Monday, 25 November 2013

To a curious reader....

I received an email last week from someone concerned about the implications of UK shale gas development, with particular focus on the implications in terms of climate change. I ended up writing quite a long response, which I think is worthy of sharing with a larger audience. I have posted in below:

Hi J____,

Thanks for getting in touch. You are quite correct, I am far too young to have grandchildren.

I think you might have been somewhat mislead in your comment that Germany generates 60% of its energy, and Denmark generates more energy than it needs, from renewable sources. Looking at the annual review of world energy statistics (p 41), Germany gets 9% of it's total energy consumption from renewables, while Denmark gets 18%. Clearly, there is still some way to go before we are producing all of our energy from renewables. 

Indeed, I think that James Hansen, probably the leading expert in climate change, one of the first scientists to realise the threat it posed, put it well when he said in an essay in 2011: "suggesting that renewables will let us phase rapidly off fossil fuels in the US, China or India, or the world as a whole, is almost the equivalent of believing in the Easter Bunny and Tooth Fairy".

I agree your premise that there is probably an upper limit to the amount of CO2 that we can safely put into the atmosphere, and that number is less than existing fossil fuel reserves. However, it is important to consider relative contributions of the various fossil fuels to these reserves, the relative rates at which they are burned, and the amount of energy produced from each fuel per tonne of CO2 produced. The first figure attached shows where the CO2 in our reserves is embedded, while the second shows where the world's CO2 emissions come from presently:

These figures make clear that the biggest problem is coal, and especially coal being burned in China. Any 'environmental' policy that does not address this is, to my mind, not an environmental policy. 

Natural gas, when burned, produces twice as much energy per unit of CO2 as does coal (i.e., coal produces twice as much CO2 per unit energy). If we accept that we have an upper limit to the amount of CO2 we can produce, then it makes sense to use the fuel that gives us as much energy as possible for that given amount of CO2. For example, if increased natural gas abundance leads China to switch from a coal-dominated to a gas-dominated power sector, it would cut that big purple column on the left hand side above in half. That would be a much bigger impact that wiping the UK's emissions off the map completely. So while full renewables penetration would be the ideal situation, we should not let perfect stand in the way of good, because switching natural gas for coal wherever possible would produce significant impacts.

Natural gas has other advantages as well, including reduced air emissions. However, the one I will focus on now is its flexibility, relative to coal and/or nuclear. It takes a long time (days, as far as I'm aware) to turn coal and nuclear plants on and off, whereas gas turbines can be switched on and off in minutes. This makes gas an ideal complement to large-scale renewable energy penetration, as they provide the flexibility to adapt to the intermittence inherent in renewable sources. If you won't take my word for it, perhaps the Texas Clean Energy Coalition comments will be of interest. Equally, ClimateDesk reports on the chief of the US Solar Energy Industries Association: 
'Natural gas and renewables complement each other very nicely,' Rhone Resch, CEO of the Solar Energy Industries Association, said this morning at a press conference for the release of Bloomberg New Energy Finance’s 2013 Factbook, an exhaustive analysis of the state of clean energy in America. 
The report, based on a blend of original and existing government research, is unequivocal in placing natural gas in the same ‘clean energy’ boat as renewables, a new arrangement Resch and Dave McCurdy, head of the American Gas Association, agreed they were happy to see. 'Natural gas can fill the gap when renewables go intermittant,' he said, 'ramping up when the wind stops or the sun goes down.'
The Director General of the International Renewable Energy Agency stated:
"Shale gas at low cost can help to create a hybrid system, whereby more gas-fired power is fed to the grid, supplanting coal, and augmented by wind and solar."
I have a blog post describing this in more detail here. It's a little known fact that of all the US states, Texas has deployed more wind energy than any other in the last 10 years. That's big, bad Texas, home of the shale gas revolution. The abundance of cheap natural gas is making renewables more attractive. Equally, the improved economic conditions, part fuelled by the shale developments, leaves more money in state finances to fund renewable developments. Contrast that with the situation in the UK - rising energy costs mean that the additional charges needed to promote renewable development are becoming increasingly politically unpopular, while the poor economic situation in which our government is stuck means that there is little government cash to fund this.

My take on the situation is as follows: Firstly, the development of UK shale gas should not be seen as a panacea for all our energy and economic problems. It will help, but it's not a solution to all our problems (I know that some in the media have presented it as such). However, even the most optimistic predictions for renewables development show that we will be burning gas in this country for some time to come. Remember, only 1/3 of the gas use in this country is used for electricity, another 1/3 is used for domestic heating and cooking, and the final 1/3 is used as feedstock in industrial processes (such as at the Grangemouth plant that was nearly forced to close 2 weeks ago, in part because of the increased costs of raw materials).

At present, we are increasingly importing this gas from abroad. This is money lost to the UK economy, to be spend by Qataris on fast cars and an air conditioned football world cup. Given that a potential equivalent resource exists within the UK, it seems irresponsible to be allowing this money to leave our economy when we could be developing a home-grown alternative instead. However, it is important that this opportunity is leveraged to our advantage, unlike our past development of North Sea oil and gas. I would like to see the government ring-fence the taxes taken from future UK shale developments, to be spent only on energy efficiency initiatives and/or research into improving renewable energy technologies. I have already written to various MPs to make this suggestion (see also my blog post on this aspect).

I hope this goes some way to answering your questions. I realise that I've sent quite a long reply, but I think it is a subject worthy of lengthy discussion, rather than the 30 second soundbites provided by the media.

Kind regards, and my best wishes to your grandkids,


Monday, 18 November 2013

Seismometer Deployments at Balcombe: Final Report

Cuadrilla's drilling at Balcombe attracted a lot of headlines. In a previous post I described (mainly by way of lots of holiday snaps) the deployment of seismometers by Bristol colleagues and I.

We have now completed our data analysis, and our results are available for you to read!

Hydraulic stimulation was not planned for this phase of Cuadrilla's operations. Therefore, we did not expect to see any induced seismic events. Nevertheless, we saw this as a good opportunity to attempt several objectives:

The first objective was simply about public perception. The average member of the public does not know much about earthquakes or about seismometers. They don't really understand magnitude scales, and they are not aware of the detection capabilities of modern seismometers. We hoped that the high levels of publicity surrounding Balcombe would give us a chance to help educate the public in these regards.

However, we had two main technical objectives as well. These relate to DECC's proposed traffic light scheme, whereby operators are required to stop if they trigger events above magnitude 0.0. Traffic light schemes are common for such operations - the Swiss in particular seem to like them. However, the minimum threshold here is far lower than anything used by the Swiss. Our aim is not to say whether this is appropriate or not, but its operation does pose some additional challenges, which our work seeks to address.

The first issue stems from the Gutenberg-Richter law, which states that the number of earthquakes (N) that occur which are larger than a given magnitude (M) is given by
                             log(N) = a - bM.
where a and b are measurable constants. The BGS gives values for a and b in the UK of 3.82 and 1.03, respectively. Using a magnitude of 0.0 (the lowest cutoff for the traffic lights), this relationship tells us that over 5,000 such events occur every year. The existing BGS seismic network is not capable of detecting these low magnitude events.

In order for the traffic light scheme to work effectively, we need to be able to distinguish between the 5,000 naturally occurring magnitude 0.0 and greater quakes that occur each year, and those induced by hydraulic stimulation. This requires us to have data about the naturally occurring events, which we do not currently have. Therefore, one purpose of our array was to begin to establish baseline measurements around a potential drilling site so that we can characterise any pre-existing, natural seismicity. This is but a small start, with only 1 month of background data. In an ideal scenario we'd want to have at least a year of baseline data.

The second purpose of our array was to measure typical levels of seismic noise and detectability thresholds for small, temporary arrays such as ours. The traffic light threshold of magnitude 0.0 is often at the threshold of detectability for surface seismometers. The detectability is controlled in part by the levels of noise on the seismometers. Although you might think the British countryside is a quiet place, there are many potential sources of noise, such as trains, roads, farm machinery, rivers. We wanted to see whether a small, relatively cheap array like ours would be helpful in administering the traffic light scheme, or whether more expensive microseismic monitoring methods are likely to be needed.

So, what did we find?
Well, the most obvious thing we saw was the train, made famous by local concerns about seismic impacts on the viaduct. We saw the train on all 4 seismic stations that we deployed. Here is an example:
You can see that the train is coming from the north. It is seen on station BA02 first, which is the northernmost, and on BA04 last, which is the southernmost. BA04 is only 150m from the rail line, so you can see the biggest signal on this station.

We wanted to compare the vibration from the train with typical earthquake magnitudes. To do this we used the UK magnitude scale, which is defined as
                             Ml = log(A) + 0.95log(R) + 0.00183R - 1.76,
where A is the amplitude of the signal at the station, and R is the distance between earthquake and seismometer. We modelled earthquakes occurring directly below the drilling site, and found that a quake with magnitude of 1.5 (the same as the 2nd Preese Hall quake) produced a similar amount of vibration to the train going past at 150m.

We used an automated trigger algorithm to search our data for potential local seismic events. Sadly, we didn't see anything that looked like a local earthquake, either before or during drilling.

The seismometers that we used are actually designed to detect earthquakes from around the globe. We did spot a number of such events (called "teleseismic arrivals"). Here's an example from a magnitude 7.7 event in Pakistan:
This map shows all 25 such events that we spotted:

One of our stations was only 300m from the drilling site. We did notice that things got slightly noisier on this station when drilling started. This figure compares the background noise before and during drilling. A simulated M0.5 event is shown - this shows up above the noise for both cases.
We didn't see any events during our monitoring period. However, we wanted to work out what we could have seen, had something happened. We simulated earthquakes occurring below the drill site, with a variety of magnitudes, and ran the simulated data through our automated detection algorithm, to see what was the smallest that could be reliably identified, given our recorded noise levels

We found that magnitude -0.2 was the smallest we could see. This simulated event is shown below:
As you can see, it just peaks up above the noise. This is the smallest event we can expect to see. This is just below what is required for the traffic light scheme, so a small array like this could work. However, I'd want to see a larger number of stations to really push the detection limits below the magnitude 0.0 cutoff.

Discussion - Accurate event magnitudes?
We finish with a number of recommendations for the implementation of the traffic light scheme (TLS). A fact unbeknownst to most non-seismologists is that there are in fact a number of different magnitude scales, depending on how magnitude is measured. They are all designed to be close to each other, however they are not always exactly the same.

The most common magnitude scale is known as "local magnitude", or ML. This is basically the good ol'fashioned Richter scale, and is fairly simple to compute. You simply measure the maximum amplitude of the seismic trace, you take the distance from source to receiver, and you put it into a local magnitude equation as I outlined above.

An alternative magnitude scale is the "Moment magnitude", or Mw. This directly relates to the moment (read 'force' or 'energy' in layman's terms) released by the earthquake, and in turn to both the size of the fault and the amount that the fault slipped. Mw is slightly harder to compute - you have to look at the frequency content of the earthquake signals - but probably a better representation of the physical process occurring in an earthquake (as opposed to an empirical approximation, as provided by ML).

Small, local arrays such as ours will typically report ML. However, the dense coverage provided by microseismic arrays (as now installed at Preese Hall) often report Mw. It needs to be made absolutely clear how these different types of measurements will be factored into the TLS, because they may not be exactly the same - indeed at small magnitudes they can be different by half a magnitude unit or more. So, for example, what happens if a quake is measured with ML = -0.1 but Mw = +0.1?

Similarly, all measurements of magnitude are subject to an error. This is rarely reported for the large earthquakes you see on TV - the relative signal to noise ratios for a large event are so large that you can be sure that it is magnitude 6.5 (or whatever) ± a very small amount. However, as you enter the world of micro-seismic events, the signal to noise ratio deteriorates (as you can see in image #6 above). As this happens, the error in the calculation gets larger. Again, the incorporation of errors into the TLS needs to be clarified - what happens if an event has magnitude -0.1 ± 0.2?

These issues do not invalidate the traffic light scheme. However, given that operational decisions, and therefore potentially millions of pounds, hang on the accurate characterisation of event magnitudes, it would be helpful to iron out any potential inconsistencies now, rather than in the wake of another induced event.

In closing, I would like to thank the co-authors of this work, who don't yet have blogs of their own.

Friday, 15 November 2013

My first media hack job: "The Truth Behind the Dash for Gas"

The Truth Behind "The Truth Behind the Dash for Gas"

Talk to media people enough, and something like this was inevitable, but it seems that I am the star in a new anti-fracking documentary entitled "The truth behind the dash for gas" (my part starts from about 20 minutes in).

Back in November last year I received an email from a young guy who said he was looking to make his way as a film-maker just out from film-school. His email to me is quoted below:
I am putting together a short film about fracking in Somerset. The aim is to present a fair and informative assessment of the potential for fracking in Somerset, the risks and dangers associated with it, and the views of local people. The film and those working on it are independent of both the anti-fracking campaign groups and those who stand to gain from the fracking industry.
I think just by watching the first few minutes of the film you can see that their  claimed intent "to present a fair and informative assessment of the potential for fracking in Somerset" is barefaced lie. Even more barefaced is their claim that "the film and those working on it are independent of [...] the anti-fracking campaign groups". However, the film has a facebook page, in which it clearly states that the film is facilitated by Frack Free Somerset. The FrackFreeSomerset and FrackOff websites appear prominently in the credits at the end of the film.

Given that the very first contact between myself and the film makers was a lie, one can hardly expect the remainder of the film to do any better. I find it especially ironic that the 2nd word in the film title is "truth", while their very first contact with me was an obvious, barefaced and outright lie. It's not worth my time to address the content of the film as a whole, but I do want to comment on the parts in which my comments have been used.

Comment #1: that debate over hydraulic fracturing has descended into a media slanging match, and I don't think anyone could disagree with that. However, the film moves straight to the same science denialism more usually seen in the anti-climate-change world - if you can't trust the Royal Society for advice on scientific matters, the British Geological Survey, or the Geological Society, for matters geological, or Public Health England for public health matters, then I'm not sure where is left for you to turn, and the term conspiracy theorist begins to apply (see my final comment for more in this vein).  

As for my own 'close ties', I spent 3 months in the BP Institute in Cambridge as a 20-year-old M.Sci student. While BP provided the funds to set up the lab, the students who do projects there are  university students, and have no connection to BP (I certainly spoke to noone from BP while I was there, and in fact the majority of research being done when I was there was on developing energy efficient buildings). I also spent a few months in Rijswijk in Shell's research facility during my Ph.D. During my Ph.D I developed geophysical techniques to ensure safe storage of CO2 in geological reservoirs - so-called CCS, a potential method to mitigate climate change. During this time Shell asked my to come over and help apply some of these methods to their test site at Ketzin, Germany. All of this is made abundantly clear on my website.

Comment #2: I say that in many cases the impacts have been exaggerated. The Scranton Times-Tribune investigated claims made by residents about shale developments in Pennsylvania, finding that 77% of accusations were without substantiation. Surely an example of impacts exaggerated? Equally, even in cases where regulatory breaches by companies have lead to issues - the example of Dimock springs to mind - the impacts of this have been regularly exaggerated. At Dimock, while methane was found to have contaminated groundwater, there was no evidence of fracking fluids in the water. It's not good to have methane in groundwater, and this should be prevented from occurring at all times. However, methane is not toxic or harmful to human health, barring the risk of explosion if it allowed to accumulate in significant amounts. After the company had been cited and forced to repair its wells, levels of methane dropped, returning below the minimum safety levels set by the EPA (a fact never mentioned by activists, who will tell you that once contaminated, an aquifer can never be restored).

Comment #3: The most famous flaming tap in Gasland, the Markham well, had nothing to do with oil and gas drilling. This has been made abundantly clear by the Colorado State regulator (COGCC), which felt the need to release a comment to "correct several errors" in the film. The flaming tap is the headline image of Gasland, it appears in all the trailers and promotional material. That the gas is of biogenic origin, from shallow layers well above those targeted for drilling, implying that gas drilling is not the cause. This film attempts to argue that poor well casing still allowed shallow biogenic methane to migrate. However, the COGCC report makes clear that "there is little or no temporal relationship" between gas drilling in the area and the complaints made about the Markham and McClure wells. This is a fairly massive oversight to be made, one that I think that is worthy of comment. Clearly the film-makers find it easy to relate to other films that are economical with the truth in order to tell a story.

The regulators did rule that a drilling company was at fault in the case of the Ellsworth well. This company reached a settlement with the claimant (again, a fact that the film neglects to mention). The COGCC conducted sampling over a 170 sq mile area, and the Ellsworth well was the only one where any impact was detected. Strangely, we don't get to see Josh Fox setting the Ellsworth taps on fire - one can only guess at why?

The next sleight of hand is either quite clever, or monumentally dumb, I'm really not sure which. They move on to discuss the Duke methane studies, which I have discussed in previous posts here and here. Of course, there are a number of studies performed along along these lines, all of which come to very different conclusions to the Duke study. For some reason the film makers don't mention these (one wonders why). However, these film-makers can't even get the Duke PNAS study facts right! A screen-grab of the PNAS abstract is shown, highlighting an apparent claim that methane was found in 82% of drinking water within 1km of a gas well.
 How about we look at that section of the abstract in full:
In fact, you can clearly see that the 82% figure refers to all the water sampled, not just the ones near gas drilling sites. Methane was found in 82% of water samples, REGARDLESS OF WHETHER THEY ARE NEAR GAS WELLS OR NOT! Incidentally, this is a similar percentage to that found by Molofsky et al., who sampled a much larger dataset (1,700 samples vs 140 samples), finding that 78% of samples contained methane, regardless of proximity of gas wells. In fact this is why establishing whether shale development has caused problems is so difficult in Pennsylvania - there is already a lot of methane in the groundwater. Where studies have been conducted in areas where natural methane is not present in shallow water, they have not seen an impact from drilling.

I honestly find it hard to believe that this accidental highlighting of parts of two sentences, conveniently removing the context to make a scarier quote, is accidental. Either way it is particularly dumb to hope that people familiar with the source material won't spot the attempted trick.

Comment #4 is about well integrity. The astute among you will notice a cut in the editing between the start and end of my answer. Clearly, other things I've said have been edited out. Sadly, this interview was conducted a year ago, so I can't remember exactly what I said, and back then I was too naive to make my own recordings (not a mistake I'll make again), but presumably it was something that didn't fit with the narrative being portrayed.

The films then cuts to the SLB Oilfield Review from 2003. Always a good litmus test of a shale gas commentator is how they treat this report. Firstly this report covers data from deep offshore in the Gulf of Mexico. This is a very challenging drilling environment, so it's not surprising to have more problems offshore than onshore. The only statistics relevant to onshore UK shale drilling are stats from other onshore wells.

More importantly, the film describes the stats as showing either "leakage" or "failure". In fact, they depict incidents of Sustained Casing Pressure. SCP isn't a good thing, and again it should be avoided, but it doesn't equate to the mass leakage of hydrocarbons into shallow layers. Categorically, these stats have no bearing on the rate at which well integrity issues are causing contamination, which is what, misleadingly, the film tries to claim.

The most obvious place to look for wellbore integrity-related contamination issues from onshore wells drilled under a UK regulatory system, is of course to look onshore in the UK, where we have drilled 2,000 wells already, many of them in the 1960s, 1970s and 1980s (making most of them 30 years old at least). One of the few things this film gets right is that whether a well is fracked or not has no bearing on wellbore integrity issues. Therefore, if the statistical claims made in this film were true, there would be 1,000 onshore contamination incidents already. If the bold claim that follows ("all wells leak eventually") were true, we'd surely have 2,000 incidents by now. Clearly the claims made in the film do not add up, because I'm not aware of any problems associated with onshore wells in the UK.

Similarly, after the Piper Alpha disaster, regulations were significantly tightened to prevent such an event ever happening again. Again, the North Sea has not been turned into an environmental wasteland - we're still so keen to eat North Sea cod that there's almost none left!

We can also look to the US, which has hundreds of thousands of onshore wells, and actually examine statistics relating to actual incidents of groundwater contamination, as opposed to SCP. Luckily, the US Groundwater Protection Council has done exactly this, in a study released in 2011. They find that of 187,000 wells drilled in Texas, and 33,000 wells drilled in Ohio, only 21 and 12 wells respectively had seen casing issues leading to contamination, rates of 0.01% and 0.04%.

Comment #5 regards regulatory differences between US and UK, and resulting differences in operating practices. The above statistics show that contamination is not endemic to shale drilling. However, even the handful of cases that have occurred is a handful too many. These few incidences are inevitably the result of poor practice, and/or the contravention of regulations.

While I'm speaking, they cut to some shots of flowback waste pits. What they fail to point out is that these are not allowed in the UK - any waste flowing back from the wells must be stored in double-lined steel tanks. This is with good reason: in the GWPC report I mention above, the majority of drilling-related contamination incidents (172 in Ohio, 190 in Texas) have come from surface activities, not from processes happening under the ground. In the US it is common to store the waste fluid in open, plastic-lined pits. These have been known to overflow during heavy rain, or for the liners to tear, allowing the contents to leak. I think the endless shots of waste-fluid pits that activists like to show indicates either that they are not aware that these are banned in the UK, or that they do know this but don't like to let facts get in the way of the story.

For example, in one well-publicised case XTO opened the valve on one of their tanks, allowing the fluid to flow out into the ground, while in another case a trucker dumped his load into a nearby storm drain, rather than taking it to the treatment plant. This sort of illegal activity should absolutely be prevented, and it is important that regulators keep a sharp eye on operators to ensure that this doesn't happen. But it doesn't show that shale gas development is inherently problematic. Again, we can look the the UK example for dealing with produced water. The existing UK onshore industry handles 70 millions barrels of produced water a year, with no apparent contamination problems.

The next interviewee, Laurence Rankin, is presented a "Former Environment Agency manager", with the obvious intention of making us think that he is an impartial commentator. Since my 3 months as a 20-year-old M.Sci student at the BP Institute is worthy of mention, maybe the film should have also pointed out that he is also a coordinator of the Sefton Green Party and member of Friends of the Earth, so perhaps slightly less impartial than first appearances might suggest. While the Green Party man seems to have a problem with Cuadrilla's activities, the Environment Agency itself doesn't, and hasn't claimed that Cuadrilla have broken any of their regulations. The fact that the Green Party man isn't familiar with fracking, doesn't mean it hasn't happened. For example, horizontal wells have been fracked at Wytch Farm in Dorset. Update - this comment reflected media reports regarding Wytch Farm. Water is injected into the Wytch Farm reservoir, but this is to increase the reservoir pressure and drive oil towards production wells (a common practice in conventional fields), not to fracture the rock.

The use of the term 'slick-water' is another slight of hand, somehow implying that slick-water is somehow worse that what has gone before. In fact, in the good old days it was common to use a mix of gelled gasoline and napalm as the frack fluid. Given the choice of water with 1% chemical additives, or gasoline and napalm as the frack fluid, the use of slick-water represents an improvement. And the fact that there were no specific references to fracking in exploration licenses is that it was considered such a normal part of oilfield and drilling activities (with 10% of existing onshore wells being hydraulically stimulated). The main difference between now and what has gone before is one of scale, with modern treatments using higher volumes, rather than any major differences in the technique itself.

The film moves on to the Cuadrilla-induced earthquake near Blackpool. The next mistake made comes with the claim that the increase in earthquakes seen in US is directly attributable to hydraulic stimulation. In fact, the increase in seismicity is caused by an increase in the volumes of waste fluids, from both conventional and unconventional operations, being disposed of by deep injection into saline aquifers. I know this because I have worked in depth on these events, including writing a report for parliament, because they have implications for CCS. There are no proposals in the UK to dispose of fracking fluids through injection into deep aquifers. As far as I am aware, we do not have suitable deep saline aquifers onshore (although we are targeting such aquifers offshore in the North Sea for CCS). Again, one is left wondering whether the film makers know this and are lying, or simply do not understand the science that is being done in this area?

There is only one case in the US where fracking has triggered seismicity - in the Eola field, Oklahoma, which occurred in January 2011, 3 months before Preese Hall event, but was not reported as such until August 2011, after Preese Hall, and one case in Canada (British Columbia), where events occurred between 2009 and 2012, although they were not reported until August 2012, a long time after Preese Hall. So Preese Hall was the first reported incident of induced seismicity triggered by hydraulic stimulation for shale gas.

With respect to reporting of the earthquake and resulting casing deformation to the Energy Minister, there was no regulatory requirement to report casing deformation to him - this is the role of the HSE. Moreover, I think the actions taken were entirely appropriate - they ceased operations to allow a 6-month scientific study to be conducted, after which the results were reported for DECC, HSE and the rest of the world to read. While we're on the point, all of the casing deformation was within the production casing string, within the target zone of production - it was actually below the depths of the frack stages that triggered the seismicity. It poses no risk whatsoever to the integrity of the well. The figure below shows the well design - the deformation is the little yellow bar right at the bottom.

I think that's it in terms of my contribution to this piece of work. I'll comment briefly on the accusation of "mission-creep" in terms of chemical use - every chemical used in the UK must be permitted by the Environment Agency, and fully disclosed to the public.

One final point in closing: the go-to 'expert' for this film appears to be Ian R. Crane, an ex-oilfield-executive, who gets the final word as far as this film is concerned. I don't usually like to stoop to ad-hom arguments, but as Mr Crane seems to appear on an increasing number of anti-fracking pieces, it'll be worth your time having a look at his profile on RationalWiki, a website dedicated to uncovering cranks, conspiracy theorists, and pseudoscience. If this is the best figure-head that the anti-fracking movement can come up with, I would suggest they need to try a little harder.

UPDATE: I checked out the FrackFreeSomerset website to look for more information. According them, the film is not just "facilitated" by FFS, but in fact "produced" by them.

UPDATE (21/11/2013): The film maker himself has left a comment for me. He is correct to point out that I failed to address my comments of water use. In the film, I describe how much water is used for a single stimulation. Of course, the issue is cumulative effects over time if many wells need to be stimulated. The water use for an individual well (~10,000 - 50,000 cubic metres) sounds like a lot, but it must be placed in context. Between the 3 largest water utilities (Severn Trent, United and Thames), 1.7 billion liters of water are lost to leaks PER DAY. If water companies were able to improve on this by just 1%, we would have available an extra 17,000 cubic metres of water, that's enough water to frack a well every day. If water consumption is your concern, don't blame frackers, get the water utilities to fix their leaks (or at least 1% of their leaks).