Examining groundwater quality in the surrounding areas of Islamabad: a comparative analysis of physical, chemical, and biological factors

A comparative illustration of groundwater quality across three peri-urban villages (Mera Abadi, Saidpur Village, and Kalajar Village) near Islamabad, showing variations in physical, chemical, and microbiological parameters. Groundwater is the primary drinking water source for peri-urban communities surrounding Islamabad, yet its quality remains insufficiently characterized. This study assessed the physicochemical and microbiological quality of groundwater from Mera Abadi, Saidpur Village, and Kalajar Village between March and June 2023. A total of 30 samples were analyzed using standard laboratory protocols for physical, chemical, and bacteriological parameters. Mean electrical conductivity exceeded the WHO guideline of 400 μS/cm at all sites, reaching 402.9 ± 30.7 μS/cm (378–480) in Mera Abadi, 399.0 ± 52.0 μS/cm (336–499) in Saidpur, and 513.7 ± 170.7 μS/cm (368–884) in Kalajar. Total dissolved solids ranged from 262 to 630 mg/L, while measured total salinity (as dissolved salts) ranged from 173 to 427 mg/L. Alkalinity averaged 147.8–185.6 mg/L but reached 300 mg/L in some samples, exceeding recommended limits. Microbiological analysis revealed total bacterial counts ranging from 5 to >300 CFU/mL, with several samples, particularly from Kalajar, exceeding the acceptable limit of 100 CFU/mL; limited coliform presence was detected in selected samples. These findings indicate potential risks of waterborne diseases such as diarrhea, typhoid, and gastrointestinal infections. This study provides a comparative assessment of groundwater quality across three peri-urban settlements and identifies spatial variability in contamination patterns. The results highlight the need for household-level filtration, improved sanitation management, community awareness programs, and routine seasonal monitoring to reduce health risks and protect drinking water safety.