• The Local Risks

    Having withdrawn their plans for drilling 10 miles to the north at Keynsham (Bath and North East Somerset) after strong local opposition, UK Methane has now expressed their intention to drill just over the border in Ston Easton.

    The likelihood is that Coal Bed Methane from the lower measures of the Somerset Coalfield will be the target for drilling on the northern side of the Mendips.

    What Are the Risks?


    Pollution of Mendip Watercourses

    The complicated and fragile geology particular to Mendip creates greater risk of leakage and pollution into watercourses through caves and smaller aquifers, including contamination with radiation, toxic chemicals and methane.

    Hundreds of chemicals have been licensed for use worldwide, including Benzene, Toluene, Phenol & Formaldehyde, several of which are carcinogenic.

    During the drilling and extraction process 20-40% of the contaminated, hazardous and potentially radioactive water used, flows back to the surface for disposal.

    The remaining 60-80% of the contaminated fluids may remain underground. Then the only thing defending underground aquifers from contamination is the integrity of the drilled wells and cement well casing. Industry research states that many well casings leak and degrade over time, so the ongoing risk of pollution of underground water courses is a real concern.

    Underground migration pathways through layers of rock can bring pollutants to the surface, its never possible to eliminate all risks from the operations involved.

    The coal seams in the Somerset Coalfield are fractured and contorted and the underlying Carboniferous Limestone is also fractured with numerous springs and fissures.

    Contaminated water from large-scale dewatering of Coal Bed Methane exploration (likely target of UK Methane on the Mendips) is likely to contain natural salts, metals, hydrocarbons, drilling fluids, injected chemicals and Naturally Occurring Radioactive Materials (NORM).  This is either stored on site and treated for disposal to water courses, or tankered off-site for treatment and disposal.

    Fracking Caves and Hydrology 10


    If any contaminated water from flowback or spillage gets into the caves, aquifers and surface streams it will have an impact downstream and in the wider environment.

    The complicated geology of Mendip, with streams sinking into caves from the plateau, feeding resurgences miles away in Wells, Wookey Hole, Cheddar, Rodney Stoke, Edford, Langford, Rickford, Litton and other areas, water pollution locally and further afield could easily occur.

    St Andrews Well - a resurgence from the Mendip cavesFor ExamplePolluted water which could get into the River Norr (Wellow Brook) (in one of the areas proposed for drilling by UK Methane), the exact source of which is unknown before it reaches a man-made culvert with numerous inlets, beneath the A37 at Ston Easton Park, would flow downstream, polluting all in its path, to enter the River Avon near Monkton Combe and continue down through Bath and Bristol to the River Severn and the Bristol Channel.

    For Example – Risk of pollution to Chew Valley reservoir, polluted flowback water escaping into the River Chew and other streams feeding Chew Valley reservoir and polluting the water supply for Bristol and the surrounding area.

    Unconventional Gas exploration activity locally may have a seismic impact on geological faults such as the Chewton Fault, a spring from which supplies Chew Valley reservoir, permanently reducing or stopping the water supply.

    For Example – Polluted water running through underground watercourses could surface in natural springs and agricultural boreholes depriving farmers of clean water for livestock.

    Historical incidents of pollution have proven that the caves and water systems within them are highly susceptible to any contamination, which can be transported for miles from its original source via the underground waterways.

    Download our presentation which highlights the vulnerability of the Mendip cave system to pollution incidents.

    Download: The Dangers of Pollution to Limestone Aquifers, with Special Ref. to Mendip Hills

    Air Pollution from Methane Gas

    Risk of Methane build-up in old coal mines including those beneath residential areas.

    The fissures caused by fracking (also used in Coal Bed Methane extraction) have been documented to migrate up to 600 metres in any direction meaning that methane gas and polluted flowback water might get into old mine levels and air shafts (including those running beneath built-up residential areas such as Farrington Gurney, Paulton, Midsomer Norton, Radstock etc.) and natural fissures in the overlying rock to cause pollution and risk of major explosion.

    There are incomplete and missing surveys of the abandoned coal mines and ventilation shafts of the Somerset Coalfield, so no certainty as to whether they will be compromised, polluted or filled with methane.

    Health Impacts of Air and Water Pollution

    Air pollution from wells producing condensate are having major recorded adverse health impacts.

    Health impacts such as headaches, nausea, and breathing difficulties have all been recorded. There are also risks of contamination to human and animal health in our food chains from water pollution.

    A study by the Center for Disease Control & Prevention in the US has shown counties over the Barnet Shale, that have been extensively fracked, are one of the only locations where breast cancer rates have been steeply rising against a wider national fall.

    Radioactive Contamination Brought to the Surface

    The local area is well known for it’s Radon Gas, contained within the rocks. Radioactive isotopes (such as radium-226) can be leached out of the rocks that fracking fluid passes through. Biological concentration of these materials up the food chain would be the largest concern.

    Industrialised Landscape

    Industrialisation of the Mendip Countryside

    The Mendip Hills are an AONB (Area of Outstanding Natural Beauty) and threat to SSSIs and Nature Reserves.

    Figures boasted by the company UK Methane, intending to drill in Somerset, could necessitate the drilling of over 2000 wells.

    If gas extraction is viable it is likely that that numerous wells would be sunk along the Somerset Coalfield (which runs roughly from Coleford in the east to Compton Martin in the west) causing life-changing disruption to the immediate rural community.

    Pipelines & Plant Operating 24hrs on the Mendips

    Pipelines, access roads, and the construction of ‘frack pads’ (large drilling sites) are all necessary. Operations and processing also cause light and noise pollution – usually 24 hours a day.

    HGV Fracking Liquid Container Trucks

    Increased Lorry Traffic on Rural Roads

    It takes over 2-4,000 large truck movements to explore one well.

    The local infrastructure is totally inadequate for the countless HGV tankers that would be clogging up the already over stressed roads 24 hours a day, both locally and between the Mendips and wherever the water is sourced and the flowback water is disposed of.

    Damage to Valuable Local Tourist Industry

    Risk of pollution to the water supply to hot springs in Bath and Bristol. Unconventional gas exploration on the Mendips may pollute the hot springs in Bath and possibly Hotwells in Bristol.

    Water from the area is presumed to flow to a depth of over 2km before resurging in Bath (and possibly Hotwells) many years later.  A paper by Tim Atkinson and R.M. Davison entitled: Is the water still hot? Sustainability and the thermal springs at Bath, is available here.

    A British Geological Survey report commissioned by Bath & Northeast Somerset Council concluded that hydraulic fracturing within Carboniferous shales would make it impossible to guarantee the impact on those strata in which the thermal waters are migrating, or to resolve any problems.

    Local Economic Impacts

    Detrimental impact on local businesses who depend on the Mendip countryside for a living (including farmers), impact on commercial and residential property prices.

    Property prices are likely to fall by 30% when the drilling industry start up, according to the following report:

    Fracking risks reducing house prices by 30%

    Threat to Local Wildlife & Caves

    The Mendip caves are a roost of national importance for Greater and Lesser Horseshoe bats.

    Unconventional Gas exploration in many areas of the Mendips could damage the caves. The Mendips are the largest caving area in the South of England. For more information on Mendip’s caves and stone mines go to the Mendip Cave Registry and Archive.

    A Damaged Legacy for Future Generations

    The potential ruin of a beautiful recreational amenity, prized and enjoyed by people from all over the UK, leaving a legacy of pollution and destruction for generations to come.

    Seismic Activity

    Fracking has also been associated with earthquakes, in the UK fracking company Cuadrilla has admitted that its exploration in Lancashire has caused earth tremors. It can also cause subsidence.

    Climate Change

    Unconventional Gas exploration worsens climate change and extinguishes any opportunities to reduce greenhouse gas emissions on a county or national level.

    Integrale Ltd

    For further information please read these Unconventional Gas Technical Briefing Notes from an applied geologist at Integrale.

    Click here to read about how the USA and Australia have been impacted by Unconventional Gas exploration and production.