While risk is talked about a lot with regard to fracking it should be born in mind that a lot of impacts, like the massive amounts of extra road traffic (particularly heavy good vehicles), are guaranteed to happen and are not “risks”. Also while a particular issue may be a risk for an individual well, when thousands are being drilled in an area it can become a certainty that some fraction of wells will have a certain impact. For instance, immediate contamination of groundwater does not happen with every well, but given that industry data shows that around 6 percent of wells are leaking in some way as soon as they are constructed, once you drill more than a few dozen wells it is almost certain that at least one of them will be leaking.
The fundamental issue with fracking is the scale and intensity of these extraction processes. It is only when the scale of the extraction effort needed for unconventional oil/gas is properly understood that overall impact can be assessed. As more and more wells are drilled in a region, the impacts of the individual wells accumulate and it is the cumulative impacts of this wholesale industrialisation which eventually becomes the dominant factor. There are also considerable variation in the timing of different impacts. Some impacts are worst during the drilling and stimulation phase, such as air pollution and truck traffic, while others such as leaking wells may get progressive worse over the following decades as the integrity of the well steadily declines.
In general shale oil has most of the impacts of other fracking extraction (shale gas and coal bed methane) plus a few extra oil specific ones for good measure. For instance the carnage on the roads, with spiking road traffic deaths caused by the thousands of fracking trucks per well, is seen in oil areas like the Bakken Shale in North Dakota and the Eagle Ford Shale in Texas, as well as shale gas areas such as Pennsylvania. The impacts on human and animal health seen as thousands of well pads, plus other infrastructure, coat the landscape are also common to both shale oil areas like North Dakota and other areas fracking areas from Pennsylvania to Queensland.
Regardless of whether they are producing oil or gas most shale formations contain significant amounts of radioactive uranium and thorium, which decays into a variety of radioactive elements, of which radium is probably the largest issue since it easily dissolves in water. Significant quantities of radioactive materials can be brought to the surface in drill cuttings, drilling mud, fracking flowback fluid and produced water. As with many other fracking areas North Dakota has been inundated by a tidal wave of radioactive waste whose effects will linger for thousands of years. Radioactive materials cannot be “treated” out of existence but only slowly decay, and have a nasty habit of bio-accumulating up the food chain.
Just one example of unique impacts from shale oil extraction is the sudden, and temporary given the steep decline rates of the wells, flows of oil from areas where little petroleum has been produced previously. While is may not seem like a major issue, transporting oil is always dangerous, with attendant risks of spills and explosions. For gas, pipelines are the only practical option for transport and given that large amounts of gas are needed to fill a pipeline a coordinated effort of pipeline building and well drilling is needed. The fact that oil can be moved, albeit less efficiently, in road or rail tankers means that a much more piecemeal approach is possible, and therefore likely. Wells are drilled and oil starts flowing out of the region by any available transport, and pipelines follow later, if at all.
This issue was brought into stark relief in July 2013 when a train carrying Bakken Shale crude oil derailed and exploded in the small Canadian town of Lac-Mégantic, Quebec. It laid waste to the centre of the town and killed 47 people, as well as leaving more lingering toxic effects. This was not an isolated incident, but part of a growing trend including major derailments involving explosions and fires in Aliceville, Alabama (Nov), Casselton, North Dakota (Dec), Vandergrift, Pennsylvania (Feb) and Lynchburg, Virginia (May). In North America, the transportation of crude oil by train has grown 50-fold in the 4 last years, while in Canada it has grown 280-fold in the same period. In fact, more oil spilled from trains in 2013 than in previous 4 decades combined.
The use of pipelines has its own set of problems, especially since large numbers of distributed well sites requires a massive pipeline network across a region. Large, high pressure gas pipelines have the potential to cause massive explosions, but oil pipelines are also dangerous and come with added risk of long term land contamination from spills. It was only after a large, well publicised spill turned a farmers fields into a toxic swamp of oil, that is emerged that North Dakota has experienced 300 oil pipeline spills in less than two years. None of which were previously reported to the public. As well as pipelines carrying oil, pipelines used to transport fracking waste have also become a major source of contamination.
In the US, flaring has grown rapidly over the past five years – soaring from 78 bcf in 2007 to 251 bcf in 2011 – a 223% increase. At night the previously rural Bakken Shale region is now visible from space, out-shining many large cities due to the flaring. Shale oil is a major culprit since the wells go into oil production immediately, but do not produce enough gas to warrant anything but flaring it. As of 2014, around a third of gas produced in the North Dakota was still being flared. This is a major cause of air pollution. Similar severe air pollution is an even larger issue in the more populous Eagle Ford shale region of Texas.
Much has been made of the economic impact of the Bakken tight oil in North Dakota. However, to put this in context it needs to be understood that North Dakota is one of the lowest population density states in the US. As with other types of fracking and extractive industries, the process is extremely energy rather than labour intensive. Any jobs and economic activity mostly benefit distant corporations and their specialist employees. In North Dakota an influx of companies and workers has completely overwhelmed the small local communities, driving many people from their homes as rental prices spike and bringing a wave of drug gangs, meth labs, violent crimes, and fraud, as well as dead and injured workers.
For a general overview of the impacts of fracking, including tight oil, a see: Mounting Evidence: The Harm Caused By Fracking