Introduction: The groundwater in arid countries such as Egypt represent the main water resources in the desert regions due to the long distance between these regions (oasis) and Nile River. Contamination of these limited water resources with toxic metals threaten the health of individuals in these regions.Methods: The current study integrates isotopic tracers, hydrogeochemistry, geophysical logs, positive matrix factorization (PMF model), and Monte Carlo (MCS) simulation for pollution source apportionment and health risks associated with heavy metals in the Nubian Sandstone aquifer (NSSA).Results and Discussion: The water resource used for drinking purposes (NSSA) is pale meteoric water (non-rechargeable aquifer). Silicate weathering, old trapped sea water, reverse ion exchange evaporation, and dissolution are the dominant mechanisms controlling water chemistry. PMF model showed that the major ions and heavy metals in groundwater of the NSSA originated from four significant sources (anthropogenic activities, dissolution of minerals, iron-bearing minerals, mixing with old trapped seawater, and hydrothermal water). The total risk (HI) oral values highlighted significant non-carcinogenic dangers for adults and children through the oral exposure. At the same time, dermal contact posed a no risk for adults and a high risk for children. Most samples had carcinogenic risk (CR) values higher than the allowed limits (1.0E-4) for metals like Cadmium, chromium, and lead, suggesting carcinogenic effects across all age groups. The Monte Carlo approach-based health concern evaluation model assessed the 5th % CR oral values (child) as 0.00012, 0.0036, and 0.0088 for Cd, Cr, and Pb, respectively, indicating more significant potential dangers to children. Urgent and comprehensive water treatment measures are imperative to mitigate the identified carcinogenic and non-carcinogenic health risks in the study area.

The historical Ukrainian rock-salt mining town of Solotvyno and its environmentally related problems are well-known. A complex monitoring system is needed to evaluate the current situation in order to revitalize the investigated area. In addition to other risks, surface deformation due to undermining is one of the major risks endangering building infrastructure in the inhabited area of the town. These processes are well-known in the area, and damages caused by the surface movement are often recognized. Measurement of the process’s intensity and identification of the impacted area are crucial for any revitalization work. Information on these processes is the most important element of the hazard management and spatial-developmental planning of the town. This study aimed to characterize the long-term surface deformation processes and to identify the spatial and temporal trends and changes of these processes to assist spatial planning. The first step was to understand the surface deformation history from 1992. An InSAR-based assessment of the surface displacement of the undermined Solotvyno area was performed using data from three satellites, namely the ERS, Envisat, and the Sentinel-1, covering the time period between 1992 and 2021. The derived quantitative analysis indicated an intensive surface displacement and subsidence over the mining area. However, these displacements have not been even in the last 30 years of the investigation. The identification of the stabilized areas and recently started movements indicated the dislocation of the processes, which requires adequate actions for geohazard management and strategic planning. The demonstrated technology (InSAR) has the potential to set up an appropriate alarm system and provides an automated mechanism for continuous risk detection. A complex systems development is able to significantly reduce the geohazards over the unstable built-up zones.

Water resources management is a vital need in arid and semi-arid regions such as Sinai Peninsula, Egypt. Accordingly, the sustainability of water resources in this arid environment should be examined in terms of the possibility of groundwater recharge, particularly through runoff water, while identifying the most appropriate potential sites for drilling new water wells to cover current and future needs. The aquifer system of El-Qaa Plain in South Sinai is considered one of the structural basins associated with the tectonic setting of the Gulf of Suez. It is the main source of high-quality water in South Sinai. The present work provided an integration of mathematical flow modeling, hydrochemical composition, environmental isotopic signature, watershed modeling system (WMS), and remote sensing (RS) tools to determine the aquifer sustainability and recharge mechanisms. The obtained results indicated the following: (a) the salinity of the water ranged between 326.4 and 2261 ppm, while the environmental isotope values ranged between −6.28 to −4.48‰ for δ¹⁸O and −29.87 to −21.7‰ for δ²H, which reveals the phase of recharge and mixing between ancient water and recent rainwater; (b) sites for three dams in three sub-watersheds were proposed to harvest approximately 790,000 m³/y of runoff water to enhance groundwater recharge of the aquifer system; (c) and five scenarios using MODFLOW indicated that water drawdown is acceptable by adding 10 new production wells (discharge rate increased by 3600 m³/day). Moreover, increasing the recharge rate by 2% from the base case, leads to an increase in the piezometric water level with an average value of 0.13 masl, which reflects the positive effects of the proposed runoff water harvesting facilities. The integration applied in this work represents an integrated management system for water resources (surface and groundwater) which is suitable for application in arid or semi-arid coastal and similar areas.

Many environmental disasters occurred in the past due to site contamination caused by leakage of leachate to surround soil, surface water and ground water aquifer. The main concern is focused on the contamination potential due to migration of the leachate produced from the waste disposal or storage sites into the soil and underlying layers. Leachate quality, quantity and properties are directly relevant to waste management methods, environment conditions and waste characteristics, as well as the process of landfill processing, and the leachate may be the major source of various pollutants and emissions Problems associated with the cleanup sites have shown that remediation technologies need to be developed that are feasible, fast, and deployable in a wide range of physical settings. Using an effective landfill liner is a common way of preventing the movement of pollutants (with gas or leachate) from landfill sites or contaminated sites (e.g. brownfields, fuel stations, accidental spills, etc.). In this study different types of Geosynthetic clay liners were reviewed and they were compared in aspects of hydraulic conductivity, strength, material and chemical to improve GCL design to optimum.

Recent studies showed a significant peak of the salt contamination in the Tisza River that exceeded ten times over the average level. The document summarizes the works performed on the investigation of ground displacement using multi-temporal satellite radar interferometry technique in Solotvyno mine located in Tiachiv region. Multi-temporal InSAR aims to identify coherent radar targets exhibiting high phase stability over the entire observation period and derives point data with locations corresponding mainly to the point-wise, man-made features. The middle area with no persecuted targets may correspond to the substantial physical changes of the surface caused by activities like mining or tunneling, adding, or removing structures or their components, and motion perceptible in one pixel.