In recent years, the identification and monitoring of polluted sites have become very important due tothe widespread of contamination phenomena. The environmental assessment of contaminated sites iscomplex and difficult for the variety of the pollutants and for the physical and chemical heterogeneity ofpolluted sites. Some studies promote an integrated approach, which combines geophysical investigationwith geochemical analysis carried out on subsoil samples to quantitatively estimate the extent and thelevel of the contamination. In this work, a contaminated site located close to Taranto city, in the southof Apulia Region (Italy), has been investigated by chemical and geophysical surveys in order tocharacterize and evaluate the pollution which is occurring since years. Soil chemical analyses of texture,electrical conductivity, pH, organic carbon content, nitrogen, available phosphorous and carbonatecontent have been carried out to characterize soil properties of this site. Analytical investigations ofpollutants have been performed using Gas Chromatography/Mass Spectrometry (GC/MS) andInductively Coupled Plasma Mass Spectrometry (ICP-MS) to identify organic or inorganic compounds,respectively. Geophysical survey has been carried out to assess the geological features of the test siteand support the results of the physical and chemical soil analysis. Particularly, an Electrical ResistivityTomography (ERT) profile has been performed to visualize geo-lithological layers and hydrogeologicalproperties for evaluating the vulnerability of the area. Moreover six high resolution ERT and InducedPolarization (IP) profiles have been conducted close to the soil sampling points to image electricalstructures in the upper part of the soil, severely contaminated by inorganic and organic pollutants.Preliminary results highlight that this integrated approach can efficiently support soil contaminationassessment.

Large-scale problems of water quality and water availability require knowledge of water travel times through the unsaturated zone and substances carried with it. A number of methods and devices are available for measuring the water content in soils but usually they are not usable with the rocks too and very few are the attempts to verify their applicability.In applying the devices for water content estimation in rocks, the main difficulty is related to the installation of the probes. The installation procedure have to ensure a good contact between the rock and the sensor in order to reduce the uncertainty due to the gap effects.In this study a non-traditional method, known as electrical impedance spectrometry (EIS), was used. Using the new apparatus Z-meter, the electrical impedance in complex form and its changes were monitored in order to verify the suitability of the device with the rock. One kind of stainless steel probes have been installed into samples of calcarenite, a sedimentary rock coming from a quarry located in Canosa (South of Italy). The relationship between water content and resistance and between the reactance and the rock characteristics, such as texture, structure, etc., were investigated within a frequency range from 100Hz to 10000Hz, by using water with different electrical conductivity (EC) values. The experimentation was performed in environment with controlled temperature, due to the influence of temperature variation on all indirect moisture measurement methods.The experimental tests have been performed three times using exactly the same experimental set up, in order to check the repeatability of the data. The results allowed to define the calibration curves at different EC values for the calcarenite. This represent an important result because defines the possibility of using a new device, the Z-meter, to measure the rock water content by overcoming the issue of the gap effect that causes uncertainty of the measured values.This opens new scenarios linked to the possibility to monitor in situ flow and transport processes, that occur in the vadose zone constituted from rocks, measures rarely performed until now.

The water content (q) of the subsoil is an important parameter affecting all the processesthat occur in the vadose zone, playing a key role in the infiltration, aquifer recharge, andflow and transport of water and substances, as well as groundwater storage. Although thevadose zone is usually considered constituted of soil, it may also be comprised of rock.In the latter case, q cannot yet be operationally measured despite its unquestionableimportance. The aim of the present work was therefore to investigate the potential of anovel electrical impedance sensor for q measurement in rocks and to evaluate the effectsof frequency and salinity on the calibration of this device. In this study, only the resistance(R), i.e., the real part of the measured impedance, was investigated because of its directcorrelation with q. Calcarenite, a sedimentary porous rock, was used for the calibration inthe laboratory via the installation of penetration-type probes. The independence of themeasured R from the different frequencies set on the device was checked using a statisticalapproach. The q-R calibration functions obtained for the different saturation solutionshave a power-law dependence with a good degree of correlation. The results highlight boththe strong reproducibility of the experimental data (by using the penetration-type probes)and the suitability of the device for q measurement in calcarenite. The method could beadvantageous for field applications that involve rocks.

In Puglia le falde idriche sotterranee rappresentano una risorsa fondamentale per l'approvvigionamento idropotabile.I principali sistemi idrogeologici pugliesi sono caratterizzati da acquiferi porosi, come quelli che si impostano in rocce calcarenitiche, e acquiferi ospitati in rocce calcaree fratturate e/o carsificate.Sempre più frequentemente tali sistemi sono soggetti a processi di depauperamento qualitativo legati a situazioni di sovrasfruttamento e/o contaminazione. Per tali ragioni la conoscenza dettagliata delle proprietà idrauliche, che governano i fenomeni di flusso e trasporto della zona insatura, è di fondamentale importanza per una gestione sostenibile delle risorse idriche; in particolar modo una precisa valutazione della velocità di flusso nella zona vadosa risulta necessaria per prevedere i tempi di migrazione dei contaminanti e quindi valutare la vulnerabilità della falda.Negli anni sono stati sviluppate differenti metodologie di investigazione allo scopo di caratterizzare il sottosuolo e monitorare il flusso e il trasporto in questi complessi sistemi idrogeologici.Questo studio presenta i risultati di un approccio metodologico multidisciplinare che combina misure infiltrometriche con indagini geofisiche, precisamente, misure di resistività elettrica, eseguite in due differenti siti della Puglia, caratterizzati da differenti formazioni geologiche e quindi caratteristiche idrauliche.Un sito, vicino Altamura, in provincia di Bari, è rappresentato da calcari carsificati e fratturati, che contengono una importante falda profonda; tale area è stata soggetta a sversamento di fanghi derivanti dal trattamento di acque di scarico industriali.Il secondo sito, vicino San Pancrazio Salentino, in provincia di Brindisi, è rappresentato da una cava di calcarenite utilizzata per lo stoccaggio di rifiuti prodotti da un' industria farmaceutica. In entrambi i casi, lo sversamento ha causato contaminazione del suolo e sottosuolo.Il flusso verticale è stato monitorato misurando l'abbassamento del livello idrico all'interno di un largo anello infiltrometrico, realizzato e installato direttamente sulla roccia affiorante, e contemporaneamente sono state condotte misure di resistività elettrica del sottosuolo al fine di monitorare l'infiltrazione dell'acqua, quindi l'approfondimento del fronte umido nella zona insatura.In aggiunta, è stata condotta un'indagine di resistività elettrica azimutale, al fine di individuare eventuali direzioni di fratturazione principali presenti nelle rocce, che rappresentano vie preferenziali di flusso e trasposto di inquinanti.I risultati ottenuti supportano l'efficacia dell'approccio metodologico combinato in questi sistemi idrogeologici complessi per stimare il flusso verticale nei due differenti acquiferi.

Electrical resistivitymethods arewidely used for environmental applications, and they are particularly useful for thecharacterization and monitoring of sites where the presence of contamination requires a thorough understandingof the location and movement of water, that can act as a carrier of solutes. One such application is landfill studies,where the strong electrical contrasts between waste, leachate and surrounding formations make electrical methodsa nearly ideal tool for investigation. In spite of the advantages, however, electrical investigation of landfills posesalso challenges, both logistical and interpretational. This paper presents the results of a study conducted on adismissed landfill, close to the city of Corigliano d'Otranto, in the Apulia region (Southern Italy). The landfill is locatedin an abandoned quarry, that was subsequently re-utilized about thirty years ago as a site for urban waste disposal.The waste was thought to be more than 20 m thick, and the landfill bottom was expected to be confinedwith an HDPE (high-density poli-ethylene) liner. During the digging operations performed to build a nearby newlandfill, leachate was found, triggering an in-depth investigation including also non-invasivemethods. The principalgoal was to verify whether the leachate is indeed confined, and to what extent, by the HDPE liner.We performedboth surface electrical resistivity tomography (ERT) and mise-à-la-masse (MALM) surveys, facing the severe challengesposed by the rugged terrain of the abandoned quarry complex. A conductive body, probably associated withleachate,was found as deep as 40 mbelowthe current landfill surface i.e. at a depth much larger than the expected20 mthickness of waste. Given the logistical difficulties that limit the geometry of acquisition,we utilized syntheticforward modeling in order to confirm/dismiss interpretational hypotheses emerging from the ERT and MALM results.This integration between measurements and modeling helped narrow the alternative interpretations andstrengthened the confidence in results, confirming the effectiveness of non-invasive methods in landfill investigationand the importance of modeling in the interpretation of geophysical results.

Due to the high wells drilling cost, monitoring sites are usually selected among existing wells; nevertheless, the resulting monitoring network must assure a good assessment of the main characteristics of the considered aquifer. Groundwater managers, need to find a good balance between two conflicting objectives: maximizing monitoring information and minimizing costs. In this paper, a couple of groundwater monitoring optimization methods are presented, related to the local shallow aquifer of the Alimini Lakes, located in Apulia (South-Eastern Italy) where a large number of existing wells have been pinpointed and the need of optimally reducing exists. The proposed methods differ each other for the required amount of prior information. The first proposed method, namely Greedy Deletion, just requires the geographical position of the available sites, while the second, the Simulated Annealing, also requires the knowledge of the spatial law of the considered phenomenon. The managerial need was to halve the number of monitoring sites minimizing the information loss.

The knowledge of the unsaturated flow rate is essentialfor both groundwater protection and management, howeverit is not easy to determine experimentally, especiallyon the rocks and in the field.This study aims to evaluate the flow rate of potentialcontaminants in a porous aquifer using an integrated approachthat combines electrical resistivity measurementswith a large ring infiltrometer test.Specifically, the field tests were carried out on the outcropof sandstone in a quarry, located in Southern Italy,which has recently been affected by mycelium sludge derivedfrom pharmaceutical industry waste. The electricalresistivity tomography was carried out to visualise the infiltrationof water in the subsoil in order to evaluate the unsaturatedwater flow in the sandstone. Simultaneously, thevertical flow into the unsaturated subsoil was investigatedby measuring water levels in a large adjustable ring infiltrometer,sealed directly on the rock. The results of thisstudy confirm the efficacy of the combined methodologiesto monitor the vertical flow through unsaturated porous rock.

Although Italy boasts an age-old and solid experience in the exploitation of geothermal energy for power generation, very limited was the development regarding the direct uses. However, recently the interest in low enthalpy geothermal energy is growing mainly because, unlike the other kinds of green energies, the geothermal energy suitable for direct uses can be found anytime and almost everywhere. Particular attention should be paid to the open-loop geothermal systems that use groundwater as geothermal fluid. The installation of these kind of geothermal systems is particularly attractive in the coastal areas where, generally, the aquifers are shallow, and often affected by seawater intrusion. In this work an experimental approach was proposed for a detailed characterization of a costal area finalized to exploitation of low enthalpy geothermal resource. A costal karst area near Bari (Southern Italy), extended for about 20 Km2, was investigated. A specifically defined monitoring network, consisting of about 35 wells, was used to monitor groundwater parameters (temperature, water level, electrical conductivity). The influence of an open-loop geothermal systems on the sea water intrusion was also studied by means of a long-term pumping test. The investigated portion of aquifer was found to have a high hydraulic conductivity and transmissivity values, as well as a very short time of recharge, highlighting a good productivity of aquifer. The results of the long pumping test have showed that, the extraction of water does not affect the equilibrium of the aquifer both qualitatively and quantitatively. The high level of contamination observed in groundwater, due to both the presence of urban and industrial pollution and to the seawater intrusion, causes the absence of a strong competition for use of groundwater by making them available for geothermal use.Overall the experimental approach utilized for this study represents a good effort to define a standard methodology in order to characterize a coastal area. This approach reveals useful for a feasibility study to install an open-loop geothermal system, and to support the potential geothermal evaluation.

In recent years, geophysics is increasingly used to study the flow and transport processes in the vadose zone. Particularly, when the vadose zone is made up of rocks, it is difficult to install sensors in the subsurface to measure hydrological state variables directly. In these cases, the electrical resistivity tomography (ERT) represents a useful tool to monitor the hydrodynamics of the infiltration and to estimate hydraulic parameters and state variables, such as hydraulic conductivity and water content. We propose an integrated approach aimed at predicting water content dynamics in calcarenite, a sedimentary carbonatic porous rock. The uncoupled hydrogeophysical approach proposed consists in 4D ERT monitoring conducted during an infiltrometer test under falling head conditions. Capacitance probes were installed to measure water content at different depths to validate the estimations derived from ERT. A numerical procedure, based on a data assimilation technique, was accomplished by combining the model (i.e., Richards' equation) with the observations in order to provide reliable water content estimations. We have used a new data assimilation method that is easy to implement, based on the ensemble Kalman filter coupled with Brownian bridges. This approach is particularly suitable for strongly non-linear models, such as Richards' equation, in order to take into account both the model uncertainty and the observation errors. The proposed data assimilation approach was tested for the first time on field data. A reasonable agreement was found between observations and predictions confirming the ability of the integrated approach to predict water content dynamics in the rocky subsoil.

Sustainable groundwater management requires a thorough knowledge of the behavior of the unsaturated zone. Particularly, the evaluation of the flow rate in the unsaturated zone is important to estimate the travel time of the infiltrated water and dissolved substances in the subsurface and, hence, to quantify the recharge rate and to assess the quality of the subsurface.A quarry of calcarenite near the town of Canosa, in southern Italy, was chosen to perform an integrated hydrogeophysical field study that combines infiltrometer measurements with Electrical Resistivity Tomography (ERT). Infiltration data were collected using a 0.5-m-diameter metallic infiltrometer ring, which was installed directly on the rock, filled with about 8 L of water. A falling-head test was conducted for many hours, the water level in the ring was monitored with a pressure transducer and a metric rod fixed to the ring. Electrical resistivity measurements were carried out, using the "time-lapse" technique, to observe the dynamics of infiltration/redistribution of water in the vadose zone. Hydrogeophysical data were acquired for long periods to gain a more complete understanding of subsurface flow. The observations were used to independently estimate travel times and infiltration rates using a numerical model.

In the past decade, over-exploitation has led to a de-pletion of water resources, with impact both on quality and quantity. A sustainable groundwater management needs a detailed scientific knowledge of the behaviour of the un-saturated zone. Particularly, the evaluation of the flow-rate in the unsaturated zone is important to estimate the travel time of the infiltrated water in the subsurface and, hence, to assess the recharge rate and groundwater vul-nerability. A quarry of calcarenite near the town of Canosa, in South Italy, has been chosen to perform the field tests using an integrated hydrogeophysical approach, combin-ing infiltrometer measurements with electrical resistivity tomography (ERT). The infiltration data were collected using a metallic infiltrometer ring of 0.5 m in diameter, installed directly on the rock, filled with about 8 L of water. The test was conducted for many hours at falling head condition, and the water level within the ring was measured by means of a pressure transductor and a metric rod fixed to the ring. Simultaneously, electrical resistivity measurements were carried out using "time-lapse" technique, in order to monitor the dynamics of infiltration/redistribution of the water in the unsaturated zone. Hydrogeophysical data have been acquired for sev-eral hours to obtain a reliable hydrogeological model of the subsurface investigated. Field-saturated hydraulic conductivity has been de-termined for the calcarenite, and ERT surveys support these results.

The interest in the low enthalpy geothermal resources is growing, owing to its wide availability, and the possibility of overcoming the problems related to energy storage. Among the low enthalpy plants, the installation in coastal areas of the open-loop groundwater heat pump (GWHP) systems, that use groundwater as the geothermal fluid, is particularly attractive because of the presence of shallow aquifers. Nevertheless, these aquifers are often affected by seawater intrusion, so strict monitoring before GWHP installation is needed to check the feasibility of the plant.This work reports a detailed quali-quantitative characterization of a costal aquifer, in Southern Italy, for its exploitation as a very low enthalpy geothermal resource. The main groundwater parameters were monitored to assess the groundwater suitability to be used as geothermal fluid. A long-term pumping test, simulating the designed open-loop GWHP system, was performed to evaluate its potential impact on seawater intrusion. The results revealed that the open-loop GWHP plant do not affect the quali-quantitative equilibrium of the studied coastal aquifer. Furthermore, the study demonstrated that the used methodological approach is proper for the early assessment of the feasibility of the GWHP plant without affecting the seawater intrusion processes, and with minimum impact.

Compared to other European countries, there is limited use of geothermal resources in Italy for the heating and cooling of buildings (UGI-CNG, 2007). Low-temperature geothermal resources, which can be readily used for this purpose, can be found throughout Italy. The high cost and scarcity of fossil fuels have promoted the increased use of natural heat for a number of direct applications. Just as for fossil fuels, the exploitation of geothermal energy should consider its environmental impact and sustainability.Particular attention should be paid to so-called open loop geothermal systems, which use groundwater as geothermal fluid. From an economic point of view, the implementation of this kind of geothermal system is particularly attractive in coastal areas, which have generally shallow aquifers. The potential problem of seawater intrusion has led to laws that restrict the use of groundwater. The limited availability of freshwater could be a major impediment for the utilization of geothermal resources. We propose a methodology, based on an experimental approach, to characterize a coastal area in order to exploit low-enthalpy geothermal resources. A coastal karst-area near Bari, in Southern Italy, was selected for this purpose.A long-term pumping test was performed to create analog for an open-loop geothermal system. Electrical resistivity measurements were carried out, using "time-lapse" techniques, to monitor the dynamics of the freshwater-seawater interface. The results show that the pumping does not affect the quantitative and qualitative characteristics of the aquifer. The electric conductivity values suggest very limited sea water intrusion.

Up to now, field studies set up to measure field-saturated hydraulic conductivity to evaluate contamination risks, have employed small cylinders that may not be representative of the scale of measurements in heterogeneous media. In this study, a large adjustable ring infiltrometer was designed to be installed on-site directly on rock to measure its field-saturated hydraulic conductivity. The proposed device is inexpensive and simple to implement, yet also very versatile, due to its large adjustable diameter that can be fixed on-site. It thus allows an improved representation of the natural system's heterogeneity, while also taking into consideration irregularities in the soil/rock surface. The new apparatus was tested on an outcrop of karstic fractured limestone overlying the deep Murge aquifer in the South of Italy, which has recently been affected by untreated sludge disposal, derived from municipal and industrial wastewater treatment plants. The quasi-steady vertical flow into the unsaturated fractures was investigated by measuring water levels during infiltrometer tests. Simultaneously, subsurface electrical resistivity measurements were used to visualize the infiltration of water in the subsoil, due to unsaturated water flow in the fractures. The proposed experimental apparatus works well on rock outcrops, and allows the repetition of infiltration tests at many locations in order to reduce model uncertainties in heterogeneous media.

Porous media such as fractured rock and aggregated soils consist of two pore domains with distinct transport properties.A numerical code was developed to simulate solute concentrations in the two domains using a partitioned solution procedure to efficientlymodel transport in dual-permeability media. Furthermore, an approximate analytical solution was obtained that allows for different advectiveand dispersive terms in both flow domains, for a first-type or a third-type inlet condition. Solutions were obtained for local concentrationsin both domains as well as effluent concentration and the concentration per medium volume. The problem was solved by decoupling thetransport equations using diagonalization. This involves an error for the dispersivity matrix that is related to the difference in dispersivity ofboth domains. The correctness of the solution was assessed by comparison with numerical results. For low Damköhler numbers the solutionwas accurate even for a dispersivity ratio of 10. The need for a dual-dispersivity instead of a single-dispersivity model was illustrated withsample breakthrough curves and the solution was applied to optimize experimental breakthrough curves for an Andisol with a distinct intraaggregateand interaggregate porosity.

This study investigated the modeling of variably saturated flow and Ni transport in frac- tured rocks at a site (Altamura, southern Italy) polluted in 2001 by unauthorized sludge waste disposal. Time-lapse electrical resistivity tomography (ERT) and infiltrometer experi- mental results were used to constrain near-surface boundary conditions in an unsaturated flow model. A plastic ring was used as an infiltrometer because its experimental setup is very versatile and adaptable to many different geological conditions, taking into con- sideration irregularities in the soil and rock surfaces. The proposed methodology allows switching from the tomography to the map of water pressure contour lines obtained by the model by making the time-lapse ERT an effective tool to reduce computational uncertain- ties. Simulation results predicted both the concentration and the residence time of the Ni in the vadose zone of the Altamura site. These results were used to successively investigate the horizontal Ni transport into the deep fractured aquifer. Simulations provided apparent Ni pathways in the groundwater and expected concentrations in a downstream well, placed 10.9 km from the contamination sources. The agreement of the results with the sampling data collected has confirmed that the groundwater was polluted for 16 mo by Ni. The con- tamination plume started during the winter of 2004 and moved in the groundwater toward the sea at an average velocity of 10 m/d.

A preliminary ecological characterisation of an open quarry that had been used for the disposal of pharmaceutical wastes from a factory producing antibiotics was performed. Pharmaceutical wastes and groundwater samples were collected and analysed in order to assess both the bacterial community structure and functioning, and the contamination by organic compounds, including antibiotics. Bacterial abundance measured using the epifluorescence direct count method, cell viability measured by using two fluorescent dyes, species diversity measured by assessing the bacterial community structure using fluorescence in situ hybridisation (FISH) and soil microbial activity based on dehydrogenase activity were used as microbiological indicators to evaluate the 'quality state' of the area studied. The overall results show that groundwater has a low-quality state in terms of bacterial viability, activity and diversity, associated with trace contamination by antibiotics and chlorinated volatile organics.

The characterization and modelling of flow and transport through the vadose zone are receiving increased attention in the last years, particularly as regards the pollutant phenomena. Hence water content estimation and its monitoring, from which strongly depend the hydrological processes that occur within the unsaturated zone, is an important task.A number of methods and devices are available for measuring the water content in soils but, usually, they are not usable with the rocks too and very few are the attempts to verify their applicability.The installation of the probes is the main difficulty in applying the devices for water content estimation in rocks, because the installation procedure has to ensure a good contact between the rock and the sensor in order to reduce the uncertainty due to the gap effects. In this study a non-traditional method, known as electrical impedance spectrometry (EIS), was used. Using the new apparatus Z-meter, developed within the European International Project E!3838 of EUREKA Program, the electrical impedance in complex form and its changes over time were monitored in order to verify the suitability of the device for water content estimation in rocks. Both the real component of impedance (resistance R) and the imaginary component (capacitive reactance X) were independently investigate.One kind of stainless steel probes have been installed into samples of calcarenite, a sedimentary rock coming from a quarry located in Canosa (South of Italy). The relationship between the output device and water content was investigated within a wide frequency range (from 100Hz to 10000Hz), using different water solutions with different electrical conductivity (EC) values. Due to the influence of temperature variation on all indirect moisture measurement methods, the experimentation was performed in a temperature controlled room provided with a ventilation system.Correlating the real component of the impedance with the directly measured water content, determined using a gravimetric method, functions of exponential type, with a good correlation coefficient, were obtained for different water solutions.The independence of the real component of impedance to changing the frequencies is confirmed; any frequency can be used. On the contrary, the sensitivity of resistance to changing the EC value of the solution used for sample saturation is evident.The analysis of reactance data confirms a strong dependence on the applied frequency. The reactance outputs are not continuously recorded for all investigated range of water contents (from saturation to dry) but appear in correspondence of water contents which depend not only on applied frequency but also on the EC of the solution used to saturated the sample. Particularly, higher frequency and lower EC of solution seem to assure reactance values in a wider range of water content.This evidence, together with a lower precision of the device on reactance outputs, makes it more diffi

Two sets of soil lysimeters were amended with solid and liquid olive mill wastes and the composition ofleachate was analysed. Five treatments were carried out using: olive mill wastewater (OMW) at twodifferent rates (80 and 320 m3/ha); OMW pre-treated by catalytical digestion with MnO2; compost obtainedby exhausted olive pomace; freshwater as the control. Electric conductivity, pH, potassium, totalpolyphenols and nitrates were monitored in the leachate as indexes of potential groundwater contamination.The study demonstrated that the impact of all the selected amendments on groundwater was theminimum. OMW was safely applied to soil even at four times the rate allowed by the Italian law, and pretreatmentby catalytical digestion was not necessary to further reduce the impact on groundwater. Theapplication of olive pomace compost was equally safe.