Mines must take 'prime responsibility' for acid drainage
Tainted water gushes out of the earth and a pipe, just outside Rand Uranium property on Johannesburg’s West Rand. The water, stained orange, like Rooibos tea, collects in a pool before flowing into the Tweelopiespruit.
Johannesburg, the largest economy of any metropolitan region in sub-Saharan Africa, sprung up after a gold reef was accidentally discovered in 1886.
According to the city of Johannesburg’s website, within 10 years there was a fully fledged town on the same spot, and within 30 years it was South Africa’s largest city.
Mining companies have come and gone, leaving mines abandoned and disused to collect water. Underground water must be pumped out continually for mining to continue otherwise the water flows over the rocks and becomes toxic.
Mariette Liefferink, an environmental activist and chief executive of the Federation for a Sustainable Environment, a non-governmental organisation, is determined to put AMD on the agenda.
She offers site visits to show the damage caused by Johannesburg’s AMD problem.
Wearing a green kimono, beige high heels and matching jewellery, Liefferink is unafraid to get her hands and toes dirty to show the extent of the problem.
Acid drainage mine water not just on surface
“An unqualified volume of it [AMD] flows underground,” Liefferink told a group of concerned members of the public and journalists.
“They have not reconstructed what it looks like underground, so there is insufficient information on the volume, but what we do know is that some of it ends up in our river systems.”
Marius Keet—the Department of Water Affairs’s deputy director of water-quality management—told Parliament in July this year that the toxic water was rising at a rate of between 0,6m and 0,9m a day in the central basin of the Witwatersrand Goldfields.
According to the Department of Water Affairs, acid mine drainage arises when sulphate-bearing minerals are exposed to oxygen. This is termed pyrite oxidation, and is enhanced when water moves through and over the surfaces of acid-bearing rock.
The water has a low pH (sometimes as low as 2,2), a high number of dissolved solids, high levels of sulphates and heavy metals, particularly iron, manganese, nickel and/or cobalt.
The department said the heavy metals, low pH and high salt levels pose a “risk to human health and to the integrity of the aquatic ecosystems”.
According to independent environmental consultant Pieter Colyn, “acid mine drainage cannot be used for agriculture, you can’t drink it and you can’t bath in it. It contaminates clean underground water and will eventually escalate the cost of water.”
Nothing stirs the surface of the Lancaster Dam on the West Rand, ringed by mine dumps. There are no insects and no bird life. The once pristine dam is now classified a “radiological hotspot” by the National Nuclear Regulator.
Liefferink, now barefoot, pointed out water seeping into the soil, which would end up in the Wonderfonteinspruit. The spruit [stream] is one of the main tributaries of the Vaal River, upon which millions depend.
The nearby informal settlements of Tudor Shaft and Soul City are surrounded by abandoned mine shafts and mine dumps.
A Soul City resident, who gave her name as Dinah, said the informal settlement became “totally white” with dust from the dumps on windy days.
According to Liefferink, dust particles from the dumps contain uranium and other toxic and radioactive heavy metals.
Paul Potgieter, a former peat farmer in Carletonville, said he had to abandon his farm in 2007 after what he terms a “toxic tsunami”.
According to Potgieter’s daughter René, the water had “a rotten egg smell” and tests showed the wetlands had high levels of sulphates.
“The consequence is that South Africa now imports 90% of the peat used because the wetlands are polluted with AMD water,” Potgieter said.
Peat is used in the mushroom industry as a casing soil, because it is very good at holding water. However, if salt levels are too high (as is the case in AMD) then the yield falls.
According to Potgieter, there are now fewer than four farmers left from Randburg to Roodepoort as the mines have bought the land.
“There are currently offers for my neighbours’ farm, once a cattle farm.”
Potgieter said the cattle farmer also had to terminate his operations after a National Nuclear Regulator directive stating that his cattle were “not permitted to drink water from the property”.
AMD a legacy issue
A spokesperson from Rand Uranium, who did not want to be named, said AMD was a “legacy issue”, which arises from more than 120 years of mining under the Central, East and West Rand.
However, the spokesperson said “the AMD that is being referred to is unrelated to Rand Uranium’s current mining operations, which are located in a different area [from where the tainted water gushes from the earth]”.
The spokesperson said the mine has taken “extensive short-term measures to address the issue in the West Rand, and has contributed significantly to the development of a sustainable long-term solution, in line with its commitment to responsible environmental practices, and to supporting revitalisation of mining on the near West Rand”.
The mine spokesperson said the scale of the problem was such that it “is economically and practically impossible for one party to solve on its own” and it was spending more than R2,5-million a month on a treatment plant on the West Rand.
According to Liefferink from the Federation for a Sustainable Environment, the mine currently partially purifies about 12,5-million litres of AMD water per day, leaving between 11-million and 56-million litres per day to flow into the province’s river systems untreated.
Nevertheless, the mine is adamant that acid mine drainage can only be solved with significant investment and collective action by the mining industry, civil society and the government.
“We have been doing all we can to contain the impact on the Western basin decant, while being the lead agents in forging a long-term sustainable solution,” said the spokesperson.
According to Liefferink, Rand Uranium is not the only mining company that has to carry 120 years of “environmental liability”.
The Department of Water Affairs in 2006 ordered Australian-listed company Mintails and DRDGold to pump and treat 0,4% and 44% of their acid mine drainage respectively.
“But DRDGold has never pumped or treated this AMD water. The sole responsibility has fallen upon Mintails and Rand Uranium, but they cannot cope,” said Liefferink.
The untreated water, according to Liefferink, has now contaminated the Tweelopiespruit, the Wonderfonteinspruit catchment, Robinson Dam, Lancaster Dam, Hippo Dam, Hartbeespoort Dam and will eventually contaminate the Limpopo River catchment river systems.
Liefferink, like Colyn, believes that mining companies aren’t doing enough.
“The richest gold mines were found here in the West Rand yet they have moved off with all their money. They haven’t rehabilitated and they haven’t cleaned up properly,” said Colyn.
According to Liefferink, AMD water can be treated by reverse osmosis, but it’s extremely expensive.
Reverse osmosis is a process in which a solvent passes through a porous membrane in the opposite direction to that of natural osmosis when subjected to a hydrostatic pressure greater than the osmotic pressure.
“Anglo Coal is currently treating AMD by reverse osmosis in its Witbank plant and the treatment costs R10 per cubic metre while Rand Water currently sells its water at R3 per cubic metre.
According to the Department of Water Affairs, an inter-ministerial committee (IMC) has been established and the minister of water and environmental affairs has been mandated to convene a task team to investigate and develop a clear and coordinated strategy to deal with AMD.
The IMC had its first meeting on September 1. On Monday at a media briefing in Cape Town, the committee called on some of South Africa’s top experts to help find a solution to the AMD problem as it won’t be able to cope.
The polluter pays
Among the urgent decisions that have to be taken is where the government is going to find R218-million for a new pump station and pipeline, and an upgrade to an existing waterworks—facilities essential to treat the acid mine water.
According to the department, there is only R14-million available for this in the current budget.
“AMD is an important issue in the bigger policy question facing government and the public on how to apply the ‘polluter pays’ policy, which is entrenched in our environmental legislation, to the legacy of gold and coal mining, and how to plan for these issues in future as new mines are opened,” said Victor Munnik, Mvula programme manager.
While, Mvula—the largest NGO supporting water and sanitation development in South Africa—does not purify AMD water, it supports local government in the delivery of sustainable, reliable and affordable water services.
“Clearly the polluter pays principle means that the polluter—the mining companies—should take the prime responsibility. Government’s role is to apply policy, as well as to ultimately look after our water resources, which it holds in custodianship on behalf of all in South Africa,” Munnik said.