Collection Of Groundwater Samples Research Articles

Microbial diversity and metabolic pathways linked to benzene degradation in petrochemical-polluted groundwater

The rapid advance in shotgun metagenome sequencing has enabled us to identify uncultivated functional microorganisms in polluted environments. While aerobic petrochemical-degrading pathways have been extensively studied, the anaerobic mechanisms remain less explored. Here, we conducted a study at a petrochemical-polluted groundwater site in Henan Province, Central China. A total of twelve groundwater monitoring wells were installed to collect groundwater samples. Benzene appeared to be the predominant pollutant, detected in 10 out of 12 samples, with concentrations ranging from 1.4 μg/L to 5,280 μg/L. Due to the low aquifer permeability, pollutant migration occurred slowly, resulting in relatively low benzene concentrations downstream within the heavily polluted area. Deep metagenome sequencing revealed Proteobacteria as the dominant phylum, accounting for over 63 % of total abundances. Microbial α-diversity was low in heavily polluted samples, with community compositions substantially differing from those in lightly polluted samples. dmpK encoding the phenol/toluene 2-monooxygenase was detected across all samples, while the dioxygenase bedC1 was not detected, suggesting that aerobic benzene degradation might occur through monooxygenation. Sequence assembly and binning yielded 350 high-quality metagenome-assembled genomes (MAGs), with 30 MAGs harboring functional genes associated with aerobic or anaerobic benzene degradation. About 80 % of MAGs harboring functional genes associated with anaerobic benzene degradation remained taxonomically unclassified at the genus level, suggesting that our current database coverage of anaerobic benzene-degrading microorganisms is very limited. Furthermore, two genes integral to anaerobic benzene metabolism, i.e, benzoyl-CoA reductase (bamB) and glutaryl-CoA dehydrogenase (acd), were not annotated by metagenome functional analyses but were identified within the MAGs, signifying the importance of integrating both contig-based and MAG-based approaches. Together, our efforts of functional annotation and metagenome binning generate a robust blueprint of microbial functional potentials in petrochemical-polluted groundwater, which is crucial for designing proficient bioremediation strategies.

Machine learning prediction of health risk and spatial dependence of geogenic contaminated groundwater from the Hetao Basin, China

Geogenic contaminated groundwater (GCG), characterized by elevated arsenic, fluoride, and iodine levels, present a significant challenge to public health and government management. Conventional survey-based approaches of collecting groundwater samples, conducting physicochemical tests, and performing spatial interpolation to obtain regional groundwater chemical component maps are inefficient and costly. More importantly, it does not take into account the actual hydrogeological conditions or the characteristics of pollutant transport and enrichment. To address this issue, we utilized Support Vector Machine (SVM), Random Forest (RF), Adaptive Boosting (AdaBoost), and Extreme Gradient Boosting (XGBoost) to analyze the likelihood of occurrence of arsenic, fluoride, and iodine as well as their spatial distribution in shallow groundwater from the Hetao Basin. Our study incorporated 20 indicators related to meteorology, soil physicochemical properties, and groundwater conditions, along with 1505 labeled samples consisting of groundwater arsenic, fluoride, and iodine concentrations and their corresponding coordinates. Subsequently, the study automatically analyzed the meteorological, soil physicochemical properties and groundwater conditions by constructing a machine learning model using the available data. In order to optimise and select the best prediction model, this paper presents a quantitative evaluation of the prediction performance of various machine learning models. The accuracy (AC), area under curve (AUC) and mean squared error (MSE) were calculated to predict the spatial distribution of CGC. Subsequently, the optimized model for predicting the spatial distribution of GCG was selected. The results showed that the XGBoost algorithm provided optimal predictions for groundwater with arsenic concentrations above 10 μg/L and fluoride concentrations exceeding 1.5 mg/L, whereas the RF model provided the best predictions for groundwater with arsenic concentrations surpassing 50 μg/L and iodine concentrations exceeding 100 μg/L. Subsequently, groundwater health risk zones were delineated based on an optimal prediction model, and demographic analysis was conducted in both the direct and potential groundwater risk zones. Model predictions indicated that hundreds of thousands of people in the Hetao Basin were facing a public health crisis caused by high concentrations of arsenic, fluoride and iodine in groundwater. These findings underscore the significant health challenge in the study area. Considering the agricultural development and increasing groundwater use in the area, our findings can guide local governments in managing the extent of groundwater development, establishing control zones, and enhancing protection measures for populations at risk from groundwater contamination.

Occurrence of toxic elements in river areas along drains and groundwater resources: source of contamination and associated health risk.

The objective of the current research was to examine the water quality of the River Ravi and the River Sutlej, with a specific focus on potentially toxic elements (PTEs). Additionally, we sought to monitor the sources of pollution in these rivers by gathering samples from the primary drains that carry industrial and municipal waste into these water bodies. Furthermore, we aimed to evaluate the impact of PTEs in surface water on groundwater quality by collecting groundwater samples from nearby populated areas. A total of 30 samples were collected from these three sources: rivers (6 samples), drains (9 samples), and groundwater (15 samples). The analysis revealed that the levels of PTEs in the samples from these three resources having a mean value: arsenic (As) 23.5µg/L, zinc (Zn) 2.35mg/L, manganese (Mn) 0.51mg/L, lead (Pb) 6.63µg/L, and chromium (Cr) 10.9µg/L, exceeded the recommended values set by the World Health Organization (WHO). Furthermore, PTEs including (As 84%), (Zn 65%), (Mn 69%), (Pb 53%), (Cr 53%), and (Ni 27%), samples were beyond the recommended values of WHO. The results of the Principal Component Analysis indicated that surface water and groundwater exhibited total variability of 83.87% and 85.97%, respectively. This indicates that the aquifers in the study area have been contaminated due to both natural geogenic factors and anthropogenic sources. These sources include the discharge of industrial effluents, wastewater from municipal sources, mining activities, agricultural practices, weathering of rocks, and interactions between rocks and water. Spatial distribution maps clearly illustrated the widespread mobilization of PTEs throughout the study area. Furthermore, a health risk assessment was conducted to evaluate the potential adverse health effects of PTEs through the ingestion of drinking groundwater by both children and adults. Health risk assessment result show the mean carcinogenic values for As, Cr, Pb and Ni in children are calculated to be (1.88E-04), (2.61E-04), (2.16E-02), and (5.74E-05), respectively. Similarly, the mean carcinogenic values for the above mentioned PTEs in adults were recorded to be (2.39E-05), (3.32E-05), (1.19E-03), and (7.29E-06) respectively. The total hazard index values for As, Zn, Cr, Pb, Mn, Cu, and Ni in children were observed to be (9.07E + 00), (9.95E-07), (4.59E-04), (5.75E-04), (4.72E-05), (2.78E-03), and (5.27E-05) respectively. The analysis revealed that As has an adverse effect on the population of the study area as compared to other PTEs investigated in this study.

Assessment of groundwater quality and alkaline earth metals from the Al Masaraat basin at Al Dhahirah Governorate, Sultanate of Oman

ABSTRACT Comprehending the physicochemical properties of water is vital for efficient groundwater management in the research area. Groundwater often sees an increase in chemical element concentrations as it moves underground due to water-rock interaction. Water quality is assessed by comparing various parameter levels with drinking water standards. The primary goal of this study is to assess the groundwater quality from Al Dhahirah Governorate by analysing the physicochemical characteristics (pH, EC, TDS, TH, and T) and evaluating the concentrations of alkali and alkaline earth metals. It involved collecting groundwater samples from 11 different sites in the area and using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) to analyse various elements, such as Ca, Na, Mg, and Sr. The study’s results reveal that the quality parameters of drinking water sources are within the Omani and World Health Organization (WHO) standards, except for Na, Mg, Sr, and TH level. The average concentrations of Na and Mg were 527.64 and 87.93 mg/L, respectively, while the average TH measured 658.86 mg/L, which is classified as very hard. The analysis of correlations among groundwater quality parameters indicates that physicochemical parameters influence the chemical properties of groundwater. To ensure safe drinking water, it is advisable to treat contaminated water before use and regularly monitor its quality. The findings contribute to the understanding of water quality in this region, providing valuable insights for environmental and public health considerations.

Assessment of Spatial Variability in Groundwater Quality of Kurnool Region for Irrigation Purpose and Management Options

Assessment of Spatial variability in Groundwater quality of Kurnool region for irrigation purpose and management options was conducted by collecting groundwater samples using GPS locations at various farming situations in different mandals of Kurnool district. The irrigation water quality indices were assessed to classify the ground water for its suitability based on ionic properties viz., pH, EC, Ca+2, Mg+2, Na+ and K+; CO3-2, HCO3-, Cl-and SO4-2.The pH, EC, SAR, RSC, Kellys ratio, Saturated sodium per centage and Permeability index in groundwater ranged from 6.5-8.4, 0.4-15.6 (dSm-1), 0.44-28.77 (mmol l-1)1/2, -66.8-15.4 (me l-1), 0.15-24.61, 11.04-94.89 and 17.22-111. The concentration of cations viz., Ca+2, Mg+2, Na+ and K+ varied from 0.8-24.4, 0.4-34.8, 0.5-108 and 0.003-27.6 me l-1 with mean values of 6.71, 6.19, 12.24 and 0.59 me l-1 respectively. Concentration of anions viz.,CO3-2, HCO3-, Cl-and SO4-2varied from 0-1.2, 0.4-18.2, 0.8-77.2 and 0.001-8.39 me l-1 with an average values of 0.04, 6.59, 8.78 and 1.78 me l-1 respectively. The relative abundance of ions for most of the water samples were Na+> Ca+2> Mg+2> K+ for cations and Cl->HCO3->SO4-2> CO3- for anions. Based on physico-chemical properties the groundwater is classified into good, marginally saline, saline, high SAR saline, marginally alkali, alkali, high SAR alkali for irrigation. Thematic maps representing spatial variability in groundwater quality in respect to pH, EC, SAR, RSC and irrigation water class were prepared by inverse distance weightage interpolation method using geographical information system. This will give the information of the irrigation water quality for management options in crop production.

Hydro-Geochemical Characteristics of the Shallow Alluvial Aquifer and Its Potential Artificial Recharge to Sustain the Low Flow of the Garonne River

The complex and interconnected water challenges linked to global climate change and natural and anthropogenic water resources pressure have become major challenges in the 21st century. The Garonne River and its accompanying alluvial aquifers are considered the most important source for agricultural activities in the Garonne Valley, Nouvelle-Aquitaine Region, southwest France. The water is used for irrigation in summer and to reduce frost damage in spring. The alluvial shallow aquifer is recharged by rainfall, lateral inflow from the hillside, and seepage from the riverbed during the flood periods. The aquifer maintains the flow of the river during dry periods. Moreover, the potential recharge of this aquifer is particularly sensitive to annual climatic fluctuations and consequently affects surrounding ecosystems and related socio-economic activities. The increasing impacts of climate change have increased the concern about the availability of these resources. Various adaptation strategies have been considered to mitigate and adapt to the new situation in southwest France. The artificial recharge of the alluvial aquifer is one such regional adaptation strategy to adapt to climate change. The study has two main objectives: to assess the natural and anthropogenic influence on the groundwater chemistry, and to model water infiltration, and understand the aquifer response and, consequently, the effects on river baseflow. The TAG (Technopole Agen-Garonne) project aims to increase the economic wealth of the region while respecting the region’s agricultural traditions. Runoff water from the TAG zone is collected in retention basins and is a potential source to recharge the shallow alluvial aquifer. Sampling campaigns were carried out during the summer of 2019 to collect groundwater samples from several observation wells. Groundwater levels were measured in 132 wells/boreholes to determine the groundwater level fluctuations and create piezometric maps. Piper, spatial distribution, and ionic ratio plots were used to determine the dominant hydrochemical processes and to delineate the hydrochemical facies in the study area. The groundwater chemistry is controlled by silicate weathering and anthropogenic influence. Groundwater quality appears to be affected by the river water in the wells located in the low plain area. The measurements showed that the groundwater levels in the wells located near the river increase more than 2 m after a flood event. The artificial recharge has increased the groundwater level by more than 1 m close to the infiltration basin after a rainstorm. Similarly, a three-dimensional (3D) groundwater model shows a similar magnitude aquifer response to the induced infiltration. The modeling-obtained result shows that the infiltrated water would take about 4 months to reach the Garonne River, which is an appropriate time to maintain the river’s low-flow and thermal buffering capacity, and thus the functioning of its ecosystems during dry periods.

Preliminary study of isotope characteristics of groundwater in karst hydrogeology in Pacitan Regency, East Java

The Pacitan Karst region is well known to be one of drought area in the Pacitan Regency during the dry season. Consequently, during the dry season, springs from karst system are required as a water source for the daily life. The appearance of these springs are a result and advantage of the karst terrain, which contains potential groundwater resources. The purpose of this study was to investigate the origin and characteristics of spring’s water in the Pacitan karst region based on its isotope concentrations. This research was conducted by collecting groundwater samples from springs, dug wells, bore wells, and rivers in Pacitan Regency and analyzing their 18O and 2H concentrations. Information on the source of groundwater is thought to be necessary for sustainable groundwater protection planning (conservation). According to the results of the investigation, there are four categories of isotope ratio distribution. The pattern of 18O and 2H concentrations in the samples around the Local Meteoric Water Line (LMWL) shows that groundwater originates from the same elevation of the catchment area from where rainwater falls and has the same characteristics as rainwater or meteoric water.

GROUNDWATER QUALITY INDEX, STATISTICAL CORRELATION, SEASONAL AND ANNUAL COMPARATIVE HYDROCHEMICAL ANALYSIS OF ATHGARH BASIN, INDIA: AN INTEGRATED EMPIRICAL STUDY

This study aimed to explore and understand groundwater hydrochemistry, evaluate the groundwater quality of the Athgarh basin comprehensively using Water Quality Index (WQI) and statistical correlations. Accordingly, the quality of the groundwater was assessed for drinking purposes. Moreover, seasonal variation and annual variation of water quality have been monitored for two consecutive years after systematic collection of groundwater samples and their methodical physico-chemical analysis. For calculating the WQI, 13 parameters (viz., pH, EC, total dissolved solids, total hardness, calcium, sodium, potassium, magnesium, bicarbonate, chloride, fluoride, sulphate and nitrate) have been considered. The analyzed value is compared with the prescribed limits of WHO for drinking suitability. Hydrological facies were evaluated through Piper’s trilinear diagram and Chadha’s diagram using cation and anion values. A systematic statistical correlation study deciphers the significant linear relationship among different pairs of water quality parameters.

Public Perception of Drinking Water Quality in Bekasi City, Indonesia

The study of public perceptions regarding drinking water quality is essential for understanding how people choose and manage safe drinking water for consumption. Understanding public perceptions and the actual drinking water quality can also help to ensure the right policies to improve water quality and minimize possible risks. This study aims to analyze the association between public perceptions and the actual drinking water quality in Bekasi City, Indonesia. This study was conducted in three urban villages (Jatiluhur, Jatirangga, Sumur Batu) in Bekasi City, Indonesia, in the dry season (September-October 2021). The survey was conducted by distributing questionnaires and collecting groundwater samples at point-of-use for drinking (n=51 households). Drinking water samples were analyzed for pH, TDS, Total Coliform, and Escherichia coli. Among 51 households, 100% of respondents answered that the drinking water was safe and had good taste, 5% answered that there was a problem with the appearance (color/particles), and 2% of respondents answered that there was an odor in the drinking water consumed. Logistic regression was performed, and the result shows that measured drinking water quality does not significantly contribute to public perception of drinking water quality

Mapping and monitoring seasonal and tidal effects on the salt-freshwater interface using electrical resistivity tomography techniques

Understanding the salt-freshwater interface (SFI) migration in the coastal aquifers is of great significance for the study of seawater intrusion (SI). The electrical resistivity tomography (ERT) method in combination with the physicochemical characteristics of groundwater were used to map and capture the SFI change in the dry and wet seasons. And the west coast of Longkou city, Shandong province, China was taken as an example. And the physicochemical characteristics of groundwater mainly analyzed Cl− concentrations, TDS and EC values. Four monitoring locations, 1200 (W4), 2100m (W3), 2600m (W2) and 3200m (W1) away from and perpendicular to the west coastline, were used to collect groundwater samples and conduct continuous ERT surveys in dry and wet seasons of 2020. The SFI was captured with continuous 24-h tidal cycle and 15-day spring-neap tidal cycle. Analysis of the groundwater samples showed that the SFI was approximately located between the W2 and W3, and the groundwater levels for the four monitoring locations were higher in the wet season than that in the dry season. The ERT results were strongly supported via the Cl− concentrations, TDS, EC values and the groundwater level in the dry and wet seasons. And the ERT results indicated that the SFIs were located about 2562m and 2558m away from the coastline in the dry and wet seasons, which means the most inland part of the interface. Due to the delay effects of the 24-h high and low tidal cycle and different tidal amplitudes in 15-day spring-neap tidal cycle, the SFI retreated to seaward in high tide and spring tide, while it intruded to inland in the low tide and neap tide. Continuous monitoring surveys using the ERT had been proven to be suitable to map and capture the SFI change in the west coast of Longkou city in this study. This study can qualitatively and semi-quantitatively evaluate the location of SFI in coastal area, and the determination of the possible farthest SFI location on neap tide and low tide is helpful for the groundwater resources management and SI prevention.

An integrated study of the spatiotemporal character, pollution assessment, and migration mechanism of heavy metals in the groundwater of a subtropical mangrove wetland

Mangrove wetlands connecting the land and sea are critical and dynamic ecosystems which act as biogeochemical reactors that influence the concentrations and distributions of heavy metals in the groundwater and adjacent seawater. In this paper, a subtropical mangrove wetland in China was selected to investigate the spatiotemporal patterns of groundwater heavy metals and the driving mechanism along an intertidal transect with distinct undulated topography and vegetation zonation. Along the transect, five groundwater observation wells (W1-5) were set to collect groundwater samples at three different sediment depths (0.5, 1.2, and 2.0 m) and the advective flux between groundwater and surface water were calculated during four seasonal sampling campaigns from 2019 to 2020. The results showed that the seaward W1-3 acted as the groundwater discharge area while the landward W4-5 served as the surface water recharge area. The results of single-factor contamination index showed that a potential pollution risk of Hg existed at the study sites. The distribution of other heavy metals in the mangrove groundwater exhibited a seasonal variability along the transect during the sampling campaigns. For example, the relative high concentrations of Fe, Pb, Cu, Cr, and Zn focused in the landward zones in the dry seasons (autumn and winter 2019), whereas they changed to the seaward zones in the wet seasons (summer and autumn 2020). Moreover, the intertidal aquifer can act as a sink to enrich heavy metals in winter 2019 and autumn 2020 but become a source to discharge heavy metals to the sea in summer 2020. The above migration patterns of heavy metals were ascribed to the multiple complex factors including the seawater-groundwater interactions, vegetation zonation, biogeochemical reactions, and anthropogenic activities. This study contributed to the better understanding of heavy metal behaviors in mangrove groundwater so as to improve the sustainable management of mangrove wetlands under the pressure of anthropogenic activities and climate change.

Evaluation of Impact of Soil Properties on Strength of Flood Levees in Indus River Basin of Pakistan

Flood bunds are earthen embankments constructed along rivers to control the floods. Historically speaking, floods in Indus River Basin (IRB) in Pakistan have been posing serious threats and damages to infrastructure and human lives. A long infrastructure of flood bunds (about 6807km) exists parallel to the main river to agricultural crops, human settlements, livestock, industries, etc. from the hydro-disasters arising from the floods in the country. Punjab Province has been severely hit by heavy floods causing severe loss to human lives, infrastructure, crops, livestock, etc. A study was carried out to evaluate the “health” of flood bunds by investigating their geotechnical, geometrical, geochemical, and hydraulic properties to ascertain strength against breaching during floods. A length of about 731 km of river Chenab in Punjab Province of Pakistan was selected to investigate the vulnerability of flood embankments at 78 sites of 38 flood bunds which were found critical after the 2014 flood in Pakistan. Different field activities including density test, measurement of geometrical parameters, collection of undisturbed/disturbed soil samples, physical inspections, and collection of ground-water samples from bore holes were performed. Laboratory tests including soil texture, Atterberg’s limits, compaction, unconfined compressive strength, permeability, direct shear, etc. were performed in laboratories of Irrigation Research Institute, Lahore, Pakistan. An Index called river embankment breaching vulnerability index (REBVI) has been prescribed and calculated to evaluate the strength of the flood embankments against breaching. Cluster analysis has been carried out for different indicators keeping in view the value of REBVI. On the basis of REBVI and Cluster analysis, it was concluded that 11 out of 78 sites are showing high strength against the breaching action, while 35 sites indicated low potential against the breaching action. In other words, it has been found that the consistency of the embankment is very high for 11 sites and high for 35 flood bund sites. The consistency of the embankments is medium, low, and very low at the remaining 16, 12, and 4 flood bund sites due to moderate vulnerability, high probability of embankment breaching, and very high vulnerability respectively.

Groundwater quality assessment and its insinuations in some parts of Aheri taluka dist. - Gadchiroli, Maharashtra

Aheri tehsil of Gadchiroli district in the Indian state of Maharashtra is located on the bank of the Pranhita River, a side stream of the Godavari River. In the present study, total five villages from Aheri taluka were selected to collect groundwater samples. A total number of 25 samples were collected, where five samples represent each village. This study is concerned with physicochemical parameters mainly electrical conductivity, total dissolved solids, temperature, chloride, fluoride, total hardness, pH, nitrate, alkalinity, iron and turbidity to analyse groundwater quality. Out of 25 samples, eight samples of water were detected to be unfit for consumption. Hence, some remedial measures are suggestible. The study revealed the associations among all physicochemical parameters by correlation coefficient analysis.

Monitoring the seasonal variation of groundwaterchemistry and quality assessment for agricultural and industrial purpose of Athgarh basin, India

The groundwater chemistry of a region is sensitive to climate change and to change of agricultural practice of the surrounding region. The water quality is also largely governed by the litho hydrological character of the region. Hence monitoring the hydrochemistry of the groundwater with respect to climate change is vital for detecting its suitability for irrigation of cropland and industrial use. The present study area Athgarh basin, belongs to upper Gondwana has a varied lithology. The regional scale data can be statistically related to climate change. Moreover, seasonal variation of water quality has been monitored after systematic collection of groundwater samples and their methodical physicochemical analysis. 75 water samples were collected during pre-monsoon, monsoon and post-monsoon period of 2015-2016. The quality assessment is made through the estimation of physicochemical parameters, cations and anions. Based on these analyses, the irrigational parameters like salinity hazard, sodium absorption ratio (SAR), sodium%, residual sodium carbonate (RSC), potential soil salinity (PS), magnesium ratio (MR), corrosivity ratio (CR) and permeability index (PI) were calculated to determine the suitability of groundwater for irrigational and industrial purpose. The groundwater falling under (Doneen’s) class-II is almost good for irrigation purpose whereas groundwater falling under class-III indicates poor water quality. The groundwater samples are excellent to good as per Wilcox diagram. From Gibb’s diagrams, it can be established that the groundwater of the study area is mainly dominated by the lithology of aquifer of the concerned region.Various classifications show that present status of groundwater is suitable for irrigation purpose, except few locations, with a caution that it may deteriorate in near future

GIS-based approach qualitative features of sub-surface water from coastal district in Andhra Pradesh

Quality of water, along Mandal headquarters of a coastal district of Andhra Pradesh, India, was assessed prior to and past rainfall season to determine water's acceptability for consumption using water quality index (WQI). The present work involved collecting groundwater samples from Mandal headquarters' locations present in the entire district. All the samples were analysed in a comprehensive way for ten physicochemical parameters, including pH, magnesium, calcium, chloride, sulphate, nitrates, total dissolved solids, fluoride, potassium, and sodium. The geographical information system was used for mapping sampling sites. The coordinates of sample collection areas were recorded employing GPS. Correlation matrices for cation–anion were illustrated and from the qualitative results of the samples. Results indicate that WQI prior and past-rainfall seasons ranged from 37.53 to 312.46; 42.04 to 211.89 in 2016, while for 2017, these were in the range of 25.01 to 137.06; 30.06 to 228.83. The present study's WQI values indicate that the water samples possess poor quality, and no fluoride contaminations were observed. The analysis suggests appropriate treatment of sub-surface water from the study site before consumption.

Evaluation of the Performances of a Monolayer Cover with an Elevated Water Table Used for the Reclamation of the Abandoned Aldermac Mine Site (Québec, Canada)

Until 2008, the Aldermac mine was considered one of the most problematic abandoned mines sites in Québec due to the high production of acid mine drainage caused by mine tailings spread over a large area. The site was reclaimed between 2008 and 2009 to reduce the ecological footprint and to minimize any further tailings oxidation (production of acid mine drainage). For this purpose, a monolayer cover with an elevated water table was used as an oxygen barrier on the north zone of the site. To assess the performance of the monolayer with an elevated water table cover, a network of observation wells was set up to monitor the water table level and collect groundwater samples for the analysis of physical and chemical parameters. Results of water table level measurements show that the cover successfully maintains the tailings within the water table at all times, thus preventing further tailings oxidation. Hydrogeochemical results, interpreted with principal component analysis, show that the quality of water is improving, thus indicating that reclamation is helping to reduce groundwater contamination at the site.

Influence of groundwater level fluctuation on meliorated salontz in the northern forest-steppe of the Baraba lowland

The purpose of the study: to determine groundwater level and chemistry and their influence on soil properties. Location and time of the study. Northern forest-steppe of the Baraba lowland (Chulymsky and Chanovsky districts of the Novosibirsk region, Russia), 2011–2021. Methods. Determination of the groundwater level and subsequent collecting groundwater samples from the temporary wells in the experimental areas (with chemical melioration by applying gypsum and agrobiological melioration by destroying the solonetz horizon and sawing salt-resistant crops). Under laboratory conditions, soil and groundwater chemical properties and the cation-anion composition of the water extract of soils were measured. Main results. Changes in the standing level of soils and their mineralization were revealed. The rise in the groundwater level resulted in the accumulation of easily soluble salts the soil profile, the saturation of the soil-absorbing complex with exchangeable sodium, and the restoration of the solonetzic horizon. In medium-deep and shallow solonetzes, reclaimed by the agrobiological method, the groundwater level was located at 240-250 cm in 2021, and salinization occurred only in the lower part of the profile (35-100 cm), while in the control variant, salinization occurred along the entire 1m profile. Conclusion. In most of the Baraba Lowland, the capillary fringe of groundwater is constantly or periodically present in a soil profile. Under conditions of increased moisture in the territory, the development of degradation processes, such as soil secondary salinization and solonetzization, is diagnosed. In chemically reclaimed crusty solonetzes, with periodical groundwater rise to the 50 cm depth, the ameliorative effect had been maintained for more than 30 years, after which there took place a gradual secondary salinization of the soil profile and the accumulation of exchangeable sodium in the soil absorbing complex. Over the last decade both meliorated areas saw the groundwater table rise, bringing soil secondary salinization and solonetzization. Chemical melioration proved its efficacy in not only improving soil properties, but in sustaining it under soil secondary salinization by groundwater. Agrobiological approach to solonetz melioration can also be considered perspective for slowing soil quality deterioration and sustaining soil fertility.

Assessment of Groundwater Quality in Karimunjawa Island, Central Java - Indonesia

As a small island and tourist destination, Karimunjawa island needs freshwater to support the tourist activity, particularly to supply drinking water. Unfortunately, freshwater on a small island is obtained from groundwater which is very limited and vulnerable to climate change and anthropogenic activities. Therefore, a groundwater quality assessment in Karimunjawa island is necessary to be conducted to provide an up to date information on the groundwater. Furthermore, assessment of groundwater feasibility for drinking, and the pollutant source determination is important to be conducted. The groundwater quality assessment method was conducted in the Karimunjawa sub-district capital by collecting groundwater samples from 12 dug wells, and two samples from the swamp area to find out its impact on the adjacent groundwater. Afterward, all water samples were analyzed in the Water Quality Laboratory of Bandung Institute of Technology to obtain the value of Nutrient ( NO3-, NO2-, NH3-N); Heavy Metals (Cu, Fe, and Pb); and Salt (TDS, Cl-, Na+). Then, these obtained parameters were compared with the quality standard of the minister of health regulation of the Republic of Indonesia about water quality standards for drinking water. The result shows that generally nutrient contaminant in the groundwater is low, but some groundwater in residences area was contaminated by ammonia with the range value is 1,706 – 9,564 mg/l. Wastewater from residences that seepage into the groundwater is suspected as the source of the ammonia contamination. The heavy metal in the groundwater was undetected, but almost all samples were contaminated by salt which is indicated by a high value of TDS (500-5,580 mg/l). These salt contaminations are caused by seawater intrusion. Therefore, the groundwater in the Karimunjawa sub-district capital experienced quality degradation and it is not feasible to be consumed as drinking water. Good groundwater management, good waste management, and freshwater reservoir construction is expected to improve groundwater quality and freshwater supply in Karimunjawa Island.

Evaluation of Groundwater Quality for Heavy Metals by Using Chemical Indices Approach in Karachi, Pakistan

Freshwater consumption has been increased because of population growth and economic development. At the same time, depletion and contamination of groundwater is subject of great concern. Karachi is the industrial hub and serves as the economic backbone of Pakistan. The research aims to investigate the heavy metal pollution in the groundwater of Korangi Industrial Area, one of the largest industrial estates in Karachi. Eighteen representative locations were selected to collect groundwater samples and study the concentrations of heavy metals Cr, Fe, Ni, Cu, Zn, and Pb. Pollution load index, Nemerow's pollution index, and geo accumulation index approaches were used to interpret the basic data. The average concentrations of the measured heavy metals were 354.67 µg.L-1 , 694.33 µg.L-1 , 39.2 µg.L-1 , 12.89 µg.L-1 , 9.5 µg.L-1 , and 6.17 µg.L-1 for Fe, Zn, Cu, Pb, Cr, and Ni, respectively. The results showed that groundwater quality in the study area is poor and mainly contaminated by Pb and Fe.

Monitoring of Groundwater Quality With Cokriging of Geochemical and Geoelectrical Measurements

Abstract The study presents the possibility of using geostatistical methods for monitoring groundwater quality. Poland is one of the largest copper producers in the world. However, the extraction and production of copper requires constant care for the natural environment. Reservoir Żelazny Most which is situated in South – Western Poland was designed to store flotation tailings out of nearby copper mines. It is one of the biggest industrial dumps in the world. The reservoir stores huge amounts of tailings and industrial water. Water migrating from dump to groundwater could be a potential source of contamination with chlorides, sulphates, heavy metals, and other hazardous substances used in ore separation process in the copper mining industry, like detergent and phenols. Monitoring system around Żelazny Most dump, which was designed to track harmful substances concentrations in groundwater, contains measuring wells and piezometers. They are used to collect groundwater samples for chemical analyses. The idea of the study was to integrate information provided by chemical analyses and geoelectrical measurements by cokriging method, utilizing correlation between electrical resistance of the soil solution and total dissolved solids concentration in groundwater. This enabled to obtain spatial distribution of total dissolved solids concentrations in groundwater at the part of eastern foreground of Żelazny Most dump.