Groundwater Quality Assessment for Drinking Purposes Using CCME Water Quality Index and GIS in Narsingdi District, Bangladesh

Abstract

Groundwater is the principal source of drinking water for the majority of the population of Bangladesh, yet its quality is increasingly threatened by geogenic arsenic enrichment, salinity intrusion, and anthropogenic pollution from agricultural and industrial activities. Despite this vulnerability, no comprehensive water‐quality assessment has previously been undertaken for the Narsingdi district, a rapidly industrializing and agriculturally intensive region of central Bangladesh. This study therefore aimed to (i) assess the suitability of groundwater for drinking purposes in Narsingdi district using the Canadian Counsil of Ministers of the Environment Water Quality Index (CCME WQI), (ii) quantify heavy‐metal contamination using the Metal Index (MI), (iii) identify the probable natural and anthropogenic sources of contamination using principal component analysis (PCA), and (iv) map the spatial distribution of water‐quality parameters using GIS‐based inverse distance weighting (IDW) interpolation. Thirty‐two groundwater samples were collected across the district and analyzed for physicochemical parameters, major ions, and heavy metals (As, Cr, Cu, Fe). The CCME WQI classified groundwater quality as excellent to fair across all sampling sites (no sites fell in the marginal or poor categorize), while the MI indicated that 40.62% of samples were moderately affected and 9.37% were seriously affected by heavy‐metal contamination. Arsenic was the most critical contaminant, with 37.5% and 68.75% of samples exceeding the Bangladesh and WHO drinking‐water guideline values, respectively. PCA identified three principal components explaining 71.82% of total variance, attributing groundwater contamination primarily to natural geogenic processes (mineral dissolution and cation exchange) and secondarily to anthropogenic inputs (industrial discharge and agrochemical use). GIS‐based spatial maps delineated the northern and southwestern parts of the district as priority zones for heavy‐metal contamination, providing a practical decision‐support tool for local water‐resource managers and public‐health authorities.