Assessment of groundwater quality near municipal solid waste landfill by using multivariate statistical technique and GIS: a case study of Bandhwari (Gurugram) landfill site, Haryana, India

Water is the elixir of life, and groundwater is considered a precious natural and safe resource for domestic purposes. Groundwater quality is deteriorating day by day due to human activity. In the present study, groundwater quality is affected by improper management of municipal solid waste (MSW) landfill leachate. It is deteriorating groundwater quality near landfill sites by leachate percolation into groundwater. In this context, the present work focuses on landfill leachate characterization and its possible effect on groundwater contamination surrounding the landfill site. The water quality index was measured by collecting 24 samples near a municipal solid waste landfill site, in Bandhwari (Gurugram), Haryana, India. The Water Quality Index (WQI) of most of the samples was found to be unsuitable water quality category. Electrical conductivity (EC), total dissolved substance (TDS), calcium, magnesium, and heavy metals are major contributors to higher WQI. Overall physicochemical investigation of the quality of groundwater near the landfill site shows that it is unsuitable for drinking and domestic uses as per the BIS and WHO standards. Multivariate statistical techniques such as principal component analysis (PCA) and cluster analysis (CA) were also used to analyze the relationship between the considered parameters. PCA indicated that the existence of four PCs represents 83.69% of the variance. Hierarchical cluster analysis evaluated three different cluster types for the groundwater samples and these clusters correspond to lower, moderate, and higher contamination regions. The contamination was found maximum in areas near the landfill site, as expressed by higher EC, TDS, and hardness of groundwater samples. The multivariate statistical study showed a direct correlation between groundwater quality and physicochemical characteristics. The maximum concentration of heavy metals such as iron, zinc, and nickel was 2.34 mg/l, 1.55 mg/l, and 1.24 mg/l in groundwater. The cation, anion, and heavy metal ions are interpolated over the study area by using the GIS software to find the spatial variation of these parameters. The overall quality of groundwater indicated that it is unfit for domestic use and require further necessary precaution to prevent groundwater contamination due to landfill leachate and proper treatment for its other use.