Water & Wastewater Treatment

14 Water & Wastewater Treatment February 2014 COMMENT wwtonline.co.uk D espite the extensive media coverage of the issue in recent years and the often vociferous nature of opposition from a growing number of local pressure groups, 'fracking' for shale gas, even at this very early exploration stage, is embryonic in the UK. So the question is not only what might the impacts be, but will an industry develop at all? CIWEM has produced an in-depth independent review of the likely viability, scale and timing of shale gas exploitation in the UK. It also considers if an industry of any significant scale were to develop, what the implications of hydraulic fracturing of shale would be for water resources, water treatment and the water environment, and the regulatory requirements needed to mitigate the industry's impact on the environment. Water related risks The volume of water used in hydraulic fracturing has often been quoted as large and indeed when viewed in isolation the numbers appear significant. However, when set in the context of national or regional water supply or in comparison with other industrial uses, it equates to less than a tenth of 1% of total abstraction. Should a large industry develop later into the 2020s, when there will be greater pressures on the water environment, there could be local issues with water sourcing. Essentially, though, it will be for the individual water company or the Environment Agency to determine if there is enough to go round. Of those that CIWEM has contacted, the water companies do not, for the time being, appear concerned about their ability to supply a shale gas industry. CIWEM believes that shale gas companies should share their plans with water companies to establish the nature of any future risks and manage them accordingly. Groundwater protection Shale gas wells may be drilled in areas where there is also groundwater present. It is essential that these water resources are protected from contamination and the risk of this occurring will need to be thoroughly assessed during the planning and permitting stages. In order to establish the current condition of the water environment and successfully identify where contamination may have occurred, either as a result of shale gas-related activities or others, good baseline data is required. Experience from the US and Australia shows that without good baseline data, it is hard to scientifically establish a cause of contamination - furthering conjecture and leading to a polarised discussion lacking in robust evidence. It is important that before shale gas activities commence in the UK, baseline data for appropriate contaminants is obtained for potentially affected ground and surface waters. Regulation Risks to groundwater from well bore failure must be seriously considered by all appropriate regulators and construction closely monitored to ensure that best practice is followed. Well designs are scrutinised and monitored by the Health & Safety Executive and DECC will scrutinise company fracking plans. Where there is any doubt over risk to potable groundwater, the Environment Agency's precautionary approach to not allow any drilling in principal aquifers or source protection zone 1 should help minimise risks. Other risks to groundwater quality, such as contamination from mobilisation of methane, are considered to be less in the UK, where target shale plays exist at considerable depths below aquifers and gas would be required to migrate many hundreds, if not thousands of metres between source rock and sensitive groundwater. CIWEM believes a detailed risk assessment is needed to examine the relationship between the shale and the aquifer including a thorough evaluation of geological and hydrogeological setting in each area. Risks Risks associated with storage, transportation and operational spills represent the greatest threats to surface water, as well as to groundwater. These can be effectively managed through robust best practice and there is no reason why this should not be achievable. Close monitoring and scrutiny by regulators, allied to strict enforcement, is essential to ensure that the industry acts in an appropriately responsible manner. Treatment of produced and flowback water is an area where technology is rapidly developing and may enable extensive on-site treatment by the time an industry is in any way mature in the UK. Otherwise, a supply-chain of specialist treatment facilities is likely to develop to meet market need where this cannot already be provided by larger municipal wastewater treatment sites. Aside from the risks to the water environment, there are also risks from release of fugitive methane emissions, localised air pollution, landscape and visual amenity intrusion and the potential consequences of induced seismicity. Given all these challenges a robust regulatory regime will be required to protect the environment and to improve general public confidence in what is presently a highly controversial process. Not only this but it is vital that should an industry develop that there is adequate resource for regulators for enforcement and monitoring, but given the government's current stance on funding it does not look promising. nnn • CIWEM's policy statement on Hydraulic Fracturing of Shale in the UK is available at www.ciwem.org Hydraulic fracturing to unlock natural gas trapped in shale formations has brought the water-energy nexus to the fore, but, asks CIWEM's policy advisor, Laura Grant, what are the risks and can they be effectively managed? Between a rock and a hard place

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