Drinking Water Quality Index Research Articles

Domestic and irrigation water quality on the southern slopes of Mount Kilimanjaro

This study assessed the water quality for drinking and irrigation purposes on the southern slopes of Mt. Kilimanjaro during the dry season under low flow conditions. Fifty-one samples covering eight different water sources (i.e., stream water from natural and anthropogenic impacted streams, domestic water, spring water, rainfall, groundwater, lake water and water from irrigation canals) were collected in a snapshot sampling campaign over 10 days in February 2023. First, physical, chemical and biological parameters were analysed and compared with Tanzanian and international drinking and irrigation water quality requirements. The samples were then ranked according to their suitability for drinking and/or irrigation using water quality indices (WQI). All drinking water quality parameters except for E. coli and turbidity were within the permissible limits. A generalised problem of faecal contamination was found in the study area, including in domestic water, highlighting the need to identify sources of contamination and remediate them before distribution. The drinking water quality index (DWQI) classified 89% of the samples as unsuitable and 11% as excellent for drinking. Irrigation water quality parameters were within the guidelines of restriction of use except for pH in 5 samples. In contrast to the DWQI, the vast majority of the water samples (88%) can be used for irrigation without restrictions according to the irrigation water quality index (IWQI). The suitability of water for irrigation was also assessed using three indices, i.e., Kelley’s Index, Soluble Sodium Percentage and Magnesium Ratio, which indicated potential problems with excess of sodium (about 30% of the samples) and magnesium (about 20%). Further studies combining suitability indices, soil characteristics and crop types are recommended to assess water quality for irrigation use.

Application of Geographical Information System –Water Quality Index Techniques for Evaluating the Groundwater Quality in Kaniqirzhala Landfill, Kurdistan Region, Iraq

The aim of the current study through uses the Water Quality Index for drinking and irrigation purposes and Heavy Metal Pollution Index to determine quality groundwater in 25 wells spread throughout Kaniqirzhala landfill within the Erbil governorate during 2022. Groundwater samples from various wells have been gathered for chemical and physical analysis in order to determine the water quality. Turbidity, pH, electrical conductivity, total dissolved solids, total alkalinity, total hardness, major anions (SO4-2, Cl-1, Hco3-1, NO3-2, PO4-3) and major cations (Ca+2, Mg+2, Na+1, K+1) are all included in the analysis. In addition to heavy metals investigations were conducted on a variety of metals, including manganese (Mn), nickel (Ni), zinc (Zn), arsenic (As), barium (Ba), boron (B), cadmium (Cd), copper (Cu), iron (Fe), and lead (Pb). Results indicated that higher values of nitrate were calculated in sites 10 to 17. But, in all wells higher concentrations of alkalinity and total hardness were recorded .The concentrations of heavy metals in wells water ranged from low to high according to WHO guidelines for drinking purposes. Drinking water quality index ranged from 52.20 (good quality) at site 9 to 137.01 (poor quality) at site 14. The value of the irrigation water quality index, which is low at site 15, which indicates low restriction for irrigation uses, while the value of 50.01 recorded at site 4 indicates high restriction for irrigation purposes. In all groundwater sites under study, a heavy metal pollution index of greater than 100 indicates extremely poor water quality unsuitable for human consumption. This study concluded all examined wells were deemed to be of extremely poor to good quality for to use in for drinking water based on the water quality index, while extremely low quality based on the heavy metals pollution index .

Assessment of groundwater quality for drinking and irrigation in Dindigul district, southern India: Hydrochemical characterization and spatial analysis

There are many renewable resources, but groundwater is one of the most important. The use of groundwater for various purposes is inevitable in the modern world. This study aimed to investigate the groundwater resources in the Dindigul and Vedasandur taluks of Dindigul district, southern India, for these various uses. About 36 groundwater samples were collected from dug wells and borewells. The samples were analyzed for total dissolved solids, total hardness, and both major and minor ions to determine the water type, ion concentration and suitability for drinking purposes. Analysis reveal that, based on TH and TDS, most wells exhibited hard to very hard with fresh to brackish characteristics. TDS, TH, Mg, Na, and K levels in drinking water exceeded permissible limits in 8 %, 14 %, 14 %, 39 %, and 25 % of samples, respectively. For irrigation purposes, parameters such as sodium adsorption ratio, residual sodium carbonate, electrical conductivity, Kelley’s ratio, magnesium hazard, and permeability index were found to be unsuitable in 36 %, 3 %, 14 %, 69 %, 97 %, and 3 % of the samples, respectively. The Study area shows that 89 % of the samples are fit for drinking purposes. Sodium, bicarbonate and chloride ions were identified as the dominant hydrochemical components in the region. The hydrochemistry varied spatially, with higher concentrations observed primarily in the northwestern parts of the area. Most wells were found suitable for drinking, with the exception of a few in the northwest. The quality of water for agricultural use was generally acceptable. The drinking water quality index indicated that most areas were good for drinking, except those in the northwest. The hydrochemistry of the region appears to be influenced by processes such as evaporation, silicate weathering, and irrigation return flow. Evaporation, along with the weathering of hornblende, biotite, and charnockite rocks played a significant role in the groundwater.

Human health risk and water quality assessment due to fluoride and nitrate around Cauvery River basin, southern India.

Good quality water for human consumption, irrigation, and industrial use is very important. Today, around the world, water is contaminated by natural processes and human activities. This study aimed to evaluate the suitability of groundwater for drinking and irrigation, identifythe source of fluoride and nitrate contamination, and assess thehuman health risks around the Cauvery River basin in southern India. A total of 30 groundwater samples were collected and analyzed for hydrochemical parameters, including EC, TDS, pH, Ca, Mg, Na, K, HCO3, Cl, SO4, NO3, and F-. The majority of groundwater samples in the study area are used for drinking and irrigation. The pH of groundwater in the study area was observed to be dominantly alkaline. The levels of TDS, Ca, Na, K, F, and TH exceeded the permissible limits recommended by BIS and WHO. Fluoride and nitrate levels in groundwater exceeded the permissible limits for drinking purposes in 43% and 50% of the samples, respectively. The excessive concentration of fluoride and nitrate in groundwater could pose serious human health problems. Fluoride and nitrate concentrations in groundwater vary between 0.1 and 2mg/l and 12 and 95mg/l, respectively. Based on the computation of the drinking water quality index, about 73% of groundwater samples were classified asexcellent to good. Health risk was assessed for infants, children, and adults using non-carcinogenic risk indices such as hazard quotients (HQ), hazard indexes (HI), total hazard indices (THI), and carcinogenic risk indices (CR). Infants, children, and adults have different total hazards indexes ranging from 1.508 to 5.733, 1.579 to 6.003, and 0.011 to 0.046, respectively. Health risk assessment results indicatedthat the hazard index and hazard quotient were above the recommended limit of > 1 in most of the samples for infants and children. Non-carcinogenic risk and carcinogenic risks were more likely to affect infants and children rather than adults through ingestion of contaminated water.

Groundwater quality assessment for drinking, irrigation purposes and fuzzy logic-based water quality index for industrial suitability in Walajapet taluk, Ranipet district, Tamil Nadu, India

ABSTRACT Ranipet district in Tamil Nadu is one of the major industrial zones in India. Groundwater has been extensively used in this region for drinking, agricultural, and industrial purposes. For finding the groundwater quality, representative samples have been collected in the premonsoon (PRM) and postmonsoon (POM) seasons of 2023 and analysed for major physicochemical parameters. The drinking suitability was analysed based on drinking water quality index, and it showed that 68.52 and 70.37% of samples from the PRM and POM seasons are classified as poor groundwater for drinking. The groundwater's suitability for irrigation was analysed based on various irrigation quality indices, and it highlighted that most of the groundwater was suitable for agriculture. Industrial suitability was determined by several industrial quality indices. Due to the simultaneous application of several indices, a sample is categorised into many water quality groups, introducing bias into handling and decision-making. The Mamdani fuzzy inference system creates a unique integrated industrial water quality index to address this issue. The index revealed that only 24.07 and 9.26% of samples from the PRM and POM seasons, respectively, were free of corrosion or scaling, while the remaining samples were inappropriate for industrial use.

Evaluation of drinking water quality and associated health risks in Adama City, Ethiopia

Drinking water deterioration causes to risk of public health which is essential to supply safe water to the public. This study assessed groundwater quality and health risks in Adama City by analyzing groundwater and chlorine samples. Ion photometry techniques detected anions and cations, ensuring accuracy with quality control protocols. Water Quality Index (WQI) and chlorine decay modeling via WaterGEMs assessed water quality. Hazard index (HI) calculations evaluated exposure risks; Pearson correlation analyzed physicochemical relationships. Findings highlighted water quality and hazards. Aquachem software analyzed Adama's groundwater, revealing high total alkalinity and potassium exceeding WHO limits. Other parameters (nitrate, nitrite, chloride, fluoride, and sulfate) met WHO standards. Sodium, calcium, magnesium, iron, manganese, and boron also complied. Multivariate analysis showed significant parameter associations. Water types included Ca–Na–HCO3 (27.27 %), Na–Ca–HCO3 (36.36 %), Na–Ca–Mg–HCO3, Na–HCO3 (9.09 % each), and Na–Mg–HCO3 (18.18 %). Drinking Water Quality Index rated boreholes as "Good." Health risk assessments found no significant fluoride, iron, or manganese risks across ages. Chlorine residual analysis indicated 74 % had levels below WHO recommendations, prompting chlorine dosing adjustments. Findings inform groundwater management in Adama City.

Assessing drinking water quality based on water quality indices, human health risk, and burden of disease attributable to heavy metals in rural communities of Yazd County, Iran, 2015–2021

The water quality indices, health risk, and burden of disease attributable to heavy metals in rural communities of Yazd County, Iran during 2015–2021 were studied. The drinking water quality index (DWQI) based on 27 parameters (including heavy metals) and heavy metal pollution index (HPI) were used for assessing drinking water quality. The health risk and burden of disease from heavy metals in drinking water were estimated in terms of hazard quotient (HQ), hazard index (HI), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY). Based on the DWQI scores by community, the drinking water quality in rural communities of Yazd County was characterized as good for 61 %, fair for 25 %, marginal for 2 %, and poor for 12 %. The distribution of the rural communities into the HPI categories was as follows: 43 % for excellent, 36 % for good, 14 % for poor, and 7 % for unsuitable. In about 20 % of the rural communities, the average HI level of heavy metals was higher than the boundary limit of one. The highest average HQ level at the county level was related to arsenic (As) to be 0.44. In all the communities, the total ILCR values of the heavy metals were in the category of significant increased cancer risk (10−6 to 10−4). At the county level, As and cadmium (Cd) exhibited the two highest cancer risk levels to be 1.96 × 10−4 and 1.87 × 10−4 for ILCR, respectively. The DALY rate (per 100,000 people) induced by exposure to the heavy metals via drinking water was 13.9, which was considered relatively high as compared to that of other drinking water pollutants obtained in the previous studies. The drinking water quality improvement through decreasing Cd and As levels below the standard values can drastically reduce the attributable burden of disease and promote the public health in the rural communities.

Assessment of hydrochemical characteristics, health risks and quality of groundwater for drinking and irrigation purposes in a mountainous region of Pakistan

Renowned for its agriculture, livestock, and mining, Zhob district, Pakistan, faces the urgent problem of declining groundwater quality due to natural and human-induced factors. This deterioration poses significant challenges for residents who rely on groundwater for drinking, domestic, and irrigation purposes. Therefore, this novel study aimed to carry out a comprehensive assessment of groundwater quality in Zhob district, considering various aspects such as hydrochemical characteristics, human health risks, and suitability for drinking and irrigation purposes. While previous studies may have focused on one or a few of these aspects, this study integrates multiple analyses to provide a holistic understanding of the groundwater quality situation in the region. Additionally, the study applies a range of common hydrochemical analysis methods (acid–base titration, flame atomic absorption spectrometry, and ion chromatography), drinking water quality index (WQI), irrigation indices, and health risk assessment models, using 19 water quality parameters. This multi-method approach enhances the robustness and accuracy of the assessment, providing valuable insights for decision-makers and stakeholders. The results revealed that means of the majority of water quality parameters, such as pH (7.64), electrical conductivity (830.13 μScm–1), total dissolved solids (562.83 mgL–1), as well as various anions, and cations, were in line with drinking water norms. However, the water quality index (WQI) predominantly indicated poor drinking water quality (range = 51–75) at 50% sites, followed by good quality (range = 26–50) at 37% of the sites, with 10% of the sites exhibiting very poor quality (range = 76–100). For irrigation purposes, indices such as sodium percent (mean = 31.37%), sodium adsorption ratio (mean = 0.98 meqL–1), residual sodium carbonate (– 3.15 meqL–1), Kelley’s index (mean = 0.49), and permeability (mean = 49.11%) indicated suitability without immediate treatment. However, the magnesium hazard (mean = 46.11%) and potential salinity (mean = 3.93) demonstrated that prolonged application of groundwater for irrigation needs soil management to avoid soil compaction and salinity. Water samples exhibit characteristics of medium salinity and low alkalinity (C2S1) as well as high salinity and low alkalinity (C3S1) categories. The Gibbs diagram results revealed that rock weathering, including silicate weathering and cation exchange, is the primary factor governing the hydrochemistry of groundwater. The hydrochemical composition is dominated by mixed Ca–Mg–Cl, followed by Na–Cl and Mg–Cl types. Furthermore, the human health risk assessment highlighted that fluoride (F–) posed a higher risk compared with nitrate (NO3–). Additionally, ingestion was found to pose a higher risk to health compared to dermal contact, with children being particularly vulnerable. The average hazard index (HI) for children was 1.24, surpassing the allowable limit of 1, indicating detrimental health effects on this subpopulation. Conversely, average HI values for adult females (0.59) and adult males (0.44) were within safe levels, suggesting minimal concerns for these demographic groups. Overall, the study’s interdisciplinary approach and depth of analysis make a significant contribution to understanding groundwater quality dynamics and associated risks in Zhob district, potentially informing future management and mitigation strategies.

Evaluation of the Drinking Water Quality Index in Dibis District – Kirkuk

In this study, a weighted mathematical model was utilized to evaluate the water quality of the filtration station in the Al-Dibs district. The assessment was conducted at five different sites from October 2023 to April 2024. Various characteristics of the water samples were measured, encompassing physical properties like turbidity, total suspended solids, total dissolved solids, and electrical conductivity. Additionally, chemical properties such as pH, total alkalinity, total hardness, calcium hardness, magnesium hardness, chloride, total nitrogen, and available phosphorus were analyzed. Bacterial properties, including total bacterial count, coliform bacteria, and fecal bacteria, were also assessed. The study monitored various sites along the Lower Zab River, including the raw water collection point, water pumping area, Oil Quarter, Diyarbakır Quarter, and Kolan Quarter. Results revealed unsatisfactory water quality at the raw water collection point, while excellent quality was observed at the other sites (2, 3, 4, 5). The water quality index rankings were as follows: 18.10, 17.61, 47.96, 30.40.These findings suggest that the water treatment station effectively produces water suitable for daily sanitary purposes.

Spatial and seasonal groundwater quality assessment for drinking suitability using index and machine learning approach

Spatial and seasonal evaluation and monitoring of groundwater (GW) quality is essential for the sustainable management of this priceless resource and the provision of safe drinking water. Nevertheless, GW quality appraisal was not given due attention in the current study area (flat terrain part of the Tana sub-basin). This study sought to assess the seasonal and regional physicochemical GW quality parameters for drinking appropriateness using the drinking water quality index (DWQI) and support vector machine (SVM). The main cations in both the dry and wet study seasons were, in decreasing order, Na+, Ca2+, Mg2+, K+, and Fe2+, according to the results. Conversely, the main anions were HCO3−, CO32−, Cl− or NO3−, SO42− and PO43−, ordered from higher to lower. During the two research seasons, Ca–HCO3 and Na–HCO3 were the predominant water types based on Piper diagram results. Reverse ion exchange and evaporation were the principal hydrogeochemical processes that control the hydrogeochemistry identified by Durov and Gibbs diagrams, respectively. Excellent GW quality class for drinking was demonstrated by the majority of geographical and seasonal DWQI readings over the two seasons. Nevertheless, during the rainy season, there was a noticeable decline in the GW quality condition around the northern shores of Lake Tana. Therefore, it is advised to implement comprehensive GW quality protection measures and improve system management to mitigate pollution to reduce health hazards in the examined region.

Exploring the drinking water supply in Rwanda with panel data analysis.

This study in Rwanda offers a comprehensive analysis of water quality, reliability, and cost-effectiveness, departing from previous research by utilizing panel data analysis for a nuanced understanding of spatiotemporal dynamics. Unlike earlier studies focusing on specific aspects, this research adopts a holistic approach, examining factors crucial for water supply, quality, and cost, thus providing an integrated view of Rwanda's water sector. By analyzing data from various sources, including the Water and Sanitation Corporation (WASAC), the study evaluates the reliability, quality, and cost-effectiveness of drinking water. It identifies cost-effective water treatment plants and studies determinants such as production cost, raw water quality, and supply between 2017 and 2022, introducing novel metrics such as performance scores and a drinking water quality index. Despite an increase in lost water, WASAC notably improves water supply, resulting in a higher water access rate by 2022. The study highlights the influence of factors such as performance scores and raw water quality on water supply and quality. It emphasizes continuous monitoring, targeted interventions, and community engagement for sustainable water service delivery. The findings provide actionable insights for policymakers, stakeholders, and practitioners, aiming to enhance water management strategies and improve water access in Rwanda.

Graphical, statistical and index-based techniques integrated for identifying the hydrochemical fingerprints and groundwater quality of In Salah, Algerian Sahara.

Groundwater, a predominant reservoir of freshwater, plays a critical role in providing a sustainable potable water and water for agricultural and industry uses in the In Salah desert region of Algeria. This research collected 82 underground water samples from Albian aquifers to assess water quality and identify hydrogeochemical processes influencing mineralization. To achieve this objective, various methods were employed to evaluate water quality based on its intended uses. The drinking water quality index utilized revealed the water potability status, while the indicators of irrigation potability were employed to evaluate its quality for agricultural purposes. Additionally, an assessment of groundwater susceptibility to corrosion and scaling in an industrial context was conducted using several indices, e.g., Langelier index, Larson-Skold index, Ryznar index, chloride-sulfate mass ratio, Puckorius index, aggressiveness index, and the Revelle index. The findings of this study revealed thatthe groundwater quality for consumption fell into four categories: good (2.44%), fair (29.27%), poor (65.85%), and non-potable (2.44%). Concerning agricultural irrigation, the indexical results indicated that 15.85% of the waters exhibited adequate quality, while 84.15% were questionable for irrigation. Calculations based on various corrosion and scaling evaluation indices showed that most wells were prone to corrosion, with a tendency for calcium bicarbonate deposit formation. Furthermore, the hydrochemical study identified three water types: Na-Cl (53.66%), Ca-Mg-Cl (37.80%), and Ca-Cl (8.54%) waters. Analyses of correlation matrices, R-type clustering, factor loadings, Gibbs diagrams, scatterplots, and chloro-alkaline indices highlighted that the chemistry of the Albian groundwater is fundamentally impacted by a number of processes such as silicate weathering, evaporite dissolution, ionic exchange, and anthropogenic inputs, that played impactful role in the aquifer's water chemistry.

Heavy metal geochemistry and toxicity assessment of water environment from Ib valley coalfield, India: Implications to contaminant source apportionment and human health risks

The present study aims to investigate the hydrogeochemical evolution of heavy metals and assesses impacts of mining activities on the groundwater resources and potential human health risks in the coal mining areas of Ib valley coalfield. In this perspective, a total of one hundred and two mine water and groundwater samples were collected from different locations. The water samples were analysed for some selected heavy metals i.e. Mn, Cu, Pb, Zn, Ni, Co, As, Se, Al, Sr, Ba, Cd, Cr, V and Fe using ICP-MS. In addition, pH and SO42− concentration were also measured following APHA procedure. The water pH in the Ib valley coalfields ranged from 3.26 to 8.18 for mine water and 5.23 to 8.52 for groundwater, indicating acidic to alkaline nature of water. Mn in mine water and Zn in groundwater environment were observed as the most dominant metals. The water hazard index (WHI) reflects that around 80% of mine water are non-toxic (WHI<5), 5% slightly toxic (5<WHI>10) and 15% extremely toxic (WHI>15). Relatively high pH and low concentration of dissolved metals and SO42− in groundwater as compared to mine water indicate lesser impact of mining activities. The calculated drinking water quality index (DWQI) suggests that Mn, Al, Ni and Fe in mine water and Mn, Fe, Ni and Pb in groundwater were the major objectionable metals which caused the water quality deterioration for drinking uses. Further, the non-carcinogenic health risk assessment for adult male, female and child populations identifies Co, Mn, Ni as the key elements making the water hazardous for human health. Comparatively higher ratio of ingestion rate and body weight in child population might be causing higher health risks in child population as compared to adult male and adult female population.

Reflecting on changes in the drinking and irrigation water quality of rivers Beas, Satluj and confluence waters.

Prevention and control of water pollution for maintaining and restoring the wholesomeness of rivers are unavoidable. The current water quality approach of designated best use has some limitations such as it is non-integrative and inflexible with regard to the consideration of variables and does not provide a separate rating scale for a given designated use. We thus used water quality index approach proposed by the Canadian Council of Ministers of the Environment (CCME WQI) to evaluate and develop a separate rating system for drinking and irrigation purposes of rivers Beas, Satluj and their confluence water of the Indian Punjab using information collected over 4 years (2016 to 2019). River Beas exhibited better water quality compared to river Satluj for irrigation as well as for drinking. The overall drinking water quality index (DWQI) for Beas was marginal (45.5), whereas it was poor for Satluj (37.7) and confluence waters (40.1). The spatial variation in DWQI was greater for Satluj compared to Beas and confluence waters reflecting the effect of dumping of untreated industrial and domestic waste waters. Variables such as Total coliform (T. coli), dissolved oxygen (DO), turbidity and biological oxygen demand (BOD) contributed to the deterioration of DWQI. The irrigation water quality index (IWQI) was good for Beas (86), marginal for Satluj (60.1) and fair for confluence waters (71.2). Faecal coliform (F. coli), Kelly ratio (KR) and %Na contributed to the deterioration of IWQI. Calcium-magnesium-bicarbonate (Ca-Mg-HCO3) was the dominant water type in Beas and confluence waters, whereas for Satluj, in addition to Ca-Mg-HCO3, sodium-potassium-chloride-sulphate and mixed water types were also prevalent. The river waters witnessed salinity hazard but did not pose sodicity hazard except at a few locations of Satluj. The study indicates the need to take location specific measures for improving river water quality for drinking as well as irrigation purposes. The current status of water quality calls for an urgent need to formulate stringent policy regulations to maintain the surface water quality.

Evaluation of drinking and irrigation water quality, and potential risks indices in the Dera Ismail Khan district, Pakistan

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.

Multiple Linear Regression and Machine Learning for Predicting the Drinking Water Quality Index in Al-Seine Lake

Ensuring safe and clean drinking water for communities is crucial, and necessitates effective tools to monitor and predict water quality due to challenges from population growth, industrial activities, and environmental pollution. This paper evaluates the performance of multiple linear regression (MLR) and nineteen machine learning (ML) models, including algorithms based on regression, decision tree, and boosting. Models include linear regression (LR), least angle regression (LAR), Bayesian ridge chain (BR), ridge regression (Ridge), k-nearest neighbor regression (K-NN), extra tree regression (ET), and extreme gradient boosting (XGBoost). The research’s objective is to estimate the surface water quality of Al-Seine Lake in Lattakia governorate using the MLR and ML models. We used water quality data from the drinking water lake of Lattakia City, Syria, during years 2021–2022 to determine the water quality index (WQI). The predictive performance of both the MLR and ML models was evaluated using statistical methods such as the coefficient of determination (R2) and the root mean square error (RMSE) to estimate their efficiency. The results indicated that the MLR model and three of the ML models, namely linear regression (LR), least angle regression (LAR), and Bayesian ridge chain (BR), performed well in predicting the WQI. The MLR model had an R2 of 0.999 and an RMSE of 0.149, while the three ML models had an R2 of 1.0 and an RMSE of approximately 0.0. These results support using both MLR and ML models for predicting the WQI with very high accuracy, which will contribute to improving water quality management.

Spatial distribution of drinking and irrigation water quality in different climatic zones of Baluchistan, Pakistan.

Baluchistan's water profile was developed by dividing it into seven zones (Northern Highlands-NH, Southern Highlands-SH, Quetta Valley-QV, Desert-D, Sibbi Plains-SP, Coastal Lasbella-CL, Coastal Gwadar-CG) based on geography, water availability, and climate of the area. A total of 106 water samples were collected from karaiz, spring water, and tube wells. Spatial distribution of EC, TDS, TH, SO42-, Cl-, Na+, and K+ showed an increasing trend in concentration from the highlands towards the desert and coastal zones. For anion, HCO3- is predominant in NH, SH, and QV, Cl- in D, CL, and CG and only SO42- in SP, whereas the cationic trend in overall zones is Na+>Ca2+>Mg2+>K+. In the NH, SH, QV, and SP zones, the physicochemical parameters met the drinking water quality guidelines; however, D, CL, and CG exceeded in almost all quality parameters. Furthermore, the drinking water quality index (WQI) shows excellent to good water quality in NH, SH, QV, and D zones, while CL and CG fall in poor to unsuitable water classes. In terms of hydrogeochemical facies, maximum water samples from NH fall in Ca-Mg-HCO3, and SH, QV, and SP in Ca-Mg-Cl type, where major ion chemistry is controlled by rock-weathering, while D, CL, and CG fall in the NaCl type, where evaporation is dominant. Similarly, irrigation water quality parameters (EC, SAR, RSC, Na%, MH%, PI, SSP, and KR) reveal that NH, SH, QV, and SP have suitable water for irrigation, and D, CL, and CG require proper treatment. Additionally, USSL and Wilcox's diagrams indicated that NH, SH, QV, and SP have "excellent to permissible"; however, D, CL, and CG have "permissible to unsuitable" class water, requiring special management practices. Consequently, appropriate control measures and targetedwater purification programmes should be implemented to protect the publichealth and sustainability of water resources inBaluchistan.

Hydrochemical Characteristics and Quality Evaluation of Irrigation and Drinking Water in Bangong Co Lake Watershed in Northwest Tibetan Plateau

Bangong Lake is a narrow and long lake in the arid region of the plateau in northern Tibet. The salinity of the east of the lake is different from that the west, resulting in differences in the natural environment and human living conditions on each side. Watershed hydrochemical analysis and spatial statistical analysis can help to understand regional hydrochemical evolution and water quality evaluation. In this study, the hydrochemical characteristics of surface water (glacier, river, and lake) and groundwater in the Bangong Co Lake Watershed were investigated to reveal the relationships between various water bodies. The drinking water quality index (DWQI) and USSL classification were applied to assess groundwater quality suitability for agricultural and drinking purposes. The hydrochemical characteristics show the differences among water bodies and their spatial distribution. The analyzed groundwater and surface water samples, such as river water and glaciers, were mainly Ca-HCO3-type and the lake water was mainly categorized as Na-Cl-type with some Na-HCO3-Cl type. The lake water’s chemical components are mainly affected by evaporative karst decomposition. The main mineralization process of groundwater and river water was related to the dissolution of reservoir minerals, such as dolomite and calcite, as well as halite. The drinking water quality index (DWQI) indicates that 79% of the groundwater samples in the study area were of good enough quality for drinking. In terms of irrigation water quality, the electrical conductivity (EC), calculated sodium adsorption ratio (SAR), and magnesium hazardous ratio (MHR) showed that more than 13% of the total samples were not suitable for irrigation. However, the USSL classification indicated that glacier and river water are relatively suitable for irrigation. Additionally, some groundwater and lake water has very high alkalinity or salinity, which is alarming when considering them for irrigation.

Hydrochemical appraisal and sources of contamination in high nitrate aquifer, Saudi Arabia

A systematic study was executed in the Wadi Fatimah basin, Saudi Arabia to appraise the hydrochemical processes, contamination sources and water quality using an integrated approach namely geochemical methods, multivariate statistical analyses and water quality indices. In this aquifer, the average value of electrical conductivity and total dissolved solids is 4292 µS/cm and 2747 mg/l, respectively. The predominant hydrochemical facies are CaMgCl followed by NaCl. Further, 76% (hardness), 51% (major ions and NO3−) and 15% (F−) of samples surpassed the World Health Organization-prescribed drinking water limit. The contamination index and drinking water quality index (DWQI) also reveal that 25% and 46% of samples are not appropriate for drinking application. Spatial maps of major ions, total hardness and DWQI depict that water quality is deteriorated from upstream to downstream and extreme values exist in the downstream. Gibbs plots, ionic ratios, Pearson correlation coefficient and principal component analysis justify that groundwater chemistry is predominantly affected by evaporation, evaporite dissolution and ion exchange reactions followed by mineral weathering. High NO3− originates from nitrification, irrigation return flow and wastewater recharge. Groundwater F− is derived from weathering of fluoride minerals and enhanced by evaporation. This study emphasizes that proper treatment is required for groundwater before distribution for various uses in this basin.

Assessment of Water Quality in India’s Groundwater Sources Using the MOORA Method, Modified Drinking Water Quality Index (DWQI)

Assessment of Water Quality in India’s Groundwater Sources Using the MOORA Method, Modified Drinking Water Quality Index (DWQI)