Chemical and Isotopic Tracers for Characterization of the Groundwater in the Heterogeneous System: Case from Chichaoua-Imin’tanout (Morocco)

The geological and hydrogeological approach of the structure of the basin OuladBouSbaâ led to the definition of the geometry of the main aquifers. In general, the profiles show the complexity of the geological configuration. The filling of the depression of OuladBouSbaâ is from the Eo-Cretacian. At this level, the aquifer is recharged by direct water infiltration. The quaternary, Eocene, and Cenomanian-Turonian formations constitute the main aquifers. Horizontal as well as vertical heterogeneity lead to a higher diversification of aquifer characteristics. To define the origins and understand the groundwater flows in this complex zone, we used a multi-tracer approach with the analysis of major elements and the isotopes of δ2H and δ18O. The chemical composition is mainly governed by the interaction with the rock with low electrical conductivity except in areas around domestic landfills. Geochemical results analyzing groundwater in the Piper diagram show two distinct chemical facies: the sulfated calcium and magnesium, and the hyper-chloride calcium. The levels of δ18O range from −7.60 to −4.25 while those of δ2H vary between −53.07 and −27.03. Analyses of signature isotopes differentiate two groups. The first contains high levels of heavy isotopes (highest levels of δ2H and δ18O) having therefore been submitted to evaporation. The second with lower levels of δ2H and δ18O did not undergo evaporation. The first one belongs to the unconfined free aquifer while the second corresponds to the captive aquifer.

Isotopic and hydrogeochemical characterization of groundwater and surface water from a mine site in Tanzania

This study used the hydrochemical properties of water to reveal the causes of water quality degradation. The results showed that most samples located downstream of the mine tailings dam were slightly acidic with pH as low as 4.6. Samples with high levels of Na+, Cl−, and could not be isotopically linked to the local geochemistry, but the anthropogenic activities and evaporation were probably responsible for the observed water chemistry. The Piper diagram indicated cations were dominate by Ca and Mg, while anions were dominated by bicarbonates and sulphates. Pb and Hg levels (mean 70.29 and 17.95 μg/L, respectively) were all higher than the World Health Organization (WHO) and Tanzanian drinking water guidelines. Mining activities probably contributed to the observed low pH values and elevated concentration of cyanides, heavy metals, and metalloids. Stable isotope results indicated a vulnerability of the water to recent contamination that could be attributed to anthropogenic activities. Moreover, isotopic studies indicated a flow pattern from the eastern to the western side of the mine study site. Lowland samples were more 3H-enriched than highland ones. The present study concludes that groundwater recharge from recent local precipitation may have an impact on the sources studied.

Temporal variations in the water quality of beton spring, Gunungsewu karst area, Indonesia

Beton Spring is a water source used for fulfilling the basic needs of domestic activities, irrigation, and fisheries. Concerning water resources, it is particularly unique in that its upper course is an allogenic river with enormous groundwater potential. This research was intended to study the temporal water quality at Beton Spring. For this reason, the spring water was sampled periodically for one year. The water quality was assessed according to the drinking water quality standards, namely Regulation of the Minister of Health of the Republic of Indonesia No. 90 of 2002 and the standards set by experts. The analyses of trilinear and rectangular Piper diagrams were performed in Easy Quim v5.0 software. The analysis results showed that, temporally, the spring water had good quality because almost all samples collected in the dry and rainy seasons met the standards. The trilinear Piper diagram revealed that the Beton Spring mainly contained unpolluted and calcium-enriched groundwater. Meanwhile, the rectangular Piper diagram indicated the abundance of average bicarbonate waters, with only a few samples categorized into cation exchange-controlled groundwater.

Seawater Intrusion Assessment based on Hydrochemical Data in Gapura Sub-district of Sumenep Regency, East Java, Indonesia

Gapura is a sub-district with a large salt pond in Sumenep Regency, Madura Island, Indonesia. In this area, many residents’ houses have drilled wells to meet their water needs. One factor is that Municipal Waterwork (PDAM) does not reach the area due to limited water sources and difficult accessibility. Residents in the area claimed to have found some groundwater that tasted brackish. This study aims to apply hydrochemical analysis to identify the possibility of seawater intrusion in the area. The assessment of seawater intrusion uses the total dissolved solids (TDS) value and major ion of groundwater samples. In the analysis of thirty samples, two samples have different values from the samples of freshwater. However, the value of these two samples is relatively low to be classified as seawater intrusion. It is described on the TDS values that belong to the class of brackish water, from Simpson ratio values classified as slightly contaminated, and from the piper diagram plot that is still in the mixing zone in the middle of the diagram. The presence of brackish water in these samples can be caused by a location close to salt pond activities.

Evaluation of anthropogenic nexus on groundwater quality through integration of hydrogeochemical processes and water quality index at Nacharam watershed of greater Hyderabad, India

Anthropogenic activities such as the rapid leap of industrialization and urbanization constitute a significant concern in megacities and have become a key source of groundwater contamination. Twenty-five (25) groundwater samples were collected from tube wells and handpumps from Nacharam watershed, greater Hyderabad. The water samples were analyzed for 13 physicochemical parameters and major dissolved ions using the standard methods. WQI has been computed using a weighted arithmetic index method and integrated with GIS to identify the hotspots of contamination and their spatial distribution. The analytical data plotted on the Piper diagram showed that dominance of Ca-Mg-Cl (52%) type followed by Na-Cl type of water is dominant in 44% of samples might be resulting due to increase in anthropogenic activities such as discharge of waste water from industries. Results reveal that 96% of the samples exceed the F - concentrations compared with WHO permissible limits suggested unfit for drinking. WQI values indicate that 56% of samples fall in the poor category, 28% belong to very poor water, and 4% are unsuitable for drinking. These findings will provide valuable information to policymakers and stakeholders on the proper management and supply of potable water that reduces human health concerns .

Hydrochemical Evaluation of Groundwater in Al-Khasfa Area within Haditha, Western Iraq

The main aim of the research is to study the groundwater quality in Al-Khasfa area within Haditha district, western Iraq. To assess the groundwater, eighteen groundwater samples in the study area were collected and analyzed for major cations and anions. Results indicated that groundwater samples in the study area are between neutral and light alkaline, slightly brackish, and highly mineralized. The hydrochemical formula of the groundwater samples indicates the Ca-SO4 type dominance, except wells number 16 and 17 were of Ca-Cl water type. According to Piper diagram, the type of water is Earth-Alkaline waters. All groundwater samples are unsuitable for human drinking, industrial, and building uses, but it is suitable for livestock. For irrigation purposes, it is characterized by no Mg-harmful, good with SAR, Na%, RSC, and PI but unsuitable for salinity hazard due to very high salinity. The Water Quality Index for Euphrates aquifer in the study area in both periods are poor water for human drinking, except W-1 in dry period indicate very poor water and W-6, W-7, W-8, W-13, W-14, W-15, W-16 in wet period indicate good water.

Geochemical Approach for Seawater Intrusion Assessment in the Area around Yogyakarta International Airport, Indonesia

A total of 10 groundwater samples were obtained from groundwater wells with depths of around 8-10 meters distributed around Yogyakarta International Airport, Indonesia to test the geochemical of groundwater for assessing the seawater intrusion. Samples were taken into polyethylene bottles with a volume of 1000 ml. These bottles were rinsed to reduce the risk of any contamination prior to their filing with sampled water. Piper Diagram is used to evaluate seawater intrusion by plotting the percentages of cations and anions (in mEq/L) as a single point on the triangle. The groundwater facies' in the study area are CaHCO3 and CaNaHCO3. It suggests that the origins of the elements Ca and Na were estimated to derive from the dissolution of the plagioclase, hornblende, and pyroxene minerals found in the sand sediment, while the elements of HCO3 were estimated from the dissolution of carbonate minerals or the decomposition of organic matter and root respiration in the soil zone may enrich their concentration. The wells affected by slightly freshening were ZAM-04, ZAM-05, ZAM-06, ZAM-08, and ZAM-10. While the wells that are not affected by the intrusion or fresh were ZAM-01, ZAM-03, ZAM-07, and ZAM-09. However, ZAM-02 well which is close to the coastline and the closest to the airport development area was the only well that affected significantly by freshening, comparing with other wells. Another expected controlling factor was the fault in the northern part which continuously leads that location. By supported a flow pattern or large river, it was concluded the alluvial deposits buried the fault, and it was estimated to continue to that location.

Comparison Of Isotope And Hydrochemical Characteristics Of Springs In Sembalun – Rinjani Area, East Lombok, West Nusa Tenggara, Indonesia Before And After The Earthquake Events In 2018

The current 2019 isotope and hydrochemical study of hot and cold springs in Sembalun - Rinjani area is a re-assessment of previous similar study in 2012. The aim of this study is to assess the isotope and hydrochemical characteristics of springs due to the earthquake events in 2018. After the earthquake events in 2018, the stable isotopes δ18O and δ2H composition of Sebau hot spring and most of cold springs is shifted into more depleted values which may indicate water-rock interaction or interaction with cold waters which has more depleted δ18O and δ2H values. Also, Sebau hot spring is still plotted at mixing line of meteoric and andesitic water, but still dominant meteoric water. The hydrochemical data of all cold springs and Orok river show the enrichment of Na, probably from silicates weathering or the cation exhchange. While hydrochemical composition of Sebau hot spring is significantly decreased, except SO4, probably due to dilution with cold waters before the thermal water reach the surface. The Piper diagram showed that cold springs and Orok river are Ca-Mg-HCO3 type before and after the earthquake events. While Sebau hot spring is shifted from Ca-Cl type into mixed Ca-Mg-Cl type after the earthquake events. The temperature of Sebau hot spring slightly decreased from 35.5 °C to 34.8 °C after the earthquake events, while Na/K geothermometer calculation also indicate decreasing of sub-surface temperature, i.e. from 146–165 °C to 130–150 °C.

Major Elements in the Upstream of Three Gorges Reservoir: An Investigation of Chemical Weathering and Water Quality during Flood Events

Rivers transport terrestrial matter into the ocean, constituting a fundamental channel between inland and oceanic ecosystem and affect global climate change. To reveal chemical weathering processes and environmental health risks during flood periods, water samples were collected in the upper reaches of Three Gorges Reservoir (TGR) in 2020. HCO3− and Ca2+ were the most abundant anions and cations of the river water, respectively. The range of HCO3− concentration was between 1.81 and 3.02 mmol/L, while the mean content of Ca2+ was 1.03 mmol/L. The results of the Piper diagram and element ratios revealed that the river solutes were mainly contributed by carbonate weathering and gypsum-rich evaporite dissolution. A mass balance model indicated that the contribution order of sources to cations in the main channel (Yibin-Luzhou) was evaporites > carbonates > atmospheric input > silicates. The order in the Chongqing—Three Gorges Dam was carbonates > atmospheric input > evaporites > silicates. These results showed a lithologic control on hydrochemical characteristics. Most sampling sites were suitable for agricultural irrigation according to the water quality assessment. However, indexes sodium adsorption ratio (SAR) and soluble sodium percentage (Na%) were higher than 1.0 in Yibin-Luzhou and 30% in Yibin–Chongqing, respectively, suggesting a potential sodium hazard. In addition, except Tuojiang River and Shennong River, the risk of sodium hazard in tributaries was relatively low. High Na+ concentration in irrigation water can damage soil structure and function and ultimately affect agricultural production. Water quality in the upstream of a Piper diagram should attract enough attention.