THE UK, we are told, is gasping for gas, which accounts for nearly half of its energy use. Home-grown gas is drying up, leaving the country ever more reliant on imports. The solution, some say, is right beneath our feet: we just need to frack for shale gas.
The remarkable success of the dash for shale gas in the US has persuaded its proponents in the UK. The UK government backs it. The Environment Agency has just granted energy firm Cuadrilla permits for exploratory fracking at two sites in Lancashire. And an attempt by a group of MPs to impose a moratorium on fracking was defeated last month.
Meanwhile, NGOs say that fracking on UK soil would be an environmental disaster, one we should avoid at all costs. They cite a range of concerns, such as water and air pollution (see diagram). So would fracking really wreak havoc on the environment? And if not, should the UK press ahead and make use of this controversial source of gas?
The UK does need to re-think its energy supplies. The North Sea gas fields are reaching the end of their lives, most of its nuclear plants are to close by 2023, and a third of its coal-fired power stations are set to close by 2016 to meet European air quality regulations.
The greenest solution is a switch to renewables and the government has committed to getting 15 per cent of the nation's energy from these by 2020, and has promised to cut its greenhouse gas emissions to 80 per cent below 1990 levels by 2050.
But there is a catch. The sun doesn't shine and the wind doesn't blow 24/7. We do, however, consume energy around the clock. Until we can develop the large batteries needed to even out energy supplied from renewables we need a more reliable source.
This is where fracking comes in. Geological surveys reveal that parts of the British Isles are made of methane-rich shale, where the sediment traps natural gas inside tiny bubbles. To extract this gas, companies drill down and then horizontally over large distances. They then pump water, sand and chemicals in, which fracture the shale, allowing the gas to escape and collect in the well.
Over the last decade in the US, fracking has caused both an energy revolution and furore among environmental groups, mostly concerned about an increase in water pollution.
Avner Vengosh, a geochemist at Duke University in Durham, North Carolina, has been at the forefront of studies on the environmental effects of fracking. Just last month, he revealed that hazardous levels of ammonium, bromide and iodide were ending up in rivers as a result of fracking on New England's Marcellus shale (Environmental Science & Technology, doi.org/z2f). These come from deep inside the shale and are carried up to the surface along with the wastewater.
Minimising risk
But while news headlines pointed the finger only at fracking when such pollution occurred, Vengosh says his team found the same levels of pollution associated with conventional oil and gas operations. The problem, he says, is that oil and gas companies in the US are exempt from some federal regulation. In particular, in 2005 Congress exempted fracking chemicals from the Clean Water Act. Many conventional oil and gas operations now inject the same chemicals as for fracking into their wells. "The difference with shale is that it's closer to people's homes, so they see the impact," says Vengosh.
Vengosh is now working with the California water board to draw up stringent industry standards to address some of the federal regulatory failings. He says there are basic steps the UK could take to minimise the environmental risks. For instance, casings around drill wells should be thick, impermeable and routinely monitored for cracks to avoid any gas or chemicals contaminating drinking water. There should also be a 1 kilometre exclusion zone around drinking resources where fracking cannot occur. And live monitoring systems need to be put in place, so leaks are picked up in real time.
The risks cannot be eliminated, but they can be minimised. "It's all manageable," he says. "It's just a matter of investment." Though, as with any fuel operation, there will always be a risk of accidents.
"We're in a much better position in Europe," says Ulrich Ofterdinger, a geologist at Queen's University Belfast, UK. "Like it or not we have a lot of regulation from Brussels that should force countries to put in place decent environmental frameworks."
Ofterdinger's concern is that politicians will press ahead with fracking licences and miss the opportunity to gather baseline geological data. The difficulty in the US, he says, is that by the time people became concerned about gas and chemicals seeping into their drinking water it was too late to find out if the contamination was due to natural processes.
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