Johannesburg - The Department of Water and Sanitation (DWS) has been accused of “authorising pollution”, after its water quality tests for its acid mine drainage (AMD) plants in the Witwatersrand surpassed the government’s own water resource quality objectives.
“The graphs reveal the manganese, the sulphate and the electrical conductivity for the Central and Eastern Basins treated AMD significantly exceeds the legally binding water resource quality standards and resource quality objectives for the Upper Vaal,” explains Mariette Liefferink, chief executive of the Federation for a Sustainable Environment (FSE). “The same is true (for) the discharges of the treated AMD into the Tweelopiespruit, which is part of the Crocodile West Water Management Area.”
AMD refers to the flow, or seepage, of polluted water from old mining areas. The FSE had launched a Promotion of Access to Information Act (PAIA) application, together with the Centre for Environmental Rights, to obtain the results of the water quality monitoring of neutralised AMD discharged from the Eastern, Central and Western Basin AMD treatment plants in the Blesbokspruit, Elsburgspruit, a tributary to the Klip River, and the Tweelopiespruit, on the West Rand.
“The numerical limits for manganese, sulphate and electrical conductivity are non-compliant with the water resource quality for the Vaal and Crocodile West/Limpopo water management areas. Concisely stated, the DWS has authorised pollution,” says Liefferink.
In its response to Liefferink, the DWS stresses that “due to technical, operational limitations and financial constraints, the determinants are limited to the key parameters indicative of AMD”, and it only measures electrical conductivity, manganese, iron and pH. But AMD, says Liefferink, contains a broad spectrum of heavy metals in elevated concentrations such as lead, cobalt, the metalloid arsenic, long-living cyanide complexes, cobalt, nickel and uranium.
Next week, the DWS and the Trans Caledon Tunnel Authority will officially launch the Eastern Basin’s AMD plant, one of the largest high-density sludge plants in the world, with a maximum treatment capacity of 110 million litres a day. It has been in operation since August.
“The neutralised AMD that is discharged into the Blesbokspruit, which hosts the Marievale Bird Sanctuary, contains high levels of sulphate. This is between 1300mg to 1460mg. Consider that the water resource quality objectives for the Vaal are 600mg/* and elevated levels of manganese. The electrical conductivity is also high,” says Liefferink.
In 2014, the location of the sludge facility for the plant was the subject of a petition over fears of water contamination and blasting. “The sludge from the Eastern Basin is disposed into the Grootvlei Shaft 3. No environmental impact assessment was conducted to determine the impacts. The sludge contains toxic and radioactive metals. The impacts of the sludge on downstream water users, the groundwater and the ecology haven't been assessed,” Liefferink says.
But the DWS says an environmental authorisation for the interim trial deposition of sludge from the Eastern Basin AMD plant into the Grootvlei 3 shaft was not required. “Prior to commissioning, the proposed interim trial deposition of sludge into the shaft was presented to the authorities (with) no requirement for environmental authorisation.”
Philip de Jager, a trustee of the Grootvaly Blesbokspruit Conservation Trust, and who represents residents who raised concerns over the sludge disposal, has no knowledge of the opening next week. "But this does not surprise me as input by the locals is usually ignored,” he says.