UK Geoenergy Observatories : Glasgow borehole test pumping - groundwater chemistry

In 2015, the British Geological Survey (BGS) and the Natural Environment Research Council (NERC) were tasked with developing new centres for research into the subsurface environment to aid the responsible development of new low-carbon energy technologies in the United Kingdom (UK) and internationally. Glasgow is one of two UK Geoenergy Observatories (UKGEOS) (Figure 1). The Glasgow Observatory comprises a network of boreholes across five sites into the superficial deposits, mined and unmined bedrock in the Dalmarnock area in the east of Glasgow City (Site 10 on Figure 1b) and at the Cuningar Loop on the River Clyde in Rutherglen, South Lanarkshire (Sites 1, 2, 3 and 5 on Figure 1b). These were designed to characterise the geological and hydrogeological setting as a research infrastructure to de-risk key technical barriers to lowtemperature shallow mine water heat/storage in an urbanised former mine setting (Monaghan et al. 2017, 2019). The borehole network is intended also for baseline monitoring to assess the environmental status before and during the lifetime of the project. Figure 1c shows the details of the 11 boreholes located at the Cuningar Loop. Test pumping was carried out at nine of the Cuningar Loop boreholes in January and February 2020 to characterise the hydraulic properties of the target aquifer horizons (mine workings, bedrock, and superficial deposits), and to determine the extent to which these are hydraulically connected (Shorter et al. 2021; Figure 1c). Groundwater samples were collected during constantrate pumping tests and analysed to provide an initial hydrochemical characterisation of the aquifers and, where more than one sample was obtained during the test, to measure changes in selected constituents during pumping, to complement observed hydraulic responses. Fifteen groundwater samples were obtained and were analysed to determine the concentrations of selected chemical parameters at the BGS and associated laboratories. This report details the groundwater sampling protocols used during the test pumping, the analysis methods, and the groundwater hydrochemistry. The report accompanies the dataset: UKGEOS Glasgow Test Pumping Groundwater Chemistry Data Release