South Africa acts on acid mine drainage

25 February 2011

The Cabinet has approved the recommendations of a team of experts on the threats posed by acid mine drainage in parts of Gauteng, and agreed that work on tackling the problem should start immediately.

The government appointed the team after warnings emerged last year that South Africa faced a potential water pollution crisis that could lead to health problems due to spillage from acid mine drainage (AMD), particularly in the Witwatersrand gold fields around Johannesburg.

Speaking at a media briefing in Cape Town on Tuesday, National Planning Minister Trevor Manuel said Manuel said the experts – drawn from the Council for Scientific and Industrial Research, the Water Research Commission, the Council for Geoscience and the Departments of Science and Technology and Water and Environmental Affairs – had already started working on a permanent solution to the problem.

‘No need to panic’

“We need to ensure that we have immediate water pumping across the three [affected] basins, and we will be working continuously to ensure that we have a permanent solution to the problem,” Manuel said.

“We want to assure South Africa that there is no need to panic at the moment, as it remains our responsibility to ensure the safety of our water systems in the country.”

In his Budget speech to Parliament in Cape Town on Wednesday, Finance Minister Pravin Gordhan allocated R3.6-billion for water infrastructure and services in 2011/12, “including funding for the acid water drainage threat associated with abandoned underground mines.

“A report on this by a team of experts has been approved by Cabinet, and [Water Affairs] Minister [Edna] Molewa is taking the lead in consulting with industry on a shared and coordinated response,” Gordhan said.

  • The report is available on the Department of Water Affairs’ website, www.dwa.gov.za.

‘Pumping and treatment is critical’

Acid mine drainage (AMD) occurs when old mine shafts and tunnels fill up, leading to underground water oxidising with the sulphide mineral iron pyrite, otherwise known as “fool’s gold”.

The acid water is believed to be currently about 600m below surface of Johannesburg and surrounding areas, but is rising at an estimated rate of between 0.6 and 0.9 metres a day.

Acid mine water is said to have been overflowing from the western basin, located below the Krugersdorp-Randfontein area north-west of Johannesburg, since 2002.

“In light of the serious challenges with AMD in the Witwatersrand, the pumping and treatment of mine water is critical and should be implemented in the western, central and eastern basins as a matter of urgency,” said Molewa, who co-chairs the inter-ministerial committee formed to look into the issue.

“Although the partial treatment of mine water to neutralise acidity and remove metals will be accepted in the short-term, it is important that in the medium to long term, mine water needs to be treated to a quality suitable for direct or indirect use,” Molewa said.

The team of experts, chaired by Mineral Resources Director-General Sandile Nogcina, recommended a range of solutions, including solutions for specific sites, starting with immediate control measures to reduce the rate of flooding and the eventual decanting and pumping volume.

It recommended improved water quality management, including neutralisation and metal removal, as well as improved monitoring of mine water, groundwater, surface water, subsidence and other geotechnical impacts of mine flooding and seismicity.

Who will pay?

The team also recommended that an environmental levy, to be paid by operating mines to cover the costs of the legacies of past mining, be investigated and implemented if feasible.

Minister Molewa said: “As part of the implementation plan, which officials are working on, a notice will be published in terms of Section 19 of the National Water Act to previous and existing mining companies in the Central and Eastern basins, preventing these mines from polluting the water resources as a result of their activities.

“In respect of the Western Basin mines, directives in terms of Section 20 of the National Water Act will be issued and the department will continue to remedy the situation and claim from the responsible mining companies for the expenses incurred in the remedial process as far as is possible”.

Manuel said on Tuesday that it would be premature to estimate how much it would cost to address the crisis, considering that a lot of work needed to be done across the affected areas over the next three years.

The government was considering imposing an environmental levy, but Manual said a thorough investigation still needed to be done to determine which mines were still operating in the affected areas.

Source: BuaNews