Study of groundwater hydrochemistry and drinking suitability through Water Quality Index (WQI) modelling in Kadava river basin, India

Multi-model exploration of groundwater quality and potential health risk assessment in Jajpur district, Eastern India

The presence of fluoride and nitrate is a serious groundwater quality issue in India impacting human health. In the present study, 14 different hydrochemical parameters for 76 groundwater samples collected from the Jajpur district of Odisha, India, were evaluated. Entropy-weighted water quality index (EWQI), fixed-weight groundwater quality index (GWQI), principal component analysis (PCA), and rotated factor loading-based water quality index (PCWQI) were employed to assess groundwater quality. About 65.79 ± 4.68%, 33.55 ± 3.95%, and 0.66 ± 0.76% of the samples were rated as "excellent," "good," or "medium" quality, respectively, across the four different water quality indices, with a nominal rating discrepancy of 13.15%. Though 86% of samples consistently received excellent or good ratings across all WQI frameworks, concentrations of F- and NO3- in 36.8% and 11.84% of the samples exceeded the WHO permissible limit. In health risk assessment, about 38.15% of samples surpassed the F- hazard quotient (HQ > 1) posing non-carcinogenic health risks for children. The non-carcinogenic health risks due to NO3- were evident in 55.26% and 11.84% of samples for children and adults, respectively. The higher concentration of NO3- in some of the water samples, together with its positive correlation with HCO3-, may worsen groundwater pollution. The moderate correlation between Ca2+ and HCO3- (r = 0.410) and the insignificant correlation between Mg2+ and HCO3- (r = 0.234) suggests calcite dissolution is far more common than dolomite.

Geospatial assessment of groundwater quality using entropy-based irrigation water quality index and heavy metal pollution indices

Groundwater contamination has become a serious environmental threat throughout the world in the era of Anthropocene. Thus, the present study examined the groundwater quality for irrigation purposes based on the entropy method and heavy metal pollution indices. To compute the entropy-based groundwater irrigation quality index (EIWQI), physicochemical parameters such as pH, chloride (Cl-) and nitrate (NO3-), irrigation indices including electrical conductivity (EC), sodium absorption ratio (SAR), sodium percentage (%Na), soluble sodium percentage (SSP), residual sodium carbonate (RSC), magnesium hazard (MH), Kelley's ration (KR), permeability index (PI) and heavy metals such as manganese (Mn), iron (Fe), zinc (Zn) and arsenic (As) have been employed for the 37 sample wells of the Damodar fan delta (DFD), India, which is a semi-critical agriculture-dominated region. Shannon's entropy method has been used to assign the weights of the different parameters for constructing the EIWQI. The results portray a spatial variation of the irrigation water quality in the DFD. The EIWQI revealed that 27.03%, 59.46%, 8.11%, 2.7% and 2.7% of the sample wells, respectively, contain excellent, good, moderate, poor and very poor quality of irrigation water. On the other hand, heavy metal pollution indices (modified degree of contamination, pollution load index, Nemerow index and modified heavy metal pollution index) show that 15-20% of sample wells of the DFD are contaminated by heavy metal pollution. The pockets of pollution are concentrated in the southwestern, northeastern and central parts of the DFD. The study found that the spatial variation in groundwater quality is controlled by the higher sodium concentration, carbonate weathering and expansion of agricultural and urban-industrial areas.

Machine learning approach to evaluate the groundwater quality and human health risk for sustainable drinking and irrigation purposes in South India

The main purpose of this study was to evaluate the suitability of groundwater for sustainable drinking and irrigation purposes using various indices, such as the nitrate pollution index, agriculture suitability index (ASI), non-carcinogenic human risk assessment (NCHRA), and radial basic function (RBF) model. The novelty of the present study is to develop the ASI model and integrate with RBF model to identify the highly dominating parameter in chemical equilibrium of groundwater. Results showed that >85% of sample locations were suitable for drinking purposes, and the nitrate concentration in groundwater had a negative impact on the overall quality of water. Approximately 12 and 19 sample locations were contaminated owing to the high nitrate concentrations in the study region. The NCHRA study identified that approximately 8.5%, 27.28%, 29.54%, 40.40%, and 28.20% of area was excessively affected during the winter compared to summer season for people 6 to 12 y, 13 to 19 y, 20 to 29 y, 30 to 65 y, and >65 y of age. The RBF model shows that the R² values for each season were 0.84 and 0.85 during summer and winter, respectively. The north-east and central parts of the study region were found to be more contaminated. The present study identified that, pathway of nitrate contaminant from the agriculture field towards to the sample locations. Overall, parent rock weathering, carbonate ion dissolution, and infiltration of rainwater and leachate from municipal waste dumping yards were the dominant factors influencing the chemical composition of groundwater. The present study achieved the vibrant knowledge about source of contamination, health effect on human body and impact on agriculture uses to develop the cleaner water supply system. The study results will be helpful in enhancing the sustainable action plan for water management in the study area.

Groundwater quality enumeration and health risk in the extended part of Chhotanagpur granite gneiss complex of India

The majority of people on the earth bank largely on groundwater to quench their thirst. In the era of rapid population growth, the over-exploitation of groundwater gives rise to water scarcity, and people find themselves in distress to manage safe drinking water. In this backdrop, the present study is carried out in the terrain of Pre-Cambrian igneous and high- to low-graded metamorphic rocks, to assess the groundwater potential zones (GWPZs) and evaluation of groundwater quality. The map of GWPZ is produced employing the multi-criteria decision-making model and geospatial technology. It unveils that around 29% area of the watershed enjoys good GWPZ, whereas around 43% area experiences low GWPZ. The overall accuracy of the simulated model is 92%. The water quality index indicates that 68% of water samples belong to excellent to good water quality. A significant proportion of water samples (24%) are found to be unsuitable for drinking, which may be due to groundwater contamination by the process of leaching of mineral-rich weathered rocks. The presence of fluoride (F^-) beyond the maximum permissible limit (1.5 mg L^-1) of WHO is recorded among 18% samples of the watershed, where 24,963 souls including 3457 children aged between 0 and 6 years lived and might have ingested F^- through drinking water. Hence, the health risk of those people is quite high. Children are at a more non-carcinogenic health risk of F^- than adults. The study also confirms no statistically significant difference (p ˃ 0.05) is observed between low and high GWPZ with respect to groundwater quality. The study recommends adopting a sustainable outlook to explore GWPZ, and an assessment of drinking water quality must be done before drinking.

Application of water quality indices and health risk models in the arid coastal aquifer, Southern Saudi Arabia

A systematic study was performed in the arid coastal aquifer to evaluate groundwater quality using drinking water quality indices (DWQI) and health risk assessment models in southern Saudi Arabia. Groundwater samples were collected (n = 80) and analysed for major and minor ions. Results suggest that 85% of wells are unsuitable for drinking due to high salinity and hardness. Likewise, high NO₃^- and F^- are encountered in 51% and 46% of wells, respectively. High salinity, Cl^- and SO₄^2- are noticed in the coastal wells, which are derived from saline sources, evaporation and anthropogenic activities. High NO₃^- is originated from anthropogenic sources and the nitrification process. Recharge of wastewater with high NO₃^- is mixed with high salinity groundwater in this shallow aquifer. DWQI indicates that 66% of samples are poor to unsuitable classes. Wells with poor quality groundwater existed in the coastal belt and water quality is degraded while moving from upstream to downstream. The average values of hazard quotient (HQoral, NO₃^-, F^-) and total hazard index (THI) ensured that highly vulnerable groups are in the order of infants > children > adults. In the study region, the THI are > 1 in 75% (adults), 89% (children) and 94% (infants) of samples, respectively. The spatial distribution of HQoral reveals that groundwater in the coastal and southern regions is not advisable for direct oral ingestion, which causes serious non-carcinogenic health risk to inhabitants. Groundwater in these regions needs proper treatment to remove the contaminants before use.

Assessment of the impact of flood on groundwater hydrochemistry and its suitability for drinking and irrigation in the River Periyar Lower Basin, India

Owing to the consequences of Anthropocene climate changes, extremes of weather and climate disasters such as heavy precipitation, tropical cyclones, and floods, have strengthened in every region across the globe and are badly affecting the earth system processes. The climate change has a tremendous impact in the Western Ghats, the UNESCO heritage site in India, and has to be studied in detail. Floods are the most common (and among the most deadly) natural disasters bringing heavy destruction in the Western Ghat river basins of India, and the Periyar basin is one among them. The low-lying areas of Periyar river basin (RPLB) is one of the worst affected river basins in the 2018 Kerala floods. Since the basin was continuously monitoring, the groundwater quality has been assessed in Periyar basin during three periods (pre-flood, flood, and post-flood-April, August, and October 2018 respectively) and is described in this paper. Since the water table is shallow in RPLB, floodwaters quickly reach the groundwater table, thus influencing the groundwater quality. So, the groundwater samples were collected from 26 sites in RPLB, and analyzed for quality determining parameters. Parameters like pH, TDS, EC, TH, NH₃^-, NO₂^-, HCO₃^-, SO₄^2-, SiO₄^4-, Mg²⁺, and K⁺ decreased during flood compared to pre-flood times. On the other hand, Ca²⁺, Na, and Cl^-, turbidity values were increased during flood times. The values of pH, TDS, EC, turbidity, NH₃^-, HCO₃^-, SO₄^2-, SiO₄^4-, Mg²⁺, Na⁺, and K⁺ were slightly increased in post-flood period compared to flood period. When compared to the pre-flood values, turbidity, NH₃^-, SO₄^2-, Na⁺, and K⁺ were slightly increased in post-flood period. It was also observed that pH, TDS, EC, TH, NO₂^-, Cl^-, HCO₃^-, SiO₄^4-, PO₄^3-, Ca²⁺, Mg²⁺, and E. coli values were higher in pre-flood periods compared to the post-flood scenario. Except pH, turbidity, and E. coli, the averages of all other parameters are falling under the recommended drinking quality values of WHO. The pH belongs to acidic nature throughout the study period. The Piper plot indicates the dominance of Ca-Mg-HCO₃ type in pre-flood, and mixing of Ca-Mg-HCO₃ type in both flood and post-flood periods. The Gibbs plot reveals that the concentration of elements is mainly depending on rock weathering and sub-surface water flow. The USSL plot depicted that the 92-96% of samples are noted as lower salinity and low sodium hazard at the source of C2S1 and C1S1; however, the 4-11% of samples are noted as high salinity but low sodium hazard at a source of C4S1 and C3S1. The Wilcox diagram indicates that the 88-96% of groundwater was found as higher suitability for irrigation during the study periods. Based on GIS based WQI model, out of the 26 samples studied, 69% of wells showed improvement in water quality after flood; meanwhile, 19% well water samples in flood were observed for lower quality compared to pre-flood times and 12% of samples remain unchanged during flood. Though floods are having positive and negative impacts, from this study, it is clear that quality of the groundwater in the RPLB is not severely affected, but they became diluted to permissible limits during flood and post-flood periods except some locations. Since the flood impact studies on groundwater systems are meager, this data from Periyar basin can be used as baseline groundwater reference data for all future flood-related river basin studies and will be very beneficial for the policy and planning needs in the context of climate change. It is high time to establish the baseline data of all river basins of Western Ghats since the normal earth system processes are worse affected by the recurrence of floods which are reporting every year.

Integrated approach for the evaluation of groundwater quality through hydro geochemistry and human health risk from Shivganga river basin, Pune, Maharashtra, India

The present study is focused on seasonal variation in groundwater quality, hydrochemistry, and associated human health risk in the Shivganga river basin, Western Maharashtra, India, to promote sustainable development of groundwater resources of this semi-arid region. The qualitative geochemical analysis, contamination levels, and human health risk assessment (HHRA) of groundwater are integral steps in groundwater management in the Deccan Plateau basalt flow region of India. Representative groundwater samples (n = 68) collected from the Shivganga River basin area of Pune district, Maharashtra, during pre-monsoon (PRM) and post-monsoon (POM) seasons in 2015 were analyzed for major cations and anions. According to the World Health Organization (WHO, 2017) drinking standards, EC, total dissolved solids, hardness, bicarbonate, calcium, and magnesium surpassed the desirable limit. Boron and fluoride content exceeded the prescribed desirable limit of the WHO. The pollution and drinking suitability were assessed by computing pollution index of groundwater (PIG), groundwater quality index (GWQI), and HHRA particularly for boron and fluoride toxicity. PIG values inferred that about 6% of groundwater samples has moderate, 24% has low, and 70% has insignificant pollution in the PRM season, while only 1 sample (3%) showed high pollution, 6% showed low, and 91% showed insignificant pollution in the POM season. GWQI classification demonstrated that 27% and 15% samples are within the poor category, and only 15% and 18% of the samples fall into excellent water category in the PRM and the POM seasons, respectively. Total hazard index (THI) revealed that 88% of children, 59% of adults, and about 38% of infants are exposed to non-carcinogenic risk, as THI values (>1) were noted for the PRM season, while 62% of children, 47% of adults, and 24% of infants are vulnerable to non-carcinogenic health hazard during the POM period.

Seasonal variation in groundwater quality and beneficial use for drinking, irrigation, and industrial purposes from Deccan Basaltic Region, Western India

Sustainable management of groundwater resources requires detailed basin-wide water assessments. Semi-urbanized areas surrounding metropolitan cities in the western part of India were assessed for their suitability for domestic, irrigation, and industrial purposes. These study areas reflect rapid urban growth with residential complexes, combined with agricultural, horticultural, and industrial uses. Therefore, 68 representative groundwater samples were collected during the pre-monsoon (PRM) and post-monsoon (POM) seasons of 2015 and analyzed for major ions. According to the World Health Organization (WHO) drinking standards, parameters like EC, TDS, TH, HCO3, Ca, and Mg were found to exceed the desirable maximum limits, and the B and F content exceeded the permissible limits. The drinking suitability was studied using the modified water quality index (MWQI). The irrigation suitability was assessed using indices such as sodium adsorption ratio (SAR), percent sodium (%Na), and permeability index (PI). The industrial suitability was evaluated based on Langelier saturation index (LSI), saturation index (SI), Ryznar stability index (RSI), etc. MWQI results corroborate that 52.94 and 70% samples fall in no pollution category, and 47% and 30% samples were identified to be in the moderate category of pollution in the PRM season and POM season, respectively. The spatial variation maps of LSI, SI, RSI, Puckorius scaling index (PSI) and Larson-Skold index (LaI) show that the majority of the samples in the PRM season have low to insignificant scaling and corrosive potentials as compared to POM samples. The study results provide reliable information for water reserve managers to prepare the sustainable and more accurate basin management plans.

Integration of multivariate statistics and water quality indices to evaluate groundwater quality and its suitability in middle Gangetic floodplain, Bihar

This study is conducted along the middle Gangetic floodplain, to investigate the hydrogeochemical characteristics and suitability of groundwater for irrigation and human consumptions. Altogether 65 groundwater samples were collected and analyzed for major ions and water quality parameters. pH of all the samples except 1 is found > 7, which suggests alkaline aquifer condition. Groundwater samples predominately belong to Ca-Mg-HCO3 water type followed by Na-HCO3, Mg-HCO3 and Mg-SO4 water types. Hierarchical cluster analysis (HCA) combines groundwater into two distinct groups, Group 1 is found as less mineralized as the average EC value is found 625.3 μS/cm, while it is found 1375 μS/cm for Group 2. The results of correlation analysis and PCA suggest influence of natural and anthropogenic activities on groundwater. PCA extracts four major PCs which describes 71.7% of total variance. PC1 indicates influence of both lithogenic and anthropogenic activities on groundwater quality. PC2 and PC3 infer natural factors, and PC4 suggests influence of anthropogenic activities on groundwater. Exceeding concentration of F−, Fe and Mn above WHO guidelines are found as major public health concern. WQI of all except 4 groundwater samples suggests excellent to good water quality; however, 23% of the samples are not suitable based on WPI values. Irrigation indices suggest that groundwater is mostly suitable for irrigation; however, 10.7%, 12.3% and 3% samples for RSBC, MAR and KR, respectively, exceed the recommended limits and are unsuitable for irrigation. A proper management strategy and quality assurance is recommended before groundwater consumption and use in the study area.

Groundwater Quality Assessment Using Geospatial Techniques and WQI in North East of Adama Town, Oromia Region, Ethiopia

Assessment of groundwater quality is vital for the sustainable use of the resources for domestic and agricultural purposes. In this study spatial variation of physicochemical parameters were analyzed for Northeast Adama Town. Water Quality Index (WQI) and irrigation indices were used to determine the suitability of groundwater for drinking and irrigation purposes, respectively. Further, the physical-chemical results were compared with the Ethiopian standards and the World Health Organization (WHO) standards for drinking and public health. Using GIS interpolation methods in Arc GIS 10.3.1, spatial distribution maps of pH, TDS, EC, Cl−, HCO32−, SO42−, Ca2+, Mg2+, Na+ and K+, RSC, SAR, Na% were prepared. Results indicated that except ASTU well 2, all samples are below the desirable limits of WHO. The WQI results indicated that 85% of samples and 15% of samples were in good and poor categories, respectively. Irrigation indices show that the most groundwater samples have excellent water classes, indicating that they are suitable for irrigation purposes.