Map: British Geological Survey
A mining geologist has called for the suspension of fracking for gas in the main shale areas of northern England because he says the rocks contain high concentrations of toxic heavy metals.
Robin Grayson has written a paper, posted on the website, researchgate.net, about the presence of selenium, arsenic, cadmium and thallium in the Bowland shale.
Cuadrilla, which fracked the Bowland shale at its Preston New Road site near Blackpool before Christmas, said it had been testing for selenium, which was absent or at trace levels. “It was both unhelpful and misleading to local people to suggest otherwise”, a company spokesperson said. (Full statement at the end of this piece)
The Bowland shale is found either side of the Pennines, in parts of Lancashire, Yorkshire, Nottinghamshire and Derbyshire and is the main area licensed by the government for shale gas exploration.
As well as Preston New Road, companies have plans to explore the Bowland shale at Misson Springs in Nottinghamshire, Harthill in south Yorkshire and Bramleymoor Lane in Derbyshire. IGas’s Tinker Lane well, drilled in November 2018, was also looking for the formation but failed to find it.
Mr Grayson said other researchers have reported high levels of selenium in the Bowland shale at the surface, about 11 miles from Preston New Road. It has also been found near Pendle Hill, Walley and Earby in Lancashire and at Edale in Derbyshire, he said.
“It is now realised that the Bowland Shale has remarkably high toxic levels of selenium, everywhere its outcrops have been tested in NW England, Wales, Isle of Man and Ireland. No exceptions.”
He said selenium, while a vital nutrient in tiny quantities, is very toxic in high concentrations. He called for independent tests for selenium and the other heavy metals on rock cuttings taken from several wells drilled recently. These include Cuadrilla’s Lancashire sites at Becconsall, Preston New Road and Preese Hall and the boreholes drilled at Ellesmere Port in Cheshire and Irlam (Barton Moss) in Salford.
He said:
“Until then fracking by Cuadrilla and acidisation by IGas should be suspended with immediate effect.
“If, as I suspect, selenium levels in the boreholes are extremely toxic, then the PEDLs [Petroleum Exploration and Development Licences] should be restricted to coalbed methane from the Upper, Middle and Lower Coal Measures.”
He added that flowback waters from the Preston New Road wells should be classed as “highly toxic waste” until proved otherwise.
The paper also warned about the risk of shale gas wells encountering the poisonous and flammable gas, hydrogen sulphide (H2S), known as sour gas.
“Factual evidence shows the risk of encountering H2S is substantial, which is bad news for investors and for the health and safety of local communities, as well as for the workers.”
He said the risk arose from two different sources in the Bowland shale.
Anhydrite rock (calcium sulphate) below the formation – identified in boreholes in the Bowland basin – could produce sulphate waters in huge amounts, he said. If this came into contact with hydrocarbons then hydrogen sulphide could be produced.
He also quoted examples of unconventional shale wells in Texas producing sour gas because of the use of guar gum in fracking. He suggested that guar gum encouraged the growth of anaerobic bacteria, which generated hydrogen sulphide. This may be slowed, but not eliminated, by the use of biocides, he suggested.
DrillOrDrop put Mr Grayson’s concerns to Cuadrilla. A spokesperson for the company said:
“During our operations at Preston New Road we have carried out extensive core sampling, providing us with a unique dataset of the Bowland Shale.
“Through this continuous observation we have established that the natural gas in the shale rock contains no hydrogen sulphide, as we would expect in this geology.
“We have also been testing for other elements, including selenium, which has been absent or at trace level, with the results independently inspected by the regulator. It is both unhelpful and misleading to local people to suggest otherwise.”
Updated with a comment from Cuadrilla
Categories: Research
DRILL OR DROP? 
This isn’t new news, although definitely worth repeating. I have seen a 2010 study of a borehole drilled at Wiswell near Pendle Hill, and it showed Selenium and Arsenic levels 3 times above typical international safety limits. I’m not sure if I have a copy of the academic paper now, but I did share it various FB groups a couple of years ago.
Ah found it:
Selenium enrichment in Carboniferous Shales, Britain and Ireland: Problem or opportunity for shale gas extraction?
https://www.sciencedirect.com/science/article/pii/S0883292715300809
Mark -the authors of the paper whilst acknowledging the high Selenium levels also state in their conclusion:
‘So, should there be concern over these high metal contents in the Bowland Shale, if it is exploited for shale gas? There is awareness of the need to consider such issues in the UK (Stuart, 2012, Cai and Ofterdinger, 2014), but fortunately a very robust oil and gas regulatory system, covering licence application, planning permission, well construction and environmental permits, makes it very unlikely that the UK would experience the environmental problems encountered in the USA (The Royal Society, 2012).
The concentration of Se, and possibly other trace elements, in extraction waters could also be regarded as an opportunity. Selenium is a rare element for which demand is likely to increase (Moss et al., 2011), but the current supply as a by-product of copper production is in jeopardy as production methods change. Alternative methods of extraction that do not include high temperature (high energy) or toxic chemicals are desirable. Waters produced from Se-rich shales offer new possibilities. An understanding of how to do this can build on methodology being developed to deal with Se-rich waters associated with the storage of coal waste. Some coals, like some black shales, contain anomalous concentrations of Se, leading to environmental problems in several parts of the world, including the Elk River Valley, British Columbia (Lussier et al., 2003). Approaches to sequester Se at low temperature include precipitation onto iron oxides (Wei et al., 2012), precipitation onto activated carbon (Wasewar et al., 2009) and microbial selenate reduction (Tucker et al., 1998). These are all low-energy approaches which could contribute to securing new Se resources, and in the process add incentive to ensuring that extraction waters are processed in an environmentally sensitive manner.’
Yet another reason to consign this failing and unwanted industry to history. How much more will it take?
Good job they are not fracking in Cheshire. Salt is pretty toxic in high concentrations too!
Cobalt is a carcinogen-let’s ban electric vehicles.
“If, as I suspect”-a pretty conclusive bit of ermm-oh yes, speculation.
There will be a few queuing up for a source of selenium! Not a very intelligent attempt at a fear story.
Don’t take my word for it, do some research into animal feed vitamin/premix manufacturers. They use tonnes of the (expensive) stuff, and have done so for decades (but most have now precluded the use of cobalt.)
Looks like someone trying to ramp up the AJL share price!
McFly does a pedl licence provide the holder with all minerals and extraction rights of just those relating to o&g extraction?
Hi Martin, Selenium is a essential micronutrient for humans, livestock, pets and plants. It is used in hair shampoo. However, in high concentrations selenium is indeed hazardous. The concentrations of selenium in Bowland Shales is exceptionally high. Robin Grayson, Liberal Democrat Geologist
Hi Martin
Sorry but please note that you indeed correct that selenium is used in animal feeds (and in most shampoos), but only in tiny concentrations. The concentrations of selenium are much higher than this, high enough to be highly toxic. Please check this and reply. Robin Grayson MSc Liberal Democrat Geologist
All the tankers containing flowback fluid leaving the Preese Hall site were sampled and analysed.
This data was used in the waste license application for PNR and in the decision making by the EA.
The waste license issued by the EA for PNR designated the flowback fluid as non-hazardous based on the presence and quantities of the metals and minerals found in the Preese Hall samples.
Hi John – flowback fluid is indeed analysed for elements. But worth checking if selenium was looked for by EA for Preese Hall or indeed for PNR. Robin Grayson, Liberal Democrat Geologist
Great advice, it would indeed be worth asking the EA if they if they checked for Selenium. What did they say when you asked?
I assumed you asked, seems quite like an important question, it could have saved a lot of time and maybe even negated what it was which drove you to the write the paper.
So should access to the areas where the shale is exposed like Pendle Hill and the Forest of Bowland be banned due to the health risk from Selenium, and what about United Utilities water extraction from the areas?
Hi John, Excellent questions.
These are issues for local farmers and local well users should address, and campsite owners.
Drinking stream water is inadvisable anyhow due to risk from microbes like Cryptosporidium. Selenium is now just another reason.
Selenium poisoning of livestock is a serious issue in parts of Ireland, affecting sheep and horses.
Selenium is absorbed more by some plants, than others; and some plants biomagnify the selenium rather a lot.
As for United Utilities, they indeed do have water extraction in some of the Bowland Shale areas and should deal with the issue if they have not done so already.
Robin
Robin, the water percolating through the rock will pick up just as many minerals as the fluid used for fracking. The big difference here is that one is extracted for drinking water the other is contained and sent for treatment.
Hi John,
You are correct than the tankers containing flowback fluid leaving the Preese Hall site were sampled and analysed.
You are correct that this data was used in the waste license application for PNR and in the decision making by the EA.
You are correct that the waste license issued by the EA for PNR designated the flowback fluid as non-hazardous based on the presence and quantities of the metals and minerals found in the Preese Hall samples.
I checked the EA list of the elements they tested found in the Preese Hall samples.
Here is the list:
lead
mercury
cadmium
bromide
chloride
sodium
potassium
magnesium
phosphorus
chromium
zinc
nickel
silver
aluminium
arsenic
iron
cobalt
copper
nitrogen
vanadium
The list shows the EA did not test for selenium.
This has implications.
Robin Grayson MSc Liberal Democrat Geologist
Or was it not present in the flowback?
https://www.healthline.com/nutrition/selenium-benefits
Many things are hazardous in high concentrations, Robin. Good job that doesn’t apply with Liberal Democrats, as we don’t see the high concentrations! Certainly not in the House where few of those who were elected bother to turn up.
Selenium is no different to NaCl in that respect, except it is far more valuable. But a nice change from the radon fear story previously attempted. (Came across the radon test results for my parents property recently, when clearing out paperwork.)
Perhaps someone will establish a nice little earner if they can find selenium in the flow back and extract it? If they come across the Kraken at the same time, double whammy. I could put them in contact with a few who would be interested in quite a few tonnes-selenium, not Krakens. Modest commission required.
Eddy Stone (retr. animal feed nutritionist.)
(Off to shampoo my hair. I may be back!)
Sorry Marty but I dropped off during your response but did you confirm if a PEDL licence entitles the holder to extract non o&g minerals?
Oh and do you have the link to the article in the Gazette you mentioned?
As usual Martin , you have to include cheap political jibes in your answers. Such a shame to lower the standards. I am non-party political, just a caring parent who puts the health of families and the environment before money orientated values.
Ermm, Robin, how do you think tiny concentrations of selenium arrive in animal feed??
Someone buys tonnes of CONCENTRATED selenium and blends that into mixtures of other trace elements, vitamins and minerals and then that concentrated mixture is mixed into (maybe, 997.5kg of feed) to produce a tonne of finished feed.
So, selenium is handled and moved around in concentrated form very readily with no more precautions than would be required to avoid dust inhalation of most other materials. Easily done, and is, on a daily basis in the UK.
Cobalt, on the other hand, now carries a carcinogen warning and that is normally excluded from being used, although it was in the past. Other means of providing the same benefits to animals that addition of cobalt did, are now widely adopted.
Hi Martin, as you are doubtless fully aware, selenium is highly toxic in anything other than in tiny concentrations when it is beneficial.
If you would like some technical references to research on this, then do reply. Thanks
Robin Grayson MSc Liberal Democrat Geologist
What a ridiculous story to start the New Year with. Everything is toxic in high concentrations. Perhaps all UU customers should stop drinking their tap water / farmers stop dumping UU sludge on their fields / we should all vote Lib Dem etc etc.
Why not write a paper on the heavy metal content of house bricks? It would be more useful as these are not classified as waste….
As to H2S – why has none been produced to date by Cuadrilla?
Thanks for the report Ruth – and Robin for the information. Does anyone know if the EA have done testing independent of Cuadrilla’s own tests? Their statement seems to imply not, but surely they must?