Spatial Analysis of Groundwater Quality and Its Suitability for Drinking Purpose in SARGODHA City

Abstract

Groundwater is the principal source of drinking water for Sargodha Tehsil, Punjab, Pakistan, but its quality is increasingly influenced by urbanization, agricultural activities, and changing land-use practices. This study aimed to provide a comprehensive spatial assessment of groundwater quality, evaluate its suitability for drinking, and identify areas vulnerable to potential health risks. The research employed an integrated methodology combining physicochemical analysis, statistical techniques, Geographic Information System (GIS)-based spatial analysis, Groundwater Quality Index (GWQI), Human Health Risk Assessment (HHRA), and household survey information.

A total of 200 groundwater samples were systematically collected across Sargodha Tehsil and analyzed for nine physicochemical parameters, including pH, TDS, EC, turbidity, total hardness, chloride, sulphate, fluoride, and nitrate. The analytical results were compared with World Health Organization (WHO) drinking-water guidelines to assess groundwater suitability. Descriptive statistics, frequency distribution, box-and-whisker plots, and Pearson correlation analysis were applied to determine the variability and relationships among the investigated parameters. The results showed considerable variation in groundwater quality, with localized areas exhibiting elevated concentrations of several parameters, particularly TDS and nitrate.The georeferenced groundwater-quality data were further analyzed in ArcGIS using Spherical Kriging interpolation to generate spatial distribution maps. The maps revealed pronounced spatial heterogeneity and identified localized groundwater-quality hotspots rather than uniform contamination across the study area. A weighted arithmetic Groundwater Quality Index (GWQI) was subsequently calculated using WHO permissible limits to provide an integrated assessment of drinking-water suitability. The resulting GWQI classification identified areas with comparatively good groundwater quality as well as distinct zones where groundwater quality was poor and unsuitable for drinking.Human Health Risk Assessment was also conducted to evaluate potential non-carcinogenic health risks associated with groundwater consumption through the ingestion pathway. Hazard Index (HI) values were estimated for both adults and children. The assessment indicated comparatively higher potential health risks for children, particularly in areas where contaminant concentrations were elevated. In addition, household survey data regarding drinking-water sources, bore depths, and water-treatment practices were incorporated to provide a broader understanding of groundwater use and community exposure.Overall, the study demonstrates significant spatial variability in groundwater quality across Sargodha Tehsil, with specific zones requiring greater attention and management. The integration of hydro chemical analysis, GIS-based Spherical Kriging, GWQI, HHRA, and household assessment provides a robust framework for identifying vulnerable areas and supporting evidence-based groundwater management. The study recommends targeted groundwater-quality monitoring, zone-specific water-treatment measures, improvement of drinking-water infrastructure, public awareness, and sustainable groundwater governance to reduce potential health risks and protect groundwater resources in Sargodha Tehsil.