Groundwater is the most important water resource, on which depends human geo-economic development and survival. Recent environmental changes and anthropogenic activities render groundwater severely vulnerable. Groundwater in Central Sindh, Pakistan, is facing a similar situation. Hydrogeochemical characteristics of the groundwater in the said region were investigated by analyzing 59 groundwater samples via agricultural and drinking indices, using various statistical methods and graphical approaches to identify factors affecting groundwater. Major reactions occurring in the groundwater system were quantified by hydrogeochemical modeling. A statistical summary reveals the abundance of cations is Na+ > Ca2+ > Mg2+ > K+, while the abundance of anions is HCO3− > Cl− > SO42. Groundwater chemistry is mainly of rock dominance. Correlation analysis and graphical relationships between ions reveal that ion exchange and rock weathering such as the dissolution of halite, albite, and dissolution of carbonate minerals are important rock–water interactions, governing the evolution of groundwater chemistry. Hydrochemical facies are predominantly of mixed CaMgCl and Na-Cl type, with few samples of Ca-HCO3 type, which constitutes fresh recharged water. Based on the Water Quality Index (WQI), 28.82% samples were found to be unsuitable for drinking. A United States Salinity Laboratory (USSL) diagram, Wilcox diagram, and other agricultural indices indicate that majority of the groundwater samples fall within the acceptable range for irrigation purposes.

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Arsenic (As) contamination in drinking groundwater is a common environmental problem in Pakistan. Therefore, sixty-one groundwater samples were collected from various groundwater sources in District Sanghar, Sindh province, Pakistan, to understand the geochemical behavior of elevated As in groundwater. Statistical summary showed the cations and anions abundance in decreasing order of Na+ > Ca2+ > Mg2+ > K+, and HCO3− > Cl− > SO42− > NO3−. Arsenic was found with low to high concentration levels ranging from 5 µg to 25 µg/L with a mean value of 12.9 µg/L. A major water type of groundwater samples was mixed with NaCl and CaHCO3 type, interpreting the hydrochemical behavior of rock–water interaction. Principal component analysis (PCA) showed the mixed anthropogenic and natural sources of contamination in the study area. Moreover, rock weathering and exchange of ions controlled the hydrochemistry. Chloro-alkaline indices revealed the dominance of the reverse ion exchange mechanism in the region. The entropy water quality index (EWQI) exposed that 17 samples represent poor water, and 11 samples are not suitable for drinking.

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Undeniably water is of utmost importance while considering basic necessities. This investigation emphasized on the hydrochemical evaluation and drinking water quality assessment in District Jacobabad located in lower Indus plain, Pakistan. Certainly world's largest irrigation system emerged from Indus Basin, which is underlain by well transmissive aquifer resulting in higher water table. Water supply schemes with their water sources from ground water and surface water provide piped water for drinking purpose to the community. Water samples were collected from all the forty eight supply schemes of which thirty two were found nonfunctional. Analytical parameters were compared with World Health Organization (WHO) and Pakistan Water Quality Standards but adversely substantial samples were found nonpotable. Alkalinity, bicarbonate and nitrate met the standard safe limits while values for EC, TDS, hardness, cations and anions exceeded the limits in numerous samples. SPSS and ArcGIS softwares were used for statistical analysis and spatial distribution of parameters. Hydrochemical facies were developed and suitability assessment of water resources was examined for agricultural use. The ground water type was classified as Na-HCO 3 type with high salinity and it required treatment prior to irrigation. The proposed research exhibited the probable drinking water contamination sources and it demanded instant actions to further protect the valuable drinking water resources in District Jacobabad.