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The Can Batlló factory was built on the Can Mangala between 1877 and 1879, as a cotton yarn and fabric, as well as bleaching, printing and sizeing factory. It is intended to install a geothermal system for the air conditioning of an administrative building in the city of Barcelona in one of the factorys buildings. The purpose of this study is to confirm whether the proposed energetic demand can be achieved in a sustainable manner and to assess potential impacts in the subsurface over time.The numerical model of flow and heat has been pre-calibrated with the regional flow model and thermal response test (TRT) of the area. The results indicate that the extracted geothermal energy could be higher (12-20% more) than the initial design. This higher performance would imply an optimisation of the system. It could be implemented by means of modifying the design of the heat exchangers, by reducing their amount and their length, or by changing the location of the exchangers to the whole location of Can Batlló, and not reducing their installation to a single building. Therefore, in addition to being able to design a more efficient and economic geothermal system, the investment could be recovered sooner[Rotman Cr1] . Simulations at 10 years of geothermal exploitation indicate that a downstream plume may occur. This variation of the natural subsurface temperature can affect the environment. Although the analyses carried out have made it possible to know the behavior of the subsurface in the front of this geothermal installation, to make a deeper study would be advisable to determine in more detail the long-term effects (more than 10 years) that it can cause in the subsurface. For this reason, the following tasks are recommended: (1) To create a control network at the scale of the study area to monitor the performance and the effects of the geothermal field once its installation is on operation; (2) To define the optimal characteristics of the exchangers to obtain a better geothe

Pressure over water resources is increasing rapidly as a result of climate change and growing population. In this context, urban aquifers emerge as a valuable resource of fresh-water for cities. However, the quality of urban groundwater is degraded due to the presence of contaminants of emerging concern (CECs) that reach continuously urban aquifers from different recharge sources. The effects of CECs are largely unknown, but it is expected that they pose a risk for human health, soil, plants and animals. CECs are naturally degraded in aquifers and their degradation rates depend on the physico-chemical conditions (i.e., redox conditions and water temperature) of the groundwater, which may vary as a result of anthropogenic activities. Therefore, it is needed to establish the impact of anthropogenic activities on CECs to determine their behaviour under modified and variable physico-chemical conditions and allow the safely use of urban groundwater. One of these anthropogenic activities that potentially modify the physico-chemical conditions is the use of the subsurface to obtain cooling and heating energy through low-enthalpy geothermal energy (LEGE) systems. LEGE is a renewable and carbon-free energy whose utilization is currently growing. Thus, it is expected that in a near future the density of LEGE systems will increase over most cities. Then, our objective is to determine the impact of LEGE systems on the behaviour of CECs. We have investigated the behaviour of CECs under the influence of LEGE by means of numerical models and considering different representative scenarios. The results show that the physico-chemical variations induced by LEGE systems modify notably the degradation rates of CECs, and thus, their concentrations on the downgradient side. Our results have significant implications for predicting the behaviour of CECs in urban aquifers and suggest the possibility of specifically design LEGE systems to improve in a passive way the quality of urban groundwa

Urban aquifers are a valuable resource of freshwater for cities, however, their quality is degraded due to the presence of organic contaminants of emerging concern (CECs). The effects of organic CECs are largely unknown, but there is evidence that they pose a risk for human health, soil, plants and animals. Organic CECs are naturally degraded in aquifers and their degradation rates depend on the physico-chemical properties, i.e., redox conditions and groundwater temperature. Some anthropogenic activities, like low-enthalpy geothermal energy (LEGE), may modify subsurface physico-chemical conditions altering the behaviour of organic CECs. LEGE is a renewable and carbon-free energy that allows obtaining cooling and heating energy. The utilization of LEGE is currently growing and it is expected that in a near future the density of LEGE systems will increase. LEGE modifies the groundwater temperature and in some situations the redox state (i.e., if the dissolved oxygen increases when groundwater is returned to the aquifer as a result of a poorly design), thus, it is of paramount importance to determine the impact of LEGE related activities on the behaviour of organic CECs. The behaviour of organic CECs under the influence of LEGE is investigated by means of thermo-hydro-chemical numerical modelling. Simulation output shows that LEGE activities have the potential to modify the degradation rates of organic CECs, and thus, their concentrations in aquifers. In the simulated scenario, the concentration of the chosen CEC decreases by the 77 % at the downgradient boundary of the model. The results of this study have significant implications for predicting the behaviour of organic CECs in urban aquifers and suggest specific changes in the design of LEGE facilities aiming to improve the quality of urban groundwater by boosting in-situ attenuation mechanisms.

Urban aquifers are a valuable resource of freshwater for cities, however, their quality is degraded due to the presence of organic contaminants of emerging concern (CECs). The effects of organic CECs are largely unknown, but there is evidence that they pose a risk for human health, soil, plants and animals. Organic CECs are naturally degraded in aquifers and their degradation rates depend on the physico-chemical properties, i.e., redox conditions and groundwater temperature. Some anthropogenic activities, like low-enthalpy geothermal energy (LEGE), may modify subsurface physico-chemical conditions altering the behaviour of organic CECs. LEGE is a renewable and carbon-free energy that allows obtaining cooling and heating energy. The utilization of LEGE is currently growing and it is expected that in a near future the density of LEGE systems will increase. LEGE modifies the groundwater temperature and in some situations the redox state (i.e., if the dissolved oxygen increases when groundwater is returned to the aquifer as a result of a poorly design), thus, it is of paramount importance to determine the impact of LEGE related activities on the behaviour of organic CECs. The behaviour of organic CECs under the influence of LEGE is investigated by means of thermo-hydro-chemical numerical modelling. Simulation output shows that LEGE activities have the potential to modify the degradation rates of organic CECs, and thus, their concentrations in aquifers. In the simulated scenario, the concentration of the chosen CEC decreases by the 77 % at the downgradient boundary of the model. The results of this study have significant implications for predicting the behaviour of organic CECs in urban aquifers and suggest specific changes in the design of LEGE facilities aiming to improve the quality of urban groundwater by boosting in-situ attenuation mechanisms.

Increase of population in the current climate change scenario requires to ensure the quality of groundwater available as well as to control possible incomes of pollution into the subsurface system. The objective of this work was to evaluate the current quality of groundwater and the risk of infiltration of surface contaminants into the aquifers customizing the DRASTIC method including potential flood areas and areas with high risk of surface pollution. Hydrogeological, hydrochemical and isotopic data compiled and measured show the aquifer behavior and the main attenuation and degradation of contaminants. The vulnerability to contamination of Barcelona aquifers by direct surface contaminants is relatively low considering flood areas and traffic. However, there is a relevant area where this risk is relatively high. Nevertheless, it is required further analyses considering the drainage network of the city including as well the geometry of Sustainable Urban Drainage Systems (SUDS) already installed. The knowledge of the aquifer hydrogeological characteristics and its quality together with the identification of vulnerable to contamination areas may lead to improve the installation of SUDS, reducing the input of contaminants through these infrastructures. The implementation of this methodology aims to facilitate water users and urban managers to control their potential negative effects on the receiving water body. In addition, the outcomes of its application may be used to optimize the groundwater management in the city.

The hydrologic cycle behaviour in the Bolivian Altiplano and how it interacts with human activity are still not fully understood. The hydraulic cycle is examined in a novel way in this work by considering extended time series of associated hydrologic and climatic data. Results show that human exploitation and losses from the sewage and water supply networks in the urban areas might cause an hydraulic imbalance in the region. These anthropogenic incomes, at the same time, increase concentrations of different pollutants. Water isotopic analysis reinforces the conceptual model showing that the groundwater sampled are mainly from precipitation. Workshops with local municipalities supported and defined the most relevant anthropic pressures in the basin. This information supports a vulnerability analysis in collaboration among them. The decision-making process for government entities might be strengthened by this study, which would help to develop long-term strategies to prevent and mitigate the issues found in the evaluation of water vulnerability in the region.

Geological modelling is an essential aspect of underground investigations, with cross-sections being one of the key aspects. This modelling can be done by experienced geologists or using mathematical methods. We present Geopropy, an open-source decision-making algorithm implemented in Python, that generates 3D cross-sections (the boreholes do not have to be aligned). It performs as an intelligent agent that simulates the steps taken by the geologist in the process of creating the cross-section, coupled with data-driven decisions. The algorithm detects zones with more than one possible outcome and, based on the level of complexity (or user preference), proceeds to automatic, semiautomatic or manual stages. Geopropy could be the basis of a new, simpler, more comprehensible way of looking at geological models in industry and academia while at the same time creating the potential for using novel machine learning algorithms in geological modelling.

The drawdown in the nucleus led to a reduction of 94% of the evaporation flow that characterized the natural regime, resulting in an impact of 0.15 m3·s−1 in the water balance. The evaporation rate in the mixing zone, in both periods, reached values of 5.84 mm·d−1 in the lakes and values <0.5 mm·d−1 in areas near the nucleus and the alluvial fans where the thickness of the unsaturated zone increases. Considering the total area covered by the free water surface in the Salar de Atacama basin, an average evaporation flow of 0.24 m3·s−1 was obtained for the lakes. This value remained almost constant between both dates because the evaporation rate and the extension area covered by lakes remained almost constant. In the northern mixing zone, where the water table depth was fairly constant between 1986 and 2018, evaporation rates overall remained quite similar. In the eastern and southeastern mixing zones, the evaporation rate also remained constant in the EMZ and MMZ areas, but in the IMZ area, especially towards the nucleus side of this sub-zone, the slight drawdown of the water table caused a reduction in the evaporation rate. In percentage, the mixing zone experienced a minor reduction (13%) in the discharge flow than the nucleus, but this was enough to cause an impact in the evaporation flow of 1.67 m3·s−1, which was higher than the produced in the nucleus. Finally, the alluvial zone scarcely contributed to the water balance in 1986 and 2018 because the depth of the water table was always deeper than 2 m. When the total evaporation discharge estimated for the year 1986, 12.85 m3·s−1, is compared with the evaporation flow calculated for the year 2018, 10.95 m3·s−1, a reduction of 1.90 m3·s−1, equivalent to 15%, is evidenced. The authors would like to apologise for any inconvenience caused.

Antibiotics, such as sulfonamides (SAs), have recently raised concern as wastewater treatment plants (WWTPs) partly remove them, and thus, SAs continuously enter the aquifers. In this context, the aims of this work are to (1) investigate the temporal evolution of SAs and metabolites in an urban aquifer recharged by a polluted river; (2) identify the potential geochemical processes that might affect SAs in the river-groundwater interface and (3) evaluate the ecological and human health risk assessment of SAs. To this end, 14 SAs and 4 metabolites were analyzed in river and urban groundwater from the metropolitan area of Barcelona (NE, Spain) in three different sampling campaigns. These substances had a distinct behavior when river water, which is the main recharge source, infiltrates the aquifer. Mixing of the river water recharge into the aquifer drives several redox reactions such as aerobic respiration and denitrification. This reducing character of the aquifer seemed to favor the natural attenuation of some SAs as sulfamethoxazole, sulfapyridine, and sulfamethizole. However, most of the SAs detected were not likely to undergo degradation and adsorption because their concentrations were constant along groundwater flow path. In fact, the intensity of SAs adsorption is low as the retardation factors are close to 1 at average groundwater pH of 7.2 for most SAs. Finally, risk quotients (RQs) are used to evaluate the ecological and human health risks posed by single and mixture of SAs in river water and groundwater, respectively. Life-stage RQs of the SAs detected in groundwater for the 8 age intervals were low, indicating that SAs and their mixture do not pose any risk to human beings. Concerning the environmental risk assessment, SAs do not pose any risk for algae, fish and crustaceans as the RQs evaluated are further lower than 0.1.

Each scientist is specialized in his or her field of research and in the tools that he or she uses during the research in a specified site. Thus, he or she is the most suitable person for improving the tools by overcoming their limitations to realize faster and higher quality analysis. However, most scientists are not software developers. Hence, it is necessary to provide them with an easy approach that enables non-software developers to improve and customize their tools. This paper presents an approach for easily improving and customizing any hydrogeological software. It is the result of experiences with updating several interdisciplinary case studies. The main insights of this approach have been demonstrated using four examples: MIX (FORTRAN-based), BrineMIX (C++-based), EasyQuim and EasyBal (both spreadsheet-based). The improved software has been proven to be a better tool for enhanced analysis by substantially reducing the computation time and the tedious processing of the input and output data files.

River floodplains sustain irrigated agriculture worldwide. Despite generalised groundwater level falls, limited hard data are available to apportion groundwater sources in many irrigated regions. In this paper, we propose a workflow based on: hydrochemical analysis, water stable isotopes, radiocarbon contents and multivariate statistical analysis to facilitate the quantification of groundwater source attribution at regional scales. Irrigation water supply wells and groundwater monitoring wells sampled in the alluvial aquifer of the Condamine River (Queensland, Australia) are used to test this approach that can easily be implemented in catchments worldwide. The methodology identified four groundwater sources: 1) river/flood water; 2) modified river/flood water; 3) groundwater recharged through regional volcanic materials and 4) groundwater recharged predominantly through sands and/or sandstone materials. The first two sources are characterised by fresh water, dominant sodium bicarbonate chemistry, short residence time and depleted water stable isotope signatures. Groundwater sources 3 and 4 are characterised by saline groundwater, sodium chloride chemistries, enriched water stable isotopes and very low radiocarbon contents, inferred to correspond to long residence times. The majority of wells assessed are dominated by flood water recharge, linked to decadal >300 mm rainfall events and associated flooding in the region. The approach presented here provides a groundwater source fingerprint, reinforcing the importance of floodwater recharge in the regional water budgets. This apportioning of groundwater sources will allow irrigators, modelers and managers to assess the long-term sustainability of groundwater use in alluvial catchments.

The karst system of the Syemareh Dam site with the reservoir capacity of 3.2 , located in the Zagros fold belt, southwestern of Iran, was studied under two conditions: before and after the reservoir impoundment as pre-reservoir and post-reservoir conditions, respectively. Study focus Despite a mixing of several water resources including the dam reservoir contributed to the flow rate of the downstream springs, the number of end-members was still unknown and their mixing ratio was unquantified. In this study, firstly a statistical approach (e.g. loading plot and matrix plot) was utilized to identify possible chemical reactions. Then, End Member Mixing Analysis (EMMA) was used to determine the number of end members. Lastly, the MIX code was utilized to quantify the mixing ratios. Three scenarios (i.e. assuming three, four and five end members) were compared to find a reliable mixing model based on the best match between the observed and estimated values of species concentration. In order to improve the calibration of the reliable mixing model, the species concentrations were corrected by deduction of the effect of plausible chemical reactions. New hydrological insights for the region The five end-members mixing model consisted of three aquifers, deep groundwater, and the reservoir was suggested as the dominant mixing process. Leakage from the reservoir as an end member was quantified by calculating the mixing ratio of the reservoir through mixing modeling for the first time.

The Salar de Atacama (SdA) is the largest Li reserve globally. The origin of Li, together with the rest of solutes, has been object of debate. Thus, rock weathering at low temperature, hydrothermal leaching or magmatic origin together with subsequent evaporation has been hypothesized. However, the extreme Li enrichment (>4000 mg/L) and the location of the Li-Mg-rich brines around the Salar Fault System (SFS) that crosses the nucleus of the SdA in half remain unexplained. The objective of this work is to define the thermohaline groundwater flow in the SdA basin to account for the genesis of its extreme Li enrichment. Thermohaline flow modelling has demonstrated the critical effect of the minimum hydraulic head (MHH) of the regional water table on the groundwater flow of salt flats. The MHH divides the basin into two isolated hydrodynamic systems and constitutes the endpoint towards which the most evaporated brines converge. The spatial mismatch between the locations of the Li-Mg-rich brines in the central-western zone of the nucleus (in the SFS) and the MHH in the easternmost zone of the nucleus discards recent evaporative concentration of the recharge water as the main mechanism of Li enrichment. Moreover, the persistence of a saline interface surrounding the nucleus at depth, regardless of the temperature gradient, also precludes lateral recharge (predominantly from the east) to ascend along the SFS. On the other hand, the computed thermohaline flow is compatible with the remobilization of buried layers of Li-Mg-enriched salts and/or clays by dilute recharge waters coming from the west or southwest of the basin. Here, the role of faults and density-driven flow is key to allow efficient downward and upward flow rates that favour the remobilization of Li and Mg.

Coastal zones are increasingly demanded spots for human settlements and economic development, which subject alluvial coastal aquifers to the threat of seawater intrusion (SWI). But they are also strategic areas for the chemical exchange between the continent and marine ecosystems, providing a source of nutrients from the submarine groundwater discharge (SGD) from the aquifer. Furthermore, in these contexts, the characteristics of the freshwater-seawater interface (FW-SWI) and its dynamics are strongly conditioned by the lithology and, among others, the typology of the discharge, density contrasts and tides. The proper management of such enclaves requires full understanding of the SWI-SGD system, which can only be achieved through a multidisciplinary and multi-scale characterization of the considered aquifer. For that purpose, we have developed an experimental field site in a coastal alluvial aquifer close to the mouth of a temporary stream in the Maresme coast line (Barcelona, Spain). The aquifer is formed by unconsolidated heterogeneous and polygenic alluvial sediments ranging from very fine to very coarse grained sand with discontinuous interfingering lenses of gravel and silt. All these sediments have around 20 m thickness and are overlying a weathered granitic basement. Several boreholes were drilled perpendicular and parallel to the shoreline, at various depths to reach different hydraulic conductivity areas along the mixing zone. Geophysical techniques including electrical resistivity tomography, fiber optics and different types of logging (induction, spectral gamma ray and magnetic susceptibility) have been performed to characterize the salinity gradient and distinguish sedimentary bodies. Moreover, a fully hydrochemical investigation was carried out to define the initial groundwater composition using TOC/DOC measurements, mayor and minor elements analysis and radium and radon isotopes quantifications. Also lithological description, sedimentological correlati

In western Mediterranean areas, seawater intrusion (SWI) used to be a major issue during the 1970’s decade due to the agricultural exploitation of the fertile lands located near to the coast. Proper pumping management nearly solved the problem, but the later economic development carried out by industries and tourism added an extra pressure to these sensitive systems, reactivating SWI in some cases. A good example of this situation can be found in the northeastern coast of Spain. In this area, the topographic configuration is controlled by medium reliefs and sloped piedmonts that discharge precipitation through ephemeral streams towards the sea. These torrential flows have a groundwater component that generates a coeval submarine groundwater discharge (SGD) with the intrusion of seawater. SGD strongly determines the health of marine environments, reason why is classically neglected in SWI research: in this area, SGD has been characterized measuring natural radioactive tracers (223Ra, 224Ra, 226Ra, 228Ra) in open sea campaigns, but the impact of mixing of this seaward flow and SWI within the aquifer remains unknown. The presence of different lithologies also determines the kind of geochemical reactions that modify the conservative behavior of the tracers used to measure SGD, as well as the localization of preferential flowpaths, making hard to quantify and predict both types of reciprocal flows (SGD and SWI). To be able to understand these interactions, a detailed characterization of the solid and liquid phase of the aquifer at different scales has been performed. To do so, we built a dedicated experimental site in a coastal alluvial aquifer in the Maresme coast line (Barcelona, Spain): the Argentona experimental site. Different types of geophysical logging (induction, spectral gamma ray and magnetic susceptibility) were deployed in the drilled wells to characterize the salinity gradient and distinguish sedimentary bodies. Also, the lithology and the geochemistry of d