Posted 04 July 2011, by Brian Hayward, Times Live (AVUSA Limited), timeslive.co.za
Research said to prove for the first time that shale-gas extraction leads to contamination of drinking water has led to a mud-slinging match between those for and against controversial hydraulic fracturing mooted for the Karoo.
Caught in the crossfire are researchers who admit they are still in the dark and uncertain about the long-term implications of hydraulic fracturing, dubbed “fracking”.
A paper published recently by Duke University researchers in the US, titled “Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing”, is claimed to be first proof that fracking contaminates shallow water tables and drinking water. It reported varying methane levels in about 60 drinking wells in Pennsylvania and upstate New York and gave conclusions based on the wells’ proximity to fracking sites.
“Our results show evidence for methane contamination of shallow drinking-water systems in at least three areas of the region and suggest important environmental risks accompanying shale-gas exploration worldwide,” the paper said.
Excessive methane in water can render it flammable and toxic.
The research has led to heated debate among advocates and opponents of exploring the Karoo for shale gas through fracking.
Some dispute the research as “based on anecdotal tales” and “fruitless speculation about the origin of this [methane] gas”.
Shell SA dismissed the study, with its fracking specialist, Kim Bye Bruun, saying the sampling of wells was not only relatively small, but the wells were known to contain traces of natural gas.
“We are not aware of any study having found evidence of water well contamination from chemicals contained in HF (fire-resistant hydraulic) fluids and this study supports that. Well integrity is an essential part of the responsible development of any subsurface oil or gas resource,” Bye Bruun said yesterday.
Researchers welcome debate. “This is important because fracking hasn’t been properly investigated in terms of its long-term impact,” said Graham Kerley, director of Nelson Mandela Metropolitan University’s Centre for African Conservation Ecology.
Free State University, which leads in local fracking research, is sending researchers to Pennsylvania next month to investigate Shell’s fracking sites and speak to legislators about how shale-gas extraction is working there.
“The truth is we still don’t know in South Africa,” said Dr Danie Vermeulen, of the university’s Institute for Groundwater Studies.
“We need to have an unbiased look at fracking, because at the moment all our information is third-hand.”