Integrative water quality index (WQI) based assessment of ground water resources in Punjab, Pakistan

Abstract

The needs of more than 70% of Punjab’s residents for domestic use, agriculture and industry are met by groundwater. Today, its quality and sustainability have significantly deteriorated by fast urban growth, factory outflows, runoff from farms and unchecked water usage. The most prevalent human activity involving the subsurface of the Earth is groundwater extraction, 982 km3 of groundwater were extracted annually worldwide. Water scarcity and a reduced supply of drinking water are the results of excessive groundwater pumping. Pakistan is among the nations that, by 2030, will have fewer renewable water resources than the estimated threshold value of 1500 m3 per capita annually. A complete evaluation of groundwater quality was conducted in 36 districts of Punjab using 5,319 water samples collected from groundwater sources from both urban and rural areas. Empirical experiments involving Physical, Chemical and Bacteriological analysis were done in the laboratories. Key findings reveal alarming contamination levels, with 61.9 % of samples deemed unfit for drinking due to elevated concentrations of Total Dissolved Solids (TDS), heavy metals, and microbial pathogens. The WQI classification highlighted that over 10 districts in Punjab fall into "unsuitable for drinking" category (WQI ≥ 300), posing significant public health risks, including cancer, fluorosis, and waterborne diseases. The results emphasize to develop integrated water management plans, strengthen law enforcement, inform the public and use modern resources of Geographical Information Systems for decision making and adopt lower cost water purification systems to improve the water quality of Punjab. Actions should include developing institutions, updating water quality guidelines, and encouraging rainwater collection as well as aquifer refilling. This research follows SDG 6.1, helping policymakers build policies that reduce groundwater risks and secure safe drinking water across Punjab.