Lancashire shale gas drilling being done 'by the book'
The chief executive of a firm which is drilling for shale gas in Lancashire has sought to reassure residents and environmentalists that it is safe.
Cuadrilla Resources has been drilling on land near Kirkham and is due to start extracting gas soon.
But the Tyndall Centre for Climate Change Research is urging the government to stop the drilling until all implications are understood.
Cuadrilla CEO Mark Miller said: "We are doing this by the book".
"We are using the best technology the industry has," he added.
The gas is held in a vast bed of rock called the Bowland Shale which runs from Clitheroe to Blackpool.
The firm has sunk a test well more than 9,000ft (2,743m) down into the shale and is now due to start releasing the gas, using a process called hydraulic fraction.
The authors of the Tyndall report, commissioned by the Co-operative, want to see further studies carried out into the effects of pumping chemicals underground to help release the trapped gas.
Officials in the United States are investigating claims that shale gas has polluted water supplies.
But Mr Miller said problems with extracting shale gas were "very rare".
He said it was crucial to ensure the well is correctly designed.
"We want to meet or exceed all the UK regulations for achieving well integrity and making a leak-free well that is going to last 50 to 100 years," he added.
Professor Kevin Anderson, from the Tyndall Centre at the University of Manchester, said the UK government should halt production until more was known about the ecological implications of shale gas extraction.
"The process by which we extract it leaves us with a whole range of concerns, particularly with contamination of ground and surface water," he said.
The Department of Energy and Climate Change (Decc) has rejected the idea of suspending the drilling, however, saying that drilling for shale gas does not pose a threat.
A spokesman said: "We are aware that there have been reports from the US of issues linked to some shale gas projects.
"However, we understand that these are only in a few cases and that Cuadrilla has made it clear that there is no likelihood of environmental damage and that it is applying technical expertise and exercising the utmost care as it takes drilling and testing forward."
Cuadrilla Resources said it believed there could be enough gas in Lancashire to supply about 10% of Britain's future needs.