Department to probe sulphur stench hanging in Tshwane air
Pretoria - The smell that has been hanging in the air in Tshwane in recent days will be probed by the Department of Environment, Forestry and Fisheries.
Department spokesperson Albi Modise said they would, together with Gert Sibande District Municipality in Mpumalanga, embark on a joint operation to check up on the Sasol Secunda operations.
It is believed the area is the possible source of the sulphur stench experienced in parts of Gauteng and Mpumalanga since the weekend.
“The stench is likely a combination of elevated levels of sulphur dioxide and hydrogen sulphide.”
Modise said while there were many sources in the area that could be contributing to these elevated levels, the District municipality’s air quality officer has been informed that the Sasol Secunda operation was experiencing stressed conditions as the facility started ramping up operations.
“From the ambient air quality monitoring observations on the South African Air Quality Information System, sulphur dioxide ambient levels, while elevated, have remained in compliance with ambient standards in Johannesburg, Pretoria and Mpumalanga.”
Modise reassured that the pollutant causes an odour nuisance even at concentrations far below those that cause health hazards.
He confirmed that people who were sensitive to unpleasant odours were likely to experience headaches and nausea, which was the case with some social media users citing headaches from the weekend as the smell was prevalent.
As part of the continuous investigations, the authorities are in the process of requesting the Sasol Secunda Operations facility to account in terms of Section 30 of National Environmental Air Quality Management Act and to put mitigation measures in place, should they be found to be the source of the smell.
“Once the investigations are completed, the authorities will decide on any further course of action.”
Gauteng provincial air quality officer Jacob Legadima said weather conditions played a pivotal role in the atmosphere.
“For the last two or three weeks, the rain has been too much, and to a certain extent, water droplets affected the flaring mechanism by lowering the flame efficiency and lowering the temperature around the stack, was more likely to cause more Hydrogen Sulphide to get uncracked into the atmosphere.”
“Once it gets into the atmosphere, it cannot undergo further reaction, and, depending on the wind direction and speed, such hydrogen sulphide moves from Mpumalanga which have such big refinery plants to parts of Ekurhuleni, which has smaller sporadic refineries. Tshwane metros and the Free State also have refineries which are more likely to affect parts of Johannesburg metro like it happened.”
He said the wind direction around Gauteng is more prevalent from South and East directions and at speed between 10 and 25 miles per second in terms of baseline meteorological monitoring from the ambient stations.
“The smell would be gone for now but depending on the weather conditions if another inversion and cyclone is experienced again the smell might come again. It is the conditions of atmospheric science and chemistry,” said Legadima.