrocarbon polluted water. The water in these dams is recycled for use in Sasol’s processes.

Clean-up teams were contracted to set up a capture net in the Kleinspruit to prevent any dead fish from exiting the Sasol boundary, the report says. The fish were likely to have been affected upstream of RESM-7, a localised effect that occurred about six to 12 hours before the observation.

When the dead fish were identified, decomposition had begun; therefore, an autopsy was not available, but an aquatic assessment concluded that the “impact may have been sudden and that the fish died within a short period of time”. According to the report, rapid changes in the water course can negatively affect aquatic life.

Custodial responsibility

Sasol spokesperson Matebello Motloung said the sustainability of the Integrated Vaal River System (IVRS) was crucial to managing long-term water-supply risks, “hence we have a vested interest in the responsible management of the IVRS”.

“Consistent with our safety, health and environment policy, we recognise that we have a custodial responsibility to respect and care for the environment, in particular to prevent the deterioration of the quality of river water and associated aquatic life,” she added.

Motloung said monitoring of the Klipspruit, Trichardtspruit and Kleinspruit was conducted to keep any eye on any possible effects from Sasol’s Secunda operations on these water resources, adding: “During the monitoring, it was also observed that raw sewage from an upstream pump station, unrelated to Secunda operations or Sasol, entered the Klipspruit upstream of RESM-7.”

The matter was reported to the departments of water and sanitation and of forestry, fisheries and the environment, “in accordance with applicable statutory requirements and within the associated timelines. Initial communications occurred on the same day that the dead fish was observed”, she said.

Motloung said intermittent controlled releases of process water and stormwater occurred at Secunda operations before the dead fish was observed. 

“These are governed in terms of a directive received from the department of water and sanitation. In this regard, we wish to point out that no dead fish or other aquatic impacts were observed when subsequent controlled releases occurred,” she said.

“The controlled releases support a key safety control, necessitated as an urgent measure to manage water levels in process water dams due to the unusually high rainfall experienced in the early part of the rain season (latter part of 2021 and early in 2022).”

Managing water levels key

Managing the water levels within the design capacity of the process water dams is critical to maintaining the integrity of the infrastructure “to mitigate against a dam wall failure and potential consequential environmental catastrophe,” Motloung added.

An incident investigation related to this case, including an aquatic impact assessment and additional specialist studies, is being finalised. 

“It will inform the need for any specifics of any additional preventative measures to be implemented by Secunda operations in respect of the controlled releases, in addition to complying with the conditions of the department of water and sanitation directive,” Motloung said.

The department of forestry, fisheries and the environment referred the Mail & Guardian to the department of water and sanitation, which did not respond to queries.