Search

Arizona has a long history of groundwater use, and there is concern about long term groundwater sustainability across the state. We explore groundwater trends across Arizona and how they vary with respect to: (1) whether groundwater pumping is regulated, and (2) relative access to local or imported surface water. Well observations from the Arizona Department of Water Resources are used to quantify water table depth trends and groundwater drilling patterns. There are more than 85,000 groundwater wells in Arizona, and new wells are routinely being drilled. The number of new shallow wells (<200 ft) has decreased over time in all parts of the state. But midrange (200–500 ft) to deep (>500 ft) wells have increased in the past 10 years in regulated and groundwater dominated areas. Most wells are small with low pumping capacities that fall below the regulatory limit; however, there are still large wells being drilled in unregulated areas. Results show statewide decreasing water storage and groundwater levels. Groundwater declines are less severe in the parts of the state that have groundwater regulation. However, looking closer at this trend, groundwater recovery is strongest in areas receiving imported Colorado River water which also implement managed groundwater recharge with the imported water. Our findings indicate that groundwater recovery is very localized and driven more by managed recharge from surface water as opposed to decreased groundwater pumping. [ABSTRACT FROM AUTHOR]

Greensand filtration is a common treatment option for manganese, sulfide, and iron removal; poor maintenance, however, can compromise effectiveness and even lead to increased post-treatment Mn concentrations. A private drinking-water well in exceedance of Health Canada's maximum allowable concentration for Mn was sampled over a 1-year period to assess Mn removal via greensand filtration. Mn concentrations post-treatment were on average twofold higher than raw well water prior to media change. Reducing conditions, evidenced by negative oxidation–reduction potential (ORP) of the effluent, were central to generating soluble Mn(II). Monitoring revealed that water usage patterns caused variability in post-treatment Mn, with peak concentrations (>3.5× higher than influent water) observed after a 7-day idle period. As inadequate oxidant addition can lead to reducing conditions, monitoring ORP may facilitate proxy surveillance for Mn release. Findings underscore the importance of human factors (e.g., aesthetic concerns, barriers to maintenance, perceived risk) when evaluating overall benefits and drawbacks of treatment systems. [ABSTRACT FROM AUTHOR]

The performance of gravity recovery and climate experiment (GRACE) and GRACE-Follow On (GRACE-FO) satellites in estimating groundwater level (GWL) changes on a local scale is a challenging issue. Then, this study aims to investigate the performance of GRACE and GRACE-FO in monitoring GWL changes on a local scale compared to observations at groundwater wells and the results of groundwater modeling. The study utilized hundreds of groundwater observational data points and 180 satellite data from 2002 to 2020 in five Iranian provinces. The data from satellites GRACE and GRACE-FO were modified by subtracting hydrological parameters outputs of the global land data assimilation system (GLDAS) from the satellites' estimations. The significant trends in GWL changes were studied by Sen's slope and Mann–Kendall, which represented a significant declining trend in GWL in all studied provinces. Applying 1–2 month time lags to the observational data improved the correlation coefficients between satellite estimations and the observations at groundwater wells. The best correlation coefficients between observational GWL changes and GRACE estimations in Fars, Khorasan Razavi, Sistan and Baluchistan, East Azerbaijan, and Golestan provinces were calculated as 0.53, 0.42, 0.4, 0.51, and 0.36. Those values for GRACE-FO were calculated as 0.95, 0.67, 0.72, 0.78, and 0.3, respectively, which proved the better performance of GRACE-FO compared to GRACE. Meanwhile, the GWL changes estimated from GRACE-FO were compared to the results of groundwater modeling, which was performed by using MODFLOW via the GMS10.4 interface in Azarshahr aquifer located at East Azarbaijan revealed a satisfactory agreement. [ABSTRACT FROM AUTHOR]

The study was conducted in 2022 in shallow wells and deep boreholes owned by residents, to investigate the water quality status in the emerging developing area of Dodoma Urban municipality in central Tanzania. Eighteen boreholes and five shallow wells were assessed using the water quality index (WQI), the inverse distance weighting (IDW) method under the ArcGIS environment, and the Euclidean similarity index. The WQI classified the water samples into a good category class with a covered area of 42.5% and an excellent category class with a covered area of 57.5%, indicating that most of the deep boreholes and shallow wells were suitable for residential purposes. The IDW revealed the spatial distribution of the physico-chemical parameters and WQI, indicating that water quality improved from west to east within the study area. Yet, the Euclidean similarity index was dominated by nitrates, pH and heavy metals, with the highest correlation coefficients. Despite the WQI being above the average class, water treatment technologies should be practiced to lower those values of physico-chemical parameters existing above the threshold limits. [ABSTRACT FROM AUTHOR]

Mountains have a critical role in freshwater supply for downstream populations. As the climate changes, groundwater stored in mountains may help buffer the impacts to declining water resources caused by decreased snowpack and glacier recession. However, given the scarcity of groundwater observation wells in mountain regions, it remains unclear how mountain groundwater is being impacted by climate change across ecoregions. This study quantifies temporal trends in mountain groundwater levels and explores how various climatic, physiographic and anthropogenic factors affect these trends. We compiled data from 171 public groundwater observation wells within mountain regions across Canada and the United States, for which at least 20 years of monthly data is available. The Mann‐Kendall test for monotonic trend revealed that 54% of these wells have statistically significant temporal trends (p < 0.05) over the period of record, of which 69% were negative and therefore indicating overall declining groundwater storage. Wells in the western mountain ranges showed stronger trends (both positive and negative) than the eastern mountain ranges, and higher elevation wells showed fewer negative trends than the low elevation (<400 m asl) wells (p < 0.05). Correlation, Kruskal‐Wallis tests, stepwise multiple linear regression and random forest regression were used to identify factors controlling groundwater trends. Statistical analysis revealed that lower‐elevation mountain regions with higher average annual temperatures and lower average annual precipitation have the greatest declines in groundwater storage under climate change. Trends in temperature and precipitation, and ecoregion were also important predictors on groundwater level trends, highlighting geographic differences in how mountain wells are responding to climate change. Furthermore, sedimentary bedrock aquifers showed markedly more negative trends than crystalline bedrock aquifers. The findings demonstrate that the impact of climate change on mountain water resources extends to the subsurface, with important implications for global water resources. [ABSTRACT FROM AUTHOR]

Groundwater is a valuable and universally distributed resource on Earth. Understanding the spatial and temporal dynamics of groundwater is of utmost importance for effective management. Normally, groundwater levels are recorded at arbitrary points, but groundwater modeling requires interpolating the measured values at specific grid nodes. This study aims to dentify and evaluate the geographical variations of groundwater levels in Türkiye using three geostatistical interpolation techniques. Data from 355 groundwater wells from 1970 to 2019 were used for this purpose. In addition, an investigation of changes in annual average temperature and precipitation was conducted for two different time periods: 1985–2000 and 2001–2016. The results show an increase in the annual average temperature in Türkiye by 0.82 °C during the reference period (1985–2000). Despite regional differences in the precipitation regime, the average annual precipitation in Türkiye has not changed significantly overall. Especially in the Meriç-Ergene, Konya Closed (Konya Kapalı), and Euphrates-Tigris basins, a significant decrease in groundwater levels was observed, even though this decrease is less than 100 m in some wells. After a comprehensive analysis of all these data, possible explanations for the changes in groundwater levels were considered. [ABSTRACT FROM AUTHOR]

Both rural and urban parts of the world, groundwater is an essential reservoir of freshwater Due to drainage and consequently rising pollution are a serious risk to the planet's ability to provide safe water supplies. For both health and medical practitioners, water that has been polluted by heavy metals-specifically, the elements cadmium, arsenic, nickel, copper, lead, manganese, and mercury-is developing a serious health risk. The main objective of this research was to evaluate the amount of heavy metals in the groundwater of the Kanker district in the Indian state of Chhattisgarh's Northern Bastar region. In the premonsoon period in May-June of the study region, samples were taken using manually operated pumps, tube wells, and dug wells at 15 distinct locations. The amount of each element, including Pb, Mn, Zn, and Fe, was measured with an atomic absorption spectrophotometer (AAS) and the appropriate digestion technique. The water samples had mean concentrations of metallic elements in an order: Fe>Pb>Zn>Mn. The outcome of this study was that the extent of accumulation of heavy metals in water samples is significantly greater than the recommended limitation, indicating that residents and the environment around them may be at risk. [ABSTRACT FROM AUTHOR]

Groundwater is the main source of drinking water for the rural population in the chronic kidney disease of unknown etiology (CKDu) zone of the North Central Province (NCP) in Sri Lanka. In this study, a total of 334 groundwater samples (311 dug wells, 21 tube wells and 2 springs) during the wet season from two aquifers in the NCP were collected, and investigated their chemical characteristics and evaluate their water quality, including groundwater chemistry, main ion sources, the corrosion and scaling potential of groundwater. The results showed that the two hydrochemical types of groundwater in the NCP were mainly of the Ca-HCO 3 , Na·Ca-HCO 3 types, with the main HCO 3 −, Na+ and Ca2+ ions in both types of groundwater originating from silicate and evaporite salt dissolution and influenced by alternating cation adsorption, while the presence of NO 3 − was mainly anthropogenic. Evaluation of water stability using namely Langelier saturation index (LSI), Ryznar stability index (RSI), Puckorius scaling index (PSI) and Larson-Skold index (LS), indicated that most groundwater presents corrosion potential and has corrosion behavior tendency of metals to some degrees. The water quality of Polonnaruwa was better than that of Anuradhapura in the NCP, and when the groundwater was worse than the "good" grade, which must be properly treated before it is used as drinking water. [ABSTRACT FROM AUTHOR]

Underground water were abstracted from HDWs to determine their suitability for drinking. Physical, chemical and bacteriological parameters were carried out following standard guidelines. Total coliform count was done using the membrane filtration method. Heavy metal was determined using an Atomic Absorption Spectrophotometer (AAS BULK SCIENTIFIC MODEL 210 VGP). Samples were subjected to statistical and multivariate analysis. Results of physicochemical parameters show that they were all within the WHO standard for drinking. Cation concentrations follow the order: Na+ > Ca2+ > Mg2+ > K+, while anions are: HCO3− > SO42-> Cl−> NO3− > PO42-. As, Cd and Pb were not detected in the sampled water, but other heavy metals Cr, Cu, Fe, Mn and Zn were detected. They were, however, within the WHO's recommended range. Based on E. coli analysed, all of the water samples were free from faecal contamination since none was discovered in the water samples. Based on the water quality index, only sample G hand-dug well is of poor quality (though it could be treated) for human consumption; all other samples are good for human consumption. Deductions from Pipers' and the Durov diagram, as well as principal component analysis, revealed that there was little geological and human activity within the hand-dug wells. Based on the physicochemical, microbiological, heavy metal and water quality indexes, this study indicates that all of the water samples examined are free of pollution, but that continual monitoring of the hand-dug wells should be prioritised. [ABSTRACT FROM AUTHOR]

A static batch test was used to determine the optimal ratio of Fenton’s reagent for removing benzene and toluene from contaminated subsurface at a site, followed by a two-dimensional simulation tank experiment, where benzene and toluene were distributed throughout the tank, and then in the groundwater circulation wells. The Fenton’s reagent of 0.05 L of 3% H2O2 and 6.12 g of FeSO4·7H2O was added in the ratio of 0.05 L of 3% H2O2 and 6.12 g of FeSO4·7H2O, and the reactive circulation wells were initiated at an aeration rate of 15 L/min.The results show:The groundwater circulation close to the circulation wells is highly disturbed, the mass transfer between the gas and water phases is strong, benzene and toluene are preferentially removed, and a remediation area centered on the circulation wells is gradually formed; after 12 h of cumulative aeration, contaminants within a 50 cm radius from the circulation well were below the detection limit. Residual benzene and toluene were concentrated in the area on both sides of the simulation tank, away from the circulation well. The contaminant removal efficiency within the 50-cm radius of influence of the circulation wells was high, and the enhanced remediation of benzene- and toluene-contaminated groundwater by reactive circulation wells using Fenton’s reagent as the remediation agent was more effective. [ABSTRACT FROM AUTHOR]

Copyright of Water & Landscape (WAL) / Agua & Territorio (AYT) is the property of Editorial de la Universidad de Jaen and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent times, drilling groundwater wells for irrigation, domestic, and industrial uses is increasing at a high rate in Saudi Arabia, meaning that groundwater is becoming a primary water resource. In the study region, over-exploitation and unsustainable performance severely deteriorate groundwater. Therefore, it is important to monitor the groundwater levels and quality as well as to detect the hydraulic parameters in order to plan and maintain groundwater sustainability. Knowledge of aquifer hydraulic parameters and groundwater quality is essential for the productivity planning of an aquifer. Therefore, this study carried out a thorough analysis on measured depth to groundwater data (2017 and 2022), borehole pumping test records, and chemical analysis of the collected water samples, especially in the presence of overexploitation and scarcity of recharge scale. To accomplish this aim, measurements of 113 groundwater wells (including 103 water samples) and analysis of 29 pumping tests between step and long-duration tests were made of all aquifer characteristics. These parameters consist of well loss, formation loss, well efficiency, specific capacity, transmissivity, hydraulic conductivity, resulted drawdown, and physiochemical parameters. Thematic maps were generated for all parameters using the geographic information system (GIS) and diagrams to strategize the groundwater productivity in Al-Madinah Al-Munawarah Province. The estimated hydraulic parameters are highly variable. Four distinct portions were identified for aquifer potentiality based on these varying ranges. Both the north and east of the region are good for groundwater productivity due to good aquifer materials, whereas the southwestern and western portions have relatively poor values. The analyzed groundwater was categorized as fresh to slightly salty water, with two primary chemical types identified showing a prevalence of mixed NaCl and Ca-Mg-SO4/Cl water. Finally, groundwater productivity assessment predicts that the aquifers can support the Al-Madinah Al-Munawarah Province demand for several years if certain well distributions are adopted and for a few hours/day of pumping rate. The maps that have been created can be examined to aid in making decisions related to hydrology. [ABSTRACT FROM AUTHOR]

According to the Intergovernmental Panel on Climate Change (IPCC) of the United Nations (UN), rise in atmospheric concentration of carbon dioxide (CO 2 ) due to anthropogenic factors is considered as the primary driver for global climate change. With almost every major corporation around the world working towards their "net-zero goals", it is becoming increasingly important to have more technologies that can help reduce carbon footprint. Achieving sequestration of CO 2 in the subsurface through Carbon Capture Utilization and Storage (CCUS) technologies like CO 2 -Enhanced Oil Recovery, CO 2 -Enhanced Geothermal Systems, CO 2 -Enhanced Coal Bed Methane, etc. is well accepted. We introduce yet another attractive CCUS opportunity through well rehabilitation. Aqua Freed® and Aqua Gard® are well-known well rehabilitation and preventive well maintenance technologies that utilize (inject underground) liquid CO 2 for the purpose. The goal of this study was to quantify the storage capacity of Aqua Freed® and Aqua Gard®, and establish their CCUS credentials. Depending on the well being serviced, these technologies can inject up to 40 US tons of CO 2 per well. Based on field data collection and statistical modeling, we estimated that 82–96% (median 90%) of the injected CO 2 remains in the subsurface post injection. Overall, our results and analysis of the US market suggest that using CO 2 for well rehabilitation and maintenance has a storage potential of several megatonnes of CO 2 annually in the US alone. [ABSTRACT FROM AUTHOR]

The aim of this paper is to assess the correlation of groundwater level changes (or groundwater level anomalies (GWLA)) obtained from direct measurements in wells with groundwater storage anomalies (GWSA) calculated using Gravity Recovery and Climate Experiment (GRACE) products and Global Land Data Assimilation Systems (GLDAS) models across different climate zones, from temperate Poland to Arctic Sweden. We recognize that such validation studies are needed to increase the understanding of the spatio-temporal limits of remote sensing model applicability, not least in data-scarce sub-Arctic and Arctic environments where processes are complex due to the impacts of snow and (perma) frost. Results for temperate climates in Poland and southern Sweden show that, whereas one of the models (JPL_NOAH_GWSA) failed due to water balance term overestimation, the other model (CSR_CLM_GWSA) produced excellent results of monthly groundwater dynamics when compared with the observations in 387 groundwater wells in the region during 2003–2022 (cross-correlation coefficient of 0.8). However, for the sub-Arctic and Arctic northern Sweden, the model suitable for other regions failed to reproduce typical northern groundwater regimes (of the region's 85 wells), where winter levels decrease due to the blocking effect of ground frost on groundwater recharge. This suggests, more generally, that conventional methods for deriving GWSA and its seasonality ceases to be reliable in the presence of considerably infiltration-blocking ground frost and permafrost (whereas snow storage modules perform well), which hence need further attention in future research. Regarding long-term groundwater level trends, remote sensing results for southern Sweden show increasing levels, in contrast with observed unchanged to decreasing (~10 mm/a) levels, which may not necessarily be due to errors in the remote sensing model but may rather emphasize impacts of anthropogenic pressures, which are higher near the observation wells that are often located in eskers used for water supply. For sub-Arctic and Arctic Sweden, the (relatively uncertain) trend of the remote sensing results nevertheless agrees reasonably well with the groundwater well observations that show increasing groundwater levels of up to ~14 mm/a, which, e.g., is consistent with reported trends of large Siberian river basins. [ABSTRACT FROM AUTHOR]

Despite the negative effects that the use of pesticides (such as herbicides and insecticides) have on human health and water resources, a significant portion of the world's agricultural production depends on them. The purpose of this study was to determine selected residual concentrations of pesticides (diazinon, ethion, malathion, alachlor, methyl-parathion, trifluralin, atrazine, chlorpyrifos, and azinphosmethyl) in samples from Shiraz potable water sources. For this purpose, water treatment plant, groundwater wells, treated surface water, and a mixture of groundwater and treated surface water were taken. In addition, statistical and risk analyses (carcinogenic and non-carcinogenic) were used. According to the results, chlorpyrifos with 84.4% had the highest removal efficiency and methyl-parathion with 10% had the lowest removal rate in the Shiraz water treatment plant process. The highest mean concentration was related to azinphos- methyl (1.5 μg/L) and chlorpyrifos (0.59 μg/L) in the groundwater samples. All measured compounds in water source samples were below standard levels, except for chlorpyrifos and azinphos-methyl, which were reported in groundwater above the limit recommended by the Environmental Protection Agency (EPA). The results showed that while the selected pesticides measured had a low non-carcinogenic risk for both adults and children, malathion and trifluralin posed a high carcinogenic risk for adults. [ABSTRACT FROM AUTHOR]

The cumulative and bidirectional groundwater‐surface water (GW‐SW) interaction along a stream is defined as hydrological turnover (HT) influencing solute transport and source water composition. However, HT proves to be highly variable, producing spatial exchange patterns influenced by local groundwater, geology, and topography. Hence, identifying factors controlling HT poses a challenge. We studied spatiotemporal HT variability at two reaches of a third order tributary of the river Mosel, Germany. Additionally, we sampled for silica concentrations in the stream and in the near‐stream groundwater. Thus, creating snapshots of the boundary layer between ground‐ and surface water where HT occurs, driven by mixing processes in the hyporheic zone. We utilize an enhanced hydrograph separation method, unveiling reach differences in storage drainage based on aquifer dimension and connectivity. The data shows a site‐specific negative correlation of HT with discharge, while hydraulic gradients correlate with HT only at the reach with faster catchment drainage behavior. Examining silica concentrations between stream and wells shows that silica variation increases significantly with the decrease of HT under low flow conditions at the slower draining reach. At the fast draining reach this relationship is seasonal. In Summary, our results show that stream discharge shapes the influence of HT on solute transport. Yet, reach drainage behavior shapes seasonal states of groundwater storages and can be an additional control of HT. Hence, concentration change of pollutants could be masked by HT. Thus, our findings contribute to the understanding of HT variability along streams and its ability of influencing physico‐chemical stream water composition. Plain Language Summary: The sum of simultaneous gains and losses of water along a stream or a river is called hydrological turnover (HT). This constant exchange of water strongly varies over time and space. We investigated that exchange at two different reaches of the Olewigerbach catchment in Trier, Germany. We utilized near stream groundwater wells to characterize the boundary layer between stream and groundwater. At both reaches we measured HT, the variation of silica between stream and groundwater wells, local differences of stream and groundwater levels as well as stream discharge. The reach hydrographs were used to derive information about catchment storage drainage at each of the reaches. Our results show different correlations of HT with discharge between the two sites. Water level differences between surface water and groundwater correlate with HT only at the upstream reach where catchment storages drain faster. The silica concentrations of stream and wells show that silica variation increases significantly with the decrease of HT in summer at the downstream reach where catchment storages are drained slower. At the faster draining reach this relationship is present during winter, only. Silica as a geogenic marker is useful to differentiate between streamflow recycling and streamflow exchange with the underground. In Summary, our results show that reach drainage behavior depends on seasonal states of groundwater storages and controls HT. Thus, our findings contribute to the understanding of HT variability along streams. Key Points: Decoupling of hydraulic gradients and discharge from hydrological turnover (HT), enforces the perception of stream flow recycling along streamsSeasonal variation of HT can be attributed to site‐specific drainage behaviorGeogenic silica concentration change serves as a proxy for mixing of near stream ground and surface water induced HT [ABSTRACT FROM AUTHOR]

The current study was conducted to classify the quality of groundwater in wetlands. This research was carried out to evaluate the groundwater quality of wells in the surrounding area according to the Irrigation Water Quality Index (IWQI) to verify its suitability for agricultural purposes. The IWQI was developed in 2010 by Meireles; it was calculated based on the water quality parameters: EC, Na+1, Mg+2, Ca+2, Cl–1, and of 37 monitoring wells. The results of the IWQI show that the water quality declined significantly in July, with the majority of wells 76% within the severe restriction category (SR), which means that it's suitable only for irrigation of crops with high salt tolerance, and 14% of wells falling within the High Restriction category (HR). The lake's discharge decreases during the dry season, and most of the water quality classified as a severe restriction (SR), this indicates that the groundwater is influenced by the saline waters of Lake Fetzara, which are already loaded with chemical elements due to evaporation. As a result, the study of groundwater suitability for irrigation revealed that these waters are generally acceptable for irrigation of salt-tolerant crops on well-drained soils but require a prior control of salinity evolution. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Levels of Polycyclic Aromatic Hydrocarbons in surface and underground water sources from Ifite Ogwari, Ayamelum Local Government Area of Anambra State were investigated. Ecological and human health exposure risks were assessed following US EPA methods. The surface water sources are Isiachala, Iyiutu, Ube, Ahala Tabasi, Nabaloku, Atammele, Ogbu streams, and Omambala river. Underground water sources include Igbazine, Double, Ogba, Onowulugbe, Orator, and Commodore hand-dug wells. The water samples were collected using precleaned 500 cm3 glass bottles and were analysed for the presence of 16 US EPAPAHs using Gas Chromatography – Flame Ionisation Detector (GC- FID). The validated method showed that regression (R2) for all the PAHs ranged between 0.9622 and 0.9983. Limits of detection (LOD) ranged from 0.0033 to 0.1236 µg L−1 and limits of quantification (LOQ) from 0.0109 to 0.4115 µg L−1. Precision CV values ranged from 5.12 to 18.24%, and recovery values of the analytes in water varied between 83.94 and 99.99%. Naphthalene and chrysene were present in all the water samples while pyrene was absent in all except in Iyiutu. All the PAHs analysed were detected in Isiachala and Iyiutu except pyrene which was absent in Isiachala. All the samples contained at least three PAHs with concentrations ranging from 1.003 ng/µl of benzo[a] pyrene in Tabasi to 128.652 ng/µl of chrysene in Iyiutu. Ecological risk shows that the value was above US EPA background value. Human health risk assessment depicts that hazard index and total cancer risk ranges from 9.63E-05 to 1.93E-02. This study has shown that the inhabitants of Ifite Ogwari will experience adverse health and cancer illnesses over some time and therefore, a holistic approach by researchers and government agencies is needed to mitigate the ecological and health risk effects. [ABSTRACT FROM AUTHOR]

To examine the driver of groundwater depletion, this paper estimates a dynamic panel regression model using district-level secondary data from 1995 to 2017. Results show that the number of rainwater-harvesting structures, annual average rainfall, forest cover and net sown area improve groundwater levels. Tube well irrigation and rice cultivation can adversely affect groundwater levels. The positive relationship between surface water and improved groundwater level is consistent in all the estimated models. Hence, efficient use and management of surface and groundwater are crucial for the long-term sustainability of water resources. [ABSTRACT FROM AUTHOR]

Groundwater is an important drinking water resource in the coastal regions of island countries and has suffered from heavy seawater intrusion. However, the areas specifically affected by seawater intrusion and their groundwater hydrogeochemical compositions and evolution processes remain unclear. This study analyzed the hydrogeochemical compositions, water quality, and evolution processes of groundwater in the Mannar district, Sri Lanka, during the dry season. A total of 56 samples were collected from shallow wells and tube wells across the region, and about 64.28% of groundwater samples had good quality (WQI < 100). Geochemical compositions and water quality parameters had a high level in the north and south mainland regions, where they severely suffered from seawater intrusion with a high content of Cl− and Na+. The geochemical compositions of groundwater in the Mannar district were predominantly affected by rock weathering and/or evaporation processes. Cl-Na and HCO3-Ca facies were the main hydrochemical types, and the corresponding ions were mainly from silicate and halite dissolution. The reverse cation exchange process mainly occurred in seawater intrusion areas. The study highlights the impacts of seawater intrusion on the hydrogeochemical compositions and evolution processes in Mannar region groundwater, which will enhance the understanding of the local water quality and seawater intrusion situation and aid in protecting drinking water safety by routinely monitoring the groundwater quality and implementing targeted desalination techniques in the key areas. [ABSTRACT FROM AUTHOR]

Water quality continues to be the challenge to residents in Dar es Salaam due to various anthropogenic activities in the city. This study was conducted to assess groundwater quality by determining concentrations of heavy metals. Both probability and Nonprobability sampling techniques were used to collect samples from 40 groundwater wells in 24 wards of Temeke municipal and analysed using Microwave Plasma Atomic Emission Spectrometer (Agilent 4210 MP-AES) at the Geochemistry Laboratory of the University of Dar es Salaam. Results indicated varying heavy metal concentrations ranging from 0.71 ± 0.08 to 6.64 ± 0.21 mg/l for As, 0.02 ± 0.01 to 0.07 ± 0.01 mg/l for Co and 0.16 ± 0.01 to 0.02 ± 0.01 mg/l for Pb. The As, Co and Pb concentrations exceeded (P < 0.05) the recommended TBS standards of 0.05 mg/l, 0.003 mg/l and 0.01 mg/l respectively. Other concentrations ranged from 0.01 ± 0.01 to 0.88 ± 0.01 mg/l for Cu, 0.02 ± 0.01 to 3.55 ± 0.02 mg/l for Fe, 0.00 ± 0.00 to 4.63 ± 0.03 mg/l for Mn and 0.01 ± 0.01 to 3.00 ± 0.01 mg/l for Zn. The Cu, Fe, Mn and Zn concentrations were below (P > 0.05) the allowable TBS limits of 0.05 mg/l, 0.3 mg/l, 0.1 mg/l and 3 mg/l respectively. Health risk analysis revealed potential adverse health effects from long term consumption of As, Mn and Pb with Hazard Quotient exceeding 1 (HQ > 1). The Hazard Index (HI) for all groundwater samples was also above 1 (HI > 1) indicating a higher likelihood of adverse health effects. The study concluded that groundwater wells in Temeke Municipal are affected through natural and anthropogenic activities leading to high levels of heavy metal concentrations. Also, this study provides valuable information on risk associated by continued usage of groundwater in Temeke region and hence informs respective stakeholders on groundwater quality and potential risks thereby emphasizing the need for remedial measures and stricter regulations to safeguard public health. The study recommends the need for regular groundwater quality and safety monitoring to assess the levels of heavy metals concentrations and implement sustainable groundwater management strategies to address the increasing water demand in Temeke municipal, Dar es Salaam. [ABSTRACT FROM AUTHOR]

The construction of the New Galala City besides great mining (e.g., konoozmisr) and Seawater Reverse Osmosis Desalination Plant projects in the semiarid Gulf of Suez region of Egypt increases the demand for groundwater resources. So, the current research provides integrated stratigraphical, hydrogeochemical, and geophysical studies to investigate the shallow groundwater aquifers in Wadi Araba area on the western side of the Gulf of Suez. The stratigraphic column starts with pre-Cambrian basement rocks which are non-conformably overlain by sedimentary succession of Phanerozoic Erathem. A detailed land magnetic profile has been conducted and processed to estimate the aquifer's geometrical parameters. This includes the subsurface spatial extension and thickness to delineate the prevailed subsurface structures in the study area. Lithostratigraphically, these aquifers are represented by the Paleozoic- lower Cretaceous siliciclastic-dominated sediments of the Nubia Group and fractured carbonate-dominated facies of the upper Cretaceous Galala Formation. Lithological characters, sedimentary facies (fluvial to shallow and open marine), microfacies types, and diagenesis processes (e.g., compaction, cementation, dissolution, and fracturing) are the main factors that affect the quality of the shallow aquifers in the study area. The main microfacies of the studied aquifers are quartz arenite, subarkose, sublitharenite, mudstone/wackestone, and packstone/grainstone. These facies are characterized by different primary and secondary porosities. According to the water sampling standard methods, nineteen groundwater samples were collected from the available hand-dug wells and springs from the Nubian sandstone aquifer and the Upper Cretaceous aquifer, respectively. Inductively coupled plasma–mass spectrometry (ICP–MS), titration, spectrophotometer and a flame photometer were used to obtain a complete chemical analysis. The results of hydrochemical analyses indicated that total dissolved solids (TDS) and concentrations of major ions as well in the lower Cretaceous aquifer increase toward the Gulf of Suez and in general higher than that of springs of the Upper Cretaceous Aquifer. The predominant factors influencing groundwater chemistry include seawater intrusion, evaporation, mineral alteration, dissolution of fossils, and ion exchange. Groundwater in the study area is unsuitable for drinking except in one sample and moderately suitable for irrigation with caution for higher salinity in samples located near the Gulf of Suez. [ABSTRACT FROM AUTHOR]

About 2.5 billion people rely on groundwater as their main drinking water source, and arsenic pollution within the groundwater system can cause serious short- and long-term health issues. Within the natural environment, arsenic generally exists as oxyanions which have two oxidation states, As(III) and As(V). Under ambient pH conditions, As(V) is primarily present as an anion (i.e., H2AsO4−) while As(III) tends to be uncharged (i.e., H3AsO3), making it much more difficult to remove As(III) through existing treatment techniques such as adsorption and reverse osmosis (RO). In Eastern Wisconsin, the dolomite and dolomite/sandstone aquifers represent a major drinking water source and high arsenic concentrations have been observed. Previous studies showed that arsenic can be released into private drinking water wells due to the oxidation of sulfide-bearing minerals with arsenic impurities that are usually dispersed within the dolomite and sandstone bedrock. However, there is a lack of information on the concentrations of each arsenic species as well as arsenic dynamics during water pumping/usage. The primary goals of this research were (1) to quantify the baseline concentrations of each arsenic species within selected Eastern Wisconsin private drinking water wells, and (2) to determine how the arsenic concentrations and species could be affected by continuous water usage. Our results showed that As(III) was the dominant species of arsenic, and during continuous water usage, there could be an upward trend in arsenic concentration (there was minimal change in arsenic speciation). Upon the completion of water pumping, arsenic concentrations decreased over time and returned to pre-pumping levels. Our findings highlighted the importance of quantifying the speciation and dynamics of arsenic during water use to the assessment of public health risks and the design of appropriate water treatment techniques. [ABSTRACT FROM AUTHOR]

The main aim of the study is to present an assessment report of radon concentration in the underground water of Bokaro district, Jharkhand, India. Water samples were collected from tube-wells at 100 different locations scattered throughout the district. The radon (222Rn) concentration level varies widely between 3.5 and 598.9 Bq/l with an average value of 145.8 Bq/l. In this paper, total annual effective dose of the samples and associated excess lifetime cancer risk (ELCR) were estimated also to assess the health risk due to the consumption of the radon rich water. [ABSTRACT FROM AUTHOR]

Present work deals with radon (Rn-222) activity measurement of deep tube-well water samples collected from Raghunathpur and Jhalda, two municipalities of Purulia district, West Bengal, India. Concentration of Rn-222 in water samples collected from Raghunathpur municipality vary from 11.82 ± 0.95 to 155.64 ± 2.33 Bq/l with an average of 49.78 ± 1.81 Bq/l, whereas for Jhalda municipality the concentrations vary from 12.08 ± 1.02 to 74.74 ± 2.12 Bq/l with an average of 39.06 ± 1.40 Bq/l. The total annual effective dose associated with Rn-222 activity has been estimated for three different categories viz. adults, children and infants in terms of inhalation and ingestion. Additionally, pH and the major cations (Na+, K+, Li+, Ca2+) present in the water samples are also measured to observe the possible correlation with the Rn-222 activity. The results indicate that the groundwater in these two municipalities are radiologically safe in terms of Rn-222 and thus do not provide significant health threats to the local inhabitants. [ABSTRACT FROM AUTHOR]

Copyright of Arts Magazine is the property of Thamar University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the present work was to evaluate the seasonal and long-term concentration levels of several electrochemical and nutrient parameters in surface water and groundwater of the Alfeios River Basin, Greece. Seven seasonal sampling campaigns were conducted, each including 12 sampling sites located along the Alfeios River and its major tributaries, Enipeus, Kladheos, Selinous, Erymanthos, Ladhon, and Lousios. At each station, flow discharge was measured using four quick techniques, on-site measurements were performed, and water samples were taken for laboratory analysis. In locations near the river, on-site measurements were conducted, and water samples were collected from wells and boreholes to assess the groundwater quality. In addition, relative data from previous or later campaigns by other researchers is used to assess the long-term and possible seasonal variation of water quality along the Alfeios River and its tributaries. The results show a decrease in concentration for most of the parameters regarding surface and groundwater quality during the last few years. Statistical analysis showed that the dilution process is significant along the Alfeios River, upstream industrial wastewater discharges or agricultural runoff is responsible for high concentration values, while seasonality is evident only in the surface waters. Finally, comparing the water quality values to legislative limits of drinking water shows that exceedances occur, especially at nutrient compounds. This data could be useful for the evaluation of water quality, which is required by the implementation and update of the Alfeios River Basin Management Plan. [ABSTRACT FROM AUTHOR]

Iworoko community is a rural area where people inhabitants consume water without recourse to the quality evaluation. This research focused on the hydrogeochemistry and bacteriological evaluation of the shallow wells' water in Iworoko-Ekiti, Southwest Nigerian with a view to establish the potability and suitability status of the groundwater for other domestic and irrigational uses. The Multi-parameter Testr™ 35 Series was utilized to determine the in-situ physical parameters, which are pH, temperature (measured in degrees Celsius), electrical conductivity (μS/cm), and total dissolved solids (mg/l). The main ions were determined using Atomic Absorption Spectrometer for the concentrations of the cations and colorimetric method for the anionic concentrations. Bacteriological evaluation was done using nutrient agar technique. Findings from this investigation revealed that the temperature ranged from 25.5 to 32.5 °C (avg. 28.43 °C), while the pH, EC, and TDS values ranged from 6.4 to 12.1 (avg. 10.0), 1.46 to 807 μS/cm (avg. 295.5 μS/cm), and 1.095 to 605 (avg. 221.6 mg/l), respectively. The results indicated that virtually all the wells' water in the study area are alkaline with pH greater than 7 except for one location (L1) where the water was acidic (6.4). It was only at the well 1 that the water sample met the required standard for drinking water while all other water samples fell outside the standard. The TDS and EC were within the approved standard for drinking water. However, Water Quality Index (WQI) evaluation revealed that only 26.7% of the water samples fell in the good to excellent water categories while the rest (73.3%) were in unfit to poor water classes. Furthermore, all chemical values were within the approved standard for drinking water except nitrate in which 93% of the water samples had concentrations above the approved 50-mg/l standard for drinking water. The order of cation dominancy is Ca2+ > Na+ + K+ > Mg2+, while that of anion is Cl− > HCO3− > SO42− > NO3−. The chemical evolution of groundwater in the study area was dominantly controlled by weathering of rocks in the environment of the study area. The principal water type in the area is mixed CaMgCl water type (47%) while the CaCl and NaCl are at par accounting for a total of 53%. All irrigation parameters (Kelly's ratio, magnesium, and sodium hazard) show that the groundwater in the area are largely suitable for irrigation. The results of the microbial investigation showed that all the wells examined are contaminated with bacteria, fungus, and yeast. The groundwater in the study area is low mineralized but polluted by nitrate and microbial which are due majorly to anthropogenic activities in the area. The wells' water in the study area is not potable but good for irrigation purpose. [ABSTRACT FROM AUTHOR]

Past waste-disposal activities at Naval Air Station Whiting Field (NASWF) have led to elevated concentrations of contaminants in the underlying sand and gravel aquifer. Contaminants include two of the most commonly detected chemicals in groundwater in many countries (benzene and trichloroethylene (TCE)) and the "forever chemicals" per- and poly-fluoroalkyl substances (PFAS) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). A MODFLOW model (the Whiting Field Groundwater Model (WFGM)) was previously developed for NASWF and the surrounding area to simulate groundwater flow. To obtain insight into groundwater flow pathways for the identification of potential source areas, the MODPATH particle-tracking application was applied to the WFGM for three public supply wells and three monitoring wells at NASWF. The travel time to recharge areas was estimated using concentrations of the groundwater age-dating solutes tritium (as helium ingrowth) and chlorofluorocarbons detected in the monitoring wells. Simulated travel times agree with the groundwater ages and indicate that the calibrated WFGM reasonably represents groundwater flow velocities and pathways. The MODPATH simulations confirm suspected on-base source areas to explain chemical detection in the monitoring wells. In contrast, the particle-tracking simulations indicate that potential source areas to the public supply wells include both on- and off-base sources. This is important because PFAS chemicals can have multiple sources, including land application of sludge-based fertilizers. This approach that combines groundwater age dating with particle-tracking simulations can be applied at similar sites characterized by benzene-, TCE-, and PFAS-contaminated groundwater. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) is a critical global health concern. Animal husbandry operations are AMR hotspots due to heavy antibiotic use and dissemination of animal waste into the environment. In this systematic review, we examined the impact of swine, poultry, and cattle operations on AMR in groundwater. We searched PubMed, Web of Science, CAB Direct, and the North Carolina State University Agricultural and Environmental Science databases in June 2022. The search returned 2487 studies. Of the 23 eligible studies, 17 were conducted in high-income countries (primarily the USA, also Canada, Saudi Arabia, Cyprus), and 6 were conducted in a single upper-middle-income country (China). Studies investigated facilities for swine (13), poultry (4), cattle (3), and multiple types of animals (3). The sampling distance ranged from onsite to > 20 km from facilities; the majority of studies (19) sampled onsite. Most studies collected samples from monitoring wells; only 5 studies investigated private drinking water wells. AMR in groundwater was associated with animal husbandry operations in 74% (17/23) of all studies, 65% (11/17) of studies in high-income countries, and 100% (6/6) of studies in China. Contamination was mostly found in onsite wells, especially downgradient of waste lagoons, but also in offsite private wells up to 2–3 km away. Few studies reported weather data, but AMR contamination appeared to increase with rainy conditions. Future studies should sample private wells at varying distances from animal husbandry operations under different weather conditions and include low- and middle-income countries where food animal production is intensifying. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Repetitive, long-term inhalation of radioactive radon gas is one of the leading causes of lung cancer, with exposure differences being a function of geographic location, built environment, personal demographics, activity patterns, and decision-making. Here, we examine radon exposure disparities across the urban-to-rural landscape, based on 42,051 Canadian residential properties in 2034 distinct communities. People living in rural, lower population density communities experience as much as 31.2% greater average residential radon levels relative to urban equivalents, equating to an additional 26.7 Bq/m3 excess in geometric mean indoor air radon, and an additional 1 mSv/year in excess alpha radiation exposure dose rate to the lungs for occupants. Pairwise and multivariate analyses indicate that community-based radon exposure disparities are, in part, explained by increased prevalence of larger floorplan bungalows in rural areas, but that a majority of the effect is attributed to proximity to, but not water use from, drilled groundwater wells. We propose that unintended radon gas migration in the annulus of drilled groundwater wells provides radon migration pathways from the deeper subsurface into near-surface materials. Our findings highlight a previously under-appreciated determinant of radon-induced lung cancer risk, and support a need for targeted radon testing and reduction in rural communities. [ABSTRACT FROM AUTHOR]

The Erdenet mine (Erdenet, Mongolia) is a copper–molybdenum open pit mine with a huge tailing pond and is located next to a residential area. As the sources of drinking water in this area rely on groundwater and can be categorized into public or private wells, we aimed to assess the groundwater quality of the different types of drinking water wells. To accomplish our goal, we analyzed 18 trace metals (As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Ga, Mo, Ni, Pb, Se, Sr, Th, U, V, Zn) and 8 major metals (Al, Ca, Fe, K, Mg, Mn, Na, Si) samples using ICP-MS and ICP-OES, and the heavy metal pollution index, heavy metal evaluation index, and degree of contamination were calculated. The most concerning point is that the Mo concentration of waste water in the Erdenet mine tailing pond and at a natural spring located 300 m from the tailing pond was 1100 μg/L, which greatly exceeds the WHO permissible concentration for Mo of 70 μg/L. Furthermore, high Ca and Mg concentrations at all private wells indicated that consumers of these wells are more vulnerable to any type of water pollution, as these wells are not built with any disinfection or treatment system. A modified categorization of the water quality indices showed that the public and private wells have low–medium contamination and that the tailing pond seepage water, along with its nearest spring, have a high degree of contamination. Because many private wells are located along the tailing pond and used directly without any treatment, we suggest a continuous evaluation and monitoring of the groundwater quality in this area. [ABSTRACT FROM AUTHOR]

In this work, a method of simultaneously analyzing pesticide concentration and assessing its risks was developed. Assessments were conducted to evaluate the distribution characteristics and risks to human health of pesticides in shallow groundwater in agricultural areas. We developed multi-residue analytical methods using liquid chromatography (LC-MS/MS) and gas chromatography–tandem mass spectrometry (GC-MS/MS) to analyze 57 pesticides in groundwater. In addition, risk assessments were performed by setting scenarios considering the routes of pesticide infiltration into groundwater. For the simultaneous analysis of 57 pesticides, the liquid–liquid extraction method was applied twice using dichloromethane under acidic and alkaline conditions. The extract was concentrated and analyzed using LC-MS/MS (41 pesticides) and GC-MS/MS (16 pesticides). The precision and accuracy ranges of the analytical methods were 0.1~12.9% (within ±15%) and 80.3~113.6% (within ±20%), respectively. The limit of quantification was found to range from 0.0004 to 0.0677 μg/L. In total, 57 pesticides were monitored in 200 groundwater wells from 2019 to 2020. Twenty-six pesticides, including metolachlor and imidacloprid, were detected, with an average concentration of 0.0008 μg/L in groundwater. The pesticide types and detection levels differed depending on the survey period and surrounding land. When the risks associated with alachlor, metolachlor, and carbofuran were assessed, their health risks when found in groundwater were evaluated to be negligible (non-carcinogenic risk: less than 10−3, carcinogenic risk: less than 10−6). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tikrit University for Humanities is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The number, species composition, and taxonomic structure of fungal biota in the groundwater of natural springs and wells in Moscow and Moscow oblast were determined by the сultural method. The number of fungi was low, on average, from 10 to 300 colony-forming units (CFU) in one liter of water. From the water of one source or well, 6–16 species were isolated, and in total, 46 species were isolated from six objects studied. These were representatives of phylum Mucoromycota, class Mucoromycetes (Absidia cylindrospora var. nigra, Mucor circinelloides, M. hiemalis, and Rhizopus stolonifer), phylum Ascomycota, class Eurotiomycetes (15 species of the genera Aspergillus and Penicillium), Sordariomycetes (13 species of the genera Acremonium, Chaetomium, Fusarium, Myrothecium, Plectosphaerella, and Trichoderma), Dothidiomycetes (Alternaria alternata, A. nobilis, Amorocoelophoma cassia, Cladosporium cladosporioides, and C. sphaerospermum) and Saccharomycetes (Candida solani, C. zeylanoides, and Galactomyces pseudocandidus), and the phylum Basidiomycota, class Tremellomycetes (Mrakia gelida and Vishniacozyma victoriae) and Agaricomycetes (Phlebia acerina, Psathyrella candolleana, and Thanatephorus cucumeris). The established taxonomic structure of fungal biota in the waters of natural springs and wells of the Moscow metropolis is similar to that found in the groundwater of other regions, including groundwater at the depths of several hundred meters. The possibilities of adaptation of micromycetes to existence in groundwater, the sources of its contamination, and the need for mycological criteria for assessing water quality are discussed. [ABSTRACT FROM AUTHOR]

This study sought to asses drinking and irrigation water quality in the Dera Ismail (DI) Khan District, Pakistan with the aid of using drinking water quality index (WQI) and irrigation water quality indices (IWQI). Seventy two water samples were collected from various water sources such as tube wells, dug wells, hand pumps, streams, and springs throughout the DI Khan district. The investigated physicochemical parameters include pH, TDS, EC, turbidity, total hardness, major cations (Na, K, Ca, Mg), anions (Cl, HCO3, SO4), and heavy metals (Fe, Mo, Cr, Ni, Cu, and Zn). IWQI used in the study includes Kelly’s ratio (KR), permeability index (PI), sodium percent (Na%), Magnesium Hazard (MH), potential salinity (PS), residual sodium carbonate (RSC), and sodium adsorption ratio (SAR). With the mean value of 63, WQI revealed that most samples are placed in the good category, with a smaller fraction in the excellent and poor classes. On the other hand, a health risk assessment of the data pointed out that the molybdenum (Mo) and chromium (Cr) concentrations in drinking water could pose health risks to children of the concerned population. Rock weathering appears to be the dominant hydro-geochemical pathway controlling water chemistry, Ca-Mg-HCO3 being the dominant facies, followed by Na-HCO3. Kelly’s ratio (KR), sodium percent (Na%), sodium adsorption ratio (SAR), and residual sodium carbonate (RSC) had values higher than the recommended threshold. The use of water for irrigation of agricultural fields may raise relevant ecological concerns in the studied district. [ABSTRACT FROM AUTHOR]

Purpose. Scientific substantiation of the application of technology for the development of water wells in the conditions of the Tonirekshin field of the Mangystau Peninsula. Methodology. The tasks were solved by a complex research method, which includes a review and generalization of literary and patent sources, analytical studies on existing methods for the development of water wells and their interpretation in relation to the geological and technical conditions of the Tonirekshin groundwater field. Findings. The main exploitable aquifers that are part of the Tonirekshin groundwater field are considered and a critical analysis of information on the geological and hydrogeological features of the basin is made. The requirements for the process of development of water wells for the field conditions are formulated. Well-known advanced well development methods are analyzed. Their advantages, disadvantages and compliance with the requirements are revealed. The implosion method was chosen as the best method for the development of water wells in the conditions of the Tonirekshin field. Originality. For the first time, for the geological and technical conditions of the Tonirekshin groundwater field, using the method of expert assessments, the choice of the optimal method for the development of water wells has been scientifically substantiated, which ensures decolmatation of the near-wellbore zone and the maximum flow rate of high-quality water for domestic and drinking water supply. Practical value. For the specific geological and technical conditions of the Tonirekshin groundwater field, the most suitable method for the development of water wells was chosen – the implosion method. The application of this method will provide a significant increase in well flow rate and a solution to the problem of oasis irrigation of lands in the Beineu district of the Mangystau region (Kazakhstan). [ABSTRACT FROM AUTHOR]

The present effort is expected to consider the groundwater quality of the Erbil Central Basin. In this study, we compared the physiochemical properties and distribution of major cations and anions in groundwater to evaluate the quality assessment as a special usage (drinking and irrigation) and identify the sources and types of water quality variation and pollution. The mean richness of major cations are Ca2+ > Mg2+ > Na+ > K+, whereas the major anions are HCO3 - > SO4²- > NO3 - > Cl-. The quality of water was evaluated using SAR, sodium (%), PI, TH, MH, PS, and WQI. When the chemical and physical characteristics were compared to Iraqi and public health standards (IQS) for drinking water, it was discovered that the majority of the wells' groundwater during both periods was within the acceptable range, and suitable for all human drinking and domestic purposes except for three wells exceed the maximum permissible limit of NO3-, which are Newroz, Rizgari, and Birayaty, while HCO3- is showed a maximum in Newroz, and in Rizgari well the total hardness (TH) doesn't lie within recommended standards. The Ca and Mg- Bicarbonate type was the predominant form for the groundwater classified for both seasons, with only one well (Zanko) being Ca- Chloride type for the dry season. The majority of ionic species originated from alkaline earth metals that originate from interactions between weak acidic anions in groundwater and soil or rock. All samples were suitable for drinking water according to the WQI, only the Zanko well had poor water during the dry season. [ABSTRACT FROM AUTHOR]

The present study aimed to assess chemical risks in the drinking water of inhabitants in the basin of the Tonle Sap Great Lake. Water samples from tube wells (n = 52), dug wells (n = 13), stored rain water (n = 39), ponds/lakes (n = 19), canals/rivers (n = 24), and household pipe water (n = 45) were collected and analyzed for physicochemical properties, as well as microbial and chemical qualities using standard methods. Analytical results revealed that 42.1% of tube wells had As.10 µg L-1 while 8.3% had Cr.0.05 mg L-1. Concurrently, 55.2 and 11.8% of tube wells had Cd.3.00 µg L-1 and Pb.10 µg L-1, respectively. Moreover, 35.0% of pipe water had Fe.0.3 mg L-1, whereas 85.7% of tube wells and 69.2% of dug wells had Mn.0.1 mg L-1. All water sources including pipe water could pose risks of non-carcinogenic effects of chemical mixtures to all exposure groups through their drinking water pathway. Children were at a higher risk of chemical mixtures in their drinking water than adults. This study suggests that advanced treatment technologies should be applied to the current water treatment plants to provide inhabitants with safe drinking water. [ABSTRACT FROM AUTHOR]

The importance of groundwater in coastal plain areas is gradually increasing; however, the understanding of agricultural contamination and the hydrogeochemical processes controlling the major elemental characteristics of groundwater in these areas is still insufficient. We here examined the effects of well depth, seasonal variation, terrain characteristics, and land-use on major element hydrogeochemistry for 103 wells of surficial and bedrock aquifers in an extensive agricultural plain in the mid-western part of South Korea. We found that 81% of groundwater samples exceeded the threshold value for the national background nitrate level and degree of nitrate contamination was similar for both aquifers, indicating significant contamination in the study area. As agricultural contamination increased, the groundwater type changed from Ca-HCO3 and Na-HCO3 to Ca-Cl(NO3), and the molar ratio of (Ca2+ + Mg2+):HCO3− changed from 1:2 to 1:1. Additionally, the correlations between Ca2+, HCO3−, and SO42−; between Na+ and Cl−; and between pH and F− decreased. Principal component analysis of groundwater hydrogeochemical parameters showed that agricultural contamination was the dominant process, followed by water-bedrock interactions and shallow groundwater mineralization. Hierarchical cluster analysis showed that shallow groundwater exhibited high concentrations of K+ and Mg2+, whereas deep groundwater in the mountainous agricultural area had high agricultural contamination and elevated concentrations of Ca2+, Mg2+, Na+, K+, Cl−, SO42−, and F−. It is noteworthy that groundwater hardness increased with the increase in agricultural contamination. Our findings confirm that agricultural activities in the coastal plain not only increased the concentration of agriculture-derived elements, but also had an overall impact on major elements in groundwater of both surficial and bedrock aquifers. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this work is to give a holistic overview of the groundwater quality in Qatar in terms of its radon levels and provide a radiological risk assessment of elevated radon levels on human health. This study covered the analysis of groundwater collected from various locations throughout Qatar and maps using ArcGIS followed by a radiological risk assessment of radon in Qatar. There is no extensive study reported to investigate radon activity levels in groundwater across Qatar and their health effects. The radon level measurements of the Qatari groundwater ranged between 2.7 ± 0.2 and 60.7 ± 13.4 Bq/L with a mean value of 20.6 Bq/L, which is greater than the US EPA's maximum contamination level (11 Bq/L). About 65% of the studied samples exceeded the US EPA's MCL guidelines. The mean total annual effective dose due to radon inhalation and ingestion was 0.056 mSv/y, which is below the WHO reference level of 0.1 mSv/y. The radon radiological risk study through inhalation and ingestion clearly revealed that the contribution of the inhalation dose was higher than the ingestion dose. [ABSTRACT FROM AUTHOR]

Life on Earth is dependent on water, which is an essential component of the atmosphere. The source of household water for millions of homes in both rural and urban areas is the tube well. Groundwater is the most alternative is facing threats. Tube well and open well samples were collected at different sites of Yeliyur grama panchayath Villages, Kunigal Taluk. The Physico-Chemical properties of all the collected 20 groundwater samples were analyzed. The quality of groundwater in and around Yeliyur grama panchayath Villages, Kunigal Taluk has been studied various parameter such as pH, Total Dissolved Solid (TDS), total hardness, total alkalinity, turbidity, Na+, K+, Cl-, F-, Ca2+, Mg2+, SO42-, NO32-, DO, Chromium and Pb. The final experimental results were compared with the WHO variable standards (2021). [ABSTRACT FROM AUTHOR]

This paper confirms the regularities of the formation of increased concentrations of strontium (Sr) in fresh groundwater used for drinking water supply, depending on the time they are residen in the carbonate deposits of the aquifer. On average, every thousand years, the Sr concentration increases by 2.1–3.5 mg L−1. In addition, high strontium content is positively correlated with altitude and well depth and negatively correlated with redox conditions in the aquifer. Large relief elevations are associated with the development of marginal moraine deposits from the Last Glacial Period composed predominantly of clay, which contributes to a decrease in water exchange. The high Sr content is associated with the dissolution of significant formations of celestite and strontianite, up to their ore occurrences. For this reason, the saturation indices (SIs) for celestite and strontianite correlate with TDS and rise to − 1.42 and 2.05, respectively. Low Sr values do not correlate with the residence time of groundwater in the aquifer or the depth of wells and tend to depressions in the relief, with a virtual absence of overlying sediments and positive Eh values, which indicates an active water exchange. The low level of Sr is associated with the dissolution of gypsum, calcite, and dolomite containing strontium as an impurity. This causes the SIs for gypsum, calcite, and dolomite to correlate with TDS, while for celestite and strontianite, the SI drops to − 5.02 and − 0.92, respectively. The established patterns make it possible to more reasonably choose places for the construction of water wells to obtain drinking water of standard quality. [ABSTRACT FROM AUTHOR]

Background: Kidney cancer incidence demonstrates significant geographic variation suggesting a role for environmental risk factors. This study sought to evaluate associations between groundwater exposures and kidney cancer incidence. Methods: The authors identified constituents from 18,506 public groundwater wells in all 58 California counties measured in 1996–2010, and obtained county‐level kidney cancer incidence data from the California Cancer Registry for 2003–2017. The authors developed a water‐wide association study (WWAS) platform using XWAS methodology. Three cohorts were created with 5 years of groundwater measurements and 5‐year kidney cancer incidence data. The authors fit Poisson regression models in each cohort to estimate the association between county‐level average constituent concentrations and kidney cancer, adjusting for known risk factors: sex, obesity, smoking prevalence, and socioeconomic status at the county level. Results: Thirteen groundwater constituents met stringent WWAS criteria (a false discovery rate <0.10 in the first cohort, followed by p values <.05 in subsequent cohorts) and were associated with kidney cancer incidence. The seven constituents directly related to kidney cancer incidence (and corresponding standardized incidence ratios) were chlordane (1.06; 95% confidence interval [CI], 1.02–1.10), dieldrin (1.04; 95% CI, 1.01–1.07), 1,2‐dichloropropane (1.04; 95% CI, 1.02–1.05), 2,4,5‐TP (1.03; 95% CI, 1.01–1.05), glyphosate (1.02; 95% CI, 1.01–1.04), endothall (1.02; 95% CI, 1.01–1.03), and carbaryl (1.02; 95% CI, 1.01–1.03). Among the six constituents inversely related to kidney cancer incidence, the standardized incidence ratio furthest from the null was for bromide (0.97; 95% CI, 0.94–0.99). Conclusions: This study identified several groundwater constituents associated with kidney cancer. Public health efforts to reduce the burden of kidney cancer should consider groundwater constituents as environmental exposures that may be associated with the incidence of kidney cancer. This study analyzed 180 groundwater exposures in California and used a water‐wide association study (WWAS) platform, based on XWAS methodology, to identify associations between groundwater exposures and kidney cancer incidence. Results revealed 13 groundwater constituents meeting stringent WWAS criteria, with seven directly linked to increased kidney cancer incidence, suggesting that public health efforts should consider environmental exposures that may be associated with the incidence of kidney cancer. [ABSTRACT FROM AUTHOR]

Analysis of the distribution of uranium concentrations in the water of conjugated components of the Baikal ecosystem (the water of Lake Baikal and its tributaries, headwaters of the Angara River, and groundwater from the wells drilled on Olkhon Island, and in the southwestern coastal part of Lake Baikal) has been carried out. The essential differences of the maximum uranium concentrations in groundwater of Lake Baikal and its inflows and the close average and median values of uranium in the water of Lake Baikal and the Angara River source were determined. The data obtained on the uranium distribution fix the influence of geological and geochemical peculiarities of the structure of the Baikal ecosystem and its surroundings and the climatic and catastrophic (earthquakes, seismic geodynamic activation, etc.) events that take place in the region. The changes in the uranium concentration in the water of Lake Baikal in relation to the seismic process were analyzed on the example of strong earthquakes (M ≥ 5) in the Lake Baikal area. [ABSTRACT FROM AUTHOR]

A geophysical resistivity survey was conducted in Zehri tehsil in the district of Khuzdar for the metering of subsurface hydrogeological properties of aquifers. The Schlumberger electrode arrangement was employed with the vertical electrical sounding (VES) method for subsurface exploration. Two profile lines were designated for the survey. The distance between the two profile lines was about 1500 m and each profile contained four VES stations. The results of profile one show the aquifers were encountered in fractured limestone of the Jamburo Formation of Paleocene age at an average depth of 127 m, with an average resistivity of 39.7 Ωm, and the average aquifer thickness was 54.025 m. The result of profile two shows the aquifers were encountered only in VES four in the sandstone lithology of the Ziddi Formation with a resistivity of 79.9 Ωm, at a depth of 120 m with, and a thickness of 40 m. There was no aquifer encountered in the remaining all VES. The main lithology of these VES is thick impervious compacted limestone, shale, and clay of Jurassic age from the Ziddi Formation. The current tube wells were also rapidly depleting in the study area. The main factor behind the decline of aquifers in the study area is an uncontrolled installation of tube wells and continuous pumping of tube wells for agricultural purposes badly puts stress on aquifers and directly deteriorates the quality and quantity of groundwater. [ABSTRACT FROM AUTHOR]