From the Frack-Off
Hydraulic fracturing (fracking) is a highly destructive method of extracting gas and oil trapped in rocks underground. Over the last decade there has been a massive boom in fracking for gas trapped in impermeable shale rock.
To extract the gas, wells are drilled deep into the earth's surface and a 'fracking fluid‘ is pumped in at high pressure. This fractures the rock and release the gas. Because the rocks are impermeable this is the cheapest way to release the gas. On a typical well over 1 million litres of water and up to 10,000 litres of chemicals are used.
WHAT'S THE PROBLEM?
So much is wrong with fracking it is hard to know where to start. As a method of fossil fuel extraction it reeks of desperation!
Risk & Uncertainty - Because the fracturing process is done by brute force and the behaviour of fractures is difficult to predict there are unique and unforeseeable risks at every site. The geological structure of the area is fundamentally compromised by each fractured well as the impermeable shale may no longer act as a barrier or may channel polluted water back up to the surface. Due to lax regulation in the US where fracking is widespread, there has been little research done into the long term risks. Every well poses an ongoing risk to the surrounding area and could at any point in the next 500-1000 years make it dangerous to grow food or drink the water.
Health implications - Many of the chemicals pumped in the wells in the US are toxic and have known negative health effects; as well as impacting on respiration, reproduction, and the central nervous system, they are also linked with cancer.
Food supply contamination – from the moment that drilling commences there is a risk of polluting irrigation systems near fracking sites. With food production a global industry, the risk to food supplies is clearly not just a local issue. Shale Gas exploration is happening all over Europe and agricultural areas have no protection or exemption.
Water Contamination – The chemicals, which are injected into the ground can leak into groundwater supplies. While some of the injection fluid used in the process comes back to the surface, 30 to 40 percent is never recovered, according to the industry‘s own estimates, leaving the contaminants in the ground where they can eventually pollute the water table.
Produced Water - Fracturing the rock at high temperatures and pressures leaches harmful materials from the rock itself, which are then sucked back in the 'flowback fluid' or escape through cracks into groundwater or aquifers. The most well known is methane contamination of water sources, in some areas the methane in tap water from contaminated wells can be set of fire.
If that wasn't bad enough - where there are toxic elements within the ground such as arsenic or radioactive isotopes, fracking can cause these materials to leach out of the rocks when they are forcibly cracked.
With millions of gallons of fracking fluid created, we must also consider what will happen to the fluid that is recovered. In America there have been examples of wastewater spillages, and of the radioactive water being discharged into rivers used for drinking supplies. Even with more care, disposing of this fluid is highly problematic as public water utilities are inadequately equipped to process the large quantities of toxic liquid.
Air pollution – fracking produces both carbon dioxide (CO2) and methane. Methane is an extremely powerful greenhouse gas, 20 times more effective at trapping heat than CO2. The production and release of methane from fracking has a worse greenhouse effect per unit of useful energy produced than conventional sources including coal – the most carbon-intensive fossil fuel. In addition there are other volatile compounds emitted from fracking sites and infrastructure. There is concern that these compounds can affect the health of humans, plants and animals in the vicinity of each site.
Water use – a high volume of water needs to be pumped into the ground in order to fracture the rock. Up to 10 million litres of water are used to frack a single well, which can put considerable pressure on water supplies, particularly at the local level.
Earthquakes – Fracking, as well as disposal of fracking fluids into old wells, appears to trigger earthquakes. A recent increase of earthquakes in Arkansas declined abruptly after water injection was suspended. The first test well in the UK, in Blackpool it appears to have already caused two earthquakes within months of fracking a single test well at its first site.
More concrete, more pipes, more trucks - Development of a new industry of course requires a lot of infrastructure. Fracking sites are comparatively small with a limited supply of gas produced per site, so in order to scale up production and become economically viable it requires many wells across the landscape, which in the US have been interlinked with a network of pipelines. In Pennsylvania alone, government estimates predict that 3,000-4,000 new wells will be drilled each year for the next 30 years. In Pennsylvania each fracked well requires an average of 592 one-way truck trips!