By Julienne du Toit
In May of 2012, an academic called Professor Gerrit van Tonder changed his mind about something. Almost immediately, it made national headlines.
What he’d reconsidered was his take on one of the most controversial extraction processes in the world – hydraulic fracturing, or fracking, which injects millions of litres of water along with sand and chemicals to fracture shale rock to retrieve methane.
Van Tonder had said repeatedly fracking would not affect or harm the groundwater. As a professor at the University of the Free State’s Institute for Groundwater Studies, his opinion carried real weight.
But then in May 2012 he dropped a bombshell: If fracking was allowed to go ahead during exploration, using poisonous chemicals, it would be a catastrophe, he said. He became known in the media as the “U-turn Professor”.
It started after Van Tonder read a peer-reviewed study by American geohydrologist Tom Myers saying that contaminated water from fracked layers underground could rise to groundwater levels thanks to the drill holes which then became ‘preferential pathways’.
This, and some interesting findings raised by doctoral student Fanie de Lange set off alarm bells for Van Tonder.
“This started me thinking about the Karoo,” he said in an interview. “It also made me remember the exploration holes drilled by the gold companies on my father’s Free State farm. Water rose up them and was still warm at the surface. Also, the hot water springs that you find rising in the Karoo, in Cradock, Aliwal North and near Barrydale originate deep in the deep formations kilometres underground. In addition we have proof that certain of the exploration holes drilled by Soekor in the 1960s were artesian.
“In other words, water from depths of 1 500 metres or more rose up via these holes. Those are just a few examples. There are more to show there is a vertical movement of briny water from depth to surface. Fortunately rainwater trickling down improves shallow groundwater quality to a standard fit for human consumption and irrigation. Water quality is better and deeper in the east, where there is more rainfall, than in the west where there is less.”
The more he researched the issue, the more likely it seemed that fracked water at depth could rise rapidly in the Karoo because of its unique dolerite dykes and sills from volcanic action 183 million years ago.
“The Karoo is very similar to the Marcellus Shale in that this is a basin under pressure, but we have an additional wild card – the dolerite dykes and sills that occur all through this area. The Karoo is riddled with it – and this is the only shale field in the world with dolerite. Dolerite, which comes from volcanic action in the Karoo 183 million years ago, is well-known as a preferential pathway for water. Any Karoo farmer knows that if you are looking to drill a borehole for water, you seek out dolerite, because water travels along it.
“There is no doubt that the fracking well casings will fail, sooner or later. That is why I say that contamination is absolutely inevitable and it will be one of the biggest water pollution disasters in the world. South Africa is so short of water. We cannot risk this.”
- Prof Gerrit van Tonder died of a sudden heart attack on 22 April 2014, leaving behind his beloved wife Fransie, and his children Sanri and Gideon. He was 61.