Acid Mine Drainage: the environmental and social risks in the Witwatersrand gold fields

Written by  Mariette Liefferink Tuesday, 12 January 2016 20:54
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South Africa is at the transition point of “peak water.” This is the moment when the economy transitions from a demand-driven state to a supply-constrained state. Peak water means that supply will be limited. This will affect economic growth and may result in social instability.


By 2025, the Orange, Limpopo and Vaal River system will transition into water scarcity. For example, the Limpopo River Basin is already over-allocated by about 120%, and is facing a 241% increase in demand by 2025. Even in 2013, the Minister briefed parliament that 52 villages had no water in Limpopo.

The right of every person to water of sufficient quality and quantity is enshrined in the Bill of Rights. The notion of basic supply has been determined in regulations issued by the Department of Water Affairs. These provide that the minimum standard for basic water supply services include: a minimum quantity of potable water of 25 litres per person per day or six kilolitres per household per month, available within 200 metres of a household and with a value such that no consumer is without a supply for more than seven full days in any year. In many cases this Right is violated.

The Vaal River system is in crisis

The Vaal River System supplies water to 60% of the economy and 45% of the population of South Africa. A multi-pillar strategy has been devised to ensure the future availability of sufficient water of good quality. One of the measures involves re-using treated effluent (waste water), starting with mine water by 2014/2015. Mine water has been prioritised because of the many hazards of acidic water.

The serious ramifications of AMD in the West Rand Basin (one of three mining basins in Gauteng) was first recognised in 2002. AMD in this region threatens the Cradle of Humankind World Heritage Site as well as the 11,491 downstream landowners and agricultural activities that are largely or wholly dependent on groundwater for drinking and economic use. For the next 10 years, up to August 2012, raw or untreated AMD continued to flow into dams, rivers and streams with devastating consequences.

As well as water pollution, AMD is associated with degradation of soil quality, harming aquatic sediments and fauna, and heavy metals seeping into the environment. In addition, radioactive metals such as uranium (U) also occur in the discarded mine water. There is  a marked increase in U-levels in water resources of the whole catchment since 1997.

Long-term exposure to AMD-polluted drinking water may lead to increased rates of cancer, decreased cognitive function and appearance of skin lesions. Metals in drinking water could compromise the neural development of the foetus, which can result in mental retardation.


Sludge is the thick soft, wet Mud (or a similar viscous mixture of liquid and solid components) left over after refining processes. Currently, two high density sludge projects are operational for the immediate treatment of AMD. They are in the Western (West Rand) Basin and the Central Basin. These plants are presently treating (neutralising) around 100 million litres (Ml) of AMD daily. An equivalent volume of the neutralised water is then discharged to the environment.

However, the metal sludge is currently disposed of in unlined pits and on storage facilities for the ore waste of mines (known as ‘tailings’ – what we call mine dumps). The numerous open pits in the West Rand Goldfield have been identified as a major single source of entry into disused mines.

Combating salinity 

The  water  quality  results  of  the supposedly neutralised AMD were supplied to the Federation for a Sustainable Environment by the Department of Water Affairs in 2013. They showed sulphate levels of between 2,395 and 3,012 mg/l. The World Health Organisation’s standard for sulphate in drinking water is 200mg/l. Sulphate concentrations of 600 mg/l and more cause diarrhoea in most individuals and adaption may not occur. 

The highest cost burden of combating salinity is currently being carried by the household sector and not, as might be expected, by industry in accordance with the ‘polluter pays principle’

If AMD is not treated to a level where the salt load is removed, the Upper Vaal will go into deficit. In drought conditions, this is what will happen:

  • Restrictions will be placed on domestic users in the Upper Vaal; or
  • The dilution standard at Vaal Barrage will be relaxed, resulting in very poor quality water reaching the users in the Middle and Lower Vaal (Kosh area, Free State Goldmines and all the mining activity in the Northern Cape on the Vaal Gamagara Scheme);
  • With the Upper Vaal in deficit there would then be no possibility of transferring water into the Olifants-, Crocodile West/Marico and Limpopo catchments, and economic activities in six provinces could be affected if water consumption is curtailed

Limited plans

There are many sources of AMD such as seepage from tailings storage facilities, contaminated wetlands and rivers, open pits, waste rock dumps, and secondary sources of contaminants that remain in the soil after a dump has been removed. They are not addressed in the current treatment of AMD. 

Very few specialist investigations appear to have been done to identify the status of the geohydrological regime,  the extent of contamination, preferential pathways and predictions regarding long– term migration. As a result there are very limited mitigation or management options that specifically deal with the containment or rehabilitation of contaminated groundwater.

There are no proactive management plans in place by the South African government to cope with the flooding and possible decant [overflow] of water from the Far Western Basin, the Free State goldfields and the Kosh Basin.

What should be done?

The cost of water has increased drastically because of the cost of energy. There are more affordable and reliable technologies. Both of these factors make local solutions much more viable. The Department of Water and Sanitation’s decision to “pump and treat” should be revisited since this will result in pumping the polluted water for ever, at excessive cost. It has been suggested by respected academics (such as Prof. Dr. Habil Frank Winde) that the disused mines should be allowed to fill. This will require no deep pumping. As a result, less AMD will be produced and so there will be a smaller quantity of AMD to be treated. A prerequisite will be effective surface reclamation and land re-use.

Combating salinity

The  water  quality  results  of  the supposedly neutralised AMD were supplied to the Federation for a Sustainable Environment by the Department of Water Affairs in 2013. They showed sulphate levels of between 2,395 and 3,012 mg/l. The World Health Organisation’s standard for sulphate in drinking water is 200mg/l. Sulphate concentrations of 600 mg/l and more cause diarrhoea in most individuals and  adaption may not occur. 

If AMD is not treated to a level where the salt load is removed, the Upper Vaal will go into deficit. In drought conditions, this is what will happen:

  • Restrictions will be placed on domestic users in the Upper Vaal; or
  • The dilution standard at Vaal Barrage will be relaxed, resulting in very poor quality water reaching the users in the Middle and Lower Vaal (Kosh area, Free State Goldmines and all the mining activity in the Northern Cape on the Vaal Gamagara Scheme);
  • With the Upper Vaal in deficit there 
  • Innovative technologies must be investigated and piloted to find the best practicable environmental option. That is, the option that causes the least damage to the environment at a cost acceptable to society in the short and long term. Sibanye Gold, for example, has a research facility and works with the University of Cape Town and Mintek on value recovery solutions, using precipitation, ion-exchange, reverse osmosis, and organisms.

It is imperative that mining companies implement zero effluent strategies and treat AMD from its source.



The SAHRC launched its Report on the National Hearing on the Underlying Socio-economic Challenges of Mining-affected Communities in South Africa on the 22nd of August 2018. The FSE participated in the Hearing and many of its issues of concern are addressed in the Report. The Report may be opened here as a PDF document.

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BUSINESS DAY EXCLUSIVE: Liquidation allows Mintails to shirk environmental liabilities

21 August 2018 - 05:04 Mark Olalde   Pollution: Water resource management consultant Anthony Turton, with the Mintails gold plants and water treatment tanks in the background. Picture: BUSINESS DAY/FREDDY MAVUNDA Mintails Mining and several related companies have announced their liquidation, throwing into question the environmental rehabilitation of highly polluting operations near Johannesburg. Mintails mines and processes gold from a sprawling 1,715ha complex of waste piles and open pits in Krugersdorp and has for years been flagged for noncompliance. Its operations are bordered by informal settlements and suburbs housing thousands of residents, many of whom have complained of health effects, which they blame on radioactive dust and water pollution from Mintails’ mines. Records show that the cost to clean up the environment would be about R330m, but there is only R25.6m available. Observers fear that the situation could deteriorate further, as happened at the Blyvooruitzicht Gold Mine, an abandoned large-scale operation on the West Rand. A case study in the country’s deeply flawed mine closure system, Mintails teetered on the verge of collapse for years and entered business rescue in October 2015. Mariette Liefferink, the activist CEO of the Federation for a Sustainable Environment, tracked Mintails for more than a decade and is now working to intercede in the liquidation proceedings as the legal voice for what she labels the "mute environment". "There was poor planning. [Mintails’] due diligence was flawed. They overestimated the gold grade and the resource that could be reclaimed. "They continued to exploit the resource, to reclaim only the profitable parts and never top up the financial provisions," Liefferink says. As the company slips into liquidation, it passes the brunt of its environmental liability to taxpayers and, to an extent, to other mining companies. After Mintails fought for nearly three years to save the company, business rescue practitioner Dave Lake notified the Johannesburg high court in early August of his intention to liquidate the company. Provisional liquidation was granted on August 17 and a liquidator is expected to be appointed soon. THERE IS NO LONGER A REASONABLE PROSPECT OF RESCUING THE COMPANY. The business rescue plan called for the refurbishment of a gold ore processing plant but, according to a memo dated August 1 that Lake sent to the court and to affected parties, it failed when multiple investors ceased funding Mintails. "There is no longer a reasonable prospect of rescuing the company," the memo read. The liquidator will now decide how to pay back creditors with the remaining assets. Environmentalists fear this process could leave environmental liabilities low on the list of what deserves money. According to the business rescue plan, written in December 2016, Mintails owed various creditors more than R1bn, including a shortfall of about R300m in reclamation funding. Due to a web of involved companies, it remains unclear if a large portion of the already insufficient financial provisions can be accessed for environmental cleanup. DRDGold formerly held one of the mining rights and the corresponding trust fund, which are now in the Mintails group. DRDGold CEO Niël Pretorius says he believes that the trust fund contained R18m but he did not identify the trustees, whose consent is vital to unlocking the money. Documents show the Mintails group acknowledged that rehabilitation would probably cost between R300m and R336.5m, but it declined to top up financial provisions. According to the environmental management programme from one of Mintails’ mining rights: "These liabilities are also historic and predate Mintails’ involvement and should thus not be for Mintails’ account." Experts debate this narrow interpretation of the law. Lake wrote in the business rescue plan: "The Mintails group’s rehabilitation liabilities have remained largely unfunded for some time, and there are simply no free funds available to the [business rescue practitioner] to enable him to immediately provide such funding." Legal Resources Centre attorney Lucien Limacher is representing the Federation for a Sustainable Environment. "This is a trend that has been occurring for a couple of years where mining companies have undertaken a business rescue plan or have applied for liquidation because they have failed to really look after the rehabilitation fund," he says. The Legal Resources Centre sent letters to several government agencies, including the department of mineral resources, the department of water & sanitation and the department of energy, asking them to intervene in the situation and threatening to pursue legal action if the department of mineral resources fails to act. Department of water & sanitation spokesperson Sputnik Ratau says they are "engaging Mintails so that the immediate measures can be put into place to ensure water resources protection. A longer-term plan is required to ensure rehabilitation of the mining-impacted areas." Lake declines to answer questions about the failed business rescue and the liquidation but he wrote for Moneyweb in January 2017 and laid out his argument for Mintails’ use of business rescue: "Mintails was sick – but it wasn’t terminal." Now the situation has become what Liefferink calls "pass the parcel", with Mintails playing the part of a "scavenger company", a term coined by researchers to describe under-resourced outfits that buy the scraps left over from larger mining companies and ultimately abandon them. Large gold, coal and platinum mines rarely, if ever, properly close in SA and there wasn’t one large-scale mine in Gauteng that achieved full, legal closure between 2011 and 2016. Mintails’ case will not affect the law that ring-fences financial assurances for reclamation, Limacher says. "But it is precedent-setting in that mines might now start applying for liquidation to avoid paying the cost of rehabilitation." Mintails’ West Rand concessions came in part from DRDGold, which also remines waste piles, and from Mogale Gold, which was in judicial management when Mintails acquired it in 2006. Since then, Mintails engaged in a pattern of environmental degradation. For example, the department of water & sanitation found in an August 2014 inspection that Mintails transported "slurry/sludge" in unlined trenches, completed insufficient monitoring, spilled slurry from pipelines and implemented no storm water management system at a pollution control dam. In December 2016, polluted runoff from waste piles was found to be seeping through a dam wall into the Wonderfonteinspruit, which has immediate downstream agricultural uses in the community of Kagiso. Now it will largely be up to the liquidator and regulators to protect the environment and public health. "That is the pattern that seems to be followed in the gold mining industry, and, I assume, would be followed in the coal and platinum mining industries, as well. "As soon as a mine is no longer very profitable, it transfers its assets," Liefferink says. "That seems to have the tacit support of the department of mineral resources." However, the department of mineral resources sent a statement that reads: "The department will engage with the appointed provisional liquidators with the intention to safeguard the environmental and social responsibilities." Mintails former CEO Johan Moolman declined to comment except to say he quit on June 26 when he learned a new investor had bought the company. Mvest Capital agreed to purchase Mintails from Paige, a vehicle of the UK-based Harbour family, with the understanding that Mvest would inject R30m into the beleaguered company to stimulate the business rescue plan. Mvest decided against handing over the full amount, paying only R5.5m. Mvest director Matthew Moodley acknowledges the initial agreement and the R5.5m. He says that after a month it became apparent the deal would require more investment to succeed. "With the increased need for working capital in July, Mvest took a decision to withdraw from the transaction," Moodley says, adding that Mvest did not "conclude a transaction with Paige". Liefferink says these companies are all "jumping from a sinking ship". She fears Mintails will go the way of the abandoned Blyvooruitzicht Gold Mine, which was once one of the country’s most productive gold operations and is now a source of pollution, violent illegal mining gangs and headaches for adjacent mines. Mintails has followed a strikingly similar pattern. In the Blyvooruitzicht case, two companies, DRDGold and Village Main Reef, almost completed a business deal to sell the nearly exhausted mine and both walked away, claiming the other carried responsibility. "That whole area, just like Blyvooruitzicht, will be left like it is," Liefferink said. While neighbouring mining companies will probably have to pump water from the void in Mintails’ absence, the consequences of "the dust fallout and the toxic water in the river systems" will be carried by communities and by the municipality. Additional reporting by #MineAlert manager Tholakele Nene

Polluted lives: The cost of South Africa's gold rush

Johannesburg in South Africa has one of the world's largest gold deposits. After decades of mining, large swathes of the population are thought to be exposed to toxic and radioactive mine waste. The BBC's Sophie Ribstein went to meet people living close to the dumps to find out what effect it is having on their health. Filmed and edited by Christian Parkinson.


Water Crisis

More than two decades ago, science advocate IsmailMore than two decades ago, science advocate IsmailSerageldin forewarned that “the wars of the next centurywill be fought over water, unless we change our approachto managing this precious and vital resource”. Thissentiment is perilously close for comfort for South Africa,whose water crisis is manifesting with dire consequences.Given that the country has done little in the recent past to rectifyits water challenges, it will soon pay the price, financially, socially andeconomically, says Mariette Liefferink, CEO of the Federation for aSustainable Environment (FSE). The rest of the Document may be opened as a PDF document.



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