The Department of Environment, Forestry and Fisheries (DEFF) says it cannot isolate the main source of the sulphur stench experienced in parts of Gauteng and Mpumalanga following investigations.
In a statement, the department said the stench was likely a combination of elevated levels of sulphur dioxide and hydrogen sulphide.
This is after the department, along with the Gert Sibande municipality, visited the Sasol plant in Secunda, Mpumalanga to check on its operations which were believed to be the possible source of the sulphur stench, almost two weeks ago on 18 February 2021.
“During the inspection it was found that the release of sulphur dioxide and hydrogen sulphide from the Sasol plant were within the approved limits of the atmospheric emission licence (AEL) issued to them by the Gert Sibanda municipality on 23 April 2019,” DEFF spokesperson Albi Modise said.
Modise said the department and the municipality could not definitively say what the major source of the air pollution was at this stage.
“The DEFF and Gert Sibanda municipality suspect the smell experienced in parts of Gauteng earlier this month may have been the result of the cumulative impact of a number of sources in the surrounding areas.
“While initial investigations have shown the sulphur dioxide levels were in compliance with ambient air quality standards across all stations in the week of 11 to 17 February 2021, levels of hydrogen sulphide were found to have been elevated at times during the week in question,” he said.
He further said the department would also investigate a possible source in Gauteng.
“There was also a low-pressure system in the north of the Mozambique Channel that gave rise to a rather uncommon circulation pattern over the region.
“These conditions created prevailing south-easterly winds that allowed for transportation of air pollution from the Mpumalanga industrial region into Gauteng, particularly over the cities of Ekurhuleni, Johannesburg and Pretoria.
“It has therefore been recommended that other sources that could have contributed to the odour experienced in the Gauteng also be investigated.
“These include power plants and waste water works that also emit hydrogen sulphide. The findings of the probe will be made available once completed,” he concluded.