Baseline groundwater chemistry: the Corallian of the Vale of Pickering, Yorkshire

This report describes the regional geochemistry of the groundwater from the Corallian aquifer in the Vale of Pickering, North Yorkshire. The study aims to assess the likely natural baseline chemistry of the groundwater. Data have been collected from strategic sampling of 24 groundwater sources, in conjunction with collation of existing groundwater, rainfall, and mineralogical data. The Corallian aquifer comprise Upper Jurassic shallow shelf marine sediments, with a variety of facies including muds to micritic limestone and oolites, to bioclastic limestones with interbeds of silts and sands. These strata represent an important groundwater source in north-east England. The main chemical properties of the groundwater are determined by the interaction of rainwater recharge reacting with the aquifer minerals. Within the Corallian aquifer, groundwater major ion composition is dominantly influenced by reaction with calcite, and little variation is seen within the major ion proportions. Human impacts on the water quality are clearly evident, mainly through the presence of NO3-N as an indicator contaminant. The widespread presence, commonly in excess of the drinking water limit and the increases over time suggest that the aquifer is heavily influenced by agricultural practices. Agricultural land dominates the area underlain by the unconfined aquifer. With the exception of NO3-N, the available data for groundwater within the Corallian aquifer of the Vale of Pickering indicate they are of good quality for the analytes tested, with few elevated concentrations of potentially harmful trace elements. For many analytes the 95th percentile serves as a first approximation of the upper limit of the baseline range of concentrations, as this serves to eliminate the most extreme outlier concentrations

The cognitive interview: a tiered approach in the real world

This chapter will examine how the cognitive interview (CI) has been applied into the real world of policing. We will consider the impact the CI has had on every-day policing, ranging from front-line communication, to being utilised within a visually recorded interview, which may replace live evidence in the court-room (depending on the legislative framework of the country it is being applied). As the CI is utilised in a multitude of different types of information and evidence gathering scenarios the way in which the CI needs to be applied, and thus trained should reflect the context within which it is to be used in the field. Accordingly, the UK has developed the ‘Tiered approach’ to interview training (Clarke & Milne, 2011), whereby interviewers learn interviewing skills (including the CI) incrementally, across a police investigator’s career span. This approach has been adopted in numerous countries and the chapter will explain the approach, outline a model of training to maximize transference of skills into the workplace, and the research base examining its effectiveness in the field

Geochemical properties of aquifers and other geological formations in the UK

The intrinsic geochemical characteristics of geological for-mations have a considerable influence in controlling solute and pollutant transport behaviour during groundwater flow through the shallow geosphere. The interactions between solute or pollutants and the surface geochemistry of the rock matrix will often determine both the extent and speed of solute transport in the saturated and unsaturated zones. Consequently, understanding these processes is of critical importance for a range of environmental management re-quirements, such as landfill leachate monitoring or contam-inated land evaluation, including requirements related to statutory obligations for ensuring good groundwater status under the EU Water Framework Directive. Risk assessment and management approaches frequent-ly make use of numerical geochemical modelling to predict contaminant transport. These models necessarily require parameterization of the geochemical properties of the geo-logical formations involved and the predictions which can be obtained are inevitably only as good as the quality of the data which are used. However, the natural variation in li-thologies and extensive spatial heterogeneities of the UK rock formations result in considerable variability of the most important geochemical properties. Identifying or ob-taining good relevant data for calculations can be difficult; new laboratory measurements can be expensive and time-consuming, published data are relatively sparse and existing data from previous site investigations are often held com-mercially and are difficult to get hold of. This study, supported by the British Geological Survey and the Environment Agency, presents the first comprehen-sive national compilation of geochemical properties data of relevance to geochemical modelling. An assessment has been made of existing available primary data. Relatively few data are available, but those which are have been col-lated. To underpin this the project has undertaken an exten-sive programme of new experimental measurements on the geochemical properties of samples from geological for-mations across the country. Initially attention was focussed on England and Wales, but this was later expanded to in-clude data and samples from Scotland. Over 600 new sam-ples have been included, providing by far the largest high-quality internally-consistent dataset currently available for these parameters. The geochemical properties addressed are those consid-ered to be of greatest significance for the purposes of mod-elling and risk assessment, namely: • cation exchange capacity (CEC); • fractions of organic and inorganic carbon (fOC, fIC); • extractable (readily soluble) element contents of iron (Fe), manganese (Mn) and sulphur (S); • whole-rock and clay-fraction mineralogy. It is intended that the Geochemical Properties Manual rep-resented by this report and database should provide a relia-ble reference resource for practitioners carrying out site in-vestigations in the future. Whilst site-specific parameter measurements will always provide the greatest confidence, this manual will provide a benchmark of what is known and what can reasonably be expected for the geochemical prop-erties of given types of geological formations. In this re-spect the manual is related to the manuals of physical prop-erties of major and minor aquifers produced by BGS previ-ously. However, for geochemical properties date have been included for any geological formations, not only aquifers, as aquitards and aquicludes also play an important role in constraining transport behaviour. Chapters 1 and 2 of the report introduce the data compi-lation, structure and presentation. Chapters 3 and 4 provide a brief overview of the principles of geochemical modelling and of the use of geochemical data in geochemical model-ling. Chapters 5-8 then provide the bulk of the report, cata-loguing the available data by geology for a selection of the key geochemical parameters relevant to numerical model-ling. The data are presented as numerical and graphical sta-tistical summaries to try to assist the user in finding the most suitable parameter values to use in their own circum-stances. This report (OR/12/090) supersedes an earlier version (CR/06/216N) which is now withdrawn. It contains some corrections, updated lithostratigraphical classifications and additional data added to the database up to the end of De-cember 2012

An improved approach to characterize potash-bearing evaporite deposits, evidenced in North Yorkshire, United Kingdom

Traditionally, potash mineral deposits have been characterized using downhole geophysical logging in tandem with geochemical analysis of core samples to establish the critical potassium (% K2O) content. These techniques have been employed in a recent exploration study of the Permian evaporite succession of North Yorkshire, United Kingdom, but the characterization of these complex deposits has been led by mineralogical analysis, using quantitative X-ray diffraction (QXRD). The novel QXRD approach provides data on K content with the level of confidence needed for reliable reporting of resources and also identifies and quantifies more precisely the nature of the K-bearing minerals. Errors have also been identified when employing traditional geochemical approaches for this deposit, which would have resulted in underestimated potash grades. QXRD analysis has consistently identified polyhalite (K2Ca2Mg(SO4)4·2(H2O) in the Fordon (Evaporite) Formation and sylvite (KCl) in the Boulby Potash and Sneaton Potash members as the principal K-bearing host minerals in North Yorkshire. However, other K hosts, including kalistrontite (K2Sr(SO4)2) a first recorded occurrence in the UK, and a range of boron-bearing minerals have also been detected. Application of the QXRD-led characterization program across the evaporitic basin has helped to produce a descriptive, empirical model for the deposits, including the polyhalite-bearing Shelf and Basin seams and two, newly discovered sylvite-bearing bittern salt horizons, the Pasture Beck and Gough seams. The characterization program has enabled a polyhalite mineral inventory in excess of 2.5 billion metric tons (Bt) to be identified, suggesting that this region possesses the world’s largest known resource of polyhalite. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed

Probing the dynamics of plasmon-excited hexanethiol-capped gold nanoparticles by picosecond X-ray absorption spectroscopy

Picosecond X-ray absorption spectroscopy (XAS) is used to investigate the electronic and structural dynamics initiated by plasmon excitation of 1.8 nm diameter Au nanoparticles (NPs) functionalised with 1-hexanethiol. We show that 100 ps after photoexcitation the transient XAS spectrum is consistent with an 8% expansion of the Au-Au bond length and a large increase in disorder associated with melting of the NPs. Recovery of the ground state occurs with a time constant of ∼1.8 ns, arising from thermalisation with the environment. Simulations reveal that the transient spectrum exhibits no signature of charge separation at 100 ps and allows us to estimate an upper limit for the quantum yield (QY) of this process to be <0.1

Risk maps for evaluation of water-quality monitoring requirements in England & Wales

This report details the steps taken in the process of producing risk (hazard) maps for chemical parameters listed in the European Commission Directive 98/83/EC on the quality of water intended for human consumption and the national Water Supply (Water Quality) Regulations that implement the requirements of the directive for drinking water in England and Wales. Amendments to 98/83/EC set out in Directive 2015/1787 provide the terms for reduced monitoring requirements by European Member States for drinking water where evidence indicates that waterquality risk is low. On the basis of the Water Safety Plan approach of the World Health Organization, DWI requires mapping of available data on raw-water sources in England and Wales to provide an evaluation of spatial distributions of the listed chemical parameters and their concentration ranges as evidence of risk for drinking water. An evaluation of temporal variability was also required to assess evidence for any trends to aid with decision making on future drinkingwater monitoring requirements. Data for an agreed list of 27 chemical parameters were collated, screened, evaluated and mapped, with surface water and groundwater being treated separately. This report details the data sources and steps taken to collate, evaluate, process and map them. Risk maps produced for individual parameters include expected values and 95th percentiles of measured values relative to the prescribed concentration or value (PCV) at any given location. The methodology employed required prediction of the entire statistical distribution of each parameter at each prediction location so that both expected value and percentile values for each parameter could be determined. This required the use of a statistical model to represent the variation of the data. The produced risk maps are produced for water-quality data analysed over the last three years, in line with the requirements of the 2015/1787 Directive. The correspondence between the two layers is an indication of the spatial data availability and the strength of correlation between measurements from nearby sites. The maps are presented in ArcGIS with additional explanatory layers comprising open-source data for coastline, multiscaled atlases, postcode sectors, place names, simplified geology, Environment Agency region boundaries and local authority boundaries as points of reference. The GIS is presented as a separate mxd file. The maps have inevitable limitations derived from inability to guarantee complete elimination of errors from the cleaned datasets, paucity of data for some parameters, spatial and temporal variability of available data for others, variable spreads of surface-water drainage or aquifers, variable detection limits for some trace elements, and for groundwaters, variable chemistry with depth, especially for concealed and/or stacked aquifers. Nonetheless, the maps provide an estimate of the current best-available spatial distributions for parameters for surface water and groundwater to aid DWI in assessing drinking-water risks and determining monitoring requirements, in line with Directive 2015/1787. It is anticipated that the maps will be used alongside available sitespecific water-quality monitoring data and site risk assessments for decision making in the context of the Directive. Temporal variability of raw water chemical data have also been assessed. As temporal trends vary significantly spatially for individual parameters and between parameters, recommendations for timescales of map revision are difficult to make. As a pragmatic recommendation, a mapping renewal interval on the order of 10 years is considered appropriate. In the case of amendments to the statutory PCVs in the meantime, remapping is possible using the existing rasters and relating to the revised threshold values

Numerical and experimental investigation of vortical flow-flame interaction

A massively parallel coupled Eulerian-Lagrangian low Mach number reacting flow code is developed and used to study the structure and dynamics of a forced planar buoyant jet flame in two dimensions. The numerical construction uses a finite difference scheme with adaptive mesh refinement for solving the scalar conservation equations, and the vortex method for the momentum equations, with the necessary coupling terms. The numerical model construction is presented, along with computational issues regarding the parallel implementation. An experimental acoustically forced planar jet burner apparatus is also developed and used to study the velocity and scalar fields in this flow, and to provide useful data for validation of the computed jet. Burner design and laser diagnostic details are discussed, along with the measured laboratory jet flame dynamics. The computed reacting jet flow is also presented, with focus on both large-scale outer buoyant structures and the lifted flame stabilization dynamics. A triple flame structure is observed at the flame base in the computed flow, as is theoretically expected, but was not observable with present diagnostic techniques in the laboratory flame. Computed and experimental results are compared, along with implications for model improvements

Preliminary assessment of the environmental baseline in the Fylde, Lancashire

This report presents the collated preliminary results from the British Geological Survey (BGS) led project Science-based environmental baseline monitoring associated with shale gas development in the Fylde, Lancashire. The project has been funded by a combination of BGS National Capability funding, in-kind contributions from project partners and a grant awarded by the Department of Business Energy and Investment Strategy (BEIS). It complements an on-going project, in which similar activities are being carried out, in the Vale of Pickering, North Yorkshire. Further information on the projects can be found on the BGS website: www.bgs.ac.uk. The project has initiated a wide-ranging environmental baseline monitoring programme that includes water quality (groundwater and surface water), seismicity, ground motion, atmospheric composition (greenhouse gases and air quality), soil gas and radon in air (indoors and outdoors). The motivation behind the project(s) was to establish independent monitoring in the area around the proposed shale gas hydraulic fracturing sites in the Fylde, Lancashire (Cuadrilla Resources Ltd) before any shale gas operations take place. As part of the project, instrumentation has been deployed to measure, in real-time or near real-time, a range of environmental variables (water quality, seismicity, atmospheric composition). These data are being displayed on the project’s web site (www.bgs.ac.uk/lancashire). Additional survey, sampling and monitoring has also been carried out through a co-ordinated programme of fieldwork and laboratory analysis, which has included installation of new monitoring infrastructure, to allow compilation of one of the most comprehensive environmental datasets in the UK. The monitoring programme is continuing. However, there are already some very important findings emerging from the limited datasets which should be taken into account when developing future monitoring strategy, policy and regulation. The information is not only relevant to Lancashire but will be applicable more widely in the UK and internationally. Although shale gas operations in other parts of the world are well-established, there is a paucity of good baseline data and effective guidance on monitoring. The project will also allow the experience gained, and the scientifically-robust findings to be used, to develop and establish effective environmental monitoring strategies for shale gas and similar industrial activities

Impacts on groundwater quality from abandoned hydrocarbon wells - final report

This report details a reconnaissance investigation carried out between 2016 and 2018 from a British Geological Survey (BGS)–Environment Agency (EA) collaboration on the impacts of abandoned hydrocarbon (HC) wells on groundwater quality in England. The investigation involved collation of a database of HC wells that were identified from records provided by DECC (Department of Energy & Climate Change; now BEIS: Business, Energy & Industrial Strategy) as being abandoned (as opposed to operational or unspecified), categorising according to factors such as oil or gas designation, depth of HC resource, time since abandonment, productive life, absence of active wells nearby, and occurrence and type of overlying aquifer(s). From this categorisation, a subset of 27 sites were shortlisted for further investigation and fact sheets were produced for each outlining regional geology, hydrogeology and potential groundwater monitoring points in the area. Using these factsheets, four study areas were assessed as being most suitable for further field investigation. These comprised two gas fields: Nooks Farm (Staffordshire), and Ashdown (Sussex), and two oil fields: Hemswell (Lincolnshire) and Lomer (Hampshire). Groundwater sampling campaigns were conducted in 2016–2017 in the four study areas, with potential sampling points identified within a 5 km buffer zone around (downstream of) the HC well or HC field. In several areas, the number of sampling points was very limited as locations of HC wells do not necessarily have any relationship with locations of overlying aquifers. In others, large numbers of sites were deemed unsuitable for sampling, for reasons including disuse, decommissioning, safety or lack of access. This made representative sampling of groundwater a severe challenge. Suitable sites from the four study areas were sampled twice during the project, with a total of 48 groundwater samples being collected over the two campaigns. Results from both sampling rounds have shown that the presence of hydrocarbons in the groundwater is limited. In the first sampling round, a maximum dissolved methane (CH4) concentration of 407 μg/L was recorded. However, this relatively high value was not repeated when the site was visited during the second round of groundwater sampling. The value was below the threshold required for δ13CCH4 isotopic analysis. Some groundwater samples showed detectable quantities of organic compounds including VOCs (volatile organic compounds) and PAHs (polycyclic aromatic hydrocarbons) as well as pesticides, herbicides, fungicides, surfactants, analgesics and veterinary compounds. These were, however, almost invariably present in low concentrations, none could be linked unequivocally to the presence of abandoned HC wells and many were clearly due to other anthropogenic activities. As a result of the difficulties finding representative and suitable groundwater sampling sites, a further reconnaissance was undertaken in May 2017 to identify potential alternative gas and oil fields. This confirmed further the difficulties in finding suitable areas for investigating groundwater quality and further groundwater sampling was therefore not attempted. An alternative approach was used to investigate two abandoned HC well areas: Ashdown, one of the original study areas, and a new location at Bolney (also Sussex). A soil gas survey was completed at each of these locations in order to investigate whether soil gas proximal to the former well location contained any evidence of HC leakage. Due to poor ground conditions at the time of sampling, the results are ambiguous, but do show elevated concentrations of both CO2 and CH4. Further work in dry ground conditions would be required to say with certainty that these concentrations are linked directly to the presence of the gas wells