Drinking Water Quality Assessment in Groundwater-Fed Supply Systems: A Case Study of Female Residential Halls at Khulna University, Bangladesh

Securing safe drinking water remains a pressing public health challenge in Bangladesh, where groundwater quality is increasingly undermined by a combination of natural factors and human-induced activities. This study examined the drinking water quality of two female residential halls such as Bangamata Begum Fazilatunnessa Mujib (BBFM) Hall and Aparajita Hall (AP) at Khulna University over a six-month period. An integrated approach was applied, combining physico-chemical and microbial analyses with multivariate and risk assessment methods such as Pearson’s correlation, Water Quality Index (WQI), Principal Component Analysis (PCA), Pollution Index of Groundwater (PIG), Quantitative Microbial Risk Assessment (QMRA) and Chemical Health Risk Assessment. Physical analyses indicated neutral to slightly alkaline water, with moderate electrical conductivity (EC) and total dissolved solids (TDS) reflecting natural geogenic influences. Chemical evaluation revealed a sodium-chloride-bicarbonate-dominated profile, while nitrate, phosphate, and sulfate remained within safe limits, though salinity indicators highlight potential long-term risks. Microbiological assessment detected total coliform (TC), fecal coliform (FC) and<i> Escherichia coli (</i><i>E. </i><i>coli</i> ) above World Health Organization (WHO) thresholds, indicating fecal contamination and immediate public health concerns. PCA and correlation analyses identified salinity, carbonate buffering, and phosphorus enrichment as key hydrochemical drivers, whereas the WQI ranged from 42.66 to 51.71, classifying most samples (except BBFM 4) as good<i>.</i> The PIG values (<1.0) indicated insignificant pollution. QMRA estimated annual infection probabilities of 12% to 44%, far above the WHO benchmark (≤10⁻⁴), underscoring cumulative exposure risks. Chemical health risk assessment confirmed no significant non-carcinogenic threat from nitrate or sodium intake. These results indicate that although the water is largely safe from a chemical standpoint, it carries considerable microbial health risks. Based on these findings, a comprehensive management approach is advised, incorporating immediate actions, short to mid-term interventions, and long-term infrastructural improvements, alongside the implementation of a Water Safety Plan (WSP) to ensure safe and sustainable drinking water in university residential facilities.