LONDON, April 17 (UPI) -- Proposals aimed at reducing the likelihood of seismic events tied to hydraulic fracturing of shale are open for comment, the British government said.
Last year, Cuadrilla Resources halted shale gas extraction in northwestern England because small tremors reported near its operations.
A study commissioned by Cuadrilla determined that minor earthquakes reported last year "were caused by fracking," otherwise known as hydraulic fracturing.
"This comprehensive independent expert review of Cuadrilla's evidence suggests a set of robust measures to make sure future seismic risks are minimized," said David MacKay, chief scientific adviser for the British Department of Energy and Climate Change, in a statement.
The DECC suggested fracking procedures should include small-scale operations following by a monitoring stage. Fracking would stop immediately if a seismic event of 0.5-magnitude or greater was recorded.
Scientists in the United States said they found a link between the injection of wastewater from the development of shale natural gas into deep disposal wells. The U.S. Interior Department said seismic events weren't tied directly to fracking.
"The invitation for comment runs for six weeks from today," said the British government. "All comments received will be considered and taken into account before any decision is taken on further fracking for shale gas."