Shale gas developer Cuadrilla Resources will start fracking for gas at its Preston New Road site in northwest England next week, the company said on Oct. 5.

Hydraulic fracturing, or fracking, involves extracting gas from rocks by breaking them up with water and chemicals at high pressure. It was halted in Britain seven years ago after causing earth tremors.

But the British government, keen to cut its reliance on imports, which have soared to more than 50% of British gas supplies, has tightened regulation of the industry.

This year it gave consent for Cuadrilla to start fracking at two wells at Preston New Road.

Results from a six-month test period are expected in the first quarter of next year, which Cuadrilla said would provide information on how much gas it could potentially recover.

“This will allow us to make an assessment of the commercial viability and future of this exploration site,” Cuadrilla CEO Francis Egan said in a statement.

The British Geological Survey estimates shale gas resources in northern England alone could amount to 1,300 trillion cubic feet of gas, 10% of which could meet the country’s demand for almost 40 years.

The practice of fracking has been opposed by environmental and local community campaigners concerned about the potential effect on the environment and ground water. They also argue that extracting more fossil fuel is at odds with the country’s commitment to reducing greenhouse gas emissions.

Three protestors were given prison sentences in September for blocking a convoy of trucks carrying drilling equipment to the site.