User guide : Aquifer Productivity (Scotland) GIS Datasets. Version 2

This report describes a revised version (Version 2) of the aquifer productivity (Scotland) datasets produced by the British Geological Survey (BGS). There are two maps: bedrock aquifer productivity and superficial deposits aquifer productivity. Version 1 of these datasets was produced in 2004. Version 2 uses updated geological linework and a slightly modified methodology. The aquifer productivity maps describe the potential of aquifers across Scotland to sustain various levels of borehole water supply, and the dominant groundwater flow types in each aquifer. The bedrock aquifer productivity map has five aquifer productivity classes (very high, high, moderate, low and very low); and three groundwater flow categories (significant intergranular flow; mixed fracture/intergranular flow; and fracture flow). The superficial deposits productivity map has four productivity classes (high; moderate to high; moderate; and a category to signify that a deposit is ‘not a significant aquifer’). All superficial deposits aquifers in Scotland are assumed to have primarily intergranular groundwater flow. The aquifer productivity maps are a tool to indicate the location and productivity of aquifers across Scotland. They have been used to help characterise groundwater bodies as required by the Water Framework Directive, and may have several other uses, including in policy analysis and development; to prioritise aquifer and site investigations; to inform planning decisions; and to improve awareness of groundwater in general. The complexity and heterogeneity of geological formations means that the maps are only a guide. They are designed to be used at a scale of 1:100,000, and not to assess aquifer conditions at a single point

National geological screening : the Wealden district

This report is the published product of one of a series of studies covering England, Wales and Northern Ireland commissioned by Radioactive Waste Management (RWM) Ltd. The report provides geological information about the Wealden district region to underpin the process of national geological screening set out in the UK’s government White Paper Implementing geological disposal: a framework for the long-term management of higher activity radioactive waste (DECC, 2014). The report describes geological features relevant to the safety requirements of a geological disposal facility (GDF) for radioactive waste emplaced onshore and up to 20 km offshore at depths between 200 and 1000 m from surface. It is written for a technical audience but is intended to inform RWM in its discussions with communities interested in finding out about the potential for their area to host a GDF

UK Geoenergy Observatories: Glasgow Geothermal Energy Research Field Site : science infrastructure

The purpose of this report is to give an overview of the planned research infrastructure and proposed data acquisition at the Glasgow Geothermal Energy Research Field Site. The report also gives a brief overview of the geological characterisation and environmental baseline at the site. The report is intended for a technical, science community audience. It summarises the state of play at August 2018, is subject to change and will be updated. Please note that in the information below, all designs, infrastructure, kit, data to be collected etc. are subject to chang

National geological screening : Northern England region

This report is the published product of one of a series of studies covering England, Wales and Northern Ireland commissioned by Radioactive Waste Management (RWM) Ltd. The report provides geological information about the Northern England region to underpin the process of national geological screening set out in the UK’s government White Paper Implementing geological disposal: a framework for the long-term management of higher activity radioactive waste (DECC, 2014). The report describes geological features relevant to the safety requirements of a geological disposal facility (GDF) for radioactive waste emplaced onshore and up to 20 km offshore at depths between 200 and 1000 m from surface. It is written for a technical audience but is intended to inform RWM in its discussions with communities interested in finding out about the potential for their area to host a GDF

National geological screening : London and the Thames Valley

This report is the published product of one of a series of studies covering England, Wales and Northern Ireland commissioned by Radioactive Waste Management (RWM) Ltd. The report provides geological information about the London and the Thames Valley region to underpin the process of national geological screening set out in the UK Government’s White Paper Implementing geological disposal: a framework for the long-term management of higher activity radioactive waste (DECC, 2014). The report describes geological features relevant to the safety requirements of a geological disposal facility (GDF) for radioactive waste emplaced onshore and up to 20 km offshore at depths between 200 and 1000 m from surface. It is written for a technical audience but is intended to inform RWM in its discussions with communities interested in finding out about the potential for their area to host a GDF

UK Geoenergy Observatories Glasgow : groundwater chemistry data collected during the borehole construction phase

The United Kingdom Geoenergy Observatory (UKGEOS) in Glasgow comprises 11 boreholes at the Cuningar Loop, South Lanarkshire and one seismic observation borehole in Dalmarnock in east Glasgow. Boreholes are drilled into superficial deposits, unmined bedrock and mined bedrock to characterise the geological and hydrogeological setting, and to provide access for baseline monitoring and mine water abstraction/ reinjection. The aims of the Observatory include de-risking key technical barriers to low-temperature shallow mine water heat energy and heat storage from groundwater in former coal mine workings; and providing environmental characterisation and monitoring to assess any change in ambient conditions. This report details baseline groundwater monitoring carried out during the construction phase of the Glasgow Observatory. It includes a description of the sampling methods and hydrochemical data for groundwater samples collected between December 2018 and December 2019. Eight groundwater samples and two mains water samples were analysed to determine the concentrations of selected chemical parameters at the British Geological Survey (BGS) and associated laboratories. The samples were collected to provide an initial indication of groundwater chemistry, primarily for water discharge purposes. The report accompanies the release of the construction phase groundwater hydrochemistry dataset. Sampling locations and methodology Groundwater samples were collected from the main Observatory borehole cluster at the Cuningar Loop, Rutherglen, South Lanarkshire from boreholes GGA02 at Site 1, GGA05 at Site 2, GGB04, GGB05 at Site 5, as well as from the seismic monitoring borehole GGC01 at Site 10 in Dalmarnock, Glasgow City. In the case of boreholes GGA02 and GGC01, they are the only groundwater chemistry samples that will be collected from these boreholes. Water was obtained from the Glasgow Upper mine working in GGA02 and Glasgow Main mine working in GGA05 by stopping the drilling at the mine working and retrieving a sample during and after purging. Groundwater from the bedrock and the superficial deposits was drawn from borehole GGB04 and borehole GGB05, respectively. Scope of analysis Groundwater samples were collected for analysis of major, minor and trace elements, Cr(VI), NPOC and stable isotopes (δ2H, δ18O, δ13C). In addition, field measurements of water temperature, pH, specific electrical conductance (SEC), redox potential (Eh) and dissolved oxygen (DO) were made. Total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) were analysed in samples from GGA02 and GGA05 only. Key Findings Both mine waters are net–alkaline with a near–neutral pH (Glasgow Upper pH 6.92 and Glasgow Main pH 7.12); they have a high alkalinity (as field-HCO3) (Glasgow Upper field-HCO3 609 mg/L and Glasgow Main field-HCO3 792 mg/L) and a high SEC of 1637 to 1723 µS/cm. Similarly, the bedrock and the superficial deposits waters have pH values of ~7.5 and alkalinity as field-HCO3 between 415 mg/L and 462 mg/L. The SEC is also high 1078–1183 µS/cm. All the waters belong to the bicarbonate (HCO3) type, with sodium (Na) as the dominant cation in the superficial deposits and bedrock groundwaters (Na–HCO3 waters), and Na, calcium (Ca) and, to a lesser extent, magnesium (Mg) in the two mine waters (Na–Ca–(Mg)–HCO3 water type). Water from all four lithologies ranges in sulphate (SO4) concentration between 165 and 302 mg/L. The chloride (Cl) range is 51–82 mg/L, with the highest value in the Glasgow Main mine working groundwater. Iron (Fe) concentrations range between 1.8 to 2.6 mg/L in the mine water and bedrock; a much lower concentration of 0.007 mg/L is measured in the superficial deposits groundwater. Chromium(VI), a known industrial contaminant in the area, was not detected above the lower limit of detection (LLD) in any samples. The stable isotope δ2H, δ18O values plot broadly on the global meteoric water line with no evidence of evaporation prior to recharge. The O-isotope values (δ18O -7.4 ‰ and -7.1 ‰) are all within the range of groundwater samples reported previously from Carboniferous sedimentary aquifers across the Midland Valley of Scotland. The mine waters have heavier δ13C (-9.9 and -10.8 ‰) than the bedrock and superficial deposits (-15.6 and -12.1 ‰). All lithologies’ groundwaters fall on the middle to upper range of the δ13C values from -22 ‰ to -10 ‰ of groundwater samples from other studies of the Coal Measures Group across the Midland Valley of Scotland. All samples are saturated with respect to calcite, dolomite, siderite, rhodochrosite, amorphous ferric hydroxide, gibbsite, and barite, and remain undersaturated with respect to gypsum, halite and jarosite. Water was also obtained during the installation of the GGC01 seismic monitoring borehole. However, given the sampling method (a bailer lowered to only a few meters from the top of the borehole) and evidence of dilution during flushing and residual contamination from the tracer/additive and drilling fluid, the chemical analyses of the groundwater samples from this borehole are not to be considered representative of the unmined Coal Measures aquifer(s) intercepting the borehole. Very high concentrations of boron (B) and dissolved organic carbon (NPOC) were found, which decreased between the two sampling dates, showing an increase in groundwater flowing into the borehole after drilling and flushing. The water was alkaline, and with a SEC of 310–650 µS/cm. Sodium was the most enriched cation, with HCO3 and Cl the most enriched anions. Chromium(VI) was not detected above the LLD in either sample. The δ2H, δ18O signature of the groundwater was similar to the samples taken in the four Cuningar Loop boreholes while the δ13C isotope signature was lighter

Geological structure as a control on floodplain groundwater dynamics

Groundwater in upland floodplains has an important function in regulating river flows and controlling the coupling of hillslope runoff with rivers, with complex interaction between surface waters and groundwaters throughout floodplain width and depth. Heterogeneity is a key feature of upland floodplain hydrogeology and influences catchment water flows, but it is difficult to characterise and therefore is often simplified or overlooked. An upland floodplain and adjacent hillslope in the Eddleston catchment, southern Scotland (UK), has been studied through detailed three-dimensional geological characterisation, the monitoring of ten carefully sited piezometers, and analysis of locally collected rainfall and river data. Lateral aquifer heterogeneity produces different patterns of groundwater level fluctuation across the floodplain. Much of the aquifer is strongly hydraulically connected to the river, with rapid groundwater level rise and recession over hours. Near the floodplain edge, however, the aquifer is more strongly coupled with subsurface hillslope inflows, facilitated by highly permeable solifluction deposits in the hillslope–floodplain transition zone. Here, groundwater level rise is slower but high heads can be maintained for weeks, sometimes with artesian conditions, with important implications for drainage and infrastructure development. Vertical heterogeneity in floodplain aquifer properties, to depths of at least 12 m, can create local aquifer compartmentalisation with upward hydraulic gradients, influencing groundwater mixing and hydrogeochemical evolution. Understanding the geological processes controlling aquifer heterogeneity, which are common to formerly glaciated valleys across northern latitudes, provides key insights into the hydrogeology and wider hydrological behaviour of upland floodplains

UKGEOS: Glasgow Geothermal Energy Research Field Site (GGERFS): initial summary of the geological platform

The preferred second UKGEOS site is at Clyde Gateway, in the east end of Glasgow, Scotland. The focus of this, the Glasgow Geothermal Energy Research Field Site (GGERFS), is on characterising and monitoring the subsurface for minewater and hot sedimentary aquifer geothermal energy, and for cooling and heat storage. This report details BGS data and knowledge at late 2016, to define initial characterisation of the ‘geological platform’ relevant for the planning of a geothermal research facility and associated environmental baseline monitoring. The report covers knowledge of the bedrock and superficial deposits geology, abandoned coal mines, hydrogeology, geothermal datasets, geochemistry, remote sensed data, seismicity, stress fields, engineering geology and rock property datasets. BGS holds a great deal of legacy borehole, mining and geochemistry data and has updated existing bedrock and superficial deposits models of the area. However, deep borehole and seismic data are lacking to define the geology and structure of the area below a few hundred metres. Hydrogeological and temperature data are also lacking for the bedrock strata. Regional datasets and knowledge have (and can be further) used to reduce uncertainty and risk in these aspects of the geological characterisation