A controversial gas extraction method called fracking which triggered the occurrence of two earthquakes near Blackpool last year should not cause any tremors or water contamination if proper regulation standards are employed, experts have said.
A review by the Royal Society and the Royal Academy of Engineering released on 29 June, 2012 has indicated that hydraulic fracturing (often termed "fracking") can be managed effectively in the UK as long as best operational practices are implemented and robustly enforced through regulation.
"There has been much speculation around the safety of shale gas extraction following examples of poor practice in the US," stated Professor Robert Mair FREng FRS, Chair of the review's working group. "We found that well integrity is of key importance but the most common areas of concern, such as the causation of earthquakes with any significant impact or fractures reaching and contaminating drinking water, were very low risk."
The study team said that hydraulic fracturing is not completely risk-free. Strong regulation and robust monitoring systems must be put in place and best practice strictly enforced if the government is to give the go-ahead to further exploration.
The review also emphasises the need for further development and support of the UK's regulatory system, together with environmental risk assessments for all shale gas operations and more extensive inspections and testing to ensure the integrity of every well.
The review examined the scientific and engineering evidence relating to the environmental and health and safety risks associated with onshore extraction of shale gas. They found that the risk of contamination of aquifers from fractures is very low provided that shale gas extraction takes place at depths of many hundreds of metres.
Earth tremors induced by hydraulic fracturing are likely to be of a smaller magnitude than the UK naturally experiences; they will also be lower compared to coal mining activities, which are themselves, low by world standards.
A particular cause for concern is that that poor cementation and casing failures of wells could lead to leakages and wider environmental contamination, as they have in some cases in the US. Therefore, the review concludes that the priority must be to ensure the integrity of every well throughout its lifetime.