Acid Mine Water Poses Serious Threat in Africa
Companies owning big factories have a lot to answer for when it comes to pollution. They pollute the atmosphere, rivers and oceans; causes oil spillage in the sea killing millions of creatures and their habitat, and poses many other environmental threats.
In Africa, one such problem brought by mining companies is acid mine water or acid mine drainage (AMD).
Acid Mine Drainage
AMD is produced when a mineral known as iron pyrite comes in contact with water elevating in abandoned mine workings. Iron pyrite, when comes in contact with air and water, creates a highly hazardous material called sulfuric acid.
If ignored, this contaminated water then overflows out the mine and pours into nearby rivers and streams. What’s more worrying is the fact that even before AMD has risen out of unused mines; it may already have polluted water from beneath the ground, water that’s being relied on by nearby communities.
However, the Department and Ministry of Water Sanitation has already recognized the issue and has been working for it in years.
Back in 2010, the concern regarding unused mines over at Witwatersrand –a 56 kilometer long north escarpment – has drawn so much attention that a committee has been formed to tackle the problem. Five years later there has been significant progress on the matter.
The Two-Pronged and Triage approach
Those that were tasked with finding a solution to AMD partitioned Witwatersrand into three separate areas; areas that have a combined acid mine water of 170 million liter a day. To put it into perspective, that’s equal the amount of 60 Olympic-size swimming pools.
The divided areas – Western, Central, and Eastern Basin – have been individually tackled by different groups of the committee which came up with a two-pronged solution.
First is to neutralize the AMD and decreasing the amount of metals it contains. The Western Basin, which has an emergency treatment plant established between 2011 and 2012, was renovated. The plant stopped the overflow but the basin’s environmental critical level (ECL) remains elevated. It’s estimated that it will take four years to bring it down below ECL.
A treatment plant over at the Central Basic is faring better treating about 60 million liters a day, while a treatment plant is being built over at the Easter Basin is expected to reach completion in April next year and is approximated to treat 80 to 110 million liters a day.
The second phase is to desalinate the salt-laden water from the treatment plants through dilution using water from the Vaal Dam. However, the dam may not have sufficient water supply come 2017 onwards to continue such large scale diluting.
One solution proposed is to re-use the diluted salt-laden water back into the Vaal Dam to continue the phase two process.
As these areas are being addressed, there are still others that are posing serious AMD threats located in Free State, KwaZulu-Natal, Limpopo, Mpumalanga, and the Northern Cape. Right now there are still over 5,000 unused mines in Africa.
While there are certainly those accountable for these man-made threats, now isn’t the time to point fingers. Right now it’s more important to act.