Stirrings of action on acid mine drainage

What do you fear most—nationalisation or acid mine drainage (AMD)? Chances are, particularly if you live in Gauteng, you’re more worried about the latter. You may be able to survive the pernicious effects of nationalisation, but a water supply turned toxic is no basis for any future.

There are two main worries, one being that acidic underground water is rising, turning lakes into dead sludge and threatening tourist attractions such as Gold Reef City. Much of the Witwatersrand, it would appear, swims on a corrosive underpin.

The other worry, though, is that the government does not appear to have a plan to deal with AMD.
The miners who created the problem in the first place, some as long ago as 120 years ago, have packed their bags, leaving hundreds of open mine shafts and tailings dams which, in some cases, have sufficient radioactivity, to make the area unsuitable for human habitation.

Last week the government made a long-awaited report available which it has commissioned for an inter-ministerial committee tasked to deal with the AMD issue.

It says AMD is “formed by a series of chemical reactions which occur between water [and] sulphide minerals such as pyrite and oxygen, which combine to form an iron-rich sulphuric acid solution”.

The report notes that gold mining on the Witwatersrand has created an interconnected system of tunnels. “As a consequence, as mines within a basin stop operating and stop pumping water from their underground workings this water flows into adjacent mines, increasing the volume of water which the adjacent mines need to pump.

“Eventually, the last mine in a basin will cease operations and stop pumping, after which the underground workings will flood and the water level will continue to rise until it reaches the surface and decants to a low-lying shaft or other pathway(s) to the surface.”

No pumping in the central basin
No pumping has taken place in the central basin, the largest on the Witwatersrand, since 2008, the report says. The water level is rising by about 59cm a day. At this rate, it will have risen to the surface at the ERPM mine on the East Rand by March 2013, sterilising still exploitable gold reserves at a depth of 400 metres.

“Of even greater consequence, it will not only have flooded the shallower underground tourist facilities at Gold Reef City but also compromised the shallow groundwater resource associated with the dolomitic strata located to the south-east of Johannesburg,” the report says.

The team of experts recommends that pumping operations should begin in three priority basins and that the pumped water be treated to address its low pH, high acidity and high content of iron and other metals. It says steps should be taken to reduce as far as possible the flow of water into underground workings.

It is clear, though, that the experts see these initiatives as first steps: “The aim of these recommendations is to avert impending crises and stabilise the situation.”

The report says two plants are currently treating AMD to potable quality in South Africa. “These are, however, not financially self-sustaining. This is similar to the experience internationally that has shown that AMD treatment is unlikely to be financially self-sustaining.” The treatment costs are estimated at about R11 a cubic metre. “This relies on a subsidy from the mining companies.”

From confusion to clarity
Water expert Anthony Turton says the report for the IMC represents a move from an earlier state of denial and confusion to one of greater clarity. He says the report should be seen as triage—an attempt to stabilise the patient for continuing treatment.

Turton says the IMC report is part of a trio of reports that address AMD in Gauteng. A second report, for the provincial authorities, considers the impact of AMD on the Cradle of Humankind and a third, with Turton as lead researcher, examines a two-kilometre wide strip spanning 98km along Main Reef Road from Krugersdorp to Springs.

Turton says this strip represents the oldest mining operations on the Reef, an industry that was essentially unregulated for 120 years.

“There are hundreds of tailings dams, most in the wrong positions and using unacceptable engineering standards.”

He says that in one case, in Mogale City, a study by the national nuclear regulator has found that radiological levels are too high for human habitation. An issue now is whether the tailings dams or the people should be moved. Both informal and formal settlements are affected.

An incentive to fix the mess
Turton favours giving companies that specialise in reworking tailings dams the job of clearing or consolidating the remaining dams, the idea being that the value they can extract from their operations can act as an incentive to help fix the present environmental mess.

This approach seeks to try to solve the AMD problem by making use of resources other than those provided by the taxpayer. Turton notes that one company, IProp, has been successfully rejuvenating land that has been taken down to the bedrock after being cleared by the tailings operators.

The land is then made available for factories and warehousing, having been transformed from badlands to part of the rates-generating base for the municipality.

The high levels of radiation, says Turton, result in part from sanctions against apartheid South Africa, where an inability to export uranium led to it simply being dumped in the tailings dams. He says a study by Chris Hartnady has shown that peak gold production was reached in 1972. “His study shows that the value of gold in the ground is less than the associated environmental costs. The only remaining value is in the tailings dams.”

South Africa’s Apollo 13 moment
Turton likens the present situation to the country’s own Apollo 13 moment. He says there is progress in that the politicians are acknowledging that there is a problem. Failure is not an option, but AMD is now no longer seen as an intractable issue but one that can be met once it has been broken down into solvable pieces.

“AMD has changed from being a predicament with no easy solution to a problem that can be solved.”

Part of the present predicament is that water is priced artificially low, way below its production cost, says Turton. In the longer term, the cost of water will need to rise.

The cost of treating water has been falling but is still double that charged by Rand Water. While these prices are moving closer together, Turton says that massive upgrades to the Tugela and Lesotho schemes will be needed to get enough water to help neutralise AMD water.

So, either way, water costs will be going up. It would be better to find cost-effective ways of re-treating AMD water, which a higher price of water will make possible.

The government can only regulate and incentivise, says Turton. Given the scale of the AMD challenge it has been reluctant to accept liability as this will put great strain on the fiscus. It will therefore be preferable to find non-tax solutions.

If you doubt this, consider that the present study is limited to the gold industry and the Witwatersrand. AMD associated with the coal mining industry, says Turton, is a nationwide problem—and a bigger one at that.

Kevin Davie

Kevin Davie

Kevin Davie is M&G's business editor. A journalist for more than 30 years, he has worked in senior positions at most major titles in the country. Davie is a Nieman Fellow (1995-1996) and cyberspace innovator, having co-founded SA's first online-only news portal, Woza, and the first online stockbroking operation. He is a lecturer at Wits Journalism. In his spare time he can be found riding a bicycle, usually somewhere remote. Read more from Kevin Davie

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