Assessment of surface water quality using advanced statistical techniques around an urban landfill: A multi-parameter analysis

• WQI was established on surface water quality adjacent to an urban landfill, Dhaka, by measuring 19 water quality parameters. • Clustering indicates that the first one comprised samples collected nearer to the landfill, exhibiting excessive COD, BOD, and TSS. • Three samples WQIs were very bad (WQI < 31) and seven samples WQIs were bad (WQI between 31 and 51.9) • PCA demonstrated that the five principal components accounted for 92.16% of the WQI variation. The present experimental research focuses on surface water quality adjacent to an urban landfill, Dhaka, Bangladesh, where collected samples were analysed in laboratories by assessing 19 physicochemical parameters, and advanced statistical techniques were performed to establish a Water Quality Index (WQI). Providing valuable insights into the spatial extent and characteristics of surface water pollution, the study intends to support local authorities in identifying high-risk zones for targeted water quality and in developing policies for monitoring waterbodies to ensure sustainable landfill management. Results indicated moderate total dissolved solids (TDS) (about 400 mg/L), low dissolved oxygen (DO) (less than 4 mg/L), and significant pollutant variability. Clustering indicated that the first one consisted of samples collected nearer to the landfill, exhibiting excessive chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS), while the second one contained samples collected farther away from the landfill, demonstrating superior water quality. The WQI categorized three samples as very bad 405 (WQI < 31) and seven as bad (WQI between 31 and 51.9), with the lowest value recorded as a WQI of 1.85 from a sewer. Principal component analysis (PCA) identified five principal components (PCs), with PC1, PC2, and PC3 accounting for 38.5 %, 21.38 %, and 16.35 of the total variance, respectively. These findings indicate the necessity for immediate measures: the establishment of engineered landfills, leachate treatment, and the enforcement of more stringent waste restrictions to mitigate health and environmental hazards around the urban landfill. The study’s scientific significance resides in its provision of a comprehensive WQI and specific pollution data, thereby augmenting the understanding of urban landfill effects on water quality in densely populated areas. The study has the potential to guide the development of policies for sustainable waste management, presenting a framework for reducing urban surface water pollution.