Assessment of surface water quality around a landfill using multivariate statistical method, Sylhet, Bangladesh

Abstract

Solid waste generation is rising consequently with the increasing population growth in Sylhet city. Mogla Bazar, an only dumping zone is affecting the surrounding environment enormously. This study aims to determine the surface water quality of the adjacent water bodies that lie within the 500 m buffer zone of the landfill utilizing multivariate statistical methods. Physicochemical and microbial parameters along with anions were considered for evaluating water quality. Multivariate statistical techniques viz. Principal Component Analysis (PCA), Factor Analysis (FA) and Cluster Analysis (CA) were applied to assess the water quality. Besides, the Pearson correlation matrix was performed to detect the interrelation among the variables and water quality index (WQI) was also used to classify the pollution sources. All the parameters were compared with the established acceptable limit given by the World Health Organization (WHO)/ Bureau of Indian Standards (BIS). PCA/FA resulted in three principal components with a total variance of 59.89 % and 57.14 % for haor and fishing zone, wetland respectively. Factor analysis derived from principal components shows that organic substances, anthropogenic activity, fertilization, chemical waste, and wastewater runoff are responsible for deteriorating the water quality. CA and WQI detect that sampling sites of haor and fishing zone that lies on the 200 m buffer zone were highly susceptible to water pollution. Besides, topographical variation, changes in slope, and seasonal variation were also treated as an influencing factor. Finally, all the analysis implied that the declining water quality would be dangerous to the neighbourhood of the landfill and there is a high chance of exposure to the dwellers residing nearby.