Hydraulic fracking, as the name implies, is water-intensive. Any discussion on fracking, therefore, must consider what effect it is going to have on this valuable resource.
Before continuing however, it is worth turning the clock back to 1868 – the height of Britain’s drive towards industrialisation – and the Victorian tort case of, Rylands v Fletcher.
This case involved a reservoir which the defendant, Mr Rylands, had built by a company of expert engineers to service his mill. Shortly after completion water leaked from the reservoir into a neighbouring coal mine owned by Mr Fletcher who, in turn, sued for damages. Mr Rylands was found liable and ordered to pay damages.
Lord Blackbourne summed the principles derived from the case up as follows:
“…….. the person who for his own purposes brings on his lands and collects and keeps there anything likely to do mischief if it escapes, must keep it at his peril, and, if he does not do so, is prima facie answerable for all the damage which is the natural consequence of its escape.”
From a literary (forget the legal for the moment) point of view the language is a real treat. Lord Blackboure’s judgement reads like a cautionary Victorian nursery tale of ne’er-do-well, perilous creatures, that if contained can be of great benefit – but release the will-o-the-wisp from the sealed jar and it will turn from benign to malign, wreaking mayhem and havoc where ever it may choose to wander.
The 1868 Rylands v Fletcher case established a strict liability rule and is one of the earliest known English environmental cases. Although the strict liability rule for this kind of land tort no longer exists in English law it is still good law and the cautionary tale of Rylands v Fletcher – and some subsequent cases – may be relevant when considering what impact hydraulic fracking could have on Europe’s water resources.
The definition of hydraulic fracking is the process by which a liquid under pressure causes a geological formation to crack open. Whilst 99% of the liquid mixture used in hydraulic fracking is water, water on its own is not enough for the whole process to succeed. Sand or mud, acting as a proppant is added plus a mixture of chemicals that accounts for roughly 1% or less of the total mix.
Until recently American energy companies kept their list of chemicals secret, claiming they were a “proprietary right” rather like Coca Cola has kept its ingredients secret for over 100 years. This is no longer the case and a full list of the chemicals used in fracking can be found on fracfocus.org . Put simply, the chemicals added serve to congeal the liquid to prevent the cracks, once fractured, from collapsing in on themselves.
Once the pressure is released the water flows back to the surface of the well. The “flow-back” or “produced water” that returns to the surface, however, is not the same beast that initially went down, meaning it is no longer simply 99% water, some proppant and 1% chemicals. Nor does the same volume injected return to the surface – some of it will remain underground.
The AEA study notes that the waste water that does re-surface, may include dissolved solids, gases (e.g. methane, ethane), trace metals, naturally occurring radioactive elements (e.g. radium, uranium), and organic compounds. The flow-back water can also have a very high saline content reflecting the marine origin of shale.
Industry tries to re-use as much of the recovered flow-back water as possible but the high salinity content of the produced water makes this problematic. The produced water that is not re-used is collected in tanks, removed and treated elsewhere. In some cases it is left in tailings dams close-by to evaporate.
Ground water and surface water contamination from produced water is of considerable public concern in the United States where, to recall, fracking is becoming wide-spread.
Critics of the film Gaslands, accuse it of hyperbole, scare-mongering and incorrect facts. Yet, dramatic pictures of putrefying tailings dams spewing forth noxious gases, taps that spurt fire and filthy drinking water in properties neighbouring hydraulic fracking wells – combined with industry’s previous stance of preventing disclosure of their chemicals – results in increased public suspicion that fracking is not as clean as is suggested.
What then of the risks? Does fracking deplete water sources that should be available to the public? Can fracking contaminate surface water and or underground aquifers that act as the source of our drinking water?
As noted, not all of the water used for fracking can be reused, nor does all of the water pumped down return to the surface. Drawing on fresh water supplies appears inevitable and can not be avoided though industry is committed to re-using 100% of all the water it uses when fracking. In the meantime certain areas of the United States have suspended water removal licences for fracking purposes because of the intensity of water consumption.
Of most concern, however, is the migration of produced water from the shale layer to underground aquifers. Industry, refutes this stating, “ since there is no pathway between the fractures and aquifers – there are typically several thousand metres of rock between the fracturing fluids and groundwater sources – hydraulic fracturing cannot contaminate groundwater.”
According to the IEA worldenergyoutlook (p 37) “The deepest potential underground sources of drinking water in the Barnett shale are at a depth of 350 metres, whereas the shale layer is at 2 000 to 2 300 metres.”
The AEA agrees, suggesting that where there is more than 600 m separation between the drinking water source and the producing zone, the likelihood of properly injected fracturing liquid reaching underground sources of drinking water through fractures is remote.
For this to hold true, however, there must be excellent well design – and the design must hold good for a number of years – even after the site has been abandoned. Industry insists that best practice and correct well-design will effectively eliminate all risk of water contamination – both surface and ground level. This may well be the true.
Yet, as was the case with issues relating to fracking and seismic activity, one of the most worrying aspects of water contamination lies not just in the production of shale gas itself but in the practice of getting rid of the produced water in disposal wells. Disposal wells are a sub-class of “injection wells” that the US Environmental Protection Agency has, in turn, divided into various Classes. The depth of an injection well varies from 520 m to more than 3 500 m.
Class 1 wells refers to hazardous, non-hazardous and municipal waste. There are 550 Class 1 injection wells in the United States and they are subject to the most stringent regulation.
Class II injection wells on the other hand are reserved exclusively for the oil and gas industry. The EPA states that there are 151,000 Class II wells in operation in the US (significantly more than there are Class 1 wells) in which, 2 billion gallons of brine are poured every day.
To complicate matters somewhat Class II injection wells are sub-divided into three further categories. The first “Enhanced Recovery Wells” (ERW) are nothing more than a hydraulic fracking well itself– and they account for 80% of Class 2 injection wells.
The second category of Class 2 wells are “Disposal Wells” – these are the wells into which the oil and gas industry pours the flow-back water. Disposal wells account for approximately 20% of all Class 2 injection wells.
An interesting article in Scientific American has highlighted the fact that over the past few years the oil and gas industry has exploited the division of disposal wells into various classes and has succeeded in lowering the level of regulatory supervision for such disposal wells.
Moreover there is increasing evidence that the practice of using disposal wells in which to pour produced water is actually increasing the risk of seismic activity – a link backed up by a recent University of Texas study . (See also previous post, Fracking: Earth).
Although there are assurances that properly constructed, designed and supervised hydraulic fracking wells can and will contain any pollutants there is always the possibility of unexpected leakages – either during the drilling process itself, at the disposal stage, during the transportation of waste water in trucks – or long after the well site has been abandoned.
Returning to the case of Ryland v Fletcher what then of the will-o-the-wisp? Can the oil and gas industry contain the potentially dangerous liquid and prevent it from causing perilous mischief to the surrounding environment?
As any homeowner will know water has a nasty habit of seeping even from the best sealed spaces. One moment the homeowner has invested in an expensive new insulated roof, modern drains and silicone sealed windows – the next a damp patch appears in one of the upstairs bedrooms. Water has a nasty habit of migrating. If it can find an outlet – no matter how small, like our will-o-the-wisp – water will escape.
Consider also the 1994 case of Cambridge Water v Eastern Leather Counties. Unbeknownst to the defendant (Eastern Leather Counties) a chemical known as perchloroethene (PCE) had for years been seeping from their tannery premises into the sub-soil. From there the PCE travelled some miles into an underground aquifer which provided drinking water to the residents of Cambridge. The pollutant was only discovered thanks to the introduction of an EU Directive requiring the UK water authorities to check for this particular organic compound.
Unlike Mr Rylands, Eastern Leather Counties was not found liable. Their Lordships decided to weaken the strict liability requirement so that now foreseeability was an essential requirement. They judged that Eastern Leather Counties could not have foreseen that the PCE used could have escaped into a nearby aquifer. (Note: this judgement has been criticised).
Foreseeable or not – the facts of the case illustrate clearly that liquids seep, migrate and escape into all sorts of unexpected quarters and in unexpected ways – and that when they do so they can cause considerable harm to the supply of clean drinking water. The escaping mischief can take years to manifest itself and may pop up to taunt a person long after industry has shut-up shop and moved on to pastures green.