“Controversial “fracking” for shale gas should only take place at least 600 metres down from aquifers used for water supplies, scientists said on Wednesday.
A new study revealed the process, which uses high-pressure liquid pumped deep underground to split shale rock and release gas, caused fractures running upwards and downwards through the ground of up to 588 metres from their source. The research, published in the journal Marine and Petroleum Geology, found the chance of a fracture extending more than 600 metres upwards was exceptionally low, and the probability of fractures of more than 350 metres was 1%.
Researchers said the study showed it was “incredibly unlikely” that fracking at depths of 2km to 3km below the surface would lead to the contamination of shallow aquifers which lie above the gas resources.
“The researchers from Durham University, Cardiff University and the University of Tromso, Norway, looked at thousands of natural and induced rock fractures in the US, Europe and Africa, and found none of the artificially caused ones were more than 600 metres.”
Read more: The Guardian