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This report is the final of a series of reports resulting from a BGS-EA collaboration to characterise the risks to groundwater from new developments in onshore oil and gas (OOG) exploration in England. The previous three reports (Mallin Martin and Smedley, 2020, Mallin Martin and Smedley, 2021a, Mallin Martin and Smedley, 2021b) were focused on establishing groundwater baseline chemical compositions, particularly of those analytes that are and could be associated with OOG activities, in order to facilitate distinction between current compositions and any new industrial contamination from such activities. This synthesis report uses the experience gained from these earlier reports to develop an assessment methodology for identifying the influence of both the baseline environment and anthropogenic impact on groundwater quality prior to any new OOG activity. The methodology also has relevance for other subsurface activities. The previous three reports in this series concluded that key influencing factors on baseline groundwater quality when considering OOG-type compounds were not the location of hydrocarbon extraction sites, but instead aquifer lithology and overlying superficial deposits. The methodology detailed in this report has been designed to provide a rapid assessment for the potential presence of OOG-type contaminants and other deep subsurface compounds in groundwater. The assessment has been designed to consider the magnitude of influence that each factor is likely to have on groundwater quality. The compounds may be either organic or inorganic: each are essential to understanding sources of contamination, but also for understanding the hydrogeological system. The findings from the case study area reports have been used to justify the weighting that each factor has on groundwater quality. The key factors to be considered are geological (e.g. aquifer lithology, proximity to organic rich sediments), hydrogeological (confined, unconfined) and anthropogenic activi

This report details the hydrogeochemistry of a broad suite of inorganic and organic analytes in groundwater from the Lower Greensand aquifer of south-east England. The study aims to establish the groundwater baseline chemical compositions, particularly of those analytes that are and could be associated with Onshore Oil and Gas (OOG) activities, in order to facilitate distinction between current compositions and any new industrial contamination from such activities. Analytes of particular interest in this context include indicators of salinity, indicators of redox conditions, dissolved gases including carbon dioxide (CO2) and methane (CH4), naturally-occurring radioactive materials (NORM) and organic compounds including volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Much of the exposed unconfined aquifer is oxic in nature, with groundwater pH controlled by the sporadic presence of calcite within the aquifer matrix. Concentrations of a number of dissolved ions increase along the regional flow path, including Ca, HCO3, Mg, K, Sr, F, Al, As, Mn, Cu, Ni, Fe and Mn. The unconfined aquifer is susceptible to a number of anthropogenic impacts. These include diffuse pollution from agricultural activities (indicated by elevated concentrations of nitrate in groundwater across the northern half of the study area), and mobilisation of metals by acidic rainfall recharge in parts of the aquifer where acid-buffering carbonate minerals are absent. Dissolved organic carbon content of the Lower Greensand groundwater is typically low, with an upper baseline concentration of 4.6 mg/L. Anthropogenic organic chemicals detected as part of this study included chloroform, trichloroethene and chlorodibromomethane, but concentrations detected are orders of magnitude below the drinking-water standard for these compounds and not a cause for concern. Dissolved CH4 concentrations in the Lower Greensand aquifer are generally low; most samples in the investigation area

This report presents the summarised responses from participants at two stakeholder workshops, held in Iloilo and Pampanga, between 28th January and 5th of February 2020. The workshop focus centred on how stakeholders access hydrological information relevant to their jobs, and the required format that this data needs to take. Participants were asked about their current access routes to information, and their ideal access platform/web portal for hydrological data. This was so that the outputs of the PhiGO project could be tailored to meet as many stakeholder requirements as possible. Stakeholders clearly identified several common points for data access and formats across a number of sectors, and both in their professional and personal environments. Stakeholders required that data is predominantly visual, with a strong focus on maps, figures, and graphs, but backed up by information that can be interrogated, whether that be tabular data or summarised reports. Stakeholders desired a web portal that needed to be clean and easy to use, with guidance for navigation and explanation of complex terms. Detailed information must also be readily available, and the data should be available for offline downloading. The feedback from these stakeholders will feed directly into the final design of the PhiGO data portal.

This report details the hydrogeochemistry of a broad suite of inorganic and organic analytes in groundwater from the Sherwood Sandstone aquifer of the East Midlands and South Yorkshire. The study aims to establish the groundwater baseline chemical compositions, particularly of those analytes that are and could be associated with onshore oil and gas (OOG) activities, in order to facilitate distinction between current compositions and any new industrial contamination from such activities. Analytes of particular interest in this context include indicators of salinity, indicators of redox conditions, dissolved gases including CO2 and CH4, naturally-occurring radioactive materials and organic compounds including volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Groundwater from the Sherwood Sandstone aquifer of the region shows a range of chemical compositions resulting from inputs of modern atmospheric and surface pollution from varying sources, superimposed on natural water-rock interactions. Natural reactions are dominated by carbonate equilibrium, redox reactions, gypsum/anhydrite dissolution and time-dependent silicatemineral reaction. The Sherwood Sandstone crops out in the East Midlands but further northwards into Yorkshire, the aquifer in places becomes confined or semi-confined by overlying Quaternary superficial silts and clays. The Sherwood Sandstone dips gently eastwards and becomes confined by the poorly-permeable marls and mudstones of the Mercia Mudstone Group (MMG). At outcrop, the groundwater is young and oxic with evidence of inputs of pollutants including NO3, SO4 and Cl and possibly of Br, Cu, Pb and Zn from urban, industrial (including mine drainage) and agricultural sources. Small quantities of PAHs, pesticides and solvents are detected occasionally in the unconfined aquifer. Further north into Yorkshire, the aquifer is oxic in parts but becomes anoxic in places with superficial cover and with increasing depth. The reduc

This report presents the results and interpretation for Phase 5 of an integrated environmental monitoring programme that is being undertaken around two proposed shale gas sites in England – Preston New Road, Lancashire and Kirby Misperton, North Yorkshire. The report should be read in conjunction with previous reports freely available through the project website1 . These provide additional background to the project, presentation of earlier results and the rationale for establishment of the different elements of the monitoring programme.

This report describes the results of activities carried out as part of the Environmental Monitoring Project (EMP) led by the British Geological Survey (BGS) in areas around two shale gas sites in England – Kirby Misperton (Vale of Pickering, North Yorkshire) and Preston New Road (Fylde, Lancashire). It focuses on the monitoring undertaken during the period April 2018–March 2019 but also considers this in the context of earlier monitoring results that have been covered in reports for earlier phases of the project (Phases I–IV) 2 . The EMP project is a multi-partner project involving BGS together with Public Health England (PHE), University of Birmingham, University of Bristol, University of Manchester, Royal Holloway University of London (RHUL) and University of York. The work has been enabled by funding from a combination of the BGS National Capability programme, a grant awarded by the UK Government’s Department for Business Energy & Industrial Strategy (BEIS) and additional benefit-in-kind contributions from all partners. The project comprises the comprehensive monitoring of different environment compartments and properties at and around the two shale-gas sites. The component parts of the EMP are all of significance when considering environmental and human health risks associated with shale gas development. Included are seismicity, ground motion, water (groundwater and surface water), soil gas, greenhouse gases, air quality, and radon. The monitoring started before hydraulic fracturing had taken place at the two locations, and so the results obtained before the initiation of operations at the shale-gas sites represent baseline conditions. It is important to characterise adequately the baseline conditions so that any future changes caused by shale gas operations, including hydraulic fracturing, can be identified. This is also the case for any other new activities that may impact those compartments of the environment being monitored as part of the project. In the per

The UK shale gas industry might see significant growth in the near future, with many energy companies already having gained approval and others in the stages of seeking approval for exploration. Exploratory boreholes have been in place in the Vale of Pickering, North Yorkshire, and the Fylde Basin, Lancashire, since 2013 and 2010 respectively. Since then, several other sites around the UK have been earmarked for future exploration. The current absence of producing shale gas wells within the UK means it is too early to assess any actual impact of these operations at the local, regional and national scale. However, international analogues may provide some indications based on areas elsewhere in the world where a shale gas industry is more developed (e.g. the Marcellus Shale, USA) albeit with obvious limitations due to differences in geology and setting. While regulation and compliance of shale gas operations varies between countries, the process and method of extraction and the environmental risks are comparable. The general requirements for water, drilling mud/fluids, hydraulic fracturing fluids (“frac fluids”) and the design of wells and well pads can all be extracted from an already mature international experience. However, the requirements in the UK will be modified by the regulatory requirements and restrictions that exist. There are ongoing discussions within the UK to determine whether shale gas is beneficial, economically viable and environmentally safe. In this report, the impact on land use, groundwater quality and water resources of one well in a selection of approved Petroleum Exploration and Development Licence (PEDL) areas will be considered, followed by an estimation of the cumulative impacts that may result from multiple extraction sites within these areas. The exercise will depend on ranges of input parameters informed by international analogues applied in a UK geo-environmental setting. To recognise the variability in parameters and uncertainty in UK