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Environmental cost is mining's acid test

Pat Motshweneng, Miner's Choice Deputy Editor

We live in a time lag between spectacular development and affluence afforded by mining and technology, and spectacular degradation of our air, water, soil and food.

We do not feel the pinch of air pollution in most parts of Africa, as much as the far East and Europe do, but our generally poor soil, our expensively purified water, an our agriculture are under pressure.
Pollution and expensive food means inflation, more imports, expensive finance, and yet more pressure on food prices. Ecosystems are collapsing under a century of externalised mining costs.


Aquatic sulphur, in the form of sulphate salt, combines with water in underground mine voids and produces sulphuric acid, which in turn manifests itself as acid mine drainage (AMD).
AMD poses large health and environmental risk in Mpumalanga. One river draining an old coal mining area has a very low pH, being highly acidic, causing localised acid rain over coal waste and maize crops.
Nearby maize plants have deformed roots and stunted growth, thus prone to drought. Thus coal gives instant growth and comfort everywhere we could flick a switch, and coal slowly takes away growth everywhere it touches moisture.


The Department of Water Affairs and Environment, in a brief to an AMD committee in four areas of the Witwatersrand, noted high sulphate levels, radio activity, elevated levels of heavy metals, and possibly seismic events, due to flooding of old mines.
Pumping at Johannesburg's Central Basin had stopped in October 2008 due to safety risks. DWE said it could not predict the effects and location of uncontrolled AMD, but central Johannesburg groundwater could be toxified.
This water is currently 558 metres below surface, and thus below most groundwater sources, but could rise during summer. Mines and geoscience experts are monitoring the rate of rise. A new pumping station and upgrades to high density sludge treatment works are urgently required.
In the Western Basin, AMD started decanting in 2002. The state allocated R6.9-m for three months, and is investigating interim treatment measures.
Mines had their first proposal rejected, and came up with a second set of short, medium and long term solutions. Our industry is facing the AMD and poverty challenge where Gauteng's wealth started a century ago, but decisions and implementations would have to speed up to avoid rising toxins, and rising costs of the eventual set of solutions.


Meanwhile every ton of sulphur dioxide, carbon oxide, chloro fluoro carbon, lead, nitrogen oxide, and related compounds that our various productive industries release into the atmosphere, in the service of humanity, combines with moisture to form acid rain, snow, fog, gas and dust.


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