Groundwater quality assessment in upper Kabul basin and Paghman aquifer

In Afghanistan, groundwater is widely used for drinking water, but its quality poses a health threat. This study investigates the physical, chemical, and bacteriological characteristics of groundwater in the Upper Kabul Sub-basin. Fifteen samples were collected and analyzed from different parts of the study area. The qualitative determination of parameters such as pH, Electrical conductivity (EC), Total dissolved solids (TDS), Salinity, Total hardness, Calcium, Magnesium, Sodium, Chloride, Fluoride, Sulfate, Phosphate, Potassium, Nitrite, Nitrate, Ammonia, Iron, Manganese, Copper, Aluminum, Arsenic, Total coliform, and Fecal coliform bacteria was carried out. The results were compared with WHO and ANSA standards to assess their suitability for drinking purposes. The analyzed samples indicate that physical parameters generally fall within permissible limits according to WHO and ANSA standards. However, certain wells exhibited elevated levels of chemical and bacteriological contaminants. Specifically, Magnesium concentrations exceeded the WHO guideline of 30 mg/L in all of the samples, and Calcium levels surpassed the recommended limit of 75 mg/L in 53% of the samples. Total coliform bacteria were detected in 33.33% of the samples, while fecal coliform bacteria were within the WHO and ANSA permissible limit for drinking water. The Pearson's correlation coefficient (R) suggested significant correlations between EC, TDS, and total hardness with other physical and chemical parameters. For instance, EC showed a strong positive correlation (R = 1.00) with TDS, EC and Salinity (R = 0.981), EC and Fluoride (R = 0.838) EC and Sulfate (R = 0.853), TDS and Salinity (R = 0. 981), TDS and Fluoride (R = 0.838), TDS and Sulfate (R = 0.853). The findings demonstrate that correlation coefficient analyses of water quality parameters provide a valuable means for monitoring water quality. These results offer critical insights for ensuring a safe water supply in the region.